0000950170-22-004425 | 10-K | XBRL Viewer

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Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 149,063	$ 17,393
Restricted cash and deposits	23	19
Prepaid expenses and other current assets	4,618	1,043
Total current assets	153,704	18,455
Restricted cash and deposits, net of current portion	125	75
Right of use assets - operating lease	950
Property and equipment, net	5,251	3,574
Total Assets	160,030	22,104
Current liabilities:
Accounts payable	2,401	611
Short-term operating lease liability	615
Accrued expenses and other current liabilities	4,256	2,050
Total current liabilities	7,272	2,661
Deferred rent		8
Long-term operating lease liability	360
Warrant liability	83	72
Total Liabilities	7,715	2,741
Commitments and Contingencies (Note 12)
Convertible preferred stock(Note 7)		128,076
Stockholders’ Deficit:
Common stock, $0.00001 par value, 150,000,000 and 232,697,999 authorized at December 31, 2021, and December 31, 2020, and 29,211,643 and 381,123 shares issued and outstanding at December 31, 2021, and December 31, 2020, respectively
Additional paid-in capital	304,452	8,173
Accumulated deficit	(152,137)	(116,886)
Total Stockholders' Equity (Deficit)	152,315	(108,713)
Total Liabilities, Convertible Preferred Stock, and Stockholders’ Deficit	$ 160,030	$ 22,104

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	150,000,000	232,697,999
Common stock, shares issued	29,211,643	381,123
Common stock, shares outstanding	29,211,643	381,123

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Expenses:
Research and development	$ 25,161	$ 18,042
General and administrative	10,089	4,164
Total operating expenses	35,250	22,206
Total operating loss	(35,250)	(22,206)
Other income (expense):
Change in fair value of warrant liability	(11)	3
Interest income (expense), including amortization of discount	13	(3)
Loss on disposal of assets	(3)
Total other expense	(1)
Net loss and comprehensive loss	(35,251)	(22,206)
Net loss attributable to common stockholders - basic and diluted (Note 13)	$ (46,193)	$ (30,132)
Net loss per share attributable to common stockholders—basic and diluted	$ (8.95)	$ (82.06)
Weighted average common stock outstanding- basic and diluted	5,159,973	367,204

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	IPO	Common Stock	Common Stock IPO	Additional Paid-in Capital	Additional Paid-in Capital IPO	Accumulated Deficit	Series A Convertible Preferred Stock	Series A-1 Convertible Preferred Stock	Series A-2 Convertible Preferred Stock	Series B Convertible Preferred Stock	Series C-1 and C-2 Convertible Preferred Stock	Series D-1 and D-2 Convertible Preferred Stock	Series E Convertible Preferred Stock
Beginning Balance at Dec. 31, 2019	$ (87,406)				$ 7,274		$ (94,680)
Convertible preferred stock, Beginning Balance at Dec. 31, 2019								$ 3,368	$ 7,837	$ 5,373	$ 20,806	$ 41,099	$ 39,686
Convertible preferred stock, Beginning Balance, Shares at Dec. 31, 2019								1,701,141	3,298,732	4,324,998	22,531,819	91,327,903	57,878,742
Beginning Balance, Shares at Dec. 31, 2019			340,591
Issuance of convertible preferred stock													$ 9,907
Issuance of convertible preferred stock, Shares													14,469,710
Stock-based compensation expense	736				736
Stock options exercises	163				163
Stock options exercises, Shares			40,532
Net loss	(22,206)						(22,206)
Ending Balance at Dec. 31, 2020	(108,713)				8,173		(116,886)
Convertible preferred stock, Ending Balance at Dec. 31, 2020	128,076							$ 3,368	$ 7,837	$ 5,373	$ 20,806	$ 41,099	$ 49,593
Convertible preferred stock, Ending Balance, Shares at Dec. 31, 2020								1,701,141	3,298,732	4,324,998	22,531,819	91,327,903	72,348,452	0
Ending Balance, Shares at Dec. 31, 2020			381,123
Issuance of convertible preferred stock													$ 6,982	$ 80,246
Issuance of convertible preferred stock, Shares													10,128,771	102,671,041
Issuance of common stock - as a result of IPO, net of issuance costs		$ 78,320				$ 78,320
Issuance of common stock - as a result of IPO, net of issuance costs, Shares				6,210,000
Conversion of convertible preferred stock to common stock upon closing of IPO	215,304				215,304			$ (3,368)	$ (7,837)	$ (5,373)	$ (20,806)	$ (41,099)	$ (56,575)	$ (80,246)
Conversion of convertible preferred stock to common stock upon closing of IPO, Shares			22,550,561					(1,701,141)	(3,298,732)	(4,324,998)	(22,531,819)	(91,327,903)	(82,477,223)	(102,671,041)
Stock-based compensation expense	2,307				2,307
Stock options exercises	348				348
Stock options exercises, Shares			69,959
Net loss	(35,251)						(35,251)
Ending Balance at Dec. 31, 2021	$ 152,315				$ 304,452		$ (152,137)
Ending Balance, Shares at Dec. 31, 2021			29,211,643

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Common Stock
Stock issuance cost, net	$ 8,620
Series D Convertible Preferred Stock
Stock issuance cost, net	18	$ 93
Series E Convertible Preferred Stock
Stock issuance cost, net	$ 237

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (35,251)	$ (22,206)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	831	831
Change in fair value of warrant liability	11	(3)
Stock-based compensation expense	2,307	736
Gain on disposal of property and equipment	3
Operating lease expense	4
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(3,575)	(165)
Accounts payable	1,054	(1,721)
Accrued expenses and other liabilities	2,206	(1,793)
Net cash used in operating activities	(32,410)	(24,321)
Cash flows from investing activities:
Purchases of property and equipment	(2,125)	(771)
Net cash used in investing activities	(2,125)	(771)
Cash flows from financing activities:
Proceeds from issuance of common stock upon IPO, net of issuance costs	78,697
Proceeds from exercise of stock options	349	163
Other	(15)	(34)
Net cash provided by financing activities	166,259	10,036
Net increase (decrease) in cash, cash equivalents and restricted cash	131,724	(15,056)
Cash, cash equivalents and restricted cash at beginning of period	17,487	32,543
Cash, cash equivalents and restricted cash at end of period	149,211	17,487
Supplemental disclosure of cash flow information:
Purchases of property and equipment in accounts payable and accrued expenses and other liabilities	386
Initial measurement of operating lease right-of-use assets and liabilities	536
Right-of-use assets obtained in exchange for operating lease liabilities	516
Remeasurement of operating lease right-of-use assets and liabilities for lease modification	390
Deferred offering costs in accounts payable	377
Series D Convertible Preferred Stock
Cash flows from financing activities:
Proceeds from issuance of convertible preferred stock, net of issuance costs	6,982	$ 9,907
Series E Convertible Preferred Stock
Cash flows from financing activities:
Proceeds from issuance of convertible preferred stock, net of issuance costs	$ 80,246

Consolidated Statements of Cash Flows - Reconciliation of Cash, Cash Equivalents, and Restricted Cash - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents, end of period	$ 149,063	$ 17,393
Short-term restricted cash, end of period	23	19
Long-term restricted cash, end of period	125	75
Cash, cash equivalents and restricted cash at end of period	$ 149,211	$ 17,487

Description of Business

12 Months Ended

Dec. 31, 2021

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Description of Business

1. Description of Business

Aura Biosciences, Inc. (the “Company” or “Aura”) is a clinical-stage biotechnology company leveraging its novel targeted oncology platform to develop a potential new standard of care across multiple cancer indications, with an initial focus on ocular and urologic oncology. Within these consolidated financial statements, unless the context otherwise requires, references to the Company or Aura refer to Aura Biosciences, Inc. The Company’s proprietary platform enables the targeting of a broad range of solid tumors using Virus-Like Particles, or VLPs, that can be conjugated with drugs or loaded with nucleic acids to create Virus-Like Drug Conjugates, or VDCs. The Company’s VDCs are largely agnostic to tumor type and can recognize a surface marker, known as HSPGs, that are specifically modified and more broadly expressed on many tumors. The Company is developing AU-011, its first VDC product candidate for the first line treatment of primary choroidal melanoma, a rare disease with no drugs approved. The Company is also developing AU-011 for additional ocular oncology indications and in non-muscle invasive bladder cancer. Aura’s team combines expertise in cancer cell biology, ophthalmology, and targeted therapies together with experience in the development and commercialization of orphan products for significant unmet medical needs. Aura’s headquarters are located in Cambridge, Massachusetts.

The Company’s operations to date have consisted primarily of conducting research and development and raising capital.

The Company is subject to risks common to companies in the biotechnology industry, including, but not limited to, the successful development and commercialization of products, fluctuations in operating results and financial risks, need for additional financing or alternative means of financial support or both to fund its current operating plan, protection of proprietary technology and patent risks, compliance with government regulations, dependence on key personnel and collaborative partners, competition, customer demand, management of growth, and the effectiveness of marketing by the Company.

Reverse Stock Split

On October 22, 2021, the Company effected a reverse stock split of the Company’s common stock on a 1-for-13.7 basis, or the Reverse Stock Split. In connection with the Reverse Stock Split, the conversion ratio for the Company’s convertible preferred stock was proportionately adjusted such that the common stock issuable upon conversion of such preferred stock was decreased in proportion to the Reverse Stock Split. Accordingly, all common stock share and per share amounts, for all periods presented in these consolidated financial statements, have been retroactively adjusted, to reflect this reverse stock split and adjustment of the convertible preferred stock conversion ratios.

Initial Public Offering

On November 2, 2021, the Company completed its initial public offering or the IPO, in which it issued and sold 6,210,000 shares of common stock, including the full exercise of the underwriters’ option to purchase additional shares at a price to the public of $14.00 per share for aggregate gross proceeds of $86.9 million. The Company received approximately $78.3 million in net proceeds after deducting underwriting discounts, commissions and offering expenses.

Liquidity and Going Concern

Through December 31, 2021, the Company has funded its operations primarily with proceeds from the initial closing and additional closings of its convertible preferred stock financings, through its license agreements, and through its IPO. On November 2, 2021, the Company completed its IPO, in which it issued and sold 6,210,000 shares of common stock, including the full exercise of the underwriters’ option to purchase additional shares at a price to the public of $14.00 per share for aggregate gross proceeds of $86.9 million. The Company received approximately $78.3 million in net proceeds after deducting underwriting discounts, commissions and offering expenses. The Company has incurred recurring losses and negative operating cash flows from operations since its inception, including net losses of $35.3 million and $22.2 million for the years ended December 31, 2021 and 2020, respectively. As of December 31, 2021, the Company had cash and cash equivalents of $149.1 million and an accumulated deficit of $152.1 million. The Company expects to continue to generate operating losses for the foreseeable future.

As of the issuance date of these consolidated financial statements for the year ended December 31, 2021, the Company expects that its cash and cash equivalents will be sufficient to fund its operating expenses and capital expenditure requirements through at least 12 months from the issuance of these consolidated financial statements. The future viability of the Company beyond that point is dependent on its ability to raise additional capital to finance its operations.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation and Principles of Consolidation

The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). The consolidated financial statements include those accounts of the Company and its subsidiaries after elimination of all intercompany accounts and transactions.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. Significant items subject to such estimates and assumptions include the fair value of stock-based compensation and accrued research and development costs. Management bases its estimates on historical experience and on various other market-specific relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ from those estimates.

Segment Information

Operating segments are defined as components of an entity about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating segment operating exclusively in the United States.

Cash and Restricted Cash

Cash consists of standard checking accounts. As of December 31, 2021 and 2020, the restricted cash account is comprised of a $0.1 million security deposit held by the lessor for the Company’s facility lease, and a $0.02 million deposit that is collateral for the Company’s corporate credit card.

Cash Equivalents

Cash equivalents are highly liquid investments with an original maturity of 90 days or less at the date of purchase and consist of time deposits and investments in money market funds that invest in U.S. Treasury obligations and government funds with commercial banks and financial institutions.

Fair Value Measurements

Accounting Standards Codification 820, Fair Value Measurement (“ASC 820”), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs).

Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances.

ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three-tier fair value hierarchy that distinguishes between the following:

▪

Level 1—Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities.

▪

Level 2—Inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly.

▪

Level 3—Inputs are unobservable inputs that reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement.

To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to concentration of credit risk consist primarily of cash and cash equivalents. The Company maintains its cash in bank deposit accounts which, at times, may exceed federally insured limits. The Company has not experienced any losses in such accounts. The Company believes it is not exposed to any significant credit risk on cash.

Property and Equipment

Property and equipment are recorded at cost and depreciated using the straight-line method over the estimated useful life of the assets. Upon sale or retirement, the cost and accumulated depreciation is eliminated from their respective accounts and the resulting gain or loss is included in income or loss for the period. Repair and maintenance expenditures are charged to expense as incurred. The estimated useful lives of the Company’s respective assets are as follows:


		Estimated Useful Life
Leasehold improvements		2 years
IT equipment		3 years
Laboratory equipment		5 years
Office furniture		7 years

Costs for capital assets not yet placed into service are capitalized as construction-in-progress and depreciated in accordance with the above guidelines once placed into service. Upon retirement or disposal of property and equipment, the cost and related accumulated depreciation are removed from the consolidated balance sheet and any gain or loss is reflected in the consolidated statements of operations and comprehensive loss.

Impairment of Long-Lived Assets

The Company reviews all long-lived assets for impairment whenever events or circumstances indicate the carrying amount of such assets may not be recoverable. Recoverability of assets to be held and used is measured by comparison of the carrying value of the assets to the future undiscounted net cash flows expected to be generated by the asset. If such asset is considered to be unrecoverable, the impairment recognized is measured by the difference between the estimated fair value of the asset and its carrying value. The Company did not recognize any material impairments during the years ended December 31, 2021 or 2020.

Research and Development

Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including salaries, stock-based compensation and benefits, facilities costs, depreciation, third-party license fees, and external costs of outside vendors engaged to conduct preclinical development activities and clinical trials as well as to manufacture research and development materials. The Company accrues costs for clinical trial activities and contract manufacturers based upon estimates of the services received and related expenses incurred that have yet to be invoiced by the contract research organizations, clinical study sites, contract manufacturers, laboratories, consultants, or other vendors that perform the activities.

Non-refundable prepayments for goods or services that will be used or rendered for future research and development activities are deferred. Such amounts are expensed as the goods are delivered or the related services are performed or until it is no longer expected that the goods will be delivered, or the services rendered.

Costs incurred in obtaining technology licenses are recognized as research and development expense as incurred if the technology licensed has not reached technological feasibility and has no alternative future uses.

Patent and Trademark Costs

All patents and trademark related costs incurred in connection with filing and prosecuting patent and trademark applications are expensed as incurred due to uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses in the consolidated statements of operations and comprehensive loss.

Leases

Prior to January 1, 2021, the Company accounted for leases in accordance with ASC 840, Leases ("ASC 840"). At lease inception, the Company determined if an arrangement was an operating or capital lease. For operating leases, the Company recognized rent expense, inclusive of rent escalation, holidays and lease incentives, on a straight-line basis over the lease term. The difference between rent expense recorded and the amount paid was charged to deferred rent. The Company presented lease incentives as deferred rent and amortized the incentives as a reduction to rent expense on a straight-line basis over the lease term. The Company classified deferred rent as current and noncurrent liabilities based on the portion of the deferred rent that was scheduled to mature within the proceeding twelve months.

Effective January 1, 2021, the Company accounts for leases in accordance with ASU No. 2016-02, Leases (Topic 842) (“ASC 842”). At contract inception, the Company determines if an arrangement is or contains a lease. A lease conveys the right to control the use of an identified asset for a period of time in exchange for consideration. If determined to be or contain a lease, the lease is assessed for classification as either an operating or finance lease at the lease commencement date, defined as the date on which the leased asset is made available for use by the Company, based on the economic characteristics of the lease. For each lease with a term greater than twelve months, the Company records a right-of-use asset and lease liability.

The Company adopted the new leasing standard effective January 1, 2021, using the modified retrospective transition approach which uses the effective date, or January 1, 2021, as the date of initial application. As a result, prior periods are presented in accordance with the previous guidance in ASC 840. ASC 842 provides several optional practical expedients in transition. The Company has elected to apply the package of practical expedients requiring no reassessment of whether any expired or existing contracts are or contain leases, the lease classification of any expired or existing leases, or the capitalization of initial direct costs for any existing leases.

A right-of-use asset represents the economic benefit conveyed to the Company by the right to use the underlying asset over the lease term. A lease liability represents the obligation to make lease payments arising from the lease. The Company elected the practical expedient to not separate lease and non-lease components for all classes of underlying assets and therefore measures each lease payment as the total of the fixed lease and associated non-lease components. Lease liabilities are measured at lease commencement and calculated as the present value of the future lease payments in the contract using the rate implicit in the contract, when available. If an implicit rate is not readily determinable, the Company uses an incremental borrowing rate measured as the rate at which the Company could borrow, on a fully collateralized basis, a commensurate loan in the same currency over a period consistent with the lease term at the commencement date. Right-of-use assets are measured as the lease liability plus initial direct costs and prepaid lease payments, less lease incentives granted by the lessor. The lease term is measured as the noncancelable period in the contract, adjusted for any options to extend or terminate when it is reasonably certain the Company will extend the lease term via such options based on an assessment of economic factors present as of the lease commencement date. The Company elected the practical expedient to not recognize leases with a lease term of twelve months or less.

Components of a lease are split into three categories: lease components, non-lease components, and non-components. The fixed and in-substance fixed contract consideration (including any consideration related to non-components) are allocated, based on the respective relative fair values, to the lease components and non-lease components. The Company has elected to account for lease and non-lease components together as a single lease component for all underlying assets and allocate all of the contract consideration to the lease component only.

The Company’s operating leases are presented in the consolidated balance sheet as operating lease right-of-use assets, classified as noncurrent assets, and operating lease liabilities, classified as current and noncurrent liabilities. Operating lease expense is recognized on a straight-line basis over the lease term. Variable costs associated with a lease, such as maintenance and utilities, are not included in the measurement of the lease liabilities and right-of-use assets but rather are expensed when the events determining the amount of variable consideration to be paid have occurred.

Income Taxes

The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the Company’s consolidated financial statements and/or tax returns. Deferred tax assets and liabilities are based upon the differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities and for loss and credit carryforwards using enacted tax rates expected to be in effect in the years in which the differences are expected to reverse. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that some portion or all the deferred tax asset will not be realized.

The Company provides reserves related to uncertain tax positions when management determines the related tax benefit is not more likely than not to be realized. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as the consideration of the available facts and circumstances. The Company has no reserves related to uncertain tax positions as of December 31, 2021 and 2020.

Interest and penalty charges, if any, related to uncertain tax positions would be classified as income tax expense in the accompanying consolidated statements of operations and comprehensive loss. As of December 31, 2021, and 2020, the Company had no accrued interest related to uncertain tax positions.

Deferred Offering Costs

The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process preferred stock or common stock financings as deferred offering costs until such financings are consummated. After the closing of the IPO, these costs were recorded in stockholders' equity (deficit) as a reduction of additional paid-in capital generated as a result of the offering.

Convertible Preferred Stock Classification

The Company records all convertible preferred stock upon issuance at its respective fair value or original issuance price less issuance costs. The Company classifies its convertible preferred stock outside of stockholders’ deficit as the redemption of such shares is outside the Company’s control. The Company does not adjust the carrying values of the convertible preferred stock to redemption value unless and until it becomes probable that the instrument will become redeemable. As of December 31, 2020, the Company’s convertible preferred stock was not adjusted to redemption value. After the closing of the IPO, all of the Company's outstanding shares of convertible preferred stock automatically converted into shares of common stock.

Stock-Based Compensation

The Company recognizes stock-based compensation expense for all stock-based awards based on their grant date fair value.

The Company recognizes compensation expense over the requisite service period, which is generally the vesting period of the award. For awards that include performance-based vesting conditions, expense is recognized using the accelerated attribution method when the performance condition is deemed to be probable of being satisfied. As of December 31, 2021, the Company has no performance-based awards. The Company accounts for forfeitures as they occur. The Company determines the fair value of restricted stock awards in reference to the fair value of its common stock less any applicable purchase price.

The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the expected stock price volatility, the expected term of the option, the risk-free interest rate for a period that approximates the expected term of the option and the Company’s expected dividend yield. The Company determines the volatility for awards granted based on an analysis of reported data for a group of guideline companies that have issued options with substantially similar terms. The expected volatility has been determined using a weighted-average of the historical volatility measures of this group of guideline companies. The Company expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options granted to employees has been determined utilizing the “simplified” method, using the midpoint between the vesting date and the contractual term. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. The Company has not paid, and does not anticipate paying, cash dividends on its common stock; therefore, the expected dividend yield is assumed to be zero.

Before the IPO, as there has been no public market for the Company's common stock, the estimated fair value of its common stock was been determined by its Board of Directors, with input from management, considering third-party valuations of the common stock as well as the Board of Directors’ assessment of additional objective and subjective factors that it believed were relevant and which may have changed from the date of the most recent third-party valuation through the date of the option grant. These third-party valuations were performed in accordance with the guidance outlined in the American Institute of Certified Public Accountants’ Accounting and Valuation Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation. The Company's common stock valuations were prepared using either an option pricing method, or OPM, or a hybrid method, both of which used market approaches to estimate the Company's enterprise value. The hybrid method is a probability-weighted expected return method, or PWERM, where the equity value in one or more of the scenarios is calculated using an OPM. The PWERM is a scenario-based methodology that estimates the fair value of common stock based upon an analysis of future values for the company, assuming various outcomes. The common stock value is based on the probability-weighted present value of expected future investment returns considering each of the possible outcomes available as well as the rights of each class of stock. The future value of the common stock under each outcome is discounted back to the valuation date at an appropriate risk-adjusted discount rate and probability weighted to arrive at an indication of value for the common stock. A discount for lack of marketability of the common stock is then applied to arrive at an indication of value for the common stock. The OPM treats common stock and preferred stock as call options on the total equity value of a company, with exercise prices based on the value thresholds at which the allocation among the various holders of a company’s securities changes. Under this method, the common stock has value only if the funds available for distribution to stockholders exceeded the value of the preferred stock liquidation preferences at the time of the liquidity event, such as a strategic sale or a merger.

In addition to considering the results of these third-party valuations, the Company's Board of Directors considered various objective and subjective factors to determine the fair value of the Company's common stock as of each grant date, including:


	∎		The prices at which the Company sold shares of preferred stock and the superior rights and preferences of the preferred stock relative to its common stock at the time of each grant;


	∎		The progress of Aura's research and development programs, including the status and results of preclinical studies for its product candidates;


	∎		The Company's stage of development and commercialization and its business strategy;


	∎		External market conditions affecting the biotechnology industry and trends within the biotechnology industry;


	∎		The Company's financial position, including cash on hand, and its historical and forecasted performance and operating results;


	∎		The lack of an active public market for Aura's common stock and convertible preferred stock;


	∎		The likelihood of achieving a liquidity event, such as an IPO, or sale of the Company in light of prevailing market conditions; and


	∎		The analysis of an IPO and the market performance of similar companies in the biotechnology industry.

The assumptions underlying these valuations represented management’s best estimate, which involved inherent uncertainties and the application of management’s judgment. As a result, if the Company had used different assumptions or estimates, the fair value of its common stock and stock-based compensation expense could have been materially different.

The Company classifies stock-based compensation expense in its consolidated statements of operations and comprehensive loss in the same manner in which the award recipient’s cash compensation costs are classified.

Warrants

The Company accounts for warrants on capital stock based on guidelines provided in ASC Topic 815, Derivatives and Hedging—Contracts in Entity’s Own Equity (“ASC 815”), which provides guidance on contracts that are settled in the Company’s own shares as either a liability or as an equity instrument depending on the warrant agreement. The Company's warrants are all classified as equity instruments. As such, the Company uses the Black-Scholes pricing model, depending on the applicable terms of the warrant agreement, to value the warrants.

Net Loss per Share

Net loss per share attributable to common stockholders is computed by using the two-class method, which is an earnings allocation formula that determines loss per share for the holders of the Company’s common stock and participating securities. All series of preferred stock contain participation rights in any dividend declared or accumulated by the Company and are deemed to be participating securities. Income available to common stockholders and participating convertible preferred stock is allocated to each share on an as-converted basis as if all of the earnings for the period had been distributed. The participating securities do not include a contractual obligation to share in losses of the Company and are not included in the calculation of net loss per share in the periods that have a net loss.

