Inozyme Pharma (INZY) 10-Q 10 Nov 22 2022 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Nov. 07, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Entity Registrant Name	INOZYME PHARMA, INC.
Entity Central Index Key	0001693011
Entity Incorporation, State or Country Code	DE
Entity File Number	001-39397
Entity Tax Identification Number	38-4024528
Entity Address, Address Line One	321 Summer Street
Entity Address, Address Line Two	Suite 400
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02210
City Area Code	857
Local Phone Number	330-4340
Title of 12(b) Security	Common stock, par value $0.0001 per share
Trading Symbol	INZY
Security Exchange Name	NASDAQ
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		40,394,363

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 44,044	$ 23,316
Short-term investments	97,408	88,485
Prepaid expenses and other current assets	4,474	3,541
Total current assets	145,926	115,342
Property and equipment, net	2,197	2,383
Other assets	354	354
Right-of-use assets	1,734	2,053
Prepaid expenses, net of current portion	3,810	3,409
Total assets	154,021	123,541
Current liabilities:
Accounts payable	1,391	2,394
Accrued expenses	10,948	8,508
Operating lease liabilities	794	731
Total current liabilities	13,133	11,633
Operating lease liabilities, net of current portion	2,035	2,640
Long term debt, net	4,073
Total liabilities	19,241	14,273
Commitments and contingencies (Note 7)
Stockholders’ equity:
Preferred stock, $0.0001 par value - 5,000,000 shares authorized at September 30, 2022 and December 31, 2021; No shares issued and outstanding at September 30, 2022 or December 31, 2021
Common Stock, $0.0001 par value - 200,000,000 shares authorized at September 30, 2022 and December 31, 2021; 40,394,363 shares issued and outstanding at September 30, 2022 and 23,668,747 shares issued and outstanding at December 31, 2021	4	2
Additional paid in-capital	331,470	256,948
Accumulated other comprehensive (loss) income	(477)	18
Accumulated deficit	(196,217)	(147,700)
Total stockholders’ equity	134,780	109,268
Total liabilities and stockholders’ equity	$ 154,021	$ 123,541

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (Unaudited) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	40,394,363	23,668,747
Common stock, shares outstanding	40,394,363	23,668,747

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating expenses:
Research and development	$ 12,191	$ 9,346	$ 34,012	$ 24,169
General and administrative	4,721	4,916	15,130	13,720
Total operating expenses	16,912	14,262	49,142	37,889
Loss from operations	(16,912)	(14,262)	(49,142)	(37,889)
Other income (expense):
Interest income	737	47	1,118	168
Other expenses	(197)	(65)	(493)	(149)
Other income, net	540	(18)	625	19
Net loss	(16,372)	(14,280)	(48,517)	(37,870)
Other comprehensive (loss) income:
Unrealized (losses) gains on available-for-sale securities	(60)	(6)	(417)	10
Foreign currency translation adjustment	(20)	(9)	(78)	(9)
Total other comprehensive (loss) income	(80)	(15)	(495)	1
Comprehensive loss	(16,452)	(14,295)	(49,012)	(37,869)
Net loss attributable to common stockholders—basic and diluted	$ (16,372)	$ (14,280)	$ (48,517)	$ (37,870)
Net loss per share attributable to common stockholders- basic	$ (0.38)	$ (0.60)	$ (1.36)	$ (1.61)
Net loss per share attributable to common stockholders- diluted	$ (0.38)	$ (0.60)	$ (1.36)	$ (1.61)
Weighted-average common shares and pre-funded warrants outstanding - basic	43,657,718	23,643,494	35,755,695	23,521,981
Weighted-average common shares and pre-funded warrants outstanding - diluted	43,657,718	23,643,494	35,755,695	23,521,981

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance at Dec. 31, 2020	$ 158,103	$ 2	$ 249,175	$ 2	$ (91,076)
Balance, shares at Dec. 31, 2020		23,384,969
Stock-based compensation	1,577		1,577
Exercise of stock options	249		249
Exercise of stock options, shares		88,734
Comprehensive loss:
Unrealized loss on investments	10			10
Net loss	(11,050)				(11,050)
Balance at Mar. 31, 2021	148,889	$ 2	251,001	12	(102,126)
Balance, shares at Mar. 31, 2021		23,473,703
Balance at Dec. 31, 2020	158,103	$ 2	249,175	2	(91,076)
Balance, shares at Dec. 31, 2020		23,384,969
Comprehensive loss:
Net loss	(37,870)
Balance at Sep. 30, 2021	125,974	$ 2	254,915	3	(128,946)
Balance, shares at Sep. 30, 2021		23,664,747
Balance at Dec. 31, 2020	158,103	$ 2	249,175	2	(91,076)
Balance, shares at Dec. 31, 2020		23,384,969
Comprehensive loss:
Net loss	(56,600)
Balance at Dec. 31, 2021	109,268	$ 2	256,948	18	(147,700)
Balance, shares at Dec. 31, 2021		23,668,747
Balance at Mar. 31, 2021	148,889	$ 2	251,001	12	(102,126)
Balance, shares at Mar. 31, 2021		23,473,703
Stock-based compensation	1,813		1,813
Exercise of stock options	106		106
Exercise of stock options, shares		96,890
Comprehensive loss:
Unrealized loss on investments	6			6
Net loss	(12,540)				(12,540)
Balance at Jun. 30, 2021	138,274	$ 2	252,920	18	(114,666)
Balance, shares at Jun. 30, 2021		23,570,593
Stock-based compensation	1,752		1,752
Exercise of stock options	243		243
Exercise of stock options, shares		94,154
Comprehensive loss:
Unrealized loss on investments	(6)			(6)
Foreign currency translation adjustment	(9)			(9)
Net loss	(14,280)				(14,280)
Balance at Sep. 30, 2021	125,974	$ 2	254,915	3	(128,946)
Balance, shares at Sep. 30, 2021		23,664,747
Balance at Dec. 31, 2021	109,268	$ 2	256,948	18	(147,700)
Balance, shares at Dec. 31, 2021		23,668,747
Stock-based compensation	1,752		1,752
Exercise of stock options	240		240
Exercise of stock options, shares		149,664
Comprehensive loss:
Unrealized loss on investments	(132)			(132)
Foreign currency translation adjustment	(15)			(15)
Net loss	(16,884)				(16,884)
Balance at Mar. 31, 2022	94,229	$ 2	258,940	(129)	(164,584)
Balance, shares at Mar. 31, 2022		23,818,411
Balance at Dec. 31, 2021	$ 109,268	$ 2	256,948	18	(147,700)
Balance, shares at Dec. 31, 2021		23,668,747
Exercise of stock options, shares	210,977
Comprehensive loss:
Net loss	$ (48,517)
Balance at Sep. 30, 2022	134,780	$ 4	331,470	(477)	(196,217)
Balance, shares at Sep. 30, 2022		40,394,363
Balance at Mar. 31, 2022	94,229	$ 2	258,940	(129)	(164,584)
Balance, shares at Mar. 31, 2022		23,818,411
Stock-based compensation	2,185		2,185
Issuance of common stock, net of issuance costs	56,137	$ 2	56,135
Issuance of common stock, net of issuance costs, shares		16,276,987
Issuance of pre-funded warrants, net of issuance costs	12,150		12,150
Exercise of stock options	4		4
Exercise of stock options, shares		1,678
Comprehensive loss:
Unrealized loss on investments	(225)			(225)
Foreign currency translation adjustment	(43)			(43)
Net loss	(15,261)				(15,261)
Balance at Jun. 30, 2022	149,176	$ 4	329,414	(397)	(179,845)
Balance, shares at Jun. 30, 2022		40,097,076
Stock-based compensation	1,849		1,849
Exercise of stock options	115		115
Exercise of stock options, shares		59,635
Exercise of pre-funded warrants		197,240
Shares purchased in Employee Stock Purchase Plan	92		92
Shares purchased in Employee Stock Purchase Plan, Shares		40,412
Comprehensive loss:
Unrealized loss on investments	(60)			(60)
Foreign currency translation adjustment	(20)			(20)
Net loss	(16,372)				(16,372)
Balance at Sep. 30, 2022	$ 134,780	$ 4	$ 331,470	$ (477)	$ (196,217)
Balance, shares at Sep. 30, 2022		40,394,363

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating activities
Net loss	$ (48,517)	$ (37,870)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	546	492
Loss on disposal of fixed assets	4	0
Stock-based compensation expense	5,786	5,142
Amortization of premiums and discounts on marketable securities	(1,082)	146
Reduction in the carrying value of right-of-use assets	319	279
Non-cash interest expense and amortization of debt issuance costs	27
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(933)	(2,014)
Accounts payable	(1,003)	(2,482)
Accrued expenses	2,435	942
Operating lease liabilities	(542)	(457)
Prepaid expenses - noncurrent	(401)	1,113
Net cash used in operating activities	(43,361)	(34,709)
Investing activities
Purchases of marketable securities	(126,007)	(104,994)
Maturities of marketable securities	117,750	138,660
Purchases of property and equipment	(364)	(357)
Net cash (used in) provided by investing activities	(8,621)	33,309
Financing activities
Net proceeds from issuance of common stock	56,137
Net proceeds from issuance of pre-funded warrants	12,150
Net proceeds from issuance of long-term debt	4,050
Proceeds from exercise of stock options	359	598
Proceeds from issuance of common stock for cash under employee stock purchase plan	92
Net cash provided by financing activities	72,788	598
Net increase (decrease) in cash, cash equivalents and restricted cash	20,806	(802)
Effect of foreign currency exchange rate in cash	(78)	(9)
Cash, cash equivalents and restricted cash at beginning of period	23,670	28,394
Cash, cash equivalents and restricted cash at end of period	44,398	27,583
Supplemental cash flow information:
Cash and cash equivalents	44,044	27,229
Restricted cash	354	354
Cash, cash equivalents and restricted cash at end of period	44,398	27,583
Property and equipment unpaid at end of period	0	78
Right-of-use asset at adoption of Topic 842	0	2,431
Operating lease liabilities at adoption of Topic 842	$ 0	$ 3,997

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	1. Organization an d Basis of Presentation Inozyme Pharma, Inc. (the “Company”) is a clinical-stage rare disease biopharmaceutical company developing novel therapeutics for the treatment of diseases impacting the vasculature, soft tissue and skeleton. The Company is pursuing the development of therapeutics to address the underlying causes of these debilitating diseases. It is well established that two genes, ENPP1 and ABCC6, play key roles in a critical pathway and that defects in these genes lead to pathologic mineralization and intimal proliferation. The Company is initially focused on developing a novel therapy to treat rare genetic diseases of ENPP1 Deficiency and ABCC6 Deficiency. The Company’s lead product candidate, INZ-701, is a soluble, recombinant, or genetically engineered, fusion protein that is designed to correct defects in a pathway involving ENPP1 and ABCC6 Deficiencies. This pathway is central to the regulation of calcium deposition throughout the body and is further associated with intimal proliferation leading to a narrowing of blood vessels. Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles ("U.S. GAAP") for interim financial information. Accordingly, these unaudited condensed consolidated financial statements do not include all of the information and note disclosures required by U.S. GAAP for audited year-end financial statements. The accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments that are, in the opinion of management, necessary for a fair presentation of the interim period results. The results for the three and nine month periods ended September 30, 2022 are not necessarily indicative of results to be expected for the year ending December 31, 2022, any other interim periods, or any future year or period. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2021. Any reference in these notes to applicable guidance is meant to refer to authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). Liquidity, Capital Resources, and Going Concern Since the Company’s incorporation in 2017 and through September 30, 2022, the Company has devoted substantially all of its efforts to raising capital, building infrastructure, developing intellectual property and conducting research and development activities. The Company incurred net losses of $ 48.5 million in the nine months ended September 30, 2022 and $ 56.6 million in the year ended December 31, 2021 and had an accumulated deficit of $ 196.2 million as of September 30, 2022. The Company had cash, cash equivalents, and short-term investments of $ 141.5 million as of September 30, 2022. The Company has incurred recurring losses and negative cash flows from operations since inception and has primarily funded its operations with proceeds from the issuance of convertible preferred stock, offerings of common stock and pre-funded warrants and the Loan Agreement (see Note 8). The Company expects its operating losses and negative operating cash flows to continue into the foreseeable future as it continues to expand its research and development efforts. The accompanying condensed consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets, and the satisfaction of liabilities and commitments in the ordinary course of business. The Company believes its available cash, cash equivalents, and short-term investments as of September 30, 2022 will be sufficient to fund its cash flow requirements for at least twelve months from the date of filing this Quarterly Report on Form 10-Q. Management’s expectations with respect to its ability to fund current and long term planned operations are based on estimates that are subject to risks and uncertainties. If actual results are different from management’s estimates, the Company may need to seek additional strategic or financing opportunities sooner than would otherwise be expected. However, there is no guarantee that any of these strategic or financing opportunities will be executed on favorable terms, or at all, and some could be dilutive to existing stockholders. If the Company is unable to obtain additional funding on a timely basis, it may be forced to delay, reduce or eliminate some or all of its research and development programs, portfolio expansion or commercialization efforts, which could adversely affect its business.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Principles of Consolidation The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries, Inozyme Securities Corp., which is a Massachusetts subsidiary created to buy, sell, and hold securities, Inozyme Ireland Limited, and Inozyme Pharma Switzerland GmbH. All intercompany transactions and balances have been eliminated. Summary of Significant Accounting Policies The significant accounting policies and estimates used in the preparation of the accompanying consolidated financial statements are described in the Company’s audited consolidated financial statements for the year ended December 31, 2021 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021. The Company adopted a warrant accounting policy detailed below following the closing of the Company's underwritten offering in April 2022 and a debt and debt issuance costs accounting policy following the closing of the Loan Agreement in July 2022. Apart from these adoptions, there have been no material changes in the Company’s significant accounting policies during the nine months ended September 30, 2022 . Use of Estimates The preparation of the Company’s financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Estimates and judgments are based on historical information and other market-specific or various relevant assumptions, including, in certain circumstances, future projections that management believes to be reasonable under the circumstances. Actual results could differ materially from estimates. Significant estimates and assumptions are used for, but not limited to, the accruals for research and development expenses. The Company evaluates its estimates and assumptions on an ongoing basis. All revisions to accounting estimates are recognized in the period in which the estimates are revised and in any future periods affected. Accrued Research and Development Costs The Company records accrued liabilities for estimated costs of research and development activities conducted by service providers for sponsored research, preclinical studies, clinical trials, and contract manufacturing activities. The Company records the estimated costs of research and development activities based upon the estimated amount of services provided but not yet invoiced and includes these costs in accrued expenses in the accompanying condensed consolidated balance sheets and within research and development expense in the accompanying condensed consolidated statements of operations and comprehensive loss. The Company accrues for these costs based on factors such as estimates of the work completed and in accordance with agreements established with service providers. The Company makes significant judgments and estimates in determining the accrued liabilities balance in each reporting period. As actual costs become known, the Company adjusts its accrued liabilities. The Company has not experienced any material differences between accrued costs and actual costs incurred since its inception. Research and Development Costs Research and development costs are expensed as incurred. Research and development costs consist of direct and indirect internal costs related to specific projects as well as fees paid to other entities that conduct certain research and development activities on the Company’s behalf. Net Loss Per Share The Company follows the two-class method when computing net loss allocable to common securities per share as the Company had previously issued shares that meet the definition of participating securities. The two-class method requires a portion of net income to be allocated to the participating securities to determine net income allocable to the common securities. During periods of loss, there is no allocation required under the two-class method since the participating securities do not have a contractual obligation to fund the losses of the Company. Basic net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock and pre-funded warrants outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock and pre-funded warrants and potentially dilutive securities outstanding using the treasury-stock and if-converted methods. The Company has generated a net loss in all periods presented, therefore the basic and diluted net loss per share attributable to common stockholders are the same as the inclusion of the potentially dilutive securities would be anti-dilutive. Fair Value Measurements The Company categorizes its assets and liabilities measured at fair value in accordance with the authoritative accounting guidance that establishes a consistent framework for measuring fair value and expands disclosures for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as the 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 such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: • Level 1- Unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets or liabilities; • Level 2- Quoted prices for similar assets and liabilities in active markets, quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability; or • Level 3- Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). Concentration of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and short-term investments and, from time to time, long-term investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits and limits its exposure to credit risk by placing its cash with high credit quality financial institutions. The Company’s investments are comprised of U.S. Treasury securities and commercial paper of corporations. The Company mitigates credit risk by maintaining a diversified portfolio and limiting the amount of investment exposure as to institution, maturity and investment type. The Company has no significant off-balance sheet risk such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Debt and Debt Issuance Costs Debt issuance costs and the Lender Expenses (see Note 8) are presented on the condensed consolidated balance sheet as a direct deduction from the related debt liability. Debt issuance costs represent legal and other direct costs incurred in connection with the Company’s term loan under the Loan Agreement. These costs are amortized as a non-cash component of interest expense using the effective interest method over the term of the loan. Any final payments are included in the cash flows to determine the effective interest rate and are recognized using the effective interest method over the term of the loan. Warrants The Company determines the accounting classification of warrants that are issued, as either liability or equity, by first assessing whether the warrants meet liability classification in accordance with ASC 480-10, Accounting for Certain Financial Instruments with Characteristics of Both Liabilities and Equity , and then in accordance with ASC 815-40, Accounting for Derivative Financial Instruments Indexed to, and Potentially Settled in, a Company’s Own Stock . Under ASC 480-10, warrants are considered liability classified if the warrants are mandatorily redeemable, obligate the issuer to settle the warrants or the underlying shares by paying cash or other assets, or must or may require settlement by issuing variable number of shares. If warrants do not meet liability classification under ASC 480-10, the Company assesses the requirements under ASC 815-40, which states that contracts that require or may require the issuer to settle the contract for cash are liabilities recorded at fair value, irrespective of the likelihood of the transaction occurring that triggers the net cash settlement feature. If the warrants do not require liability classification under ASC 815-40, in order to conclude equity classification, the Company assesses whether the warrants are indexed to its common stock and whether the warrants are classified as equity under ASC 815-40 or other applicable U.S. GAAP. After all relevant assessments are made, the Company concludes whether the warrants are classified as liability or equity. Liability classified warrants are required to be accounted for at fair value both on the date of issuance and on subsequent accounting period ending dates, with all changes in fair value after the issuance date recorded in the statements of operations as a gain or loss. Equity classified warrants are accounted for at fair value on the issuance date with no changes in fair value recognized after the issuance date.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2022
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	3. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption. Recently Issued and Adopted Accounting Standards In December 2019, the FASB issued ASU 2019-12, Income Taxes – Simplifying the Accounting for Income Taxes . The new guidance simplifies the accounting for income taxes by removing several exceptions in the current standard and adding guidance to reduce complexity in certain areas, such as requiring that an entity reflect the effect of an enacted change in tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date. The Company adopted this standard effective January 1, 2022. There was no material impact to the Company's financial statements upon adoption. In August 2020, the FASB issued ASU 2020-06, Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40) . ASU 2020-06 simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity’s own equity. The Company elected to early adopt this standard effective January 1, 2022. There was no material impact to the Company's financial statements upon adoption. Recently Issued Accounting Standards 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 . ASU 2016-13 and its subsequent related updates establish a new forward-looking “expected loss model” that requires entities to estimate current expected credit losses on accounts receivable and financial instruments by using all practical and relevant information. The new standard and its subsequent related updates are effective for the Company for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, with early adoption permitted. The Company is currently assessing the impact that adopting this standard will have on its consolidated financial statements but does not expect it to be material.

Balance Sheet Details

Balance Sheet Details	9 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Details	4. Balance Sheet Details Short-term investments consisted of the following (dollar amounts in thousands): September 30, 2022 Description Maturity Amortized Gross Gross Estimated Commercial paper 1 year or less $ 74,935 $ — $ ( 231 ) $ 74,704 U.S. Treasury securities 1 year or less 22,887 — ( 183 ) $ 22,704 $ 97,822 $ — $ ( 414 ) $ 97,408 December 31, 2021 Description Maturity Amortized Gross Gross Estimated Commercial paper 1 year or less $ 78,456 $ 5 $ ( 3 ) $ 78,458 U.S. Treasury securities 1 year or less 5,025 — — 5,025 U.S. government agency debt securities 1 year or less 5,002 — — 5,002 $ 88,483 $ 5 $ ( 3 ) $ 88,485 The Company concluded that the declines in market value of available-for-sale securities were temporary in nature and did not consider any of the investments to be other-than-temporarily impaired. In accordance with its investment policy, the Company invests in investment grade securities with high credit quality issuers, and generally limits the amount of credit exposure to any one issuer. The Company evaluates securities for other-than-temporary impairment at the end of each reporting period. Impairment is evaluated considering numerous factors, and their relative significance varies depending on the situation. Factors considered include the length of time and extent to which fair value has been less than the cost basis, the financial condition and near-term prospects of the issuer, and the Company’s intent and ability to hold the investment to allow for an anticipated recovery in fair value. Furthermore, the aggregate of individual unrealized losses that had been outstanding for 12 months or less was not significant as of September 30, 2022 and December 31, 2021. The Company does not intend to sell these investments and it is not more likely than not that the Company will be required to sell the investments before a recovery of their amortized cost bases, which may be maturity. The Company also believes that it will be able to collect both principal and interest amounts due at maturity. Prepaid expenses and other current assets consisted of the following (dollar amounts in thousands): At September 30, At December 31, Interest receivable $ 96 $ 62 Prepaid insurance 1,897 1,728 Prepaid research studies 1,643 1,190 Prepaid other 838 561 Total $ 4,474 $ 3,541 Prepaid expenses, net of current portion, consisted of the following (dollar amounts in thousands): At September 30, At December 31, Prepaid clinical trial and other $ 3,810 $ 3,409 $ 3,810 $ 3,409 Property and equipment consisted of the following (dollar amounts in thousands): At September 30, At December 31, Laboratory equipment and manufacturing equipment $ 806 $ 591 Furniture and fixtures 258 258 Computer equipment and software 571 440 Leasehold improvements 2,095 2,095 3,730 3,384 Less accumulated depreciation ( 1,533 ) ( 1,001 ) Total $ 2,197 $ 2,383 Depreciation expense for the three months ended September 30, 2022 and 2021 was $ 189 thousand and $ 167 thousand, respectively. Depreciation expense for the nine months ended September 30, 2022 and 2021 was $ 546 thousand and $ 492 thousand, respectively. Accrued expenses consi sted of the following (dollar amounts in thousands): At September 30, At December 31, Payroll and related liabilities $ 2,263 $ 2,379 Professional fees 524 727 Research and development costs 7,649 5,066 Other 512 336 Total $ 10,948 $ 8,508 The Company had $ 0.4 million of restricted cash at September 30, 2022 and September 30, 2021 . This amount is included in the "other assets" line item on the balance sheets.

Fair Value Measurement

Fair Value Measurement	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurement	5. Fair Value Measurement The following tables represent the Company’s financial assets measured at fair value on a recurring basis and indicate the level of fair value hierarchy utilized to determine such fair values (in thousands): Fair Value Measurements at Reporting Date Description September 30, Quoted Significant Significant Assets: Money market funds (included in cash and cash $ 38,936 $ 38,936 $ — $ — Commercial paper (including amounts in cash and cash equivalents) 77,688 — 77,688 — U.S. Treasury securities 22,704 22,704 — — Total assets $ 139,328 $ 61,640 $ 77,688 $ — Fair Value Measurements at Reporting Date Description December 31, Quoted Significant Significant Assets: Money market funds (included in cash and cash $ 14,302 $ 14,302 $ — $ — Commercial paper 78,457 — 78,457 — U.S. Treasury securities 5,026 5,026 — — U.S. government agency debt securities 5,002 — 5,002 — Total assets $ 102,787 $ 19,328 $ 83,459 $ — There have been no transfers between fair value levels during the three or nine months ended September 30, 2022 .

License and Sponsored Research

License and Sponsored Research Agreements	9 Months Ended
	Sep. 30, 2022
Research and Development [Abstract]
License and Sponsored Research Agreements	6. License and Sponsored Research Agreements In January 2017, the Company entered into a license agreement with Yale University (“Yale”), which was amended in May 2020 and July 2020, under which the Company licensed certain intellectual property related to ectonucleotide pyrophosphatase/phosphodiesterase enzymes that is the basis for the Company’s INZ-701 development program. Pursuant to the license agreement, as partial upfront consideration, the Company made a payment of approximate ly $ 0.1 mill ion to Yale, which amount reflected unreimbursed patent expenses incurred by Yale prior to the date of the license agreement. The Company is responsible for paying Yale an annual license maintenance fee in varying amounts throughout the term ranging from the low tens of thousands of dollars to the high tens of thousands of dollars. As of September 30, 2022, the Company incurred a total of $ 0.2 m illion in license maintenance fees to Yale. The Company is required to pay Yale up to $ 3.0 million, based on the achievement of a specified net product sales milestone or specified development and commercialization milestones, for each therapeutic and prophylactic licensed product develope d. In January 2022, the Company paid Yale an approximately $ 0.3 million milestone payment following dosing of the first patient in Company’s Phase 1/2 clinical trial of INZ-701 in adult patients with ENPP1 Deficiency in November 2021. In March 2022, the Company paid Yale an approximately $ 0.3 million milestone payment following completion of the first cohort of the Company's Phase 1/2 clinical trial of INZ-701 in adult patients with ENPP1 Deficiency in January 2022. In addition, the Company is required to pay Yale an amount in the several hundreds of thousands of dollars, based on the achievement of a specified net product sales milestone or specified development and commercialization milestones, for each diagnostic licensed product developed. While the agreement remains in effect, the Company is required to pay Yale low singl e-digit percentage royalties on aggregate worldwide net sales of certain licensed products. Yale is guaranteed a minimum royalty payment amount (ranging in dollar amounts from the mid six figures to low seven figures) for each year after the first sale of a therapeutic or prophylactic licensed product that results in net sales. Yale is guaranteed a minimum royalty payment amount (ranging from the low tens of thousands of dollars to the mid tens of thousands of dollars) for each year after the first sale of a diagnostic licensed product that results in net sales. The Company must also pay Yale a percentage in the twenties of certain types of income it receives from sublicensees. The Company is also responsible for costs relating to the prosecution and maintenance of the licensed patents. Finally, subject to certain conditions, all payments due by the Company to Yale will be tripled following any patent challenge or challenge to a claim by Yale that a product is a licensed product under the agreement, made by the Company against Yale if Yale prevails in such challenge. In January 2017, the Company also entered into a corporate sponsored research agreement with Yale (the "Sponsored Research Agreement"), which was amended in February 2019, under which the Company agreed to provide research support funding in the aggregate amount of $ 2.4 million over the five year period from contract inception through December 2021 . The Sponsored Research Agreement was amended in February 2022, under which the contract was extended through June 30, 2022 subject to the terms of the existing agreement. The Sponsored Research Agreement was amended again in May 2022, under which the contract was extended through April 2023 with approximately $ 0.1 million of Company-provided research sup port funding for such extended period. The Company recorded research and development expenses associated with this arrangement of less than $ 0.1 million and approximately $ 0.1 million in the three and nine months ended September 30, 2022, respectively, and $ 0.1 million and $ 0.4 million in the three and nine months ended September 30, 2021, respectively.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies Operating Leases The Company held the following significant operating leases of office and laboratory space as of September 30, 2022: • An operating lease for 8,499 square feet of office space in Boston, Massachusetts that expires in 2025 , with an option to extend the term for five years ; and • An operating lease for 6,244 square feet of laboratory space in Boston, Massachusetts that expires in 2025 . During the nine months ended September 30, 2022 , cash paid for amounts included in the measurement of lease liabilities was $ 0.6 million and the Company recorded operating lease expense of $ 0.5 million. Future lease payments under non-cancelable leases as of September 30, 2022 are as follows (dollar amounts in thousands): Year Ending December 31, 2022 (remaining 3 months) $ 243 2023 992 2024 1,016 2025 944 Thereafter — $ 3,195 Indemnification Agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters arising out of the relationship between such parties and the Company. In addition, the Company has entered into indemnification agreements with members of its board of directors and senior management that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company is not aware of any claims under indemnification arrangements, and it has not accrued any liabilities related to such obligations as of September 30, 2022 or December 31, 2021. Legal Proceedings The Company is not currently a party to any material legal proceedings. At each reporting date, the Company evaluates whether or not a potential loss amount or a potential range of loss is probable and reasonably estimable under the provisions of the authoritative guidance that addresses accounting for contingencies. The Company expenses the costs related to its legal proceedings as they are incurred. No such costs have been incurred during the three and nine months ended September 30, 2022 and 2021 .

Convertible Debt

Convertible Debt	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Convertible Debt	8. Convertible Debt Loan Agreement with K2 HealthVentures LLC On July 25, 202 2, the Company, as borrower, entered into a loan and security agreement (the “Loan Agreement”) with K2 HealthVentures LLC (“K2HV”, together with any other lender from time to time, the “Lenders”), K2HV, as administrative agent for the Lenders, and Ankura Trust Company, LLC, as collateral agent for the Lenders. The Loan Agreement provides up to $ 70.0 million principal in term loans, subject to certain customary conditions. The Company received $ 5.0 million from the first tranche commitment upon closing. The first tranche commitment contains an additional $ 20.0 million available to be drawn at the Company’s option though March 31, 2023. Two subsequent tranche commitments totaling $ 20.0 million in the aggregate are available to be drawn at the Company’s option during certain availability periods, subject to the achievement of certain clinical and regulatory milestones relating to INZ-701. A fourth tranche commitment of $ 25.0 million may be made available to be drawn down at the Company’s option through August 31, 2025, subject to use of proceeds limitations and Lender's consent in its discretion. The fourth tranche commitment is subject to an additional 0.75 % facility fee. As security for its obligations under the Loan Agreement, the Company granted the Lenders a first priority security interest on substantially all of the Company’s assets (other than intellectual property), subject to certain exceptions. The term loan matures on August 1, 2026 and the Company is obligated to make interest only payments for the first 36 months and then interest and equal principal payments through the maturity date. The term loan bears a variable interest rate equal to the greater of (i) 7.85 %, and (ii) the sum of (A) the prime rate last quoted in The Wall Street Journal (or a comparable replacement rate if The Wall Street Journal ceases to quote such rate) and (B) 3.85 %; provided that the interest rate cannot exceed 9.60% . The interest rate as of September 30, 2022, was 9.60 % based upon an increase in the prime rate in September 2022. The Company has the option to prepay all, but not less than, the outstanding principal balance and all accrued and unpaid interest with respect to the principal balance being repaid of the term loans, subject to a prepayment premium to which the Lenders are entitled. The prepayment fee is 3 % prior to the second anniversary of the July 25, 2022 funding date, 2 % after the second anniversary but prior the third anniversary of the funding date, and 1 % thereafter if prior to the maturity date. Upon final payment or prepayment of the loans, the Company must pay a final payment equal to 6.25 % of the loans borrowed ("Final Fee"), which is being accrued as interest expense over the term of the loan using the effective interest method. The Lenders may elect, prior to the full repayment of the term loans, to convert up to $ 5.0 million of outstanding principal of the term loans into shares of the Company’s common stock, at a conversion price of $ 6.21 per share, subject to customary adjustments and 9.99 % and 19.99 % beneficial ownership limitations. The Company determined that the embedded conversion option was not required to be separated from the term loan. The embedded conversion option met the derivative accounting scope exception since the embedded conversion option is indexed to the Company’s own common stock and qualifies for classification within stockholders’ equity. The Loan Agreement contains customary representations and warranties, events of default and affirmative and negative covenants, including covenants that limit or restrict the Company’s ability to, among other things, dispose of assets, make changes to the Company’s business, management, ownership or business locations, merge or consolidate, incur additional indebtedness, incur additional liens, pay dividends or other distributions or repurchase equity, make investments, and enter into certain transactions with affiliates, in each case subject to certain exceptions. Upon the occurrence of an event of default, a default interest rate of an additional 5.00 % per annum may be applied to the outstanding loan balances, and the Lender may declare all outstanding obligations immediately due and payable and exercise all of its rights and remedies as set forth in the Loan Agreement and under applicable law. As of September 30, 2022, the Company was in compliance with all covenants under the Loan Agreement. Subject to certain conditions, the Company granted the Lenders the right, prior to repayment of the term loans, to invest up to $ 5.0 million in the aggregate in future offerings of common stock, convertible preferred stock or other equity securities of the Company that are broadly marketed and offered to multiple investors, on the same terms, conditions and pricing afforded to others participating in any such financing. The Company incurred debt issuance costs of $ 0.5 million in connection with the term loan. In addition, at the time of closing the Company paid to the Lenders a facility fee of $ 0.4 million, as well as $ 0.1 million of other expenses incurred by the Lenders and reimbursed by the Company ("Lender Expenses"). The debt issuance costs, Lender Expenses and the Final Fee are being amortized as additional interest expense over the term of the loan using the effective interest method. The Company recorded interest expense of $ 0.1 million during the three and nine months ended September 30, 2022. At September 30, 2022, the carrying value of the Loan Agreement approximates the fair value of the term loan, considering that it bears interest that is similar to prevailing market rates. The following table summarizes the impact of the term loan, on the Company’s condensed consolidated balance sheet at September 30, 2022: September 30, (in thousands) Gross proceeds $ 5,000 Unamortized debt issuance costs ( 927 ) Carrying value $ 4,073 Future principal payments, which include the Final Fee, in connection with the Loan Agreement as of September 30, 2022 are as follows (dollar amounts in thousands): Fiscal Year 2022 (remaining three months) $ — 2023 — 2024 — 2025 1,617 2026 3,695 Total $ 5,312

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2022
Equity [Abstract]
Stockholders' Equity	9. Stockholders’ Equity April 2022 Underwritten Offering On April 14, 2022, the Company entered into an underwriting agreement with Jefferies LLC and Cowen and Company, LLC, relating to an underwritten offering of 16,276,987 shares of the Company’s common stock (the "Shares") and, in lieu of common stock to certain investors, pre-funded warrants to purchase 3,523,013 shares of common stock. The closing of the offering took place on April 19, 2022. The offering price of the Shares was $ 3.69 per share and the offering price of the pre-funded warrants was $ 3.6899 per share underlying each pre-funded warrant. Warrants must be exercised by means of a cashless exercise. Net proceeds from the offering were approximately $ 68.3 million, after deducting underwriting discounts and commissions and offering expenses. On June 10, 2022, the Company and each holder of the pre-funded warrants entered into amended and restated pre-funded warrants solely to eliminate the seven-year expiration date of the pre-funded warrants. Each amended and restated pre-funded warrant is now exercisable for $ 0.0001 per share of common stock from the original date of issuance until the date the pre-funded warrant is exercised in full. All other terms of the pre-funded warrants remain unchanged. The pre-funded warrants contain standard adjustment provisions if certain corporate events were to happen. The pre-funded warrants are classified as a component of permanent equity and were recorded at the issuance date using a relative fair value allocation method. The pre-funded warrants are equity classified because they are freestanding financial instruments that are legally detachable and separately exercisable from the equity instruments, are immediately exercisable, do not embody an obligation for the Company to repurchase its shares, and permit the holders to receive a fixed number of shares of common stock upon exercise. In addition, such pre-funded warrants do not provide any guarantee of value or return. As of September 30, 2022 , 197,251 pre-funded warrants have been exercised by means of cashless exercise in exchange for the issuance of 197,240 shares of the Company's common stock. Equity Incentive Plans In January 2017, the Company’s board of directors and stockholders adopted the 2017 Equity Incentive Plan, which was amended and restated in July 2017 (as so amended and restated, the “2017 Plan”), which provided for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards and other stock awards. The maximum number of shares of common stock that were authorized for issuance under the 2017 Plan was 2,730,496 . On July 17, 2020, the Company’s stockholders approved the 2020 Stock Incentive Plan (the “2020 Plan”), which became effective on July 23, 2020. The 2020 Plan provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards. The number of shares of the Company’s common stock reserved for issuance under the 2020 Plan was 1,588,315 shares, plus the 426,065 shares of common stock remaining available for issuance under the 2017 Plan as of July 23, 2020. The number of shares reserved under the 2020 Plan will be annually increased on each January 1 through January 1, 2030 by the lower of (i) 4 % of the number of shares of common stock outstanding on the first day of such fiscal year and (ii) an amount determined by the Company’s board of directors. As of the effective date of the 2020 Plan, no further awards will be made under the 2017 Plan. Any options or awards outstanding under the 2017 Plan are governed by their existing terms. The shares of the Company’s common stock subject to outstanding awards under the 2017 Plan that expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right will be added back to the shares of common stock available for issuance under the 2020 Plan. No more than 1,588,315 shares of the Company's common stock may be granted subject to incentive stock options under the 2020 Plan. On January 1, 2022, the number of shares of common stock reserved under the 2020 Plan was increased by 946,749 shares. As of September 30, 2022 , 333,216 shares of common stock remain available for future issuance under the 2020 Plan. The following table summarizes stock option activity under the Company’s equity incentive plans for the nine months ended September 30, 2022: Options Weighted- Weighted- Aggregate (in years) (in thousands) Outstanding at December 31, 2021 3,582,613 $ 10.63 8.32 $ 7,428 Granted 1,740,069 4.92 Exercised ( 210,977 ) 1.70 Forfeited ( 304,196 ) 10.28 Outstanding at September 30, 2022 4,807,509 $ 8.98 8.28 $ 831 Exercisable at September 30, 2022 1,967,985 $ 9.29 7.39 $ 741 Vested and expected to vest at September 30, 2022 4,807,509 $ 8.98 8.28 $ 831 (1) The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock. The weighted-average grant date fair value of options granted during the three and nine months ended September 30, 2022 was $ 2.28 per share and $ 3.62 per share, respectively. The aggregate intrinsic value of stock options exercised during the three months ended September 30, 2022 was $ 0.1 million. The aggregate intrinsic value of stock options exercised during the nine months ended September 30, 2022 was $ 0.5 million. For purposes of calculating stock-based compensation expense, the Company estimates the fair value of stock options using the Black-Scholes option-pricing model. This model incorporates various assumptions, including the expected volatility, expected term, and interest rates. The underlying assumptions used to value stock options granted to participants using the Black-Scholes option-pricing were as follows: For the Three Months Ended September 30, For the Nine Months Ended September 30, 2022 2021 2022 2021 Risk-free interest rate range 2.63 % to 4.04 % 0.93 % to 0.98 % 1.58 % to 4.04 % 0.48 % to 1.15 % Dividend yield 0 % 0 % 0 % 0 % Expected term of options (years) 6.08 to 6.48 5.98 to 6.08 5.08 to 6.48 5.37 to 6.48 Volatility rate range 84.50 % to 86.40 % 88.57 % to 89.25 % 84.50 % to 87.15 % 88.57 % to 91.19 % The total compensation cost recognized in the statements of operations associated with all the stock-based compensation awards granted by the Company is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Research and development $ 931 $ 798 $ 2,923 $ 2,495 General and administrative 918 954 2,863 2,647 Total $ 1,849 $ 1,752 $ 5,786 $ 5,142 The total unrecognized compensation cost related to outstanding employee awards as of September 30, 2022 was $ 14.9 million and is expected to be recognized over a weighted-average period of 2.6 years. Employee Stock Purchase Plan On July 17, 2020, the Company’s stockholders approved the 2020 Employee Stock Purchase Plan (the “ESPP”), which became effective on July 23, 2020. The ESPP initially provides participating employees with the opportunity to purchase up to an aggregate of 198,539 shares of the Company’s common stock. The number of shares of common stock reserved for issuance under the ESPP will automatically increase on each January 1 through January 1, 2031, in an amount equal to the lowest of (1) 397,079 shares of the Company’s common stock, (2) 1 % of the number of shares of the Company’s common stock outstanding on the first day of such fiscal year and (3) an amount determined by the Company’s board of directors . The number of shares available for grant under this plan increased by 236,687 on January 1, 2022 due to this provision. As of September 30, 2022 , 40,412 shares have been purchased by employees under the ESPP. The Company activated its first offering period under the ESPP on April 1, 2022. The offering period ended on September 30, 2022. A second offering period began on October 1, 2022 and will end on March 31, 2023. During the three and nine months ended September 30, 2022, the Company recorded less than $ 0.1 million of stock-based compensation expense under the ESPP. The Company did no t record any stock-based compensation expense under the ESPP in the three and nine months ended September 30, 2021 .

Net Loss per Share

Net Loss per Share	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Net Loss per Share	10. Net Loss per Share Net Loss per Share Attributable to Common Stockholders The following table sets forth the computation of basic and diluted net loss per share for the three months ended September 30, 2022 and 2021 (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Net loss attributable to common stockholders—basic $ ( 16,372 ) $ ( 14,280 ) $ ( 48,517 ) $ ( 37,870 ) Net loss per share attributable to common $ ( 0.38 ) $ ( 0.60 ) $ ( 1.36 ) $ ( 1.61 ) Weighted-average common shares and pre-funded warrants outstanding—basic 43,657,718 23,643,494 35,755,695 23,521,981 The Company has generated a net loss in all periods presented, therefore the basic and diluted net loss per share attributable to common stockholders are the same as the inclusion of the potentially dilutive securities would be anti-dilutive. Since the shares underlying the pre-funded warrants are issuable for little or no consideration, they are considered outstanding for both basic and diluted earnings per share from the date of issuance. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Options to purchase common stock 4,807,509 3,361,497 4,807,509 3,361,497 4,807,509 3,361,497 4,807,509 3,361,497

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2022
Retirement Benefits [Abstract]
Employee Benefit Plans	11. Employee Benefit Plans The Company established a defined contribution savings plan in 2018 for all eligible U.S. employees under Section 401(k) of the Internal Revenue Code. Employees can designate the investment of their 401(k) accounts into several mutual funds. Effective January 1, 2021, the Company implemented a matching policy under which the Company matches 50 % of an employee’s contributions to the 401(k) plan, up to a maximum of 6 % of the employee’s base salary and bonus paid during the year. For the three and nine months ended September 30, 2022, the Company made employer contributio ns to the 401(k) plan totaling $ 60 thousand and $ 202 thousand, respe ctively.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles ("U.S. GAAP") for interim financial information. Accordingly, these unaudited condensed consolidated financial statements do not include all of the information and note disclosures required by U.S. GAAP for audited year-end financial statements. The accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments that are, in the opinion of management, necessary for a fair presentation of the interim period results. The results for the three and nine month periods ended September 30, 2022 are not necessarily indicative of results to be expected for the year ending December 31, 2022, any other interim periods, or any future year or period. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2021. Any reference in these notes to applicable guidance is meant to refer to authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”).
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries, Inozyme Securities Corp., which is a Massachusetts subsidiary created to buy, sell, and hold securities, Inozyme Ireland Limited, and Inozyme Pharma Switzerland GmbH. All intercompany transactions and balances have been eliminated. Summary of Significant Accounting Policies The significant accounting policies and estimates used in the preparation of the accompanying consolidated financial statements are described in the Company’s audited consolidated financial statements for the year ended December 31, 2021 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021. The Company adopted a warrant accounting policy detailed below following the closing of the Company's underwritten offering in April 2022 and a debt and debt issuance costs accounting policy following the closing of the Loan Agreement in July 2022. Apart from these adoptions, there have been no material changes in the Company’s significant accounting policies during the nine months ended September 30, 2022 .
Use of Estimates	Use of Estimates The preparation of the Company’s financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Estimates and judgments are based on historical information and other market-specific or various relevant assumptions, including, in certain circumstances, future projections that management believes to be reasonable under the circumstances. Actual results could differ materially from estimates. Significant estimates and assumptions are used for, but not limited to, the accruals for research and development expenses. The Company evaluates its estimates and assumptions on an ongoing basis. All revisions to accounting estimates are recognized in the period in which the estimates are revised and in any future periods affected.
Accrued Research and Development Costs	Accrued Research and Development Costs The Company records accrued liabilities for estimated costs of research and development activities conducted by service providers for sponsored research, preclinical studies, clinical trials, and contract manufacturing activities. The Company records the estimated costs of research and development activities based upon the estimated amount of services provided but not yet invoiced and includes these costs in accrued expenses in the accompanying condensed consolidated balance sheets and within research and development expense in the accompanying condensed consolidated statements of operations and comprehensive loss. The Company accrues for these costs based on factors such as estimates of the work completed and in accordance with agreements established with service providers. The Company makes significant judgments and estimates in determining the accrued liabilities balance in each reporting period. As actual costs become known, the Company adjusts its accrued liabilities. The Company has not experienced any material differences between accrued costs and actual costs incurred since its inception.
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred. Research and development costs consist of direct and indirect internal costs related to specific projects as well as fees paid to other entities that conduct certain research and development activities on the Company’s behalf.
Net Loss Per Share	Net Loss Per Share The Company follows the two-class method when computing net loss allocable to common securities per share as the Company had previously issued shares that meet the definition of participating securities. The two-class method requires a portion of net income to be allocated to the participating securities to determine net income allocable to the common securities. During periods of loss, there is no allocation required under the two-class method since the participating securities do not have a contractual obligation to fund the losses of the Company. Basic net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock and pre-funded warrants outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock and pre-funded warrants and potentially dilutive securities outstanding using the treasury-stock and if-converted methods. The Company has generated a net loss in all periods presented, therefore the basic and diluted net loss per share attributable to common stockholders are the same as the inclusion of the potentially dilutive securities would be anti-dilutive.
Fair Value Measurements	Fair Value Measurements The Company categorizes its assets and liabilities measured at fair value in accordance with the authoritative accounting guidance that establishes a consistent framework for measuring fair value and expands disclosures for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as the 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 such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: • Level 1- Unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets or liabilities; • Level 2- Quoted prices for similar assets and liabilities in active markets, quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability; or • Level 3- Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity).
Concentration of Credit Risk and Off-Balance Sheet Risk	Concentration of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and short-term investments and, from time to time, long-term investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits and limits its exposure to credit risk by placing its cash with high credit quality financial institutions. The Company’s investments are comprised of U.S. Treasury securities and commercial paper of corporations. The Company mitigates credit risk by maintaining a diversified portfolio and limiting the amount of investment exposure as to institution, maturity and investment type. The Company has no significant off-balance sheet risk such as foreign exchange contracts, option contracts, or other foreign hedging arrangements.
Debt and Debt Issuance Costs	Debt and Debt Issuance Costs Debt issuance costs and the Lender Expenses (see Note 8) are presented on the condensed consolidated balance sheet as a direct deduction from the related debt liability. Debt issuance costs represent legal and other direct costs incurred in connection with the Company’s term loan under the Loan Agreement. These costs are amortized as a non-cash component of interest expense using the effective interest method over the term of the loan. Any final payments are included in the cash flows to determine the effective interest rate and are recognized using the effective interest method over the term of the loan.
Warrants	Warrants The Company determines the accounting classification of warrants that are issued, as either liability or equity, by first assessing whether the warrants meet liability classification in accordance with ASC 480-10, Accounting for Certain Financial Instruments with Characteristics of Both Liabilities and Equity , and then in accordance with ASC 815-40, Accounting for Derivative Financial Instruments Indexed to, and Potentially Settled in, a Company’s Own Stock . Under ASC 480-10, warrants are considered liability classified if the warrants are mandatorily redeemable, obligate the issuer to settle the warrants or the underlying shares by paying cash or other assets, or must or may require settlement by issuing variable number of shares. If warrants do not meet liability classification under ASC 480-10, the Company assesses the requirements under ASC 815-40, which states that contracts that require or may require the issuer to settle the contract for cash are liabilities recorded at fair value, irrespective of the likelihood of the transaction occurring that triggers the net cash settlement feature. If the warrants do not require liability classification under ASC 815-40, in order to conclude equity classification, the Company assesses whether the warrants are indexed to its common stock and whether the warrants are classified as equity under ASC 815-40 or other applicable U.S. GAAP. After all relevant assessments are made, the Company concludes whether the warrants are classified as liability or equity. Liability classified warrants are required to be accounted for at fair value both on the date of issuance and on subsequent accounting period ending dates, with all changes in fair value after the issuance date recorded in the statements of operations as a gain or loss. Equity classified warrants are accounted for at fair value on the issuance date with no changes in fair value recognized after the issuance date.
Recently Issued and Adopted Accounting Standards	Recently Issued and Adopted Accounting Standards In December 2019, the FASB issued ASU 2019-12, Income Taxes – Simplifying the Accounting for Income Taxes . The new guidance simplifies the accounting for income taxes by removing several exceptions in the current standard and adding guidance to reduce complexity in certain areas, such as requiring that an entity reflect the effect of an enacted change in tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date. The Company adopted this standard effective January 1, 2022. There was no material impact to the Company's financial statements upon adoption. In August 2020, the FASB issued ASU 2020-06, Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40) . ASU 2020-06 simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity’s own equity. The Company elected to early adopt this standard effective January 1, 2022. There was no material impact to the Company's financial statements upon adoption.
Recently Issued Accounting Standards Not Yet Adopted	Recently Issued Accounting Standards 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 . ASU 2016-13 and its subsequent related updates establish a new forward-looking “expected loss model” that requires entities to estimate current expected credit losses on accounts receivable and financial instruments by using all practical and relevant information. The new standard and its subsequent related updates are effective for the Company for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, with early adoption permitted. The Company is currently assessing the impact that adopting this standard will have on its consolidated financial statements but does not expect it to be material.

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	9 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Short-Term Investments	Short-term investments consisted of the following (dollar amounts in thousands): September 30, 2022 Description Maturity Amortized Gross Gross Estimated Commercial paper 1 year or less $ 74,935 $ — $ ( 231 ) $ 74,704 U.S. Treasury securities 1 year or less 22,887 — ( 183 ) $ 22,704 $ 97,822 $ — $ ( 414 ) $ 97,408 December 31, 2021 Description Maturity Amortized Gross Gross Estimated Commercial paper 1 year or less $ 78,456 $ 5 $ ( 3 ) $ 78,458 U.S. Treasury securities 1 year or less 5,025 — — 5,025 U.S. government agency debt securities 1 year or less 5,002 — — 5,002 $ 88,483 $ 5 $ ( 3 ) $ 88,485
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (dollar amounts in thousands): At September 30, At December 31, Interest receivