0000950170-23-040138 | 10-Q | XBRL Viewer

Net Loss Per Share (Tables)

6 Months Ended

Jun. 30, 2023

Summary of Basic and Diluted Net Loss Per Share

The Company has calculated basic and diluted net loss per share for the three and six months ended June 30, 2023 and 2022 as follows (in thousands, except share and per share data):


	Three Months Ended June 30,						Six Months Ended June 30,
	2023			2022			2023			2022
Numerator:
Net loss	$	(18,299	)	$	(13,468	)	$	(35,765	)	$	(26,303	)
Denominator:
Weighted-average common stock outstanding—basic and diluted		37,855,533			29,251,480			37,820,104			29,232,661
Net loss per common share—basic and diluted	$	(0.48	)	$	(0.46	)	$	(0.95	)	$	(0.90	)

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:


	Six Months Ended June 30,
	2023		2022
Stock options to purchase common stock		4,627,518		4,135,212
Restricted stock units that vest into common stock		643,108		206,933
Warrants to purchase common stock		12,686		12,686
Total potential dilutive shares		5,283,312		4,354,831

Accrued Expenses and Other Current Liabilities

6 Months Ended

Jun. 30, 2023

Payables and Accruals [Abstract]

Accrued Expenses and Other Current Liabilities

7. Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	June 30, 2023		December 31, 2022
Accrued research and development expenses	$	2,468	$	1,543
Accrued compensation		2,100		2,705
Other		766		325
Accrued expenses and other current liabilities	$	5,334	$	4,573

Condensed Consolidated Statements of Cash Flows (Unaudited) - Reconciliation of Cash, Cash Equivalents, and Restricted Cash - USD ($) $ in Thousands	Jun. 30, 2023	Jun. 30, 2022
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents, end of period	$ 47,732	$ 53,849
Short-term restricted cash, end of period	20	28
Long-term restricted cash, end of period	768	893
Cash, cash equivalents and restricted cash at end of period	$ 48,520	$ 54,770

Stock-Based Compensation - Summary of stock option activity under the 2018 Plan to 2021 Plan (Details) - 2021 Plan $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Options Outstanding, Beginning balance \| shares	4,303,336
Options, Granted \| shares	984,725
Options, Exercised \| shares	(138,853)
Options, Cancelled/Forfeited \| shares	(521,690)
Options Outstanding, Ending balance \| shares	4,627,518	4,303,336
Options, Exercisable at June 30, 2023 \| shares	2,432,054
Weighted Average Exercise Price, Beginning balance \| $ / shares	$ 8.06
Weighted Average Exercise Price, Granted \| $ / shares	10.45
Weighted Average Exercise Price, Exercised \| $ / shares	5.80
Weighted Average Exercise Price, Cancelled/Forfeited \| $ / shares	10.87
Weighted Average Exercise Price, Ending balance \| $ / shares	8.32	$ 8.06
Weighted Average Exercise Price, Exercisable at June 30, 2023 \| $ / shares	$ 6.79
Weighted Average Remaining Contractual Term (years)	7 years 7 months 2 days	7 years 11 months 1 day
Weighted Average Remaining Contractual Term (years), Exercisable at June 30, 2023	6 years 6 months 29 days
Aggregate Intrinsic Value, Outstanding \| $	$ 21,242	$ 16,204
Aggregate Intrinsic Value, Exercisable June 30, 2023 \| $	$ 14,655

Description of Business - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended				6 Months Ended		12 Months Ended
	Dec. 05, 2022	Nov. 01, 2022	Nov. 02, 2021	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Description Of Business [Line Items]
Aggregate offering price		$ 250,000
Net losses				$ 18,299	$ 17,466	$ 13,468	$ 12,835	$ 35,765	$ 26,303
Cash and cash equivalents and marketable securities				162,000				162,000
Accumulated deficit				$ 246,665				246,665		$ 210,900
Initial Public Offering
Description Of Business [Line Items]
Share price			$ 14.00
Aggregate gross proceeds from IPO			$ 86,900
Net proceeds from the IPO			$ 78,300
At-the-Market Offering
Description Of Business [Line Items]
Sale of common stock through agreement		$ 75,000
Proceeds from issuance of common stock								$ 2,100		$ 9,200
Common Stock \| Initial Public Offering
Description Of Business [Line Items]
Shares issued and sold			6,210,000
Common Stock \| Follow-On Offering
Description Of Business [Line Items]
Shares issued and sold	7,705,000
Share price	$ 12.00
Proceeds from issuance of common stock	$ 92,500
Net proceeds from follow-on offering	$ 86,700
Common Stock \| At-the-Market Offering
Description Of Business [Line Items]
Shares issued and sold								169,200		732,189
Share price				$ 12.58				$ 12.58		$ 12.51

Marketable Securities - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Marketable securities [Line items]
Amortized Cost	$ 114,505	$ 67,302
Unrealized Gains	5	20
Unrealized Losses	(229)	(93)
Fair Value	114,281	67,229
Commercial Paper
Marketable securities [Line items]
Amortized Cost	48,116	27,476
Unrealized Losses	(68)
Fair Value	48,048	27,476
Corporate Bonds
Marketable securities [Line items]
Amortized Cost	15,549	18,191
Unrealized Losses	(49)	(92)
Fair Value	15,500	18,099
U.S. Government Agencies
Marketable securities [Line items]
Amortized Cost	46,594	21,635
Unrealized Gains	5	20
Unrealized Losses	(95)	(1)
Fair Value	46,504	$ 21,654
Yankee Bonds
Marketable securities [Line items]
Amortized Cost	2,946
Unrealized Losses	(12)
Fair Value	2,934
Asset-Backed Securities
Marketable securities [Line items]
Amortized Cost	1,300
Unrealized Losses	(5)
Fair Value	$ 1,295

Stock-Based Compensation

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [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, or 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 rights. The Board of Directors, or 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, or 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 increased on January 1, 2022 and will continue to increase 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. On January 1, 2023, the shares reserved for issuance was increased to 6,850,986 shares.

2021 Employee Stock Purchase Plan

The 2021 Employee Stock Purchase Plan, or 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 increased on January 1, 2022 and will continue to increase 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 January 1, 2023, the shares reserved for issuance was increased to 962,550 shares. The purchase price of the shares under the ESPP are at 85% of the lower of the fair market value of the Company’s common stock on the first trading day of the offering period or on the purchase date. As of June 30, 2023, 955,915 shares were available to be issued under the ESPP. The Company recognized $0.03 million share-based compensation expense related to the ESPP for the six months ended June 30, 2023. The Company recognized $0.02 million share-based compensation expense related to the ESPP for the three months ended June 30, 2023.

Stock Options

With the transfer of the available options from the 2018 Plan to the 2021 Plan, there were 4,324,297 options and restricted stock units available for grant under the 2021 Plan at June 30, 2023.

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 2018 Plan and 2021 Plan for the six months ended June 30, 2023:


	Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2022		4,303,336		$	8.06		7.92	$	16,204
Granted		984,725			10.45
Exercised		(138,853	)		5.80
Cancelled/Forfeited		(521,690	)		10.87
Outstanding at June 30, 2023		4,627,518		$	8.32		7.59	$	21,242
Exercisable at June 30, 2023		2,432,054		$	6.79		6.58	$	14,655

The weighted-average grant date fair value of stock options granted during the six months ended June 30, 2023 and 2022 was $7.66 and $11.56 per share, respectively. The fair value of options vested during the six months ended June 30, 2023 and 2022 was $3.4 million and $1.2 million, respectively. The total intrinsic value of options exercised was $0.9 million and $0.6 million for the six months ended June 30, 2023 and 2022, respectively.

The fair value of the stock options issued for the three and six months ended June 30, 2023 and 2022 was measured with the following weighted-average assumptions:


	Three Months Ended June 30,						Six Months Ended June 30,
	2023			2022			2023			2022
Risk-free interest rate		3.69	%		3.09	%		3.57	%		2.53	%
Expected term (years)		5.91			5.84			6.02			5.90
Expected volatility of the underlying stock		85.43	%		76.85	%		84.97	%		75.44	%
Expected dividend rate		—	%		—	%		—	%		—	%

Restricted Stock Units

The Company has granted restricted stock units with service-based vesting conditions. Unvested shares of restricted common stock may not be sold or transferred by the holder.

A summary of the restricted stock units activity during the six months ended June 30, 2023 is as follows:


	Restricted Stock Units			Weighted- Average Grant Date Fair Value
Unvested at December 31, 2022		153,950		$	14.00
Granted		598,445			10.17
Vested/Released		—			—
Forfeited		(109,287	)		11.00
Unvested at June 30, 2023		643,108		$	10.95

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 six months ended June 30, 2023.

Stock-based Compensation Expense

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


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Research and development	$	709	$	465	$	1,476	$	1,020
General and administrative		1,222		822		2,368		1,861
Total	$	1,931	$	1,287	$	3,844	$	2,881

As of June 30, 2023, there was $14.2 million of unrecognized compensation expense related to stock options, which is expected to be recognized over a weighted-average period of 2.5 years.

As of June 30, 2023, there was $6.0 million of unrecognized compensation expense related to restricted stock units, which is expected to be recognized over a weighted-average period of 3.14 years.

Subsequent Events

6 Months Ended

Jun. 30, 2023

Subsequent Events [Abstract]

Subsequent Events

15. Subsequent Events

Subsequent events have been evaluated through the date of filing of the unaudited condensed consolidated financial statements. The Company has not identified any subsequent events that require disclosure.

Property and Equipment, Net

6 Months Ended

Jun. 30, 2023

Property, Plant and Equipment [Abstract]

Property and Equipment, Net

4. Property and Equipment, Net

Property and equipment, net, consisted of the following (in thousands):


	June 30, 2023			December 31, 2022
Assets under construction	$	1,600		$	1,805
IT equipment		133			133
Lab equipment		7,786			7,297
	$	9,519		$	9,235
Less—accumulated depreciation		(4,462	)		(3,864	)
Property and equipment, net	$	5,057		$	5,371

Depreciation expense was $0.3 million and $0.3 million for the three months ended June 30, 2023 and 2022, respectively. In addition, depreciation expense was $0.6 million and $0.6 million for the six months ended June 30, 2023 and 2022, respectively.

Commitments and Contingencies - Summary of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Leases [Abstract]
Operating lease costs	$ 881	$ 155	$ 1,761	$ 309
Variable lease costs	217	161	443	337
Short-term lease costs	2	2	4	4
Total lease costs	$ 1,100	$ 318	2,208	650
Cash paid for amounts included in the measurement of lease liabilities--operating leases			$ 1,537	$ 305
Weighted-average remaining lease term—operating leases (years)	9 years 1 month 2 days	1 year 29 days	9 years 1 month 2 days	1 year 29 days
Weighted-average discount rate—operating leases	10.71%	3.51%	10.71%	3.51%

Common Stock Warrants - Additional Information (Details) - Series B Warrants - Common Stock Warrants - $ / shares	1 Months Ended
	May 31, 2015	Feb. 28, 2015	Jun. 30, 2023	Nov. 02, 2021	Jun. 30, 2021
Class Of Warrant Or Right [Line Items]
Number of Warrants converted				12,686
Exercise price of warrants				$ 17.03
Warrants outstanding			12,686		173,827
Series B Convertible Preferred Stock
Class Of Warrant Or Right [Line Items]
Number of warrants issued	887,536	1,650,098
Exercise price of warrants	$ 1.24235	$ 1.24235
Warrants expiration period	10 years	10 years

Fair Value of Assets and Liabilities

6 Months Ended

Jun. 30, 2023

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 June 30, 2023 and December 31, 2022 (in thousands):


Description	June 30, 2023		Quoted prices active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant other observable inputs (Level 3)
Financial assets
Cash equivalents:
Money market funds		47,220	$	47,220	$	—	$	—
Marketable securities:
Commercial paper		48,048		—		48,048		—
Corporate bonds		15,500		—		15,500		—
U.S. Government agencies		46,504		—		46,504		—
Yankee bonds		2,934		—		2,934		—
Asset-backed securities		1,295		—		1,295		—
Total financial assets	$	161,501	$	47,220	$	114,281	$	—


Description	December 31, 2022		Quoted prices active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant other observable inputs (Level 3)
Financial assets
Cash equivalents:
Money market funds	$	118,582	$	118,582	$	—	$	—
Marketable securities:
Commercial paper		27,476		—		27,476		—
Corporate bonds		18,099		—		18,099		—
U.S. Government agencies		21,654		—		21,654		—
Total financial assets	$	185,811	$	118,582	$	67,229	$	—

- 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

Net Loss Per Share - Summary of Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	5,283,312	4,354,831
Stock Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	4,627,518	4,135,212
Restricted Stock Units that Vest into Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	643,108	206,933
Warrants to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	12,686	12,686

Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Combined Stock Option Activity under 2018 Plan and 2021 Plan

The following table summarizes stock option activity under the 2018 Plan and 2021 Plan for the six months ended June 30, 2023:


	Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2022		4,303,336		$	8.06		7.92	$	16,204
Granted		984,725			10.45
Exercised		(138,853	)		5.80
Cancelled/Forfeited		(521,690	)		10.87
Outstanding at June 30, 2023		4,627,518		$	8.32		7.59	$	21,242
Exercisable at June 30, 2023		2,432,054		$	6.79		6.58	$	14,655

Schedule of Fair Value of Stock Options, Valuation Assumptions

The fair value of the stock options issued for the three and six months ended June 30, 2023 and 2022 was measured with the following weighted-average assumptions:


	Three Months Ended June 30,						Six Months Ended June 30,
	2023			2022			2023			2022
Risk-free interest rate		3.69	%		3.09	%		3.57	%		2.53	%
Expected term (years)		5.91			5.84			6.02			5.90
Expected volatility of the underlying stock		85.43	%		76.85	%		84.97	%		75.44	%
Expected dividend rate		—	%		—	%		—	%		—	%

Schedule of Nonvested Restricted Stock Units Activity

A summary of the restricted stock units activity during the six months ended June 30, 2023 is as follows:


	Restricted Stock Units			Weighted- Average Grant Date Fair Value
Unvested at December 31, 2022		153,950		$	14.00
Granted		598,445			10.17
Vested/Released		—			—
Forfeited		(109,287	)		11.00
Unvested at June 30, 2023		643,108		$	10.95

Summary of Stock-Based Compensation Expense

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


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Research and development	$	709	$	465	$	1,476	$	1,020
General and administrative		1,222		822		2,368		1,861
Total	$	1,931	$	1,287	$	3,844	$	2,881

Description of Business

6 Months Ended

Jun. 30, 2023

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 envisioning a new way to treat cancer. Leveraging its novel targeted oncology platform, the Company has the goal to develop a new standard of care across multiple cancer indications. Within these consolidated financial statements, unless the context otherwise requires, references to the Company or Aura refer to Aura Biosciences, Inc. and its subsidiaries on a consolidated basis. The Company’s initial focus is on ocular and urologic oncology where the disease is diagnosed early and there is a high unmet medical need for targeted local therapies. 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 subset of modified tumor associated glycosaminoglycans that are part of the heparan sulphate chain of HSPGs expressed on the cell surface of many tumor cells and in the tumor microenvironment. Bel-sar, the Company’s first VDC candidate, is being developed for the first-line treatment of early-stage choroidal melanoma, a rare disease with no drugs approved where the standard of care leaves many patients with blindness. The Company is also developing bel-sar for additional ocular oncology indications, including choroidal metastasis, and in non-muscle invasive bladder cancer, or NMIBC. Aura’s headquarters are located in Boston, 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.

Liquidity

Through June 30, 2023, the Company has funded its operations primarily with proceeds from the initial and additional closings of its convertible preferred stock financings, and through its IPO, follow-on offering and at-the-market offering, or ATM. On December 5, 2022, the Company issued and sold 7,705,000 shares of common stock, including the full exercise of the underwriters’ option to purchase additional shares at a price to the public of $12.00 per share for aggregate gross proceeds of $92.5 million, or the Follow-On Offering. The Company received approximately $86.7 million in net proceeds from the Follow-On Offering after deducting underwriting discounts, commissions and offering expenses. On November 1, 2022, the Company filed a shelf registration statement on Form S-3, or the 2022 Shelf, with the SEC in relation to the registration of up to an aggregate offering price of $250.0 million of common stock, preferred stock, debt securities, warrants and units or any combination thereof. The Company also simultaneously entered into the Open Market Sale AgreementSM, or Sales Agreement, with Jefferies LLC, or the Sales Agent, to provide for the offering, issuance and sale by the Company of up to an aggregate of $75.0 million of common stock from time to time in the ATM under the 2022 Shelf and subject to the limitations thereof. The Company issued 169,200 shares of common stock at an average price of $12.58 for aggregate gross proceeds of $2.1 million during the six months ended June 30, 2023 under the ATM. In addition, the Company issued 732,189 shares of common stock at an average price of $12.51 for aggregate gross proceeds of $9.2 million as of December 31, 2022 under the ATM. 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 $35.8 million and $26.3 million for the six months ended June 30, 2023 and 2022, respectively. As of June 30, 2023, the Company had cash and cash equivalents and marketable securities of $162.0 million and an accumulated deficit of $246.7 million. The Company expects to continue to generate operating losses for the foreseeable future.

As of the issuance date of these unaudited condensed consolidated financial statements for the three and six months ended June 30, 2023, the Company expects that its cash and cash equivalents and marketable securities 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.

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net loss	$ (35,765)	$ (26,303)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	628	552
Accretion on marketable securities	(2,032)	(143)
Stock-based compensation expense	3,844	2,881
Non-cash lease expense	669	288
Changes in operating assets and liabilities:
Prepaid expenses and other assets	3,940	(892)
Other long-term assets	(277)
Accounts payable	(2,382)	(1,515)
Accrued expenses and other liabilities	761	(404)
Operating lease liabilities	(443)	(292)
Net cash used in operating activities	(31,057)	(25,828)
Cash flows from investing activities:
Purchases of property and equipment	(302)	(673)
Purchase of marketable securities	(88,847)	(71,266)
Maturities of marketable securities	43,677	3,000
Net cash used in investing activities	(45,472)	(68,939)
Cash flows from financing activities:
Proceeds from exercise of stock options	805	326
Proceeds from issuance of common stock under ATM facility, net of issuance costs	1,818
Proceeds from ESPP purchase	56
Net cash provided by financing activities	2,679	326
Net (decrease) increase in cash, cash equivalents and restricted cash	(73,850)	(94,441)
Cash, cash equivalents and restricted cash at beginning of period	122,370	149,211
Cash, cash equivalents and restricted cash at end of period	48,520	54,770
Supplemental disclosure of cash flow information:
Purchases of property and equipment in accounts payable and accrued expenses and other liabilities	13	$ 426
Common stock issued under ATM settled in future period	$ 247

Net Loss Per Share - Summary of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Numerator:
Net loss	$ (18,299)	$ (17,466)	$ (13,468)	$ (12,835)	$ (35,765)	$ (26,303)
Denominator:
Weighted average common stock outstanding - basic	37,855,533		29,251,480		37,820,104	29,232,661
Weighted average common stock outstanding - diluted	37,855,533		29,251,480		37,820,104	29,232,661
Net loss per common share - basic	$ (0.48)		$ (0.46)		$ (0.95)	$ (0.90)
Net loss per common share - diluted	$ (0.48)		$ (0.46)		$ (0.95)	$ (0.90)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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+ Details

Compensation

6 Months Ended

Jun. 30, 2023

Retirement Benefits [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 $0.2 million and $0.1 million for the three months ended June 30, 2023 and 2022, respectively. The Company made matching contributions in the amount of $0.4 million and $0.3 million for the six months ended June 30, 2023 and 2022, respectively.

- Definition

The entire disclosure for retirement benefits.

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+ Details

Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions			6 Months Ended	12 Months Ended
	Dec. 05, 2022	Nov. 01, 2022	Jun. 30, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Common stock, shares authorized			150,000,000	150,000,000
Common stock, par value			$ 0.00001	$ 0.00001
Common stock, shares issued			38,086,606	37,771,918
Common stock, shares outstanding			38,086,606	37,771,918
Preferred stock, shares authorized			10,000,000	10,000,000
Preferred stock, par value			$ 0.00001	$ 0.00001
Preferred stock, shares issued			0	0
Preferred stock, shares outstanding			0	0
Aggregate offering price		$ 250.0
At-the-Market Offering
Class of Stock [Line Items]
Proceeds from issuance of common stock			$ 2.1	$ 9.2
Sale of common stock through agreement		$ 75.0
Common Stock \| Follow-On Offering
Class of Stock [Line Items]
Shares issued and sold	7,705,000
Share price	$ 12.00
Proceeds from issuance of common stock	$ 92.5
Net proceeds from follow-on offering	$ 86.7
Common Stock \| At-the-Market Offering
Class of Stock [Line Items]
Shares issued and sold			169,200	732,189
Share price			$ 12.58	$ 12.51

Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Jun. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. GAAP. In management’s opinion, the accompanying unaudited condensed consolidated financial statements include all adjustments, consisting of normal recurring adjustments, which are necessary to present fairly the Company’s financial position, results of operations, and cash flows. The financial data and other information disclosed in these notes related to the three and six months ended June 30, 2023 and 2022 are also unaudited. The unaudited condensed results of operations are not necessarily indicative of the operating results that may occur for the full fiscal year ending December 31, 2023. Certain information and footnote disclosures normally included in annual consolidated financial statements prepared in accordance with U.S. GAAP have been omitted pursuant to instructions, rules, and regulations prescribed by the United States Securities and Exchange Commission, or the SEC. Management believes that the disclosures provided here are adequate to make the information presented not misleading when these unaudited condensed consolidated financial statements are read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K.
Significant Accounting Policies	Significant Accounting Policies The Company’s significant accounting policies are disclosed in the audited consolidated financial statements for the year ended December 31, 2022, in the Company’s Annual Report on Form 10-K filed with the SEC on March 15, 2023. There have been no changes to the Company’s significant accounting policies except as noted below.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” which was subsequently amended in November 2018 through ASU No. 2018-19, “Codification Improvements to Topic 326, Financial Instruments—Credit Losses.” ASU No. 2016-13 will require entities to estimate lifetime expected credit losses for trade and other receivables, net investments in leases, financing receivables, debt securities and other instruments, which will result in earlier recognition of credit losses. Further, the new credit loss model will affect how entities in all industries estimate their allowance for losses for receivables that are current with respect to their payment terms. ASU No. 2018-19 further clarifies that receivables arising from operating leases are not within the scope of Topic 326. Instead, impairment from receivables of operating leases should be accounted for in accordance with Topic 842, Leases. As per the latest ASU 2020-02, FASB deferred the timelines for certain small public and private entities, thus the new guidance was adopted by the Company for the annual reporting period beginning January 1, 2023, including interim periods within that annual reporting period. The standard will apply as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The Company adopted the standard on January 1, 2023 and it did not have a material impact on its results of operations, financial condition, and financial statement disclosures.

Prepaid Expenses and Other Current Assets

6 Months Ended

Jun. 30, 2023

Prepaid Expense and Other Assets, Current [Abstract]

Prepaid Expenses and Other Current Assets

5. Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	June 30, 2023		December 31, 2022
Prepaid insurance	$	864	$	2,174
Prepaid research and development expenses		2,326		4,982
Other		988		715
Prepaid expenses and other current assets	$	4,178	$	7,871

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Operating Expenses:
Research and development	$ 15,120	$ 9,510	$ 29,524	$ 17,786
General and administrative	5,156	4,306	10,196	8,841
Total operating expenses	20,276	13,816	39,720	26,627
Total operating loss	(20,276)	(13,816)	(39,720)	(26,627)
Other income (expense):
Interest income, including amortization and accretion income	2,009	292	4,000	319
Other income (expense)	(32)	56	(45)	5
Total other income	1,977	348	3,955	324
Net loss	$ (18,299)	$ (13,468)	$ (35,765)	$ (26,303)
Net loss per common share - basic	$ (0.48)	$ (0.46)	$ (0.95)	$ (0.90)
Net loss per common share - diluted	$ (0.48)	$ (0.46)	$ (0.95)	$ (0.90)
Weighted average common stock outstanding - basic	37,855,533	29,251,480	37,820,104	29,232,661
Weighted average common stock outstanding - diluted	37,855,533	29,251,480	37,820,104	29,232,661
Comprehensive loss:
Net loss	$ (18,299)	$ (13,468)	$ (35,765)	$ (26,303)
Other comprehensive items:
Unrealized loss on marketable securities	(178)	(123)	(151)	(128)
Total other comprehensive loss	(178)	(123)	(151)	(128)
Total comprehensive loss	$ (18,477)	$ (13,591)	$ (35,916)	$ (26,431)

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Jan. 01, 2023	Nov. 01, 2021	Jan. 01, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of stock options granted			$ 7.66	$ 11.56
Fair value of options vested			$ 3,400	$ 1,200
Total intrinsic value of options exercised			900	600
Unrecognized compensation expense related to stock options	$ 14,200		$ 14,200
Unrecognized compensation expense weighted average period			2 years 6 months
Share-based compensation expense	1,931	$ 1,287	$ 3,844	$ 2,881
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense related to stock options	$ 6,000		$ 6,000
Unrecognized compensation expense weighted average period			3 years 1 month 20 days
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					6,850,986	3,352,166
Common stock outstanding percentage	5.00%		5.00%
Cumulative increase in shares of common stock	3,352,166		3,352,166
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for future issuance	4,324,297		4,324,297
Number of shares reserved for issuance	955,915		955,915		962,550		335,217
Share-based compensation expense	$ 20		$ 30
Percentage of the lower of the fair market value of common stock	85.00%		85.00%
Common stock outstanding percentage	1.00%		1.00%

Fair Value of Assets and Liabilities (Tables)

6 Months Ended

Jun. 30, 2023

Fair Value Disclosures [Abstract]

Financial Assets and Liabilities Measured at Fair Value on Recurring Basis


Description	June 30, 2023		Quoted prices active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant other observable inputs (Level 3)
Financial assets
Cash equivalents:
Money market funds		47,220	$	47,220	$	—	$	—
Marketable securities:
Commercial paper		48,048		—		48,048		—
Corporate bonds		15,500		—		15,500		—
U.S. Government agencies		46,504		—		46,504		—
Yankee bonds		2,934		—		2,934		—
Asset-backed securities		1,295		—		1,295		—
Total financial assets	$	161,501	$	47,220	$	114,281	$	—


Description	December 31, 2022		Quoted prices active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant other observable inputs (Level 3)
Financial assets
Cash equivalents:
Money market funds	$	118,582	$	118,582	$	—	$	—
Marketable securities:
Commercial paper		27,476		—		27,476		—
Corporate bonds		18,099		—		18,099		—
U.S. Government agencies		21,654		—		21,654		—
Total financial assets	$	185,811	$	118,582	$	67,229	$	—

Compensation - Additional Information (Details) - 401(k) Plan - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
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	$ 0.2	$ 0.1	$ 0.4	$ 0.3

Marketable Securities - Additional Information (Details)	6 Months Ended
	Jun. 30, 2023 USD ($) Security
Investments, Debt and Equity Securities [Abstract]
Number of marketable securities \| Security	41
Unrealized losses of marketable securities with contractual maturities of one year or less	$ 200,000
Impairments of asset	$ 0

Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued research and development expenses	$ 2,468	$ 1,543
Accrued compensation	2,100	2,705
Other	766	325
Accrued expenses and other current liabilities	$ 5,334	$ 4,573

Commitments and Contingencies (Tables)

6 Months Ended

Jun. 30, 2023

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 three and six months ended June 30, 2023 and 2022 (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Lease Cost
Operating lease costs		881		155		1,761		309
Variable lease costs		217		161		443		337
Short-term lease costs		2		2		4		4
Total lease costs	$	1,100		318	$	2,208	$	650


Cash paid for amounts included in the measurement of lease liabilities—operating leases	$	1,537		$	305
Weighted-average remaining lease term—operating leases (years)		9.09			1.08
Weighted-average discount rate—operating leases		10.71	%		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 June 30, 2023 (in thousands):


	Operating lease payments as of June 30, 2023
2023	$	1,575
2024		3,205
2025		3,301
2026		3,400
2027		3,502
Thereafter		17,430
Total lease payments		32,413
Less: interest		(11,998	)
Total operating lease liabilities at June 30, 2023		20,415
Less: current portion of lease liabilities		3,008
Lease liabilities, net of current portion	$	17,407

Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2023

Investments, Debt and Equity Securities [Abstract]

Summary of Marketable Securities

Marketable securities consist of the following (in thousands):


	June 30, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Commercial paper	$	48,116	$	—	$	(68	)	$	48,048
Corporate bonds		15,549		—		(49	)	$	15,500
U.S. Government agencies		46,594		5		(95	)	$	46,504
Yankee bonds		2,946		—		(12	)	$	2,934
Asset-backed securities		1,300		—		(5	)	$	1,295
Total	$	114,505	$	5	$	(229	)	$	114,281


	December 31, 2022
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Commercial paper	$	27,476	$	—	$	—		$	27,476
Corporate bonds		18,191		—		(92	)	$	18,099
U.S. Government agencies		21,635		20		(1	)	$	21,654
Total	$	67,302	$	20	$	(93	)	$	67,229

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 9,519	$ 9,235
Less—accumulated depreciation	(4,462)	(3,864)
Property and equipment, net	5,057	5,371
Assets Under Construction
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,600	1,805
IT Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	133	133
Lab Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 7,786	$ 7,297

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 47,732	$ 121,582
Marketable securities	114,281	67,229
Restricted cash and deposits	20	20
Prepaid expenses and other current assets	4,178	7,871
Total current assets	166,211	196,702
Restricted cash and deposits, net of current portion	768	768
Right of use assets - operating lease	20,003	20,671
Other long-term assets	700	423
Property and equipment, net	5,057	5,371
Total Assets	192,739	223,935
Current liabilities:
Accounts payable	553	2,921
Short-term operating lease liability	3,008	2,963
Accrued expenses and other current liabilities	5,334	4,573
Total current liabilities	8,895	10,457
Long-term operating lease liability	17,407	17,895
Total Liabilities	26,302	28,352
Commitments and Contingencies (Note 12)
Stockholders Equity:
Common stock, $0.00001 par value, 150,000,000 authorized at June 30, 2023 and December 31, 2022, and 38,086,606 and 37,771,918 shares issued and outstanding at June 30, 2023 and December 31, 2022, respectively
Additional paid-in capital	413,325	406,555
Accumulated deficit	(246,665)	(210,900)
Accumulated other comprehensive loss	(223)	(72)
Total Stockholders' Equity	166,437	195,583
Total Liabilities and Stockholders Equity	$ 192,739	$ 223,935

Marketable Securities

6 Months Ended

Jun. 30, 2023

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

6. Marketable Securities

Marketable securities consist of the following (in thousands):


	June 30, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Commercial paper	$	48,116	$	—	$	(68	)	$	48,048
Corporate bonds		15,549		—		(49	)	$	15,500
U.S. Government agencies		46,594		5		(95	)	$	46,504
Yankee bonds		2,946		—		(12	)	$	2,934
Asset-backed securities		1,300		—		(5	)	$	1,295
Total	$	114,505	$	5	$	(229	)	$	114,281


	December 31, 2022
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Commercial paper	$	27,476	$	—	$	—		$	27,476
Corporate bonds		18,191		—		(92	)	$	18,099
U.S. Government agencies		21,635		20		(1	)	$	21,654
Total	$	67,302	$	20	$	(93	)	$	67,229

As of June 30, 2023, the unrealized losses on the Company’s investments in commercial paper, corporate bonds, U.S. government agencies securities, Yankee bonds, and asset-backed securities were caused by interest rate increases. The current credit ratings are all within the guidelines of the investment policy of the Company and the Company does not expect the issuers to settle any security at a price less than the amortized cost basis of the investment. The Company does not intend to sell the investments and it is not probable that the Company will be required to sell the investments before recovery of their amortized cost basis.

As of June 30, 2023, 41 marketable securities with contractual maturities of one year or less were in an unrealized loss position totaling $0.2 million.

As of June 30, 2023, all marketable securities held by the Company had remaining contractual maturities of one year or less.

There were no impairments of the Company’s assets measured and carried at fair value during the six months ended June 30, 2023.

Commitments and Contingencies- Schedule of Fair Value of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Leases [Abstract]
2023	$ 1,575
2024	3,205
2025	3,301
2026	3,400
2027	3,502
Thereafter	17,430
Total lease payments	32,413
Less: interest	(11,998)
Total operating lease liabilities at June 30, 2023	20,415
Less: current portion of lease liabilities	3,008	$ 2,963
Lease liabilities, net of current portion	$ 17,407	$ 17,895

Net Loss Per Share

6 Months Ended

Jun. 30, 2023

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 per common share 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 net loss per share for the three and six months ended June 30, 2023 and 2022 as follows (in thousands, except share and per share data):


	Three Months Ended June 30,						Six Months Ended June 30,
	2023			2022			2023			2022
Numerator:
Net loss	$	(18,299	)	$	(13,468	)	$	(35,765	)	$	(26,303	)
Denominator:
Weighted-average common stock outstanding—basic and diluted		37,855,533			29,251,480			37,820,104			29,232,661
Net loss per common share—basic and diluted	$	(0.48	)	$	(0.46	)	$	(0.95	)	$	(0.90	)

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:


	Six Months Ended June 30,
	2023		2022
Stock options to purchase common stock		4,627,518		4,135,212
Restricted stock units that vest into common stock		643,108		206,933
Warrants to purchase common stock		12,686		12,686
Total potential dilutive shares		5,283,312		4,354,831

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,931	$ 1,287	$ 3,844	$ 2,881
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	709	465	1,476	1,020
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,222	$ 822	$ 2,368	$ 1,861

Accrued Expenses and Other Current Liabilities (Tables)

6 Months Ended

Jun. 30, 2023

Payables and Accruals [Abstract]

Summary of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	June 30, 2023		December 31, 2022
Accrued research and development expenses	$	2,468	$	1,543
Accrued compensation		2,100		2,705
Other		766		325
Accrued expenses and other current liabilities	$	5,334	$	4,573

Stock-Based Compensation - Schedule of Fair Value of Stock Options, Valuation Assumptions (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Risk-free interest rate	3.69%	3.09%	3.57%	2.53%
Expected term (years)	5 years 10 months 28 days	5 years 10 months 2 days	6 years 7 days	5 years 10 months 24 days
Expected volatility of the underlying stock	85.43%	76.85%	84.97%	75.44%
Expected dividend rate	0.00%	0.00%	0.00%	0.00%

Equity

6 Months Ended

Jun. 30, 2023

Equity [Abstract]

Equity

8. Equity

The Company had 150,000,000 authorized shares of common stock, par value $0.00001 per share, of which 38,086,606 and 37,771,918 shares were issued and outstanding at June 30, 2023 and December 31, 2022, respectively. In addition, the Company had 10,000,000 authorized shares of preferred stock, par value $0.00001 per share, all of which shares of preferred stock will be undesignated. No authorized shares of preferred stock were issued and outstanding at June 30, 2023 and December 31, 2022.

Financings

On December 5, 2022, the Company issued and sold 7,705,000 shares of common stock, including the full exercise of the underwriters’ option to purchase additional shares at a price to the public of $12.00 per share for aggregate gross proceeds of $92.5 million in the Follow-On Offering. The Company received approximately $86.7 million in net proceeds from the Follow-On Offering after deducting underwriting discounts, commissions and offering expenses.

On November 1, 2022, the Company filed the 2022 Shelf with the SEC in relation to the registration of up to an aggregate offering price of $250.0 million of common stock, preferred stock, debt securities, warrants and units or any combination thereof. The Company also simultaneously entered into the Sales Agreement with the Sales Agent to provide for the offering, issuance and sale by the Company of up to an aggregate of $75.0 million of common stock from time to time in the ATM under the 2022 Shelf and subject to the limitations thereof. The Company issued 169,200 shares of common stock at an average price of $12.58 for aggregate gross proceeds of $2.1 million during the six months ended June 30, 2023 under the ATM. In addition, the Company issued 732,189 shares of common stock at an average price of $12.51 for aggregate gross proceeds of $9.2 million as of December 31, 2022 under the ATM.

- 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.

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+ Details

Stock-Based Compensation - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units	6 Months Ended
	Jun. 30, 2023 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Beginning Balance	153,950
Granted	598,445
Vested/Released	0
Forfeited	(109,287)
Ending Balance	643,108
Unvested, Weighted -Average Grant Date Fair Value \| $ / shares	$ 14.00
Granted, Weighted-Average Grant Date Fair Value \| $ / shares	10.17
Forfeited, Weighted -Average Grant Date Fair Value \| $ / shares	11.00
Unvested, Weighted -Average Grant Date Fair Value \| $ / shares	$ 10.95

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid insurance	$ 864	$ 2,174
Prepaid research and development expenses	2,326	4,982
Other	988	715
Prepaid expenses and other current assets	$ 4,178	$ 7,871

Summary of Significant Accounting Policies	6 Months Ended
Summary of Significant Accounting Policies	Jun. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. GAAP. In management’s opinion, the accompanying unaudited condensed consolidated financial statements include all adjustments, consisting of normal recurring adjustments, which are necessary to present fairly the Company’s financial position, results of operations, and cash flows. The financial data and other information disclosed in these notes related to the three and six months ended June 30, 2023 and 2022 are also unaudited. The unaudited condensed results of operations are not necessarily indicative of the operating results that may occur for the full fiscal year ending December 31, 2023. Certain information and footnote disclosures normally included in annual consolidated financial statements prepared in accordance with U.S. GAAP have been omitted pursuant to instructions, rules, and regulations prescribed by the United States Securities and Exchange Commission, or the SEC. Management believes that the disclosures provided here are adequate to make the information presented not misleading when these unaudited condensed consolidated financial statements are read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K. Significant Accounting Policies The Company’s significant accounting policies are disclosed in the audited consolidated financial statements for the year ended December 31, 2022, in the Company’s Annual Report on Form 10-K filed with the SEC on March 15, 2023. There have been no changes to the Company’s significant accounting policies except as noted below. Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” which was subsequently amended in November 2018 through ASU No. 2018-19, “Codification Improvements to Topic 326, Financial Instruments—Credit Losses.” ASU No. 2016-13 will require entities to estimate lifetime expected credit losses for trade and other receivables, net investments in leases, financing receivables, debt securities and other instruments, which will result in earlier recognition of credit losses. Further, the new credit loss model will affect how entities in all industries estimate their allowance for losses for receivables that are current with respect to their payment terms. ASU No. 2018-19 further clarifies that receivables arising from operating leases are not within the scope of Topic 326. Instead, impairment from receivables of operating leases should be accounted for in accordance with Topic 842, Leases. As per the latest ASU 2020-02, FASB deferred the timelines for certain small public and private entities, thus the new guidance was adopted by the Company for the annual reporting period beginning January 1, 2023, including interim periods within that annual reporting period. The standard will apply as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The Company adopted the standard on January 1, 2023 and it did not have a material impact on its results of operations, financial condition, and financial statement disclosures.

Income Taxes

6 Months Ended

Jun. 30, 2023

Income Tax Disclosure [Abstract]

Income Taxes

14. Income Taxes

The Company estimates an annual effective tax rate of 0% for the year ending December 31, 2023 as the Company incurred losses for the six months ended June 30, 2023, and is forecasting additional losses through the remainder of fiscal year ending December 31, 2023, resulting in an estimated net loss for both financial statement and tax purposes for the year ending December 31, 2023. Therefore, no federal or state income taxes are expected and none have been recorded at this time. Income taxes have been accounted for using the liability method.

Due to the Company’s history of losses since inception, there is not enough evidence at this time to support that the Company will generate future income of a sufficient amount and nature to utilize the benefits of its net deferred tax assets. Accordingly, the deferred tax assets have been reduced by a full valuation allowance, since the Company does not currently believe that realization of its deferred tax assets is more likely than not.

As of June 30, 2023, the Company had no unrecognized income tax benefits that would reduce the Company’s effective tax rate if recognized.

- 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.

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+ Details

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 300	$ 300	$ 628	$ 552

Commitment and Contingencies

6 Months Ended

Jun. 30, 2023

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. The Company has one operating lease for its office and laboratory facility with required future minimum payments as of June 30, 2023 and one operating lease that was terminated in August 2022.

On May 16, 2022, the Company entered into an office and laboratory lease in Boston, MA with an initial 10-year term and one renewal option to extend the lease for an additional seven years. The lease commenced on August 1, 2022, and estimated payments due under the initial term total $35.2 million. The lease requires a letter of credit totaling $0.8 million which is classified as long-term restricted cash and deposits on the consolidated balance sheet. The landlord will reimburse the Company up to $0.5 million for certain costs related to expansion of the laboratory space. As of June 30, 2023, the Company has incurred $0.1 million of expenses related to the expansion, and has been reimbursed for $0.1 million of these expenses.


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Lease Cost
Operating lease costs		881		155		1,761		309
Variable lease costs		217		161		443		337
Short-term lease costs		2		2		4		4
Total lease costs	$	1,100		318	$	2,208	$	650


Cash paid for amounts included in the measurement of lease liabilities—operating leases	$	1,537		$	305
Weighted-average remaining lease term—operating leases (years)		9.09			1.08
Weighted-average discount rate—operating leases		10.71	%		3.51	%

The following table reconciles the future minimum commitments to the Company’s operating lease liabilities at June 30, 2023 (in thousands):


	Operating lease payments as of June 30, 2023
2023	$	1,575
2024		3,205
2025		3,301
2026		3,400
2027		3,502
Thereafter		17,430
Total lease payments		32,413
Less: interest		(11,998	)
Total operating lease liabilities at June 30, 2023		20,415
Less: current portion of lease liabilities		3,008
Lease liabilities, net of current portion	$	17,407

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.

The Company recognized no expenses related to this agreement and related amendments for the six months ended June 30, 2023 and 2022, respectively.

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. During the six months ended June 30, 2023 and 2022, the Company recognized no milestones related to this agreement.

Life Technologies Corporation

In December 2014, the Company entered into a non-exclusive, perpetual license agreement with Life Technologies Corporation, or the Life Technologies, which allows for five licensed products. Under this agreement the Company is required to pay an initial license fee of $0.1 million for 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.

In January 2022, the Company entered into the First Amendment to the non-exclusive, perpetual license agreement with Life Technologies for use of the license in an additional indication. The cost of this amendment was a one-time fee of $0.05 million. During the six months ended June 30, 2023 and 2022, the Company recognized $0 million and $0.05 million of expenses related to this agreement, respectively.

Effective in September 2022, the Company entered into a new non-exclusive, perpetual license agreement with Life Technologies for licensed products. Under this agreement, the Company is required to pay an initial license fee of $0.4 million for the first licensed product and $0.5 million for each additional licensed product. In addition, the agreement allows the Company the right to sublicense which would lead to a $0.2 million payment for each sublicense per licensed product and a $0.03 million payment for use of the cell line document package. In the event of a change of control, there will be a change of control fee of $0.5 million. During the six months ended June 30, 2023, the Company recognized no expenses related to 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 the six months ended June 30, 2023 and 2022, the Company paid no research collaboration fees related to this agreement.

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. The Company recognized no milestones related to this agreement and related amendments for the six months ended June 30, 2023 and 2022.

An eighth amendment was effective in September 2022, requiring payment of $0.04 million within 30 days of November 1, 2022, and payment of another $0.03 million within 30 days of the 12th anniversary of the CRADA, which will be in August 2023. This eighth amendment extended the term of the CRADA to September 30, 2024. During the six months ended June 30, 2023, the Company recognized no expenses related to this agreement

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

In September 2013, the Company entered into an exclusive patent license agreement, or 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. The Company recognized no patent licensing fees for the six months ended June 30, 2023 and 2022, 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. 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 June 30, 2023. 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 six months ended June 30, 2023 and 2022.

Clearside

In July 2019, the Company entered into an exclusive license agreement with Clearside Biomedical, Inc., or 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.

The Clearside License agreement expires on a country-by-country basis upon the later of the last to expire patent or ten years from the date of the first commercial sale of a product.

The Company recognized $0.4 million and $0 million in expense related to this agreement and related amendments for the six months ended June 30, 2023 and 2022.

Prepaid Expenses and Other Current Assets (Tables)

6 Months Ended

Jun. 30, 2023

Prepaid Expense and Other Assets, Current [Abstract]

Schedule of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	June 30, 2023		December 31, 2022
Prepaid insurance	$	864	$	2,174
Prepaid research and development expenses		2,326		4,982
Other		988		715
Prepaid expenses and other current assets	$	4,178	$	7,871

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	ATM	Common Stock	Common Stock ATM	Additional Paid-in Capital	Additional Paid-in Capital ATM	Accumulated Deficit	Accumulated Other Comprehensive Loss Amount
Beginning Balance at Dec. 31, 2021	$ 152,315				$ 304,452		$ (152,137)
Beginning Balance, Shares at Dec. 31, 2021			29,211,643
Stock-based compensation expense	1,594				1,594
Stock option exercises	17				17
Stock option exercises, Shares			5,593
Unrealized gain (loss) on marketable securities	(5)							$ (5)
Net loss	(12,835)						(12,835)
Ending Balance at Mar. 31, 2022	141,086				306,063		(164,972)	(5)
Ending Balance, Shares at Mar. 31, 2022			29,217,236
Beginning Balance at Dec. 31, 2021	152,315				304,452		(152,137)
Beginning Balance, Shares at Dec. 31, 2021			29,211,643
Unrealized gain (loss) on marketable securities	(128)
Net loss	(26,303)
Ending Balance at Jun. 30, 2022	129,091				307,659		(178,440)	(128)
Ending Balance, Shares at Jun. 30, 2022			29,266,848
Beginning Balance at Dec. 31, 2021	152,315				304,452		(152,137)
Beginning Balance, Shares at Dec. 31, 2021			29,211,643
Ending Balance at Dec. 31, 2022	195,583				406,555		(210,900)	(72)
Ending Balance, Shares at Dec. 31, 2022			37,771,918
Beginning Balance at Mar. 31, 2022	141,086				306,063		(164,972)	(5)
Beginning Balance, Shares at Mar. 31, 2022			29,217,236
Stock-based compensation expense	1,287				1,287
Stock option exercises	309				309
Stock option exercises, Shares			49,612
Unrealized gain (loss) on marketable securities	(123)							(123)
Net loss	(13,468)						(13,468)
Ending Balance at Jun. 30, 2022	129,091				307,659		(178,440)	(128)
Ending Balance, Shares at Jun. 30, 2022			29,266,848
Beginning Balance at Dec. 31, 2022	195,583				406,555		(210,900)	(72)
Beginning Balance, Shares at Dec. 31, 2022			37,771,918
Stock-based compensation expense	1,913				1,913
Employee Stock Purchase Plan Issuance	56				56
Employee Stock Purchase Plan Issuance, Shares			6,635
Stock option exercises	145				145
Stock option exercises, Shares			21,549
Unrealized gain (loss) on marketable securities	27							27
Net loss	(17,466)						(17,466)
Ending Balance at Mar. 31, 2023	180,258				408,669		(228,366)	(45)
Ending Balance, Shares at Mar. 31, 2023			37,800,102
Beginning Balance at Dec. 31, 2022	195,583				406,555		(210,900)	(72)
Beginning Balance, Shares at Dec. 31, 2022			37,771,918
Unrealized gain (loss) on marketable securities	(151)
Net loss	(35,765)
Ending Balance at Jun. 30, 2023	166,437				413,325		(246,665)	(223)
Ending Balance, Shares at Jun. 30, 2023			38,086,606
Beginning Balance at Mar. 31, 2023	180,258				408,669		(228,366)	(45)
Beginning Balance, Shares at Mar. 31, 2023			37,800,102
Stock-based compensation expense	1,931				1,931
Issuance of common stock, Shares				169,200
Issuance of common stock		$ 2,065				$ 2,065
Stock option exercises	660				660
Stock option exercises, Shares			117,304
Unrealized gain (loss) on marketable securities	(178)							(178)
Net loss	(18,299)						(18,299)
Ending Balance at Jun. 30, 2023	$ 166,437				$ 413,325		$ (246,665)	$ (223)
Ending Balance, Shares at Jun. 30, 2023			38,086,606

Property and Equipment, Net (Tables)

6 Months Ended

Jun. 30, 2023

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment, Net

Property and equipment, net, consisted of the following (in thousands):


	June 30, 2023			December 31, 2022
Assets under construction	$	1,600		$	1,805
IT equipment		133			133
Lab equipment		7,786			7,297
	$	9,519		$	9,235
Less—accumulated depreciation		(4,462	)		(3,864	)
Property and equipment, net	$	5,057		$	5,371

Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2023	Aug. 04, 2023
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Entity Registrant Name	AURA BIOSCIENCES, INC.
Entity Central Index Key	0001501796
Entity File Number	001-40971
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	32-0271970
Entity Address, Address Line One	80 Guest Street
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02135
City Area Code	617
Local Phone Number	500-8864
Entity Interactive Data Current	Yes
Entity Current Reporting Status	No
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Title of 12(b) Security	Common Stock, par value $0.00001 per share
Trading Symbol	AURA
Security Exchange Name	NASDAQ
Document Quarterly Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		38,197,098

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Jun. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	38,086,606	37,771,918
Common stock, shares outstanding	38,086,606	37,771,918

Fair Value of Assets and Liabilities - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Assets
Financial assets	$ 161,501	$ 185,811
Money Market Funds
Assets
Financial assets	47,220	118,582
Commercial Paper
Assets
Financial assets	48,048	27,476
Corporate Bonds
Assets
Financial assets	15,500	18,099
U.S. Government Agencies
Assets
Financial assets	46,504	21,654
Yankee Bonds
Assets
Financial assets	2,934
Asset-Backed Securities
Assets
Financial assets	1,295
Level 1
Assets
Financial assets	47,220	118,582
Level 1 \| Money Market Funds
Assets
Financial assets	47,220	118,582
Level 2
Assets
Financial assets	114,281	67,229
Level 2 \| Commercial Paper
Assets
Financial assets	48,048	27,476
Level 2 \| Corporate Bonds
Assets
Financial assets	15,500	18,099
Level 2 \| U.S. Government Agencies
Assets
Financial assets	46,504	$ 21,654
Level 2 \| Yankee Bonds
Assets
Financial assets	2,934
Level 2 \| Asset-Backed Securities
Assets
Financial assets	$ 1,295

Commitments and Contingencies - Additional Information (Details) € in Thousands		1 Months Ended										3 Months Ended		6 Months Ended
	May 16, 2022 USD ($)	Sep. 30, 2022 USD ($)	Aug. 31, 2022 OperatingLease	Jan. 31, 2022 USD ($)	Oct. 31, 2020 USD ($)	Jul. 31, 2019 USD ($)	Dec. 31, 2014 USD ($) LicensedProduct	Jan. 31, 2014 USD ($)	Sep. 30, 2013 USD ($)	Jul. 31, 2011 USD ($)	Nov. 30, 2009 EUR (€)	Jun. 30, 2023 USD ($) OperatingLease	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) OperatingLease	Jun. 30, 2022 USD ($)
Lessee Lease Description [Line Items]
Estimated payments due												$ 32,413,000		$ 32,413,000
Operating lease liabilities												20,415,000		20,415,000
Research and development expenses												$ 15,120,000	$ 9,510,000	29,524,000	$ 17,786,000
National Institute of Health
Lessee Lease Description [Line Items]
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
Expenses for patent licensing fees														0	0
Royalty Bearing Patent License Agreement
Lessee Lease Description [Line Items]
Expenses														0	0
License agreement term											10 years
Royalty Bearing Patent License Agreement \| IND Filings
Lessee Lease Description [Line Items]
Potential milestone payments \| €											€ 10
Clearside
Lessee Lease Description [Line Items]
Expenses														400,000	0
Upfront payment						$ 100,000
Royalties on net sales						20.00%
License agreement expiration period						10 years
Clearside \| Maximum
Lessee Lease Description [Line Items]
Aggregate milestones payment						$ 21,000,000.0
LI-COR, Inc. \| Exclusive License and Supply Agreement
Lessee Lease Description [Line Items]
One-time upfront license issuance fee								$ 100,000
Research and development expenses														0	0
License agreement term								10 years
LI-COR, Inc. \| Exclusive License and Supply Agreement \| Maximum
Lessee Lease Description [Line Items]
Aggregate milestone payments								$ 200,000
LI-COR, Inc. \| 2014 Non- Exclusive Agreement
Lessee Lease Description [Line Items]
License issue fee							$ 30,000.00
Milestone payments														0	0
LI-COR, Inc. \| 2014 Non- Exclusive Agreement \| Maximum
Lessee Lease Description [Line Items]
License issue fee							300,000
Payments for development and commercial milestones							$ 400,000
Life Technologies
Lessee Lease Description [Line Items]
Number of licensed products \| LicensedProduct							5
Initial license fee							$ 100,000
Initial license fee for first licensed product		$ 400,000
Initial license fee for additional licensed product		500,000
Payment for sublicense		200,000
Payment for use of cell line document package		30,000.00
Annual development fee							100,000
Non-refundable, Non- creditable fee							300,000
Change of control fees		500,000					$ 200,000
One time perpetual license agreement fee				$ 50,000.00
Expenses														0	50,000.00
Expense related to agreement including sublicense														0
Dr. John Schiller \| 2014 Non- Exclusive Agreement
Lessee Lease Description [Line Items]
Required amendment payment		$ 40,000.00
Required amendment payment due period		30 days
Dr. John Schiller \| Collaboration Research and Development Agreement
Lessee Lease Description [Line Items]
Annual development fee										$ 30,000.00
Expenses														0
Agreement term										2 years
First payment due										30 days
Subsequent payments due										30 days
Research collaboration fees														$ 0	$ 0
Required amendment payment					$ 40,000.00
Required amendment payment due period					30 days
Dr. John Schiller \| Collaboration Research and Development Agreement \| 10th Anniversary
Lessee Lease Description [Line Items]
Required amendment payment		$ 30,000.00			$ 30,000.00
Required amendment payment due period		30 days			30 days
Office and Laboratory Facility
Lessee Lease Description [Line Items]
Number of operating lease \| OperatingLease												1		1
Number of operating lease terminated \| OperatingLease			1
Estimated payments due	$ 35,200,000
Lease commencement date	Aug. 01, 2022
Operating lease, option to extend term	7 years
Letters of credit	$ 800,000
Maximum reimbursement cost	$ 500,000
Incurred of expenses related to expansion														$ 100,000
Reimbursed expenses														$ 100,000

Income Taxes - Additional Information (Details)	6 Months Ended
Income Taxes - Additional Information (Details)	Jun. 30, 2023 USD ($)
Income Tax Disclosure [Abstract]
Effective tax rate	0.00%
Unrecognized income tax benefits that would reduce effective tax rate if recognized	$ 0

Common Stock Warrants

6 Months Ended

Jun. 30, 2023

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 were re-measured to fair value at each balance sheet date. A total of 173,827 of the Series B Warrants were outstanding and were converted into warrants to purchase 12,686 shares of common stock with an exercise price of $17.03 upon the completion of the IPO in November 2021. As a result, the 12,686 common stock warrants were converted into equity instruments and remain outstanding as of June 30, 2023.