Aura Biosciences (AURA) 10-K 15 Mar 23 2022 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Mar. 10, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
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 Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
ICFR Auditor Attestation Flag	false
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 Annual Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		37,800,102
Auditor Name	Ernst & Young LLP
Auditor Location	Boston, Massachusetts
Auditor Firm ID	42
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant’s proxy statement for the 2023 annual meeting of stockholders to be filed pursuant to Regulation 14A within 120 days after the registrant’s fiscal year ended December 31, 2022, are incorporated by reference in Part III of this Form 10-K.
Entity Public Float			$ 280.1

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 121,582	$ 149,063
Marketable securities	67,229
Restricted cash and deposits	20	23
Prepaid expenses and other current assets	7,871	4,618
Total current assets	196,702	153,704
Restricted cash and deposits, net of current portion	768	125
Right of use assets - operating lease	20,671	950
Other long-term assets	423
Property and equipment, net	5,371	5,251
Total Assets	223,935	160,030
Current liabilities:
Accounts payable	2,921	2,401
Short-term operating lease liability	2,963	615
Accrued expenses and other current liabilities	4,573	4,339
Total current liabilities	10,457	7,355
Long-term operating lease liability	17,895	360
Total Liabilities	28,352	7,715
Commitments and Contingencies (Note 12)
Stockholders' Equity:
Common stock, $0.00001 par value, 150,000,000 authorized at December 31, 2022, and December 31, 2021, and 37,771,918 and 29,211,643 shares issued and outstanding at December 31, 2022, and December 31, 2021, respectively
Additional paid-in capital	406,555	304,452
Accumulated deficit	(210,900)	(152,137)
Accumulated other comprehensive loss	(72)
Total Stockholders' Equity	195,583	152,315
Total Liabilities, Convertible Preferred Stock, and Stockholders' Equity	$ 223,935	$ 160,030

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	37,771,918	29,211,643
Common stock, shares outstanding	37,771,918	29,211,643

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Operating Expenses:
Research and development	$ 42,238	$ 25,161
General and administrative	18,057	10,089
Total operating expenses	60,295	35,250
Total operating loss	(60,295)	(35,250)
Other income (expense):
Interest income, including amortization and accretion income	1,864	13
Realized loss on marketable securities	(9)
Loss on disposal of assets	(318)	(3)
Other expense	(5)
Total other income (expense)	1,532	(1)
Net loss	(58,763)	(35,251)
Net loss attributable to common stockholders - basic and diluted (Note 13)	$ (58,763)	$ (46,193)
Net loss per share attributable to common stockholders - basic	$ (1.96)	$ (8.95)
Net loss per share attributable to common stockholders - diluted	$ (1.96)	$ (8.95)
Weighted average common stock outstanding - basic	29,937,228	5,159,973
Weighted-average common stock outstanding - diluted	29,937,228	5,159,973
Comprehensive loss:
Net loss	$ (58,763)	$ (35,251)
Other comprehensive items:
Unrealized loss on marketable securities	(72)
Total other comprehensive loss	(72)
Total comprehensive loss	$ (58,835)	$ (35,251)

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	IPO	Follow-On Offering	ATM	Common Stock	Common Stock IPO	Common Stock Follow-On Offering	Common Stock ATM	Additional Paid-in Capital	Additional Paid-in Capital IPO	Additional Paid-in Capital Follow-On Offering	Additional Paid-in Capital ATM	Accumulated Deficit	Accumulated Other Comprehensive Loss Amount	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, 2020	$ (108,713)								$ 8,173				$ (116,886)
Convertible preferred stock, Beginning Balance at Dec. 31, 2020															$ 3,368	$ 7,837	$ 5,373	$ 20,806	$ 41,099	$ 49,593
Convertible preferred stock, Beginning Balance, Shares at Dec. 31, 2020															1,701,141	3,298,732	4,324,998	22,531,819	91,327,903	72,348,452
Beginning 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		$ 78,320								$ 78,320
Issuance of common stock, 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
Issuance of common stock			$ 86,650	$ 8,549							$ 86,650	$ 8,549
Issuance of common stock, Shares							7,705,000	732,189
Stock-based compensation expense	6,412								6,412
Vesting of restricted stock					51,444
Stock options exercises	430								430
Stock options exercises, Shares					71,642
Unrealized loss on marketable securities	(72)													$ (72)
Other	62								62
Net loss	(58,763)												(58,763)
Ending Balance at Dec. 31, 2022	$ 195,583								$ 406,555				$ (210,900)	$ (72)
Ending Balance, Shares at Dec. 31, 2022					37,771,918

Consolidated Statements of Co_2

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Follow-On Offering
Stock issuance cost, net	$ 263
ATM
Stock issuance cost, net	$ 336
Common Stock
Stock issuance cost, net		$ 2,247
Series D Convertible Preferred Stock
Stock issuance cost, net		18
Series E Convertible Preferred Stock
Stock issuance cost, net		$ 237

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (58,763)	$ (35,251)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	1,177	831
Stock-based compensation expense	6,412	2,307
Accretion on marketable securities	(527)
Gain (loss) on disposal of property and equipment	(22)	3
Other	224	15
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(3,253)	(3,575)
Other long-term assets	(423)
Accounts payable	340	1,054
Accrued expenses and other liabilities	234	2,206
Net cash used in operating activities	(54,601)	(32,410)
Cash flows from investing activities:
Purchases of property and equipment	(1,094)	(2,125)
Purchase of marketable securities	(119,784)
Maturities and proceeds from the sale of marketable securities	53,009
Net cash used in investing activities	(67,869)	(2,125)
Cash flows from financing activities:
Proceeds from issuance of common stock upon initial public offering, net of issuance costs		78,697
Proceeds from issuance of common stock from follow-on offering, net of issuance costs	86,650
Proceeds from issuance of common stock under ATM facility, net of issuance costs	8,549
Proceeds from exercise of stock options	430	349
Other		(15)
Net cash provided by financing activities	95,629	166,259
Net (decrease) increase in cash, cash equivalents and restricted cash	(26,841)	131,724
Cash, cash equivalents and restricted cash at beginning of period	149,211	17,487
Cash, cash equivalents and restricted cash at end of period	122,370	149,211
Supplemental disclosure of cash flow information:
Purchases of property and equipment in accounts payable and accrued expenses and other liabilities	180	386
Initial measurement of operating lease right-of-use assets and liabilities		536
Right-of-use assets obtained in exchange for operating lease liabilities	21,210	516
Remeasurement of operating lease right-of-use assets and liabilities for lease modification		390
Deferred offering costs in accounts payable		377
Loss on termination of operating lease	$ 296
Series D Convertible Preferred Stock
Cash flows from financing activities:
Proceeds from issuance of convertible preferred stock, net of issuance costs		6,982
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 Ca_2

Consolidated Statements of Cash Flows - Reconciliation of Cash, Cash Equivalents, and Restricted Cash - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents, end of period	$ 121,582	$ 149,063
Short-term restricted cash, end of period	20	23
Long-term restricted cash, end of period	768	125
Cash, cash equivalents and restricted cash at end of period	$ 122,370	$ 149,211

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2022
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 a 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 subsidiary 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. 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 tumor associated glycosaminoglycans with unique heparan sulphate epitopes that are 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. 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 (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 Through December 31, 2022, 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, through its IPO, follow-on offering and ATM transaction. 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 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. 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 $ 58.8 million and $ 35.3 million for the years ended December 31, 2022 and 2021, respectively. As of December 31, 2022, the Company had cash and cash equivalents and marketable securities of $ 188.8 million and an accumulated deficit of $ 210.9 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, 2022, 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.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
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, 2022, the restricted cash account is comprised of a $ 0.8 million security deposit held by the lessor for the Company’s operating lease, and a less than $ 0.1 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. Marketable Securities All marketable securities have original maturities greater than 90 days. The Company has classified its investments with maturities beyond one year as short-term, based on their highly liquid nature and because such marketable securities represent the investment of cash that is available for current operations. The Company considers its investment portfolio of marketable securities to be available-for-sale. Accordingly, these investments are recorded at fair value. Unrealized gains and losses are reported as the accumulated other comprehensive items in stockholders’ equity. Amortization and accretion of premiums and discounts are recorded in other income (expense) within the consolidated statements of operations and comprehensive loss. Realized gains or losses are included in interest income or interest expense, respectively. If any adjustment to fair value reflects a decline in value of the investment, the Company considers all available evidence such as industry, financial inputs, and capital markets data to evaluate the extent to which the decline is other than temporary and, if so, marks the investment to market on the Company’s consolidated statement of operations and comprehensive loss. 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 The shorter of the life of the leasehold improvement or the remaining term of the lease IT equipment 3 years Laboratory equipment 5 years Office furniture 7 years Costs for capital assets not yet placed into service are capitalized as assets under construction 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 impairments during the years ended December 31, 2022 or 2021. 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 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. 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, 2022 and 2021. 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, 2022, and 2021 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, follow-on offering and the ATM draw downs, these costs were recorded in stockholders' equity as a reduction of additional paid-in capital generated as a result of the financings. 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, 2022 , 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. 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 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. 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. Recently Adopted Accounting Pronouncements The Company assessed the recent accounting pronouncements for the year ended December 31, 2022 and determined no pronouncements have material impact to the consolidated financial statements. Accounting Pronouncements Not Yet Adopted 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 will be 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 does not expect adoption of this new guidance to have a material impact on its results of operations, financial condition, and financial statement disclosures.

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	12 Months Ended
	Dec. 31, 2022
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, 2022 and 2021 (in thousands): Description December 31, Quoted prices markets Significant Significant 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 $ — Description December 31, Quoted prices markets Significant Significant Financial assets Cash equivalents: Money market funds $ 24,063 $ 24,063 $ — $ — Total financial assets $ 24,063 $ 24,063 $ — $ — There have been no transfers between levels for the years ended December 31, 2022 and 2021.

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	4. Property and Equipment, Net P roperty and equipment, net, consisted of the following (in thousands): Year Ended December 31, 2022 2021 Assets under construction $ 1,805 $ 2,365 IT equipment 133 85 Leasehold improvements — 13 Lab equipment 7,297 5,489 Office furniture — 63 $ 9,235 $ 8,015 Less—accumulated depreciation ( 3,864 ) ( 2,764 ) Property and equipment, net $ 5,371 $ 5,251 Depreciation expense was $ 1.2 million and $ 0.8 million for the years ended December 31, 2022 and 2021, respectively.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2022
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid Expenses and Other Current Assets	5. Prepaid Expenses and Other Current Assets P repaid expenses and other current assets consisted of the following (in thousands): Year Ended December 31, 2022 2021 Prepaid insurance $ 2,174 $ 2,734 Prepaid research and development expenses 4,982 1,754 Prepaid license agreements 3 64 Other 712 66 Prepaid expenses and other current assets $ 7,871 $ 4,618

Marketable Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	6. Marketable Securities Marketable securities consist of the following (in thousands): December 31, 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 December 31, 2022, the unrealized losses on the Company’s investments in U.S. government agencies securities and corporate bonds 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 December 31, 2022, $ 0.1 million unrealized losses were associated with marketable securities with contractual maturities of one year or less. As of December 31, 2022, all marketable securities held by the Company had remaining contractual maturities of one year or less, except for corporate bonds and U.S. government agencies securities with a fair value of $ 4.2 million that had maturities of one to two years. There were no impairments of the Company’s assets measured and carried at fair value during the year ended December 31, 2022.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	7. Accrued Expenses and Other Current Liabilities A ccrued expenses and other current liabilities consisted of the following (in thousands): Year Ended December 31, 2022 2021 Accrued research and development expenses $ 1,543 $ 1,686 Accrued compensation 2,705 2,147 Other 325 506 Accrued expenses and other current liabilities $ 4,573 $ 4,339

Equity

Equity	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Equity	8. Equity The Company had 150,000,000 authorized shares of common stock, par value $ 0.00001 per share, of which 37,771,918 and 29,211,643 shares were issued and outstanding at December 31, 2022 and 2021, respectively. 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. 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 (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 (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 Agreement SM (the “Sales Agreement”) with Jefferies LLC (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 “at-the-market” offerings (the “ATM”) under the 2022 Shelf and subject to the limitations thereof. 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 Sales Agreement.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2022
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 (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 of Directors (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, 2022, the shares reserved for issuance was increased to 4,812,748 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, 2022, the shares reserved for issuance was increased to 627,333 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 December 31, 2022, 627,333 shares were available to be issued under the ESPP. The Company recognized $ 0.02 million share-based compensation expense related to the ESPP for the year ended December 31, 2022. Stock Options With the transfer of the available options from the 2018 Plan to the 2021 Plan, there were 3,387,895 options available for grant under the 2021 Plan at December 31, 2022. 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 year ended December 31, 2022: Options Weighted- Weighted- Aggregate Intrinsic Outstanding at December 31, 2021 4,232,991 $ 7.43 8.66 $ 40,437 Granted 544,321 15.81 Exercised ( 71,642 ) 6.00 Cancelled/Forfeited ( 402,334 ) 12.25 Outstanding at December 31, 2022 4,303,336 $ 8.06 7.92 $ 16,204 Exercisable at December 31, 2022 2,099,094 $ 6.10 7.08 $ 10,610 The weighted-average grant date fair value of stock options granted during the years ended December 31, 2022 and 2021 was $ 10.79 and $ 5.84 per share, respectively. The total intrinsic value of options exercised was $ 0.8 million and $ 0.1 million for the years ended December 31, 2022 and 2021, respectively. The fair value of the stock options issued as of December 31, 2022 and 2021 was measured with the following weighted-average assumptions: Year Ended December 31, 2022 2021 Risk-free interest rate 3.00 % 1.15 % Expected term (years) 5.91 6.03 Expected volatility of the underlying stock 78.10 % 73.87 % 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 unit activity during the year ended December 31, 2022 is as follows: Restricted Stock Units Weighted- Unvested at December 31, 2021 231,920 $ 14.00 Vested/Released ( 51,444 ) 14.00 Forfeited ( 26,526 ) 14.00 Unvested at December 31, 2022 153,950 $ 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 . During the year ended December 31, 2022, 51,444 restricted stock units vested with a fair value of $ 0.7 million. Stock-based Compensation Expense The Company recorded stock-based compensation expense as follows (in thousands): Year Ended December 31, 2022 2021 Research and development $ 2,389 $ 702 General and administrative 4,023 1,605 Total $ 6,412 $ 2,307 As of December 31, 2022, there was $ 13.5 million of unrecognized compensation expense related to stock options, which is expected to be recognized over a weighted-average period of 2.54 years. As of December 31, 2022, there was $ 2.0 million of unrecognized compensation expense related to restricted stock units, which is expected to be recognized over a weighted-average period of 2.82 years.

Common Stock Warrants

Common Stock Warrants	12 Months Ended
	Dec. 31, 2022
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 December 31, 2022 .

Compensation

Compensation	12 Months Ended
	Dec. 31, 2022
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 $ 0.5 million and $ 0.3 million for the years ended December 31, 2022 and 2021, respectively.

Commitment and Contingencies

Commitment and Contingencies	12 Months Ended
	Dec. 31, 2022
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 December 31, 2022 and one operating lease that was terminated in August 2022. On March 31, 2021, the Company executed an amendment to the previous facility lease in Cambridge, MA which included an extension of the expiration date of the original leased premises, the addition of 4,516 square feet of laboratory space with a commencement date of May 1, 2021 , and the addition of 1,000 square feet of laboratory space with a 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. In August 2022, the Company entered into a termination agreement with the landlord to the end this lease effective August 31, 2022, which resulted in the Company paying the landlord a termination expense of $ 0.3 million. The Company recognized a loss on the lease of $ 0.3 million which was recorded as a loss on disposal of assets on the statements of operations and comprehensive loss and derecognized $ 0.6 million in lease liabilities and corresponding right-of-use asset on the balance sheets. 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 December 31, 2022, the Company has incurred $ 0.1 million of expenses related to the expansion. The Company also leases office 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 years ended December 31, 2022 and 2021 (in thousands): Year Ended December 31, 2022 2021 Lease Cost Amortization of finance right-of-use assets $ — $ 11 Operating lease costs 1,879 524 Variable lease costs 1,258 322 Short-term lease costs 8 4 Total lease costs $ 3,145 $ 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 liabilities—operating leases $ 1,690 $ 519 Weighted-average remaining lease term—operating leases (years) 9.59 1.58 Weighted-average discount rate—finance leases — 7.94 % 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 December 31, 2022 (in thousands): Operating lease payments as of December 31, 2022 2023 $ 3,111 2024 3,205 2025 3,301 2026 3,400 2027 3,502 Thereafter 17,430 Total lease payments 33,949 Less: interest ( 13,091 ) Total operating lease liabilities at December 31, 2022 20,858 Less: current portion of lease liabilities 2,963 Lease liabilities, net of current portion $ 17,895 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 years ended December 31, 2022 and 2021. 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 years ended December 31, 2022 and 2021, the Company recognized immaterial 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 years ended December 31, 2022 and 2021, the Company recognized $ 0.05 million and $ 0.1 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 year ended December 31, 2022, the Company recognized $ 0.4 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 the years ended December 31, 2022 and 2021, the Company paid $ nil million and $ 0.03 million of 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 years ended December 31, 2022 and 2021. 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 year ended December 31, 2022, the Company recognized $ 0.1 million of 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 (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 $ 0.02 million and $ 0.03 million for patent licensing fees for the years ended December 31, 2022 and 2021, 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 December 31, 2022. 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 no t incur any expense in the years ended December 31, 2022 and 2021. 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. 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 no expenses related to this agreement and related amendments for the years ended December 31, 2022 and 2021.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2022
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 net loss per share for the years ended December 31, 2022 and 2021 as follows (in thousands, except share and per share data): Year Ended December 31, 2022 2021 Numerator: Net loss $ ( 58,763 ) $ ( 35,251 ) Less: Accruals of dividends of preferred stock — ( 10,942 ) Net loss attributable to common stockholders—basic and diluted $ ( 58,763 ) $ ( 46,193 ) Denominator: Weighted-average common stock outstanding 29,937,228 5,159,973 Net loss per share attributable to common stockholders—basic and diluted $ ( 1.96 ) $ ( 8.95 ) 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: Year Ended December 31, 2022 2021 Stock options to purchase common stock 4,303,336 4,232,991 Restricted stock units that vest into common stock 153,950 231,920 Warrants to purchase common stock 12,686 12,686 Total potential dilutive shares 4,469,972 4,477,597

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	14. Income Taxes The Company has no t 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, 2022 and 2021 is as follows: 2022 2021 Tax provision at statutory rate 21.0 % 21.0 % State taxes, net of federal benefit 5.6 % 5.3 % Federal tax credits 2.9 % 2.6 % Permanent items ( 1.1 )% ( 0.4 )% Other 0.1 % ( 0.3 )% Decrease in valuation reserve ( 28.5 )% ( 28.2 )% Total 0.0 % 0.0 % Temporary differences that give rise to significant deferred tax assets (liabilities) as of December 31, 2022 and 2021 are as follows (in thousands): 2022 2021 Deferred tax assets: Net operating loss carryforwards $ 40,617 $ 36,287 Stock-based compensation expense 1,235 635 Capitalized research and development expenses 10,200 — Tax credit carryforwards 7,924 5,821 Accrued expenses — 517 Lease liability 5,461 248 Other 307 194 Total deferred tax assets 65,744 43,702 Deferred tax liabilities: Right of use asset ( 5,412 ) ( 241 ) Depreciable assets ( 207 ) ( 182 ) Accrued expenses ( 93 ) — Valuation allowance ( 60,032 ) ( 43,279 ) Net deferred tax asset $ — $ — As of December 31, 2022, the Company had federal gross operating loss carryforwards of approximately $ 155.1 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 $ 110.9 million do not expire. The Company had state gross operating loss carryforwards of $ 127.5 million, which may be available to offset future taxable income and which would begin to expire in 2030 , except for $ 0.7 million of state NOLs that do not expire. As of December 31, 2022, the Company had federal and state research and experimentation credit carryforwards of $ 6.4 million and $ 1.9 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 balance sheet or statement of operations 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 $ 60.0 million has been recorded at December 31, 2022. The increase in the valuation allowance of $ 16.8 million during the year ended December 31, 2022 was primarily due to the increase in net operating loss generated by the Company and capitalized R&D expenses related to the new Section 174 requirements. Beginning in 2022, the Tax Cuts and Jobs Act of 2017 eliminated the option to deduct research and development expenditures currently and requires taxpayers to amortize them, over five years for domestically incurred expenditures and over fifteen years for foreign incurred expenditures, pursuant to Internal Revenue Code Section 174. As of December 31, 2022, the Company has recorded a gross deferred tax asset of $ 39.0 million related to the Capitalized IRC Section 174 expenditures. As of December 31, 2022 and 2021, 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. The Inflation Reduction Act signed into law on Aug. 16, 2022 and includes several provisions, including the largest investment in combating climate change in U.S. history, lowers the cost of prescription drugs and raises taxes on corporations. The effects of the bill were considered and based on the Company’s taxable loss position, there is no tax impact to the provision.

Related Parties

Related Parties	12 Months Ended
	Dec. 31, 2022
Related Party Transactions [Abstract]
Related Parties	15. Related Parties During the year ended December 31, 2021, the Company incurred $ 0.04 million in expenses to a legal firm whose partner is also an investor and former officer of the Company. As of December 31, 2021, this amount was no t included in accounts payable. During the year ended December 31, 2021, the Company incurred $ 0.3 million in expenses to a stockholder that provided research and development related services. As of December 31, 2021, this amount was no t included in accounts payable. During the year ended December 31, 2022, the Company had no related party transactions.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	16. Subsequent Events The Company has not identified any subsequent events that require disclosure.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	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	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	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 and Restricted Cash Cash consists of standard checking accounts. As of December 31, 2022, the restricted cash account is comprised of a $ 0.8 million security deposit held by the lessor for the Company’s operating lease, and a less than $ 0.1 million deposit that is collateral for the Company’s corporate credit card.
Cash Equivalents	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.
Marketable Securities	Marketable Securities All marketable securities have original maturities greater than 90 days. The Company has classified its investments with maturities beyond one year as short-term, based on their highly liquid nature and because such marketable securities represent the investment of cash that is available for current operations. The Company considers its investment portfolio of marketable securities to be available-for-sale. Accordingly, these investments are recorded at fair value. Unrealized gains and losses are reported as the accumulated other comprehensive items in stockholders’ equity. Amortization and accretion of premiums and discounts are recorded in other income (expense) within the consolidated statements of operations and comprehensive loss. Realized gains or losses are included in interest income or interest expense, respectively. If any adjustment to fair value reflects a decline in value of the investment, the Company considers all available evidence such as industry, financial inputs, and capital markets data to evaluate the extent to which the decline is other than temporary and, if so, marks the investment to market on the Company’s consolidated statement of operations and comprehensive loss.
Fair Value Measurements	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	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 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 The shorter of the life of the leasehold improvement or the remaining term of the lease IT equipment 3 years Laboratory equipment 5 years Office furniture 7 years Costs for capital assets not yet placed into service are capitalized as assets under construction 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	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 impairments during the years ended December 31, 2022 or 2021.
Research and Development	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	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	Leases 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. 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	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, 2022 and 2021. 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, 2022, and 2021 the Company had no accrued interest related to uncertain tax positions.
Deferred Offering Costs	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, follow-on offering and the ATM draw downs, these costs were recorded in stockholders' equity as a reduction of additional paid-in capital generated as a result of the financings.
Stock-Based Compensation	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, 2022 , 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.
Net Loss per Share	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 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.
Comprehensive Loss	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.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements The Company assessed the recent accounting pronouncements for the year ended December 31, 2022 and determined no pronouncements have material impact to the consolidated financial statements.
Accounting Pronouncements Not Yet Adopted	Accounting Pronouncements Not Yet Adopted 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 will be 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 does not expect adoption of this new guidance to have a material impact on its results of operations, financial condition, and financial statement disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2022
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 The shorter of the life of the leasehold improvement or the remaining term of the lease IT equipment 3 years Laboratory equipment 5 years Office furniture 7 years

Fair Value of Assets and Liab_2

Fair Value of Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	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, 2022 and 2021 (in thousands): Description December 31, Quoted prices markets Significant Significant 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 $ — Description December 31, Quoted prices markets Significant Significant Financial assets Cash equivalents: Money market funds $ 24,063 $ 24,063 $ — $ — Total financial assets $ 24,063 $ 24,063 $ — $ —

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment, Net	roperty and equipment, net, consisted of the following (in thousands): Year Ended December 31, 2022 2021 Assets under construction $ 1,805 $ 2,365 IT equipment 133 85 Leasehold improvements — 13 Lab equipment 7,297 5,489 Office furniture — 63 $ 9,235 $ 8,015 Less—accumulated depreciation ( 3,864 ) ( 2,764 ) Property and equipment, net $ 5,371 $ 5,251 Depreciation expense was $ 1.2 million and $ 0.8 million for the years ended December 31, 2022 and 2021, respectively.

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2022
Prepaid Expense and Other Assets, Current [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	repaid expenses and other current assets consisted of the following (in thousands): Year Ended December 31, 2022 2021 Prepaid insurance $ 2,174 $ 2,734 Prepaid research and development expenses 4,982 1,754 Prepaid license agreements 3 64 Other 712 66 Prepaid expenses and other current assets $ 7,871 $ 4,618

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Summary of Marketable Securities	Marketable securities consist of the following (in thousands): December 31, 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

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Summary of Accrued Expenses and Other Current Liabilities	ccrued expenses and other current liabilities consisted of the following (in thousands): Year Ended December 31, 2022 2021 Accrued research and development expenses $ 1,543 $ 1,686 Accrued compensation 2,705 2,147 Other 325 506 Accrued expenses and other current liabilities $ 4,573 $ 4,339

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2022
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 year ended December 31, 2022: Options Weighted- Weighted- Aggregate Intrinsic Outstanding at December 31, 2021 4,232,991 $ 7.43 8.66 $ 40,437 Granted 544,321 15.81 Exercised ( 71,642 ) 6.00 Cancelled/Forfeited ( 402,334 ) 12.25 Outstanding at December 31, 2022 4,303,336 $ 8.06 7.92 $ 16,204 Exercisable at December 31, 2022 2,099,094 $ 6.10 7.08 $ 10,610
Schedule of Fair Value of Stock Options, Valuation Assumptions	The fair value of the stock options issued as of December 31, 2022 and 2021 was measured with the following weighted-average assumptions: Year Ended December 31, 2022 2021 Risk-free interest rate 3.00 % 1.15 % Expected term (years) 5.91 6.03 Expected volatility of the underlying stock 78.10 % 73.87 % Expected dividend rate — % — %
Summary of Restricted Stock Unit Activity	A summary of the restricted stock unit activity during the year ended December 31, 2022 is as follows: Restricted Stock Units Weighted- Unvested at December 31, 2021 231,920 $ 14.00 Vested/Released ( 51,444 ) 14.00 Forfeited ( 26,526 ) 14.00 Unvested at December 31, 2022 153,950 $ 14.00
Summary of Stock-Based Compensation Expense	The Company recorded stock-based compensation expense as follows (in thousands): Year Ended December 31, 2022 2021 Research and development $ 2,389 $ 702 General and administrative 4,023 1,605 Total $ 6,412 $ 2,307

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2022
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 years ended December 31, 2022 and 2021 (in thousands): Year Ended December 31, 2022 2021 Lease Cost Amortization of finance right-of-use assets $ — $ 11 Operating lease costs 1,879 524 Variable lease costs 1,258 322 Short-term lease costs 8 4 Total lease costs $ 3,145 $ 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 liabilities—operating leases $ 1,690 $ 519 Weighted-average remaining lease term—operating leases (years) 9.59 1.58 Weighted-average discount rate—finance leases — 7.94 % 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 December 31, 2022 (in thousands): Operating lease payments as of December 31, 2022 2023 $ 3,111 2024 3,205 2025 3,301 2026 3,400 2027 3,502 Thereafter 17,430 Total lease payments 33,949 Less: interest ( 13,091 ) Total operating lease liabilities at December 31, 2022 20,858 Less: current portion of lease liabilities 2,963 Lease liabilities, net of current portion $ 17,895

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Summary of Basic and Diluted Net Loss Per Share	The Company has calculated basic and diluted net loss per share for the years ended December 31, 2022 and 2021 as follows (in thousands, except share and per share data): Year Ended December 31, 2022 2021 Numerator: Net loss $ ( 58,763 ) $ ( 35,251 ) Less: Accruals of dividends of preferred stock — ( 10,942 ) Net loss attributable to common stockholders—basic and diluted $ ( 58,763 ) $ ( 46,193 ) Denominator: Weighted-average common stock outstanding 29,937,228 5,159,973 Net loss per share attributable to common stockholders—basic and diluted $ ( 1.96 ) $ ( 8.95 )
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: Year Ended December 31, 2022 2021 Stock options to purchase common stock 4,303,336 4,232,991 Restricted stock units that vest into common stock 153,950 231,920 Warrants to purchase common stock 12,686 12,686 Total potential dilutive shares 4,469,972 4,477,597

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
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, 2022 and 2021 is as follows: 2022 2021 Tax provision at statutory rate 21.0 % 21.0 % State taxes, net of federal benefit 5.6 % 5.3 % Federal tax credits 2.9 % 2.6 % Permanent items ( 1.1 )% ( 0.4 )% Other 0.1 % ( 0.3 )% Decrease in valuation reserve ( 28.5 )% ( 28.2 )% 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, 2022 and 2021 are as follows (in thousands): 2022 2021 Deferred tax assets: Net operating loss carryforwards $ 40,617 $ 36,287 Stock-based compensation expense 1,235 635 Capitalized research and development expenses 10,200 — Tax credit carryforwards 7,924 5,821 Accrued expenses — 517 Lease liability 5,461 248 Other 307 194 Total deferred tax assets 65,744 43,702 Deferred tax liabilities: Right of use asset ( 5,412 ) ( 241 ) Depreciable assets ( 207 ) ( 182 ) Accrued expenses ( 93 ) — Valuation allowance ( 60,032 ) ( 43,279 ) Net deferred tax asset $ — $ —

Description of Business - Addit

Description of Business - Additional Information (Details) $ / shares in Units, $ in Thousands					12 Months Ended
	Dec. 05, 2022 USD ($) $ / shares shares	Nov. 01, 2022 USD ($)	Nov. 02, 2021 USD ($) $ / shares shares	Oct. 22, 2021	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) shares
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					$ 58,763	$ 35,251
Cash and cash equivalents and marketable securities					188,800
Accumulated deficit					210,900	152,137
Net proceeds from the IPO						$ 78,697
Aggregate offering price		$ 250,000
Proceeds from issuance of common stock					86,650
Initial Public Offering
Description Of Business [Line Items]
Share price | $ / shares			$ 14
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					$ 9,200
Common Stock | Initial Public Offering
Description Of Business [Line Items]
Shares issued and sold | shares			6,210,000			6,210,000
Common Stock | At-the-Market Offering
Description Of Business [Line Items]
Shares issued and sold | shares					732,189
Share price | $ / shares					$ 12.51
Common Stock | Follow-On Offering
Description Of Business [Line Items]
Shares issued and sold | shares	7,705,000				7,705,000
Share price | $ / shares	$ 12
Proceeds from issuance of common stock	$ 92,500
Net proceeds from follow-on offering	$ 86,700

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) Segment shares	Dec. 31, 2021 USD ($)	Jan. 01, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of operating segments | Segment	1
Security deposit held by lessor	$ 800,000
Reserves related to uncertain tax positions	0	$ 0
Accrued interest related to uncertain tax positions	$ 0	$ 0
Expected dividend yield	0%	0%
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Collateral deposit for corporate credit card	$ 100,000
Performance-based Awards
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of stock awards | 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

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives of Assets (Details)	12 Months Ended
	Dec. 31, 2022
Leasehold Improvements
Property Plant And Equipment [Line Items]
Estimated Useful Life	The shorter of the life of the leasehold improvement or the remaining term of the lease
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 Liab_3

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, 2022	Dec. 31, 2021
Assets
Financial assets	$ 185,811	$ 24,063
Money Market Funds
Assets
Financial assets	118,582	24,063
Commercial Paper
Assets
Financial assets	27,476
Corporate Bonds
Assets
Financial assets	18,099
U.S. Government Agencies
Assets
Financial assets	21,654
Level 1
Assets
Financial assets	118,582	24,063
Level 1 | Money Market Funds
Assets
Financial assets	118,582	$ 24,063
Level 2
Assets
Financial assets	67,229
Level 2 | Commercial Paper
Assets
Financial assets	27,476
Level 2 | Corporate Bonds
Assets
Financial assets	18,099
Level 2 | U.S. Government Agencies
Assets
Financial assets	$ 21,654

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 9,235	$ 8,015
Less—accumulated depreciation	(3,864)	(2,764)
Property and equipment, net	5,371	5,251
Assets Under Construction
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,805	2,365
IT Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	133	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	7,297	5,489
Office Furniture
Property Plant And Equipment [Line Items]
Property and equipment, gross		$ 63

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 1,177	$ 831

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid insurance	$ 2,174	$ 2,734
Prepaid research and development expenses	4,982	1,754
Prepaid license agreements	3	64
Other	712	66
Prepaid expenses and other current assets	$ 7,871	$ 4,618

Marketable Securities - Summary

Marketable Securities - Summary of Marketable Securities (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Marketable securities [Line items]
Amortized Cost	$ 67,302
Unrealized Gains	20
Unrealized Losses	(93)
Fair Value	67,229
Commercial Paper
Marketable securities [Line items]
Amortized Cost	27,476
Fair Value	27,476
Corporate Bonds
Marketable securities [Line items]
Amortized Cost	18,191
Unrealized Losses	(92)
Fair Value	18,099
U.S. Government Agencies
Marketable securities [Line items]
Amortized Cost	21,635
Unrealized Gains	20
Unrealized Losses	(1)
Fair Value	$ 21,654

Marketable Securities - Additio

Marketable Securities - Additional Information (Details)	12 Months Ended
	Dec. 31, 2022 USD ($)
Marketable Securities [Line Items]
Impairments of asset	$ 0
Unrealized losses of marketable securities with contractual maturities of one year or less	100,000
Corporate Bonds And U.S. Government Agencies Securities
Marketable Securities [Line Items]
Marketable securities fair value, maturities of one to two years	$ 4,200,000

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Accrued research and development expenses	$ 1,543	$ 1,686
Accrued compensation	2,705	2,147
Other	325	506
Accrued expenses and other current liabilities	$ 4,573	$ 4,339

Equity - Additional Information

Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands				12 Months Ended
	Dec. 05, 2022	Nov. 01, 2022	Nov. 02, 2021	Dec. 31, 2022	Dec. 31, 2021
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				37,771,918	29,211,643
Common stock, shares outstanding				37,771,918	29,211,643
Convertible preferred stock, shares authorized			10,000,000
Convertible preferred stock, par value			$ 0.00001
Proceeds from issuance of common stock				$ 86,650
Aggregate offering price		$ 250,000
Initial Public Offering
Class of Stock [Line Items]
Share price			$ 14
At-the-Market Offering
Class of Stock [Line Items]
Proceeds from issuance of common stock				$ 9,200
Sale of common stock through agreement		$ 75,000
Common Stock
Class of Stock [Line Items]
Number of common stock upon conversion of convertible preferred stock					22,550,561
Common Stock | Initial Public Offering
Class of Stock [Line Items]
Number of common stock upon conversion of convertible preferred stock			22,550,561
Shares issued and sold			6,210,000		6,210,000
Common Stock | Follow-On Offering
Class of Stock [Line Items]
Shares issued and sold	7,705,000			7,705,000
Share price	$ 12
Proceeds from issuance of common stock	$ 92,500
Net proceeds from follow-on offering	$ 86,700
Common Stock | At-the-Market Offering
Class of Stock [Line Items]
Shares issued and sold				732,189
Share price				$ 12.51

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2022	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	$ 10.79	$ 5.84
Total intrinsic value of options exercised	$ 800	$ 100
Unrecognized compensation expense related to stock options	$ 13,500
Unrecognized compensation expense weighted average period	2 years 6 months 14 days
Stock-based compensation expense	$ 6,412	$ 2,307
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense weighted average period	2 years 9 months 25 days
Unrecognized compensation expense related to restricted stock option	$ 2,000
Restricted stock units vesting increments	25%
Restricted stock units vesting duration	4 years
Number of awards vested	51,444
Restricted stock units vested with fair value	$ 700
2021 Stock Option and Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance			4,812,748	3,352,166
Common stock outstanding percentage	5%
Cumulative increase in shares of common stock	3,352,166
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance	627,333				335,217
Common stock outstanding percentage	1%
Number of shares available for future issuance	3,387,895
Percentage of the lower of the fair market value of common stock	85%
Stock-based compensation expense	$ 20

Stock-Based Compensation - Summ

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, 2022	Dec. 31, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Options Outstanding, Beginning balance	4,232,991
Options, Granted	544,321
Options, Exercised	(71,642)
Options, Cancelled/Forfeited	(402,334)
Options Outstanding, Ending balance	4,303,336	4,232,991
Options, Exercisable at December 31, 2022	2,099,094
Weighted Average Exercise Price, Beginning balance	$ 7.43
Weighted Average Exercise Price, Granted	15.81
Weighted Average Exercise Price, Exercised	6
Weighted Average Exercise Price, Cancelled/Forfeited	12.25
Weighted Average Exercise Price, Ending balance	8.06	$ 7.43
Weighted Average Exercise Price, Exercisable at December 31, 2022	$ 6.10
Weighted Average Remaining Contractual Term (years)	7 years 11 months 1 day	8 years 7 months 28 days
Weighted Average Remaining Contractual Term (years), Exercisable	7 years 29 days
Aggregate Intrinsic Value, Outstanding	$ 16,204	$ 40,437
Aggregate Intrinsic Value, Exercisable at December 31, 2022	$ 10,610

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Fair Value of Stock Options, Valuation Assumptions (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement [Abstract]
Risk-free interest rate	3%	1.15%
Expected term (years)	5 years 10 months 28 days	6 years 10 days
Expected volatility of the underlying stock	78.10%	73.87%
Expected dividend rate	0%	0%

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units	12 Months Ended
	Dec. 31, 2022 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unvested at December 31, 2021 | shares	231,920
Vested/Released, Restricted Stock Units | shares	(51,444)
Forfeited, Restricted Stock Units | shares	(26,526)
Unvested at December 31, 2022 | shares	153,950
Unvested at December 31, 2021, Weighted-Average Grant Date Fair Value | $ / shares	$ 14
Vested/Released, Weighted-Average Grant Date Fair Value | $ / shares	14
Forfeited, Weighted-Average Grant Date Fair Value | $ / shares	14
Unvested at December 31, 2022, Weighted- Average Grant Date Fair Value | $ / shares	$ 14

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Stock-Based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 6,412	$ 2,307
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	2,389	702
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 4,023	$ 1,605

Common Stock Warrants - Additio

Common Stock Warrants - Additional Information (Details) - Series B Warrants - Common Stock Warrants - $ / shares	1 Months Ended
	May 31, 2015	Feb. 28, 2015	Dec. 31, 2022	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

Compensation - Additional Infor

Compensation - Additional Information (Details) - 401(k) Plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Defined Contribution Plan Disclosure [Line Items]
Matching contribution by employer, percentage	100%
Employer matching contribution, percent of employees contribution	6%
Matching contributions from employer	$ 0.5	$ 0.3

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) € in Thousands

1 Months Ended

12 Months Ended

May 16, 2022 USD ($)

Mar. 31, 2021 ft²

Sep. 30, 2022 USD ($)

Aug. 31, 2022 USD ($) 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 ($)

Dec. 31, 2010 USD ($)

Nov. 30, 2009 EUR (€)

Dec. 31, 2022 USD ($) OperatingLease

Dec. 31, 2021 USD ($)

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

Recognized loss on lease

$ 296,000

Operating lease liabilities

20,858,000

Estimated payments due

33,949,000

Expenses related to license agreement

42,238,000

$ 25,161,000

Biologic Materials License Agreement

Lessee Lease Description [Line Items]

One time non refundable license issuance fee

$ 20,000

Milestone payments or royalties

$ 0

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

Expenses for Patent Licensing Fees

20,000

30,000

Patent licensing reimbursement fees

30,000

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]

Expenses

0

0

Upfront payment

$ 100,000

License agreement expiration period

10 years

Royalties on net sales

20%

Clearside | Maximum

Lessee Lease Description [Line Items]

Aggregate milestones payment

$ 21,000,000

Termination Agreement

Lessee Lease Description [Line Items]

Landlord termination expense

$ 300,000

Recognized loss on lease

(300,000)

Operating lease liabilities

600,000

LI-COR, Inc. | Exclusive License and Supply Agreement

Lessee Lease Description [Line Items]

One-time upfront license issuance fee

$ 100,000

Expenses related to license agreement

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

Expenses related to license agreement

100,000

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]

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

$ 500,000

$ 200,000

Expenses

50,000

100,000

One time perpetual license agreement fee

$ 50,000

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

Expense related to agreement including sublicense

400,000

Dr. John Schiller | 2014 Non- Exclusive Agreement

Lessee Lease Description [Line Items]

Required amendment payment

$ 40,000

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

Agreement term

2 years

First payment due

30 days

Subsequent payments due

30 days

Research collaboration fees

$ 0

$ 30,000

Required amendment payment

$ 40,000

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

$ 30,000

Required amendment payment due period

30 days

30 days

Office and Laboratory Facility

Lessee Lease Description [Line Items]

Number of operating lease | OperatingLease

1

Number of Operating Lease Terminated | OperatingLease

1

Lease commencement date

Aug. 01, 2022

Operating lease, option to extend term

7 years

Estimated payments due

$ 35,200,000

Letters of credit

800,000

Maximum reimbursement cost

500,000

Incurred of expenses related to expansion

$ 100,000

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Amortization of finance right-of-use assets		$ 11
Operating lease costs	$ 1,879	524
Variable lease costs	1,258	322
Short-term lease costs	8	4
Total lease costs	3,145	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	$ 1,690	$ 519
Weighted-average remaining lease term—operating leases (years)	9 years 7 months 2 days	1 year 6 months 29 days
Weighted-average discount rate—finance leases		7.94%
Weighted-average discount rate—operating leases	10.71%	3.51%

Commitments and Contingencies-

Commitments and Contingencies- Schedule of Fair Value of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
2023	$ 3,111
2024	3,205
2025	3,301
2026	3,400
2027	3,502
Thereafter	17,430
Total lease payments	33,949
Less: interest	(13,091)
Total operating lease liabilities at December 31, 2022	20,858
Less: current portion of lease liabilities	2,963	$ 615
Lease liabilities, net of current portion	$ 17,895	$ 360

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Numerator:
Net loss	$ (58,763)	$ (35,251)
Less: Accruals of dividends of preferred stock		(10,942)
Net loss attributable to common stockholders - basic and diluted	$ (58,763)	$ (46,193)
Denominator:
Weighted-average common stock outstanding - basic	29,937,228	5,159,973
Weighted-average common stock outstanding - diluted	29,937,228	5,159,973
Net loss per share attributable to common stockholders - basic	$ (1.96)	$ (8.95)
Net loss per share attributable to common stockholders - diluted	$ (1.96)	$ (8.95)

Net Loss Per Share - Summary _2

Net Loss Per Share - Summary of Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	4,469,972	4,477,597
Stock Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	4,303,336	4,232,991
Restricted Stock Units that Vest into Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	153,950	231,920
Warrants to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	12,686	12,686

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
Net tax provision	$ 0	$ 0
Federal net operating loss carryback percentage limited to income in any year	80%
Deferred tax assets, valuation allowance	$ 60,032,000	43,279,000
Increase in valuation allowance	16,800,000
Unrecognized tax benefits	0	$ 0
Gross deferred tax asset capitalized	39,000,000
Federal
Operating Loss Carryforwards [Line Items]
Gross operating loss carryforwards	155,100,000
Operating loss carryforwards not subject to expiration	$ 110,900,000
Research and development expenditures amortization period	5 years
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	$ 6,400,000
Tax credit carryforwards begin to expire period	2029
State
Operating Loss Carryforwards [Line Items]
Gross operating loss carryforwards	$ 127,500,000
Operating loss carryforwards not subject to expiration	$ 700,000
Operating loss carryforwards begin to expire period	2030
State | Research and Experimentation
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward	$ 1,900,000
Tax credit carryforwards begin to expire period	2028
Foreign
Operating Loss Carryforwards [Line Items]
Research and development expenditures amortization period	15 years

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Federal Statutory Income Tax Rate to Company's Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Tax provision at statutory rate	21%	21%
State taxes, net of federal benefit	5.60%	5.30%
Federal tax credits	2.90%	2.60%
Permanent items	(1.10%)	(0.40%)
Other	0.10%	(0.30%)
Decrease in valuation reserve	(28.50%)	(28.20%)
Total	0%	0%

Income Taxes - Summary of Defer

Income Taxes - Summary of Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Net operating loss carryforwards	$ 40,617	$ 36,287
Stock-based compensation expense	1,235	635
Capitalized research and development expenses	10,200
Tax credit carryforwards	7,924	5,821
Accrued expenses		517
Lease liability	5,461	248
Other	307	194
Total deferred tax assets	65,744	43,702
Deferred tax liabilities:
Right of use asset	(5,412)	(241)
Depreciable assets	(207)	(182)
Accrued expenses	(93)
Valuation allowance	$ (60,032)	$ (43,279)

Related Parties - Additional In

Related Parties - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Related Party Transaction [Line Items]
Related party transactions	$ 0
Stockholder
Related Party Transaction [Line Items]
Expenses incurred to related parties		$ 300,000
Accounts payable, related parties		0
Investor
Related Party Transaction [Line Items]
Expenses incurred to related parties		40,000
Accounts payable, related parties		$ 0