Diluted net income per share is computed using the more dilutive of (a) the two-class method, or (b) the if-converted method. The Company allocates earnings first to preferred stockholders based on dividend rights and then to common and preferred stockholders based on ownership interests. The weighted-average number of common stock included in the computation of diluted loss gives effect to all potentially dilutive common equivalent shares, including outstanding stock options, warrants, and convertible preferred stock. Common stock equivalent shares are excluded from the computation of diluted loss per share if their effect is antidilutive.

The Company’s convertible preferred stock contractually entitles the holders of such shares to participate in dividends. Accordingly, in periods in which the Company reports a net loss, such losses are not allocated to such participating securities. In periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. The Company reported a net loss attributable to common stockholders for the years ended December 31, 2021 and 2020, respectively.

Comprehensive Loss

Comprehensive loss is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. For the years ended December 31, 2021 and 2020, comprehensive loss was equal to net loss.

Recently Adopted Accounting Pronouncements

Upon adoption of ASC 842, the Company recorded lease liabilities and their corresponding right-of-use assets based on the present value of lease payments over the remaining lease term. The adoption of ASC 842 resulted in the recognition of operating lease liabilities of $0.6 million and operating lease right-of-use assets of $0.5 million and the derecognition of deferred rent liabilities of $0.02 million on the Company’s consolidated balance sheet as of January 1, 2021. The adoption impact relates to the Company’s existing operating lease for operating and laboratory space. The adoption of ASC 842 did not have a material impact on the Company’s consolidated statements of operations and comprehensive loss or consolidated statements of cash flows.

Recently Issued Accounting Pronouncements Not Yet Adopted

The Company reviewed recently issued accounting pronouncements for the year end December 31, 2021 and noted no pronouncements would have a material impact on the Company's consolidated financial statements.

Fair Value of Assets and Liabilities

12 Months Ended

Dec. 31, 2021

Fair Value Disclosures [Abstract]

Fair Value of Assets and Liabilities

3. Fair Value of Assets and Liabilities

The following table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values as of December 31, 2021 and 2020 (in thousands):


Description	December 31, 2021		Quoted prices active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant other observable inputs (Level 3)
Assets
Money market funds	$	24,063	$	24,063	$	—	$	—
Total financial assets	$	24,063	$	24,063	$	—	$	—
Liability
Warrant Liability	$	83	$	—	$	—	$	83
Total financial liabilities	$	83	$	—	$	—	$	83


Description	December 31, 2020		Quoted prices active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant other observable inputs (Level 3)
Liability
Warrant Liability	$	72	$	—	$	—	$	72
Total financial liabilities	$	72	$	—	$	—	$	72

At December 31, 2021, the fair value of the warrant liability was determined based on Level 3 inputs and utilizing the Black-Scholes option pricing model (see Note 10).

During the years ended December 31, 2021 and 2020, there were no transfers into or out of Level 3.

The following table set forth a summary of changes in the fair value of the common stock warrants, which represents a recurring fair value measurement that is classified within Level 3 of the fair value hierarchy. Changes in fair value are recognized in other (expense) income as “Change in fair value of warrant liability” in the Company’s consolidated statements of operations and comprehensive loss (in thousands):


Common Stock (12,686 warrants)
Fair value at December 31, 2019	$	75
Change in fair value		(3	)
Fair value at December 31, 2020		72
Change in fair value		11
Fair value at December 31, 2021	$	83

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Property and Equipment, Net

12 Months Ended

Dec. 31, 2021

Property Plant And Equipment [Abstract]

Property and Equipment, Net

4. Property and Equipment, Net

At December 31, 2021 and 2020, property and equipment consisted of the following (in thousands):


	December 31, 2021			December 31, 2020
Assets under construction	$	2,365		$	1,154
IT equipment		85			—
Leasehold improvements		13			—
Lab equipment		5,489			4,708
Office furniture		63			64
	$	8,015		$	5,926
Less—accumulated depreciation		(2,764	)		(2,352	)
Property and equipment, net	$	5,251		$	3,574

For the years ended December 31, 2021 and 2020, depreciation expense was $0.8 million.

Prepaid Expenses and Other Current Assets

12 Months Ended

Dec. 31, 2021

Prepaid Expense and Other Assets, Current [Abstract]

Prepaid Expenses and Other Current Assets

5. Prepaid Expenses and Other Current Assets

At December 31, 2021 and 2020, prepaid expenses and other current assets consisted of the following (in thousands):


	December 31, 2021		December 31, 2020
Prepaid insurance	$	2,734	$	51
Prepaid research and development expenses		1,754		915
Prepaid license agreements		64		61
Other		66		16
Prepaid expenses and other current assets	$	4,618	$	1,043

Accrued Expenses and Other Current Liabilities

12 Months Ended

Dec. 31, 2021

Payables And Accruals [Abstract]

Accrued Expenses and Other Current Liabilities

6. Accrued Expenses and Other Current Liabilities

At December 31, 2021 and 2020, accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31, 2021		December 31, 2020
Accrued research and development expenses	$	1,686	$	750
Accrued compensation		2,147		1,023
Other		423		277
Accrued expenses and other current liabilities	$	4,256	$	2,050

Convertible Preferred Stock

12 Months Ended

Dec. 31, 2021

Temporary Equity Disclosure [Abstract]

Convertible Preferred Stock

7. Convertible Preferred Stock

As of December 31, 2020, the Company had 1,701,141 authorized, issued and outstanding shares of Series A convertible preferred stock, 3,298,732 authorized, issued and outstanding shares of Series A-1 convertible preferred stock, 4,325,021 authorized shares and 4,324,998 issued and outstanding shares of Series A-2 convertible preferred stock and, 22,705,646 authorized shares and 22,531,819 issued and outstanding shares of Series B convertible preferred stock, 58,109,711 authorized, issued and outstanding shares of Series C-1 convertible preferred stock, 33,218,192 authorized, issued and outstanding shares of Series C-2 convertible preferred stock, 57,878,742 authorized, issued and outstanding shares of Series D-1 convertible preferred stock and 24,598,481 authorized shares and 14,469,710 issued and outstanding shares of Series D-2 convertible preferred stock. All series of convertible preferred stock are collectively referred to as Preferred Stock, each with a par value of $0.00001 per share.

Series D-2 Offering

On June 25, 2020, the Company entered into the Series D-2 Purchase Agreement (the "Series D-2 Agreement”) with certain investors to sell up to 24,598,481 shares of Series D-2 convertible preferred stock at a purchase price of $0.6911 per share. The Series D-2 Agreement provides for two closings, the first on October 1, 2020 and the second upon the achievement or waiver of certain milestone events. The Company sold 14,469,710 shares of the Series D-2 convertible preferred stock on October 1, 2020 at the first tranche closing for gross proceeds of $10.0 million.

On March 5, 2021, the Company completed the second tranche of the Series D-2 convertible preferred stock offering and issued 10,128,771 shares of the Series D-2 convertible preferred stock, $0.00001 par value per share, at a purchase price of $0.6911 per share for gross proceeds of $7.0 million.

Costs incurred in connection with the Series D-2 convertible preferred stock offering totaled $0.1 million and were recorded as a reduction to the Series D-2 convertible preferred stock. The majority of offering costs were incurred during the year ended December 31, 2020. Offering costs incurred during the year ended December 31, 2021 was $0.02 million.

The Company evaluated the tranche rights pursuant to the Series D-2 Agreement and determined the tranche rights did not represent a freestanding financial instrument as they are not legally detachable from the Series D-2 convertible preferred stock issued in the first tranche.

As of December 31, 2021, all the Series D-2 convertible preferred stock have been converted to shares of common stock upon closing of the IPO.

Series E Offering

On March 18, 2021, the Company completed its Series E Stock offering and issued 102,671,041 shares of Series E convertible preferred stock, $0.00001 par value per share, at a purchase price of $0.7839 per share for gross proceeds of $80.5 million.

Costs incurred in connection with the Series E convertible preferred stock offering totaled $0.2 million during the year ended December 31, 2021 and were recorded as a reduction to Series E convertible preferred stock.

As of December 31, 2021, all Series E convertible preferred stock have been converted to shares of common stock upon closing of the IPO.

The rights and privileges of the Company’s Preferred Stock for the year ended December 31, 2020, and the period January 1, 2021 through November 2, 2021, are as follows:

Voting

Except as otherwise required by law or by other provisions, holders of the Preferred Stock vote together with the holders of common stock as a single class. Holders of Preferred Stock may cast the number of votes equal to the number of shares of common stock to which such shares of Preferred Stock are convertible into.

Dividends

Series C, D and E Dividend:

From and after the date of the issuance of any shares of Series C-1, Series C-2, Series D-1, Series D-2, and Series E, dividends at the annual rate of seven percent (7%) per annum of the original share price per share accrue on such shares of Series C-1, Series C-2, Series D-1, Series D-2, and Series E. Dividends accrue from day to day, whether or not declared, and are cumulative, but not compounding. Such dividends are only payable when and if declared by the Board or in the event of a Deemed Liquidation Event (as defined in the amended and restated Certificate of Incorporation). No other dividends may be declared or paid on any other class of stock unless the holders of the shares of Series E then outstanding first receive, or simultaneously receive, their applicable dividend. For the year ended December 31, 2020, $5.9 million, $2.6 million, $3.9 million, and $0.2 million of cumulative dividends on Series C-1, Series C-2, Series D-1, and Series D-2, respectively, are included in the liquidation preference amount indicated on the consolidated balance sheet. For the year ended December 31, 2020, there were no Series E convertible preferred stock shares issued or outstanding.

Series B Dividends:

From and after the date of the issuance of any shares of Series B, dividends at the annual rate of $0.0869645 per share accrue on such shares of Series B. Dividends accrue from day to day, whether or not declared, and are cumulative, but not compounding. Such dividends are only payable when and if declared by the Company’s Board or in the event of a Deemed Liquidation Event (as defined in the amended and restated Certificate of Incorporation). No other dividends may be declared or paid on any other class of stock unless the holders of the shares of Series B then outstanding first receive, or simultaneously receive, their applicable dividend. For the year ended December 31, 2020, $9.4 million of cumulative dividends on Series B are included in the liquidation preference amount indicated on the consolidated balance sheet.

Series A Dividends:

From and after the date of the issuance of Series A, Series A-1, and Series A-2, if the Company declares, pays or sets aside, on the same date, a dividend on shares of more than one class or series of capital stock of the Company, the dividend payable to the holders of Series A, Series A-1, and Series A-2 convertible preferred stock shall be calculated based upon the dividend on the class or series of capital stock that would result in the highest dividend. No other dividends, or dividends on common stock payable in shares of common stock, may be declared or paid unless the holders of Series A, Series A-1, and Series A-2 then outstanding first receive, or simultaneously receive, their applicable dividend. As of December 31, 2020, no dividends have been declared on the common stock or the convertible preferred stock.

Liquidation Rights

In the event of a Deemed Liquidation Event, as defined in the Company’s amended and restated Certificate of Incorporation, the assets of the Company will be distributed first to the holders of Series E convertible preferred stock. The holders of Series E convertible preferred stock will receive, in preference to all other stockholders, and amount equal to the sum of the Series E original issue price (equal to the cash price paid per share of $0.783900), plus unpaid dividends on such shares. Next, the holders of Series D convertible preferred stock will receive, in preference to all other stockholders other than Series E, an amount equal to the sum of the Series D original issue price, plus unpaid dividends on such shares. Next, the holders of Series C will receive, in preference to all stockholders other than the Series E and D convertible preferred stock holders, an amount equal to the sum of the Series C original issue price plus unpaid dividends on such shares. Next, the holders of Series B will receive, in preference to the holders of Series A, Series A-1, Series A-2 and common stock, an amount equal to the sum of the Series B original issue price plus unpaid dividends on such shares. Next, the holders of Series A, Series A-1, and Series A-2 will receive, in preference to the holders of common stock, an amount equal to the greater of their applicable liquidation preference or what they would have received had their shares converted into common stock. If the proceeds available are not sufficient to satisfy the full liquidation preference, the entire proceeds are to be distributed pro-rata among the Series E convertible preferred stock holders in proportion to the full preferential amount the Series E convertible preferred stock holders are entitled to receive.

Conversion

The Series E, together with the Series D, the Series C and the Series B convertible preferred stock, collectively the "Senior Preferred Stock", converts into common stock on a one-for-one basis. Each share of Series B, Series C-1, Series C-2, Series D-1, Series D-2, and Series E convertible preferred stock is convertible into the number of shares of common stock as is determined by dividing the respective original issue price by the conversion price in effect at the time of conversion. The Series E conversion price is set at $0.7839 per share, the Series D-1 and Series D-2 conversion price is set at $0.6911 per share, the Series C-1 conversion price is set at $0.5213 per share, the Series C-2 conversion price is set at $0.36491 per share, and the Series B conversion price is set at $1.24235 per share; none represents a beneficial conversion feature. Subject to certain exceptions, the Senior Preferred Stock has the benefit of anti- dilution protection on a weighted-average basis in the event that the Company sells stock at less than the applicable conversion price per share.

Each share of Series A and Series A-1 was originally convertible into the number of shares of common stock determined by dividing the respective Series A and Series A-1 original issue price by the conversion price in effect at the time of conversion. The Series A conversion price was originally equal to $2.00 per share and the Series A-1 conversion price was originally equal to $2.4847 per share. As Series A-2 was sold at $1.24235 per share, less than the per share prices of Series A and Series A-1, anti-dilution protections were triggered. Pursuant to the anti-dilution protection terms, on February 24, 2015, the Series A conversion price was reduced from $2.00 to $1.8191 per share of common stock and the Series A-1 conversion price was reduced from $2.4847 to $2.1898 per share of common stock and, therefore, the Series A conversion ratio was changed from 1:1 to 1:1.099 and the Series A-1 conversion ratio was changed from 1:1 to 1:1.135. The Company evaluated Series A and Series A-1 with the updated conversion ratios and determined that there was no beneficial conversion feature.

Series A-2 converts into common stock on a one-for-one basis. The Series A-2 conversion price is set at $1.24235 per share and does not represent a beneficial conversion feature.

According to the terms of the Company’s amended and restated Certificate of Incorporation, in the event that the applicable conversion price for any series of Senior Preferred Stock is reduced, then the applicable conversion price for each series of Series A convertible preferred stock shall be uniformly and concurrently reduced.

Each share of Preferred Stock will automatically convert into common stock upon (a) the occurrence of an event, specified by vote or written consent of certain stockholders or (b) the completion of a public stock offering involving a price per share of common stock of not less than $1.554975 per share, subject to certain adjustments, where such offering results in aggregate gross proceeds to the Company of at least $50.0 million and the common stock is listed for trading on either the New York Stock Exchange or the Nasdaq Stock Market.

The Company must reserve and keep available out of its authorized but unused capital stock such number of authorized shares of common stock to sufficiently effect the conversion of all outstanding Preferred Stock.

In considering the features of the convertible preferred stock, the Company determined that none of the features, including the conversion features, requires bifurcation during the year ended December 31, 2020.

The conversion ratios for the Series A stock was changed to 13.700 to 1.099, Series A-1 stock was changed to 13.7 to 1.135, and the Series A-2 stock through Series E stock was changed to 13.7 to 1 upon the Company’s filing of its amendment to its amended and restated Certificate of Incorporation on October 22, 2021.

Upon closing of the IPO on November 2, 2021, all of the Company's outstanding shares of convertible preferred stock automatically converted into 22,550,561 shares of common stock. In addition, the Company authorized 10,000,000 shares of preferred stock, par value $0.00001 per share, all of which shares of preferred stock will be undesignated.

Common Stock

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Common Stock

8. Common Stock

The Company has 150,000,000 and 232,697,999 authorized shares of common stock, par value $0.00001 per share, of which 29,211,643 and 381,123 shares were issued and outstanding as of December 31, 2021 and 2020, respectively.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Section 50
-Paragraph 13
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Section S99
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
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+ Details

Stock-Based Compensation

12 Months Ended

Dec. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation

9. Stock-Based Compensation

2018 Stock Option and Incentive Plan

On December 12, 2018, the Company adopted the Aura Biosciences, Inc. 2018 Equity Incentive Plan (the “2018 Plan”). The 2018 Plan will expire in 2028. Under the 2018 Plan, Aura may grant incentive stock options, non-qualified stock options, restricted and unrestricted stock awards and stock right. The Board has determined not to make any further awards under the 2018 Plan as of November 2, 2021. However, the 2018 Plan will continue to govern outstanding equity awards granted thereunder.

2021 Stock Option and Incentive Plan

The 2021 Stock Option and Incentive Plan, (the "2021 Plan"), was adopted by the Board on October 7, 2021, approved by the Company’s stockholders on October 22, 2021 and became effective on November 1, 2021. The 2021 Plan permits the granting of both options to purchase common stock intended to qualify as incentive stock options under Section 422 of the Code and options that do not so qualify. The number of shares initially reserved for issuance under the 2021 Plan was 3,352,166, which will automatically increase on January 1, 2022 and each January 1 thereafter, by 5% of the outstanding number of shares of common stock on the immediately preceding December 31 or such lesser number of shares as determined by the Company’s compensation committee. The maximum number of shares of common stock that may be issued in the form of incentive stock options shall not exceed the initial limit, cumulatively increased on January 1, 2022 and on each January 1 thereafter by the lesser of the annual increase for such year or 3,352,166 shares of common stock.

2021 Employee Stock Purchase Plan

The 2021 Employee Stock Purchase Plan, (the "ESPP"), was adopted by the Board on October 7, 2021, approved by the Company’s stockholders on October 22, 2021 and became effective on November 1, 2021. A total of 335,217 shares of common stock were initially reserved for issuance under this plan, which will automatically increase on January 1, 2022 and each January 1 thereafter through January 1, 2031, by the least of (i) 335,217 shares of common stock, (ii) 1% of the outstanding number of shares of common stock on the immediately preceding December 31 or (iii) such lesser number of shares of common stock as determined by the administrator of the ESPP.

On March 18, 2021, the Board approved an increase to the 2018 Plan available option pool of 2,346,228 options. As mentioned above, the 2021 Plan was initiated in November 2021. With the transfer of the available options from the 2018 Plan to the 2021 Plan, there were 2,042,774 options available for grant under the 2021 Plan at December 31, 2021.

The Board is authorized to administer the 2021 Plan. In accordance with the provisions of the 2021 Plan, the Board determines the terms of Aura options and other awards issued pursuant thereto, including the following:

▪

which employees, directors and consultants shall be granted awards;

▪

the number of shares of common stock subject to options and other awards;

▪

the exercise price of each option, which generally shall not be less than fair market value of the common stock on the date of grant;

▪

the termination or cancellation provisions applicable to options;

▪

the terms and conditions of other awards, including conditions for repurchase, termination or cancellation, issue price and repurchase price; and

▪

all other terms and conditions upon which each award may be granted in accordance with the 2018 Plan.

In addition, the Board may award restricted shares of common stock and restricted stock units to participants subject to such conditions and restrictions as it may determine. The Board or any committee to which the Board delegates authority may, with the consent of the affected plan participants, re-price or otherwise amend outstanding awards consistent with the terms of the 2021 Plan.

The following table summarizes stock option activity under the 2021 Plan for the year ended December 31, 2021:


	Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (years)		Aggregate Intrinsic Value
Outstanding at December 31, 2020		1,512,129		$	3.84		7.77	$	1,174
Granted		2,970,708			9.03
Exercised		(69,959	)		4.99
Cancelled/Forfeited		(179,887	)		4.59
Outstanding at December 31, 2021		4,232,991		$	7.43		8.66	$	40,437
Exercisable at December 31, 2021		1,174,871		$	3.95		6.82	$	15,304
Unvested as of December 31, 2021		3,058,120		$	8.78		9.30	$	25,133

The weighted-average grant date fair value of stock options granted during the years ended December 31, 2021 and 2020 was $5.84 and $2.74 per share, respectively. The total intrinsic value of options exercised was $0.1 million and $0.02 million for the years ended December 31, 2021 and 2020, respectively.

The Company has elected to use the Black-Scholes option pricing model to determine the fair value of options granted and generally recognizes the compensation cost of stock-based awards on a straight-line basis over the vesting period of the award.

The determination of the fair value of stock-based payment awards utilizing the Black-Scholes option pricing model is affected by the fair value of the Company’s common stock and a number of other assumptions, including expected volatility, expected life, risk-free interest rate, and expected dividends.

The fair value of the stock options issued as of December 31, 2021 and 2020 was measured with the following weighted-average assumptions:


	December 31, 2021			December 31, 2020
Risk-free interest rate, %		1.15	%		0.55	%
Expected term		6.03			6.02
Expected volatility of the underlying stock, %		73.87	%		74.04	%
Expected dividend rate, %		—	%		—	%

Restricted Stock Units

The Company has granted restricted stock units with service vesting based conditions. Unvested shares of restricted common stock may not be sold or transferred by the holder. They are legally issued and outstanding. These restrictions lapse accordingly to the time-based vesting of each award.

A summary of the restricted stock unit activity during the year ended December 31, 2021 is as follows:


	Restricted Stock Units			Weighted- Average Grant Date Fair Value
Granted at December 31, 2020		—		$	—
Granted		232,111			14.00
Forfeited		(191	)		14.00
Granted at December 31, 2021		231,920		$	14.00

As a result of the 2021 Equity Incentive Plan, the Company granted restricted stock units which vest in increments of 25% annually over a period of four years. No restricted stock units vested during the year ended December 31, 2021.

Stock-based Compensation Expense

The Company recorded stock-based compensation as follows (in thousands):


	Year Ended December 31,
	2021		2020
Research and development	$	702	$	193
General and administrative		1,605		543
Total	$	2,307	$	736

As of December 31, 2021, there was $16.5 million of unrecognized compensation expense related to stock options, which is expected to be recognized over a weighted-average period of 3.33 years.

As of December 31, 2021, there was $3.1 million of unrecognized compensation expense related to restricted stock units, which is expected to be recognized over a weighted-average period of 3.82 years.

Common Stock Warrants

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Common Stock Warrants

10. Common Stock Warrants

In February 2015 and May 2015, the Company issued warrants to purchase 1,650,098 and 887,536 shares of Series B convertible preferred stock, respectively, at an exercise price of $1.24235 per share (the "Series B Warrants"). Each Series B Warrant was immediately exercisable and expires ten years from the original date of issuance. Pursuant to FASB ASC Topic 480, Distinguishing Liabilities from Equity, the Series B Warrants were classified as a liability and are re-measured to fair value at each balance sheet date and immediately prior to exercise. The Series B Warrants were converted into warrants to purchase 12,686 shares of common stock upon the completion of the IPO in November 2021.

A total of 12,686 of the common stock warrants remained outstanding at December 31, 2021 and 2020.

The warrants were valued using the Black-Scholes option pricing model. The fair value of the warrants and the significant assumptions used were as follows:


Common Stock Warrants	December 31, 2021			December 31, 2020
Fair value	$	16.98		$	16.03
Volatility		80.38	%		74.00	%
Expected term (years)		3.15			4.2
Risk free rate		0.97	%		0.27	%
Dividend yield		7.00	%		7.00	%

Compensation

12 Months Ended

Dec. 31, 2021

Compensation And Retirement Disclosure [Abstract]

Compensation

11. Compensation

In January 2012, the Company adopted the Aura Biosciences 401(K) Profit Sharing Plan and Trust (the “401(k) Plan”) for its employees, which is designed to be qualified under Section 401(k) of the Internal Revenue Code. Eligible employees are permitted to contribute to the 401(k) Plan within statutory and 401(k) Plan limits. The Company makes matching contributions of 100% of the first 6% of employee contributions. The Company made matching contributions in the amount of $0.3 million and $0.2 million for the years ended December 31, 2021 and 2020, respectively.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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+ Details

Commitment and Contingencies

12 Months Ended

Dec. 31, 2021

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

12. Commitments and Contingencies

Lease Commitments

The Company has historically entered into lease arrangements for its facilities. As of December 31, 2021 and 2020, respectively, the Company had one operating lease for its office and laboratory facility with required future minimum payments. The lease does not contain any options to renew, terminate, or purchase the underlying asset, and was set to expire on July 31, 2022. As part of its adoption of ASC 842, the Company recorded a right-of-use asset and operating lease liability for this lease as of the effective date.

On March 31, 2021, the Company executed an amendment to the facility lease which included an extension of the expiration date of the original leased premises, the addition of 4,516 square feet of laboratory space with an expected commencement date of May 1, 2021, and the addition of 1,000 square feet of laboratory space with an expected commencement date of June 15, 2021. The lease term for the original and new spaces will expire on July 31, 2023, with an option to renew for an additional 12 months.

Upon the execution of the amendment, which was deemed to be a lease modification, the Company re-evaluated the assumptions made at the original lease commencement date. The Company determined the amendment consists of two separate contracts under ASC 842. One contract is related to the modification of term for the original space, and the other is related to a new right-of-use for the two additional spaces, which are to be accounted for as new leases. The Company remeasured the lease liability and corresponding right-of-use asset for the original space as of the effective date of the amendment to reflect the extended term and recorded in the second quarter of 2021 an additional right-of-use asset and lease liability upon lease commencement of each of the additional space.

The Company also leases office and laboratory equipment for which the related expense is immaterial.

The following table contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company’s leases for the year ended December 31, 2021 (in thousands):


	Year Ended December 31, 2021
Lease Cost
Amortization of finance right-of-use assets	$	11
Operating lease costs		524
Variable lease costs		322
Short-term lease costs		4
Total lease costs	$	861


Cash paid for amounts included in the measurement of lease liability—finance leases	$	15
Cash paid for amounts included in the measurement of lease liability—operating leases	$	519
Weighted-average remaining lease term—operating leases (years)		1.58
Weighted-average discount rate—finance leases		7.94	%
Weighted-average discount rate—operating leases		3.51	%

The following table reconciles the future minimum commitments to the Company’s operating lease liabilities at December 31, 2021 (in thousands):


	Operating lease payments as of December 31, 2021
2022	$	625
2023		377
Thereafter		—
Total lease payments		1,002
Less: interest		(27	)
Total operating lease liabilities at December 31, 2021		975
Less: current portion of lease liabilities		615
Lease liabilities, net of current portion	$	360

In May 2021, the Company paid in full its finance lease.

Laser Purchasing Commitment

On April 5, 2019, the Company entered into a purchase agreement for equipment with future commitments payable in three installments of €0.2 million each. The first two installments of €0.2 million were paid by the Company in April 2019 and August 2019. Upon receipt of the laser systems, the Company will assess whether the laser systems have an alternative future use and, if so, will capitalize the lasers as a component of fixed assets.

License Agreements

The Company has entered into the following key agreements that relate to the core technology under development:

LI-COR Exclusive License and Supply Agreement

In January 2014, the Company entered into an Exclusive License and Supply Agreement, or the LI-COR Exclusive License agreement with LI-COR, Inc. (LI-COR) for the license of IRDye 700DC and related licensed patents for the treatment and diagnosis of ocular cancers in humans as amended in January 2016, July 2017, April 2018 and April 2019. The LI-COR Exclusive License Agreement required a one-time upfront license issue fee of $0.1 million and aggregate milestone payments of up to $0.2 million upon certain regulatory and development milestones. The Company is also required to pay LI-COR low-single digit royalties on net sales. The term of the LI-COR Exclusive Agreement expires on a country-by-country basis, until the longer of (i) ten years from the first commercial sale of a licensed product in such country and (ii) the last to expire valid claim in such country.

For the years ended December 31, 2021, and December 31, 2020, the Company incurred, respectively, $nil and $0.1 million of expenses related to this agreement.

LI-COR Non-Exclusive License and Supply Agreement

In December 2014, the Company entered into a Non-Exclusive License Agreement with LI-COR for the supply of IRDye 700DX to the Company for the treatment and diagnosis of non-ocular solid tumor cancers in humans. Under the 2014 Non-Exclusive, the Company paid a license issue fee of $0.03 million on the effective date. The Company must also pay LI-COR a non-refundable, non-creditable fee of $0.03 million per each licensed product upon pre-IND designation, as defined of such licensed product, aggregate milestone payments of up to $0.3 million upon certain regulatory and development milestones; and during the term, the Company must pay LI-COR a low-single digit percentage royalty on net sales. LI-COR receives 10% of all sublicensee income within 30 days of the Company’s receipt from the sublicensee. The 2014 Non-Exclusive Agreement also required the Company to make certain payments upon the achievement of specified development and commercial milestones of up to $0.4 million in aggregate.

Life Technologies Corporation

In December 2014, the Company entered into a non-exclusive, perpetual license agreement with Life Technologies Corporation (“Life Technologies”), which allows for five licensed products. Under this agreement the Company is required to pay an initial license fee of $0.1 each product. An annual development fee of $0.1 million is due within a year from payment of the initial license fee and due annually or earlier of (i) payment of a commercialization fee or (ii) all development work is terminated. The commercialization fee is a one-time, non-refundable, non-creditable fee of $0.3 million due upon receipt of approval of a licensed product. In the event of a change of control, there will be a change of control fee of $0.2 million.

For the years ended December 31, 2021 and December 31, 2020, the Company incurred $0.1 million of expenses related to this agreement.

National Institute of Health (NIH)-Biologic Materials License Agreement

In December 2010, the Company entered into a Biologic Materials License Agreement with NIH for a non-exclusive right to use materials described in Schiller et al., Virology 2004 Apr.10, 321(2):205-16. This agreement required a one-time non-refundable license issuance fee of $0.02 million. No future milestone payments or royalties are due under this agreement.

National Institute of Health (NIH)-Collaboration Research and Development Agreement

In July 2011, the Company entered into a Collaboration Research and Development Agreement (CRADA), with Dr. John Schiller at the NIH, for a period of two years with the rights to an exclusive license to all technology generated within the collaboration. Under this agreement, the Company is required to make annual payments of $0.03 million to fund the research activities, the first payment of which was paid within 30 days of the effective date. Subsequent payments are due within 30 days of the anniversary of the effective date. This agreement was first amended in 2012, 2013, 2014, 2015, 2016, 2018 and most recently in September of 2020. During 2011-2021, the Company paid an aggregate of $0.4 million in research collaboration fees, $0.03 million and 0.04 million of which was paid in 2021 and 2020, respectively.

A seventh amendment was made in October 2020, requiring payment of $0.04 million within 30 days of October 1, 2020, and another $0.03 million within 30 days of the 10th anniversary of the CRADA, which was paid in July 2021. This seventh amendment extended the term of the CRADA to September 30, 2022.

National Institute of Health (NIH)-Exclusive Patent License Agreement

In September 2013, the Company entered into an exclusive patent license agreement (the “NIH Exclusive License Agreement”) with the NIH, that required the Company to pay a license issue royalty of $0.1 million and reimburse the NIH for any patent expenses incurred. Under the agreement, the Company is required to make low single-digit percentage royalty payments based on specified levels of annual net sales of licensed products subject to certain specified reductions. The Company is required to make development and regulatory milestone payments of up to $0.7 million in aggregate and sales milestone payments up to $0.6 million in the aggregate. The Company is also required to pay NIH a mid-single to low teen-digit percentage of any sublicensing revenue the Company receives. Additionally, the Company’s payment obligations to the NIH are subject to an annual minimum royalty payment of low five figures. As of December 31, 2021, the Company has paid NIH approximately $0.4 million in aggregate milestones under the NIH license agreement. The Company accrued $0.03 million and $0.02 million in patent licensing reimbursement fees as of December 31, 2021, and 2020, respectively.

In 2015, 2018 and 2019, the Company amended its exclusive patent license to include updates on the status of the commercial development and update/expand the list of licensed patents and patent applications. Each of those amendments required a $0.03 million payment that the Company paid.

Inserm-Transfert License Agreement

In November 2009, the Company entered into an exclusive, royalty-bearing patent license agreement with Inserm-Transfert of France. The agreement expires on a country by country basis based on the last to expire any patent encompassed within the scope of the patent rights or 10 years from the date of the first commercial sales by the Company, whichever is later. There are potential milestone The IND filing milestone of €0.01 million was accrued in 2016 and paid in 2017 by the Company. The milestones for the successful Phase I, II and III clinical trials are based on receiving a final report and achieving the primary endpoints defined in that trial, and those milestones have not been achieved as of December 31, 2021. Upon the sublicense by the Company of a product for which royalties are payable under the agreement, low- to mid-single-digit royalty payments would be due by the Company. The non-milestone payments in this agreement are subject to an anti-stacking clause. The Company did not incur any expense in the years ended December 31, 2021, and 2020.

Clearside

In July 2019, the Company entered into an exclusive license agreement with Clearside Biomedical, Inc. (“Clearside”), for the license of Clearside’s Suprachoroidal Microneedle Technology for use in the treatment of indeterminate lesions and choroidal tumors. Upon execution of the License Agreement, the Company paid Clearside an upfront payment of $0.1 million which was expensed as incurred. Under the Clearside License Agreement, the Company is required to pay milestones up to $21.0 million in the aggregate upon the achievement of specified regulatory and development milestones, and upon the achievement of certain commercial sales milestones. The Company is also required to pay low to mid-single digit royalties on net sales. If the Company sublicenses a product for which royalties are payable, then the Company is required to pay the greater of 20% received or low single digit royalties on net sales.

Net Loss Per Share

12 Months Ended

Dec. 31, 2021

Earnings Per Share [Abstract]

Net Loss Per Share

13. Net Loss Per Share

Basic net loss per share is calculated by dividing the net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is the same as basic net loss per share for the periods presented since the effects of potentially dilutive securities are antidilutive given the net loss of the Company.

The Company has calculated basic and diluted loss per share for the years ended December 31, 2021 and 2020 as follows (in thousands, except share and per share data):


	December 31, 2021			December 31, 2020
Numerator:
Net loss	$	(35,251	)	$	(22,206	)
Less: Accruals of dividends of preferred stock		(10,942	)		(7,926	)
Net loss attributable to common stockholders—basic and diluted	$	(46,193	)	$	(30,132	)
Denominator:
Weighted-average common stock outstanding		5,159,973			367,204
Net loss per share attributable to common stockholders—basic and diluted	$	(8.95	)	$	(82.06	)

The following potentially dilutive securities were excluded from the computation of the diluted net loss per share for the periods presented because their effect would have been antidilutive:


	December 31, 2021		December 31, 2020
Convertible preferred stock on an if converted basis		—		14,317,032
Stock options to purchase common stock		4,232,991		1,512,129
Restricted stock units that vest into common stock		231,920		—
Warrants to purchase preferred stock		—		12,686
Warrants to purchase common stock		12,686		—
Total potential dilutive shares		4,477,597		15,841,847

Income Taxes

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Income Taxes

14. Income Taxes

The Company has not recorded any net tax provision for the periods presented due to the losses incurred and the need for a full valuation allowance on net deferred tax assets. The difference between the income tax expense at the U.S. federal statutory rate and the recorded provision is primarily due to the valuation allowance provided on all deferred tax assets. The Company’s loss before income tax for the periods presented was generated entirely in the United States:

A reconciliation of the federal statutory income tax rate to the Company’s effective tax rate as of December 31, 2021 and 2020 is as follows:


	2021			2020
Tax provision at statutory rate		21.0	%		21.0	%
State taxes, net of federal benefit		5.3	%		5.4	%
Federal tax credits		2.6	%		3.8	%
Permanent items		(0.4	)%		(0.3	)%
Other		(0.3	)%		(0.4	)%
Decrease in valuation reserve		(28.2	)%		(29.5	)%
Total		0.0	%		0.0	%

Temporary differences that give rise to significant deferred tax assets (liabilities) as of December 31, 2021 and 2020 are as follows (in thousands):


	2021			2020
Deferred tax assets:
Net operating loss carryforwards	$	36,287		$	27,921
Stock-based compensation expense		635			328
Tax credit carryforwards		5,821			4,675
Accrued expenses		517			418
Lease liability		248			—
Other		194			168
Total deferred tax assets		43,702			33,510
Deferred tax liabilities:
Right of use asset		(241	)
Depreciable assets		(182	)		(157	)
Valuation allowance		(43,279	)		(33,353	)
Net deferred tax asset	$	—		$	—

As of December 31, 2021, the Company had federal gross operating loss carryforwards of approximately $138.7 million which may be available to offset future taxable income, of which $44.2 million begin to expire in 2029 and go through 2037, and $94.5 million do not expire. The Company had state gross operating loss carryforwards of $113.6 million, which may be available to offset future taxable income and which would begin to expire in 2030. As of December 31, 2021, the Company had federal and state research and experimentation credit carryforwards of $4.7 million and $1.4 million, respectively, which may be available to offset future income tax liabilities and which would begin to expire in 2029 and 2028, respectively.

The Company’s ability to use its operating loss carryforwards and tax credit carryforwards to offset taxable income is subject to restrictions under Sections 382 and 383 of the United States Internal Revenue Code (the “Internal Revenue Code”). Under the Internal Revenue Code provisions, certain substantial changes in the Company’s ownership, including the sale of the Company or significant changes in ownership due to sales of equity, have limited and may limit in the future, the amount of net operating loss carryforwards which could be used annually to offset future taxable income. The Company has not yet completed an analysis of ownership changes. The Company may also experience ownership changes in the future as a result of subsequent shifts in our stock ownership, some of which may be outside the Company’s control. As a result, the Company’s ability to use our pre-change NOLs to offset U.S. federal taxable income may be subject to limitations, which could potentially result in increased future tax liability to the Company. In addition, at the state level, there may be periods during which the use of NOLs is suspended or otherwise limited, which could accelerate or permanently increase state taxes owed. All Federal NOLs generated post tax reform have an indefinite life, are not subject to carryback provisions, and limited to 80% of income in any year.

The Company has not conducted a study of its research and development credit carryforwards. A study may result in an adjustment to the Company’s research and development credit carryforwards; however, until a study is completed, and any adjustment is known, no amounts will be presented as an uncertain tax position. A full valuation allowance has been provided against the Company’s research and development credit carryforwards and, if an adjustment is required, this adjustment would be offset by an adjustment to the valuation allowance. Thus, there would be no impact to the consolidated balance sheet or consolidated statement of operations and comprehensive loss at this time, if an adjustment were required.

Management has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets, which are principally comprised of NOL carryforwards and tax credit carryforwards. Management has determined that it is more likely than not that the Company will not realize the benefits of its deferred tax assets, and as a result, a valuation allowance of $43.3 million has been recorded at December 31, 2021. The increase in the valuation allowance of $9.9 million during the year ended December 31, 2021 was primarily due to the increase in net operating loss generated by the Company.

As of December 31, 2021 and 2020, the Company had no unrecognized tax benefits. Interest and penalty charges, if any, related to income taxes would be classified as a component of the provision for income taxes in the consolidated statements of operations. The Company does not expect any significant change in its uncertain tax positions in the next twelve months.

The Company files income tax returns in the United States federal tax jurisdiction and several state tax jurisdictions. Since the Company is in a loss carryforward position, it is generally subject to examination by federal and state tax authorities for all tax years in which a loss carryforward is available.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

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+ Details

Related Parties

12 Months Ended

Dec. 31, 2021

Related Parties

15. Related Parties

During the years ended December 31, 2021 and 2020, the Company incurred $0.04 million and $nil million in expenses to a legal firm whose partner is also an investor and former officer of the Company. As of December 31, 2021, and 2020, none of these amounts were included in accounts payable.

During the years ended December 31, 2021 and 2020, the Company incurred $0.3 million and $0.5 million in expenses to a stockholder that provided research and development related services. Of these amounts, $nil and $0.1 million were in accrued expenses as of December 31, 2021 and 2020.

Subsequent Events

12 Months Ended

Dec. 31, 2021

Subsequent Events [Abstract]

Subsequent Events

16. Subsequent Events

The Company has not identified any subsequent events that require disclosure.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Basis of Presentation and Principles of Consolidation

Use of Estimates

Segment Information

Cash and Restricted Cash

Cash Equivalents

Fair Value Measurements

▪

Level 1—Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities.

▪

Level 2—Inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly.

▪

Concentration of Credit Risk

Property and Equipment


		Estimated Useful Life
Leasehold improvements		2 years
IT equipment		3 years
Laboratory equipment		5 years
Office furniture		7 years

Impairment of Long-Lived Assets

Research and Development

Patent and Trademark Costs

Leases

Income Taxes

Deferred Offering Costs

Convertible Preferred Stock Classification

Stock-Based Compensation

The Company recognizes stock-based compensation expense for all stock-based awards based on their grant date fair value.


	∎		The prices at which the Company sold shares of preferred stock and the superior rights and preferences of the preferred stock relative to its common stock at the time of each grant;


	∎		The progress of Aura's research and development programs, including the status and results of preclinical studies for its product candidates;


	∎		The Company's stage of development and commercialization and its business strategy;


	∎		External market conditions affecting the biotechnology industry and trends within the biotechnology industry;


	∎		The Company's financial position, including cash on hand, and its historical and forecasted performance and operating results;


	∎		The lack of an active public market for Aura's common stock and convertible preferred stock;


	∎		The likelihood of achieving a liquidity event, such as an IPO, or sale of the Company in light of prevailing market conditions; and


	∎		The analysis of an IPO and the market performance of similar companies in the biotechnology industry.

Warrants

Net Loss per Share

Comprehensive Loss

Recently Adopted Accounting Pronouncements

Recently Issued Accounting Pronouncements Not Yet Adopted

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Schedule of Estimated Useful Lives of Assets

The estimated useful lives of the Company’s respective assets are as follows:


		Estimated Useful Life
Leasehold improvements		2 years
IT equipment		3 years
Laboratory equipment		5 years
Office furniture		7 years

Fair Value of Assets and Liabilities (Tables)

12 Months Ended

Dec. 31, 2021

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Financial Assets and Liabilities Measured at Fair Value on Recurring Basis


Description	December 31, 2021		Quoted prices active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant other observable inputs (Level 3)
Assets
Money market funds	$	24,063	$	24,063	$	—	$	—
Total financial assets	$	24,063	$	24,063	$	—	$	—
Liability
Warrant Liability	$	83	$	—	$	—	$	83
Total financial liabilities	$	83	$	—	$	—	$	83


Description	December 31, 2020		Quoted prices active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant other observable inputs (Level 3)
Liability
Warrant Liability	$	72	$	—	$	—	$	72
Total financial liabilities	$	72	$	—	$	—	$	72

Summary of Changes in Fair Value of Common Stock Warrants


Common Stock (12,686 warrants)
Fair value at December 31, 2019	$	75
Change in fair value		(3	)
Fair value at December 31, 2020		72
Change in fair value		11
Fair value at December 31, 2021	$	83

Property and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2021

Property Plant And Equipment [Abstract]

Schedule of Property and Equipment, Net

At December 31, 2021 and 2020, property and equipment consisted of the following (in thousands):


	December 31, 2021			December 31, 2020
Assets under construction	$	2,365		$	1,154
IT equipment		85			—
Leasehold improvements		13			—
Lab equipment		5,489			4,708
Office furniture		63			64
	$	8,015		$	5,926
Less—accumulated depreciation		(2,764	)		(2,352	)
Property and equipment, net	$	5,251		$	3,574

Prepaid Expenses and Other Current Assets (Tables)

12 Months Ended

Dec. 31, 2021

Prepaid Expense and Other Assets, Current [Abstract]

Schedule of Prepaid Expenses and Other Current Assets

At December 31, 2021 and 2020, prepaid expenses and other current assets consisted of the following (in thousands):


	December 31, 2021		December 31, 2020
Prepaid insurance	$	2,734	$	51
Prepaid research and development expenses		1,754		915
Prepaid license agreements		64		61
Other		66		16
Prepaid expenses and other current assets	$	4,618	$	1,043

Accrued Expenses and Other Current Liabilities (Tables)

12 Months Ended

Dec. 31, 2021

Payables And Accruals [Abstract]

Summary of Accrued Expenses and Other Current Liabilities

At December 31, 2021 and 2020, accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31, 2021		December 31, 2020
Accrued research and development expenses	$	1,686	$	750
Accrued compensation		2,147		1,023
Other		423		277
Accrued expenses and other current liabilities	$	4,256	$	2,050

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Combined Stock Option Activity under 2021 Plan

The following table summarizes stock option activity under the 2021 Plan for the year ended December 31, 2021:


	Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (years)		Aggregate Intrinsic Value
Outstanding at December 31, 2020		1,512,129		$	3.84		7.77	$	1,174
Granted		2,970,708			9.03
Exercised		(69,959	)		4.99
Cancelled/Forfeited		(179,887	)		4.59
Outstanding at December 31, 2021		4,232,991		$	7.43		8.66	$	40,437
Exercisable at December 31, 2021		1,174,871		$	3.95		6.82	$	15,304
Unvested as of December 31, 2021		3,058,120		$	8.78		9.30	$	25,133

Schedule of Fair Value of Stock Options, Valuation Assumptions

The fair value of the stock options issued as of December 31, 2021 and 2020 was measured with the following weighted-average assumptions:


	December 31, 2021			December 31, 2020
Risk-free interest rate, %		1.15	%		0.55	%
Expected term		6.03			6.02
Expected volatility of the underlying stock, %		73.87	%		74.04	%
Expected dividend rate, %		—	%		—	%

Summary of Restricted Stock Unit Activity

A summary of the restricted stock unit activity during the year ended December 31, 2021 is as follows:


	Restricted Stock Units			Weighted- Average Grant Date Fair Value
Granted at December 31, 2020		—		$	—
Granted		232,111			14.00
Forfeited		(191	)		14.00
Granted at December 31, 2021		231,920		$	14.00

Summary of Stock-Based Compensation

The Company recorded stock-based compensation as follows (in thousands):


	Year Ended December 31,
	2021		2020
Research and development	$	702	$	193
General and administrative		1,605		543
Total	$	2,307	$	736

Common Stock Warrants (Tables)

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Summary of Fair Value of Warrants and Significant Assumptions

The warrants were valued using the Black-Scholes option pricing model. The fair value of the warrants and the significant assumptions used were as follows:


Common Stock Warrants	December 31, 2021			December 31, 2020
Fair value	$	16.98		$	16.03
Volatility		80.38	%		74.00	%
Expected term (years)		3.15			4.2
Risk free rate		0.97	%		0.27	%
Dividend yield		7.00	%		7.00	%

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2021

Leases [Abstract]

Summary of Lease Costs

The following table contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company’s leases for the year ended December 31, 2021 (in thousands):


	Year Ended December 31, 2021
Lease Cost
Amortization of finance right-of-use assets	$	11
Operating lease costs		524
Variable lease costs		322
Short-term lease costs		4
Total lease costs	$	861


Cash paid for amounts included in the measurement of lease liability—finance leases	$	15
Cash paid for amounts included in the measurement of lease liability—operating leases	$	519
Weighted-average remaining lease term—operating leases (years)		1.58
Weighted-average discount rate—finance leases		7.94	%
Weighted-average discount rate—operating leases		3.51	%

Summary of Future Minimum Commitments of Operating Lease Liabilities

The following table reconciles the future minimum commitments to the Company’s operating lease liabilities at December 31, 2021 (in thousands):


	Operating lease payments as of December 31, 2021
2022	$	625
2023		377
Thereafter		—
Total lease payments		1,002
Less: interest		(27	)
Total operating lease liabilities at December 31, 2021		975
Less: current portion of lease liabilities		615
Lease liabilities, net of current portion	$	360

Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2021

Earnings Per Share [Abstract]

Summary of Basic and Diluted Loss Per Share

The Company has calculated basic and diluted loss per share for the years ended December 31, 2021 and 2020 as follows (in thousands, except share and per share data):


	December 31, 2021			December 31, 2020
Numerator:
Net loss	$	(35,251	)	$	(22,206	)
Less: Accruals of dividends of preferred stock		(10,942	)		(7,926	)
Net loss attributable to common stockholders—basic and diluted	$	(46,193	)	$	(30,132	)
Denominator:
Weighted-average common stock outstanding		5,159,973			367,204
Net loss per share attributable to common stockholders—basic and diluted	$	(8.95	)	$	(82.06	)

Summary of Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share

The following potentially dilutive securities were excluded from the computation of the diluted net loss per share for the periods presented because their effect would have been antidilutive:


	December 31, 2021		December 31, 2020
Convertible preferred stock on an if converted basis		—		14,317,032
Stock options to purchase common stock		4,232,991		1,512,129
Restricted stock units that vest into common stock		231,920		—
Warrants to purchase preferred stock		—		12,686
Warrants to purchase common stock		12,686		—
Total potential dilutive shares		4,477,597		15,841,847

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Summary of Reconciliation of Federal Statutory Income Tax Rate to Company's Effective Tax Rate

A reconciliation of the federal statutory income tax rate to the Company’s effective tax rate as of December 31, 2021 and 2020 is as follows:


	2021			2020
Tax provision at statutory rate		21.0	%		21.0	%
State taxes, net of federal benefit		5.3	%		5.4	%
Federal tax credits		2.6	%		3.8	%
Permanent items		(0.4	)%		(0.3	)%
Other		(0.3	)%		(0.4	)%
Decrease in valuation reserve		(28.2	)%		(29.5	)%
Total		0.0	%		0.0	%

Summary of Deferred Tax Assets (Liabilities)

Temporary differences that give rise to significant deferred tax assets (liabilities) as of December 31, 2021 and 2020 are as follows (in thousands):


	2021			2020
Deferred tax assets:
Net operating loss carryforwards	$	36,287		$	27,921
Stock-based compensation expense		635			328
Tax credit carryforwards		5,821			4,675
Accrued expenses		517			418
Lease liability		248			—
Other		194			168
Total deferred tax assets		43,702			33,510
Deferred tax liabilities:
Right of use asset		(241	)
Depreciable assets		(182	)		(157	)
Valuation allowance		(43,279	)		(33,353	)
Net deferred tax asset	$	—		$	—

Description of Business - Additional Information (Details) $ / shares in Units, $ in Thousands			12 Months Ended
	Nov. 02, 2021 USD ($) $ / shares shares	Oct. 22, 2021	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($)
Description Of Business [Line Items]
Reverse stock split description			On October 22, 2021, the Company effected a reverse stock split of the Company’s common stock on a 1-for-13.7 basis, or the Reverse Stock Split.
Reverse stock split, conversion ratio		0.072993
Net losses			$ 35,251	$ 22,206
Cash and cash equivalents			149,063	17,393
Accumulated deficit			$ 152,137	$ 116,886
Initial Public Offering
Description Of Business [Line Items]
Share price \| $ / shares	$ 14.00
Aggregate gross proceeds from IPO	$ 86,900
Net proceeds from the IPO	$ 78,300
Common Stock \| Initial Public Offering
Description Of Business [Line Items]
Shares issued and sold \| shares	6,210,000		6,210,000

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) Segment shares	Dec. 31, 2020 USD ($)	Jan. 01, 2021 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of operating segments \| Segment	1
Security deposit held by lessor	$ 100,000	$ 100,000
Collateral deposit for corporate credit card	20,000.00	20,000.00
Reserves related to uncertain tax positions	0	0
Accrued interest related to uncertain tax positions	$ 0	0
Convertible preferred stock, adjusted to redemption value		$ 0
Expected dividend yield	0.00%	0.00%
Operating lease liabilities	$ 975,000
Operating lease right of use assets	$ 950,000
Deferred rent		$ 8,000
Performance-based Awards
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stock awards outstanding \| shares	0
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]			true
Change in accounting principle, accounting standards update, adoption date			Jan. 01, 2021
Operating lease liabilities			$ 600,000
Operating lease right of use assets			500,000
Deferred rent			$ 20,000.00
Change in accounting principle, accounting standards update, immaterial effect [true false]			true

Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives of Assets (Details)	12 Months Ended
	Dec. 31, 2021
Leasehold Improvements
Property Plant And Equipment [Line Items]
Estimated Useful Life	2 years
IT Equipment
Property Plant And Equipment [Line Items]
Estimated Useful Life	3 years
Laboratory Equipment
Property Plant And Equipment [Line Items]
Estimated Useful Life	5 years
Office Furniture
Property Plant And Equipment [Line Items]
Estimated Useful Life	7 years

Fair Value of Assets and Liabilities - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets
Financial assets	$ 24,063
Liability
Financial liabilities	83	$ 72
Money Market Funds
Assets
Financial assets	24,063
Warrant Liability
Liability
Financial liabilities	83	72
Level 1
Assets
Financial assets	24,063
Level 1 \| Money Market Funds
Assets
Financial assets	24,063
Level 3
Liability
Financial liabilities	83	72
Level 3 \| Warrant Liability
Liability
Financial liabilities	$ 83	$ 72

Fair Value of Assets and Liabilities - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Assets transfers into Level 3	$ 0	$ 0
Assets, transfers out of Level 3	0	0
Liability, transfers into Level 3	0	0
Liability, transfers out of Level 3	$ 0	$ 0

Fair Value of Assets and Liabilities - Summary of Changes in Fair Value of Common Stock Warrants (Details) - Common Stock Warrants - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 72	$ 75
Change in fair value	11	(3)
Ending Balance	$ 83	$ 72

Fair Value of Assets and Liabilities - Summary of Changes in Fair Value of Common Stock Warrants (Parenthetical) (Details) - shares	Dec. 31, 2021	Dec. 31, 2020
Common Stock Warrants
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Warrants outstanding	12,686	12,686

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 8,015	$ 5,926
Less—accumulated depreciation	(2,764)	(2,352)
Property and equipment, net	5,251	3,574
Assets Under Construction
Property Plant And Equipment [Line Items]
Property and equipment, gross	2,365	1,154
IT Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	85
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	13
Lab Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	5,489	4,708
Office Furniture
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 63	$ 64

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Depreciation expense	$ 831	$ 831

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid insurance	$ 2,734	$ 51
Prepaid research and development expenses	1,754	915
Prepaid license agreements	64	61
Other	66	16
Prepaid expenses and other current assets	$ 4,618	$ 1,043

Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued research and development expenses	$ 1,686	$ 750
Accrued compensation	2,147	1,023
Other	423	277
Accrued expenses and other current liabilities	$ 4,256	$ 2,050

Convertible Preferred Stock - Additional Information (Details)					12 Months Ended
	Nov. 02, 2021 $ / shares shares	Mar. 18, 2021 USD ($) $ / shares shares	Mar. 05, 2021 USD ($) $ / shares shares	Oct. 01, 2020 USD ($) shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Oct. 22, 2021	Jun. 25, 2020 $ / shares shares	Dec. 31, 2019 shares
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized	10,000,000
Convertible preferred stock, par value \| $ / shares	$ 0.00001					$ 0.00001
Common stock dividends declared \| $						$ 0
Preferred stock liquidation rights description					In the event of a Deemed Liquidation Event, as defined in the Company’s amended and restated Certificate of Incorporation, the assets of the Company will be distributed first to the holders of Series E convertible preferred stock. The holders of Series E convertible preferred stock will receive, in preference to all other stockholders, and amount equal to the sum of the Series E original issue price (equal to the cash price paid per share of $0.783900), plus unpaid dividends on such shares. Next, the holders of Series D convertible preferred stock will receive, in preference to all other stockholders other than Series E, an amount equal to the sum of the Series D original issue price, plus unpaid dividends on such shares. Next, the holders of Series C will receive, in preference to all stockholders other than the Series E and D convertible preferred stock holders, an amount equal to the sum of the Series C original issue price plus unpaid dividends on such shares. Next, the holders of Series B will receive, in preference to the holders of Series A, Series A-1, Series A-2 and common stock, an amount equal to the sum of the Series B original issue price plus unpaid dividends on such shares. Next, the holders of Series A, Series A-1, and Series A-2 will receive, in preference to the holders of common stock, an amount equal to the greater of their applicable liquidation preference or what they would have received had their shares converted into common stock. If the proceeds available are not sufficient to satisfy the full liquidation preference, the entire proceeds are to be distributed pro-rata among the Series E convertible preferred stock holders in proportion to the full preferential amount the Series E convertible preferred stock holders are entitled to receive.
Preferred stock, conversion basis					one-for-one basis
Initial Public Offering
Temporary Equity [Line Items]
Purchase price per share \| $ / shares	$ 14.00
Common Stock
Temporary Equity [Line Items]
Number of common stock upon conversion of convertible preferred stock					22,550,561
Proceeds from issuance of convertible preferred stock \| $					$ 50,000,000.0
Offering costs \| $					$ 8,620,000
Preferred stock, conversion price \| $ / shares					$ 1.554975
Common Stock \| Initial Public Offering
Temporary Equity [Line Items]
Number of common stock upon conversion of convertible preferred stock	22,550,561
Series A Convertible Preferred Stock
Temporary Equity [Line Items]
Number of common stock upon conversion of convertible preferred stock					(1,701,141)
Convertible preferred stock, shares authorized						1,701,141
Convertible preferred stock, shares issued						1,701,141
Convertible preferred stock, shares outstanding						1,701,141			1,701,141
Preferred stock dividends declared \| $						$ 0
Preferred stock, conversion price \| $ / shares					$ 2.00
Preferred Stock, conversion price due to anti-dilution protection terms \| $ / shares					$ 1.8191
Preferred stock, conversion ratio					1.099		12.47
Series A-1 Convertible Preferred Stock
Temporary Equity [Line Items]
Number of common stock upon conversion of convertible preferred stock					(3,298,732)
Convertible preferred stock, shares authorized						3,298,732
Convertible preferred stock, shares issued						3,298,732
Convertible preferred stock, shares outstanding						3,298,732			3,298,732
Preferred stock, conversion price \| $ / shares					$ 2.4847
Preferred Stock, conversion price due to anti-dilution protection terms \| $ / shares					$ 2.1898
Preferred stock, conversion ratio					1.135		12.07
Series A-2 Convertible Preferred Stock
Temporary Equity [Line Items]
Number of common stock upon conversion of convertible preferred stock					(4,324,998)
Convertible preferred stock, shares authorized						4,325,021
Convertible preferred stock, shares issued						4,324,998
Convertible preferred stock, shares outstanding						4,324,998			4,324,998
Purchase price per share \| $ / shares					$ 1.24235
Preferred stock, conversion basis					one-for-one
Preferred stock, conversion price \| $ / shares					$ 1.24235
Preferred stock, conversion ratio					1		13.7
Series B Convertible Preferred Stock
Temporary Equity [Line Items]
Number of common stock upon conversion of convertible preferred stock					(22,531,819)
Convertible preferred stock, shares authorized						22,705,646
Convertible preferred stock, shares issued						22,531,819
Convertible preferred stock, shares outstanding						22,531,819			22,531,819
Cumulative dividends \| $						$ 9,400,000
Preferred stock annual dividend rate per share \| $ / shares					$ 0.0869645
Preferred stock, conversion price \| $ / shares					$ 1.24235
Preferred stock, conversion ratio							13.7
Series C-1 Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized						58,109,711
Convertible preferred stock, shares issued						58,109,711
Convertible preferred stock, shares outstanding						58,109,711
Convertible preferred stock dividend percentage					7.00%
Cumulative dividends \| $						$ 5,900,000
Preferred stock, conversion price \| $ / shares					$ 0.5213
Preferred stock, conversion ratio							13.7
Series C-2 Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized						33,218,192
Convertible preferred stock, shares issued						33,218,192
Convertible preferred stock, shares outstanding						33,218,192
Convertible preferred stock dividend percentage					7.00%
Cumulative dividends \| $						$ 2,600,000
Preferred stock, conversion price \| $ / shares					$ 0.36491
Preferred stock, conversion ratio							13.7
Series D-1 Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized						57,878,742
Convertible preferred stock, shares issued						57,878,742
Convertible preferred stock, shares outstanding						57,878,742
Convertible preferred stock dividend percentage					7.00%
Cumulative dividends \| $						$ 3,900,000
Preferred stock, conversion price \| $ / shares					$ 0.6911
Preferred stock, conversion ratio							13.7
Series D-2 Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized						24,598,481		24,598,481
Convertible preferred stock, shares issued						14,469,710
Convertible preferred stock, shares outstanding						14,469,710
Convertible preferred stock, par value \| $ / shares			$ 0.00001
Purchase price per share \| $ / shares			$ 0.6911					$ 0.6911
Issuance of convertible preferred stock, Shares			10,128,771	14,469,710
Proceeds from issuance of convertible preferred stock \| $			$ 7,000,000.0	$ 10,000,000.0
Offering costs \| $					$ 20,000.00	$ 100,000
Convertible preferred stock dividend percentage					7.00%
Cumulative dividends \| $						$ 200,000
Preferred stock, conversion price \| $ / shares					$ 0.6911
Preferred stock, conversion ratio							13.7
Series E Convertible Preferred Stock
Temporary Equity [Line Items]
Number of common stock upon conversion of convertible preferred stock					(102,671,041)
Convertible preferred stock, shares issued						0
Convertible preferred stock, shares outstanding						0
Convertible preferred stock, par value \| $ / shares		$ 0.00001
Purchase price per share \| $ / shares		$ 0.7839
Issuance of convertible preferred stock, Shares		102,671,041			102,671,041
Proceeds from issuance of convertible preferred stock \| $		$ 80,500,000			$ 80,246,000
Offering costs \| $					$ 237,000
Convertible preferred stock dividend percentage					7.00%
Convertible preferred stock liquidation preference \| $ / shares					$ 0.783900
Preferred stock, conversion price \| $ / shares					$ 0.7839
Preferred stock, conversion ratio							13.7

Common Stock - Additional Information (Details) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Common stock, shares authorized	150,000,000	232,697,999
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares issued	29,211,643	381,123
Common stock, shares outstanding	29,211,643	381,123

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Nov. 01, 2021	Mar. 18, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of stock options granted	$ 5.84	$ 2.74
Total intrinsic value of options exercised	$ 100	$ 20
Unrecognized compensation expense related to stock options	$ 16,500
Unrecognized compensation expense weighted average period	3 years 3 months 29 days
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense weighted average period	3 years 9 months 25 days
Unrecognized compensation expense related to restricted stock option	$ 3,100
Restricted stock units vesting increments	25.00%
Restricted stock units vesting duration	4 years
Number of awards vested	0
2021 Stock Option and Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance			3,352,166
Common stock outstanding percentage	5.00%
Cumulative increase in shares of common stock	3,352,166
Number of shares available for future issuance	2,042,774
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance			335,217
Common stock outstanding percentage	1.00%
Cumulative increase in shares of common stock	335,217
2018 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized				2,346,228

Stock-Based Compensation - Summary of Combined Stock Option Activity under 2021 Plan (Details) - 2021 Plan - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options Outstanding, Beginning balance	1,512,129
Options, Granted	2,970,708
Options, Exercised	(69,959)
Options, Cancelled/Forfeited	(179,887)
Options Outstanding, Ending balance	4,232,991	1,512,129
Options, Exercisable at December 31, 2021	1,174,871
Unvested as of December 31, 2021	3,058,120
Weighted Average Exercise Price, Beginning balance	$ 3.84
Weighted Average Exercise Price, Granted	9.03
Weighted Average Exercise Price, Exercised	4.99
Weighted Average Exercise Price, Cancelled/Forfeited	4.59
Weighted Average Exercise Price, Ending balance	7.43	$ 3.84
Weighted Average Exercise Price, Exercisable at December 31, 2021	3.95
Weighted Average Exercise Price, Unvested as of December 31, 2021	$ 8.78
Weighted Average Remaining Contractual Term (years)	8 years 7 months 28 days	7 years 9 months 7 days
Weighted Average Remaining Contractual Term (years), Exercisable	6 years 9 months 25 days
Weighted Average Remaining Contractual Term (years), Unvested	9 years 3 months 18 days
Aggregate Intrinsic Value, Outstanding	$ 40,437	$ 1,174
Aggregate Intrinsic Value, Exercisable at December 31, 2021	15,304
Aggregate Intrinsic Value, Unvested at December 31, 2021	$ 25,133

Stock-Based Compensation - Schedule of Fair Value of Stock Options, Valuation Assumptions (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk-free interest rate%	1.15%	0.55%
Expected term	6 years 10 days	6 years 7 days
Expected volatility of the underlying stock%	73.87%	74.04%
Expected dividend rate%	0.00%	0.00%

Stock-Based Compensation - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units	12 Months Ended
	Dec. 31, 2021 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted, Restricted Stock Units \| shares	232,111
Forfeited, Restricted Stock Units \| shares	(191)
Granted at December 31, 2021 \| shares	231,920
Granted, Weighted-Average Grant Date Fair Value \| $ / shares	$ 14.00
Forfeited, Weighted-Average Grant Date Fair Value \| $ / shares	14.00
Granted at December 31, 2021, Weighted- Average Grant Date Fair Value \| $ / shares	$ 14.00

Stock-Based Compensation - Summary of Stock-Based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation	$ 2,307	$ 736
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation	702	193
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation	$ 1,605	$ 543

Common Stock Warrants - Additional Information (Details) - Series B Warrants - Common Stock Warrants - $ / shares	1 Months Ended
	May 31, 2015	Feb. 28, 2015	Dec. 31, 2021	Nov. 02, 2021	Dec. 31, 2020
Class Of Warrant Or Right [Line Items]
Number of Warrants converted				12,686
Warrants outstanding			12,686		12,686
Series B Convertible Preferred Stock
Class Of Warrant Or Right [Line Items]
Number of Warrants converted	887,536	1,650,098
Exercise price of warrants	$ 1.24235	$ 1.24235
Warrants expiration period	10 years	10 years

Common Stock Warrants - Summary of Fair Value of Warrants and Significant Assumptions (Details) - Common Stock Warrants	Dec. 31, 2021	Dec. 31, 2020
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected term (years)	3 years 1 month 24 days	4 years 2 months 12 days
Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	16.98	16.03
Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	80.38	74.00
Risk Free Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0.97	0.27
Dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	7.00	7.00

Compensation - Additional Information (Details) - 401(k) Plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Defined Contribution Plan Disclosure [Line Items]
Matching contribution by employer, percentage	100.00%
Employer matching contribution, percent of employees contribution	6.00%
Matching contributions from employer	$ 0.3	$ 0.2

Commitments and Contingencies - Additional Information (Details) € in Thousands			1 Months Ended										12 Months Ended			132 Months Ended
	Mar. 31, 2021 ft²	Apr. 05, 2019 EUR (€) Installment	Oct. 31, 2020 USD ($)	Aug. 31, 2019 EUR (€)	Jul. 31, 2019 USD ($)	Apr. 30, 2019 EUR (€)	Dec. 31, 2014 USD ($) LicensedProduct	Jan. 31, 2014 USD ($)	Sep. 30, 2013 USD ($)	Jul. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Nov. 30, 2009	Dec. 31, 2021 USD ($) OperatingLease	Dec. 31, 2020 USD ($) OperatingLease	Dec. 31, 2017 EUR (€)	Dec. 31, 2021 USD ($) OperatingLease
Lessee Lease Description [Line Items]
Operating lease termination date	Jul. 31, 2023
Area of space leased \| ft²	4,516
Lease commencement date	May 01, 2021
Additional square feet of laboratory space \| ft²	1,000
Additional leased space commencement date	Jun. 15, 2021
Lease existence of option to extend	true
Operating lease, option to extend term	12 months
Non-refundable, Non- creditable fee							$ 300,000
Number of licensed products \| LicensedProduct							5
Initial license fee							$ 100,000
Annual development fee							100,000
Change of control fees							200,000
Expenses related to license agreement													$ 25,161,000	$ 18,042,000
Expenses													100,000	100,000
Patent licensing reimbursement fees													30,000.00
Exclusive License and Supply Agreement
Lessee Lease Description [Line Items]
One-time upfront license issuance fee								$ 100,000
Expenses related to license agreement													0	100,000
License agreement term								10 years
Exclusive License and Supply Agreement \| Maximum
Lessee Lease Description [Line Items]
Aggregate milestone payments								$ 200,000
2014 Non- Exclusive Agreement
Lessee Lease Description [Line Items]
License issue fee							30,000.00
Non-refundable, Non- creditable fee							30,000.00
2014 Non- Exclusive Agreement \| Maximum
Lessee Lease Description [Line Items]
Aggregate milestone payments							300,000
Payments for development and commercial milestones							$ 400,000
Biologic Materials License Agreement
Lessee Lease Description [Line Items]
One time non refundable license issuance fee											$ 20,000.00
Milestone payments or royalties											$ 0
Collaboration Research and Development Agreement
Lessee Lease Description [Line Items]
Annual development fee										$ 30,000.00
Agreement term										2 years
First payment due										30 days
Subsequent payments due										30 days
Required amendment payment			$ 40,000.00
Required amendment payment due period			30 days
Aggregate research collaboration fees													30,000.00	40,000.00		$ 400,000
Collaboration Research and Development Agreement \| 10th Anniversary
Lessee Lease Description [Line Items]
Required amendment payment			$ 30,000.00
Required amendment payment due period			30 days
National Institute of Health
Lessee Lease Description [Line Items]
Aggregate milestone payments													400,000			$ 400,000
License issue royalty fee									$ 100,000
Sales milestone payments									600,000
Development and regulatory milestone payments									$ 700,000
Patent licensing reimbursement fees													30,000.00	20,000.00
Royalty Bearing Patent License Agreement
Lessee Lease Description [Line Items]
Expenses													$ 0	$ 0
License agreement term												10 years
Royalty Bearing Patent License Agreement \| IND Filing
Lessee Lease Description [Line Items]
Potential milestone payments \| €															€ 10
Clearside
Lessee Lease Description [Line Items]
Upfront payment					$ 100,000
License agreement expiration period					10 years
Royalties on net sales					20.00%
Clearside \| Maximum
Lessee Lease Description [Line Items]
Aggregate milestones payment					$ 21,000,000.0
Office and Laboratory Facility
Lessee Lease Description [Line Items]
Number of operating lease \| OperatingLease													1	1		1
Operating lease termination date													Jul. 31, 2022
Laser System
Lessee Lease Description [Line Items]
Purchase agreement, commitments payable in each installment \| €		€ 200
Purchase agreement, number of payment installments \| Installment		3
Laser System \| Installment One
Lessee Lease Description [Line Items]
Purchase agreement, installment amount paid \| €						€ 200
Laser System \| Installment Two
Lessee Lease Description [Line Items]
Purchase agreement, installment amount paid \| €				€ 200

Commitments and Contingencies - Summary of Lease Costs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)
Leases [Abstract]
Amortization of finance right-of-use assets	$ 11
Operating lease costs	524
Variable lease costs	322
Short-term lease costs	4
Total lease costs	861
Cash paid for amounts included in the measurement of lease liability—finance leases	15
Cash paid for amounts included in the measurement of lease liability—operating leases	$ 519
Weighted-average remaining lease term—operating leases (years)	1 year 6 months 29 days
Weighted-average discount rate—finance leases	7.94%
Weighted-average discount rate—operating leases	3.51%

Commitments and Contingencies- Schedule of Fair Value of Financial Assets and Liabilities (Details) $ in Thousands	Dec. 31, 2021 USD ($)
Leases [Abstract]
2022	$ 625
2023	377
Total lease payments	1,002
Less: interest	(27)
Total operating lease liabilities at December 31, 2021	975
Less: current portion of lease liabilities	615
Lease liabilities, net of current portion	$ 360

Net Loss Per Share - Summary of Basic and Diluted Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net loss	$ (35,251)	$ (22,206)
Less: Accruals of dividends of preferred stock	(10,942)	(7,926)
Net loss attributable to common stockholders - basic and diluted	$ (46,193)	$ (30,132)
Denominator:
Weighted average common stock outstanding	5,159,973	367,204
Net loss per share attributable to common stockholders—basic and diluted	$ (8.95)	$ (82.06)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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+ Details

Net Loss Per Share - Summary of Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	4,477,597	15,841,847
Convertible Preferred Stock on an if Converted Basis
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares		14,317,032
Stock Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	4,232,991	1,512,129
Restricted Stock Units that Vest into Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	231,920
Warrants to Purchase Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares		12,686
Warrants to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	12,686

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Net tax provision	$ 0	$ 0
Federal net operating loss carryback percentage limited to income in any year	80.00%
Deferred tax assets, valuation allowance	$ 43,279,000	33,353,000
Increase in valuation allowance	9,900,000
Unrecognized tax benefits	0	$ 0
Federal
Operating Loss Carryforwards [Line Items]
Gross operating loss carryforwards	138,700,000
Operating loss carryforwards not subject to expiration	$ 94,500,000
Federal \| Earliest Tax Year
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards begin to expire period	2029
Federal \| Latest Tax Year
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards begin to expire period	2037
Federal \| 2029 through 2037
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards subject to expiration	$ 44,200,000
Federal \| Research and Experimentation
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward	$ 4,700,000
Tax credit carryforwards begin to expire period	2029
State
Operating Loss Carryforwards [Line Items]
Gross operating loss carryforwards	$ 113,600,000
Operating loss carryforwards begin to expire period	2030
State \| Research and Experimentation
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward	$ 1,400,000
Tax credit carryforwards begin to expire period	2028

Income Taxes - Summary of Reconciliation of Federal Statutory Income Tax Rate to Company's Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Tax provision at statutory rate	21.00%	21.00%
State taxes, net of federal benefit	5.30%	5.40%
Federal tax credits	2.60%	3.80%
Permanent items	(0.40%)	(0.30%)
Other	(0.30%)	(0.40%)
Decrease in valuation reserve	(28.20%)	(29.50%)
Total	0.00%	0.00%

Income Taxes - Summary of Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss carryforwards	$ 36,287	$ 27,921
Stock-based compensation expense	635	328
Tax credit carryforwards	5,821	4,675
Accrued expenses	517	418
Lease liability	248
Other	194	168
Total deferred tax assets	43,702	33,510
Deferred tax liabilities:
Right of use asset	(241)
Depreciable assets	(182)	(157)
Valuation allowance	$ (43,279)	$ (33,353)

Related Parties - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Stockholder
Related Party Transaction [Line Items]
Expenses incurred to related parties	$ 300	$ 500
Accrued expense, related party		100
Investor
Related Party Transaction [Line Items]
Expenses incurred to related parties	40
Accounts payable, related parties	$ 0	$ 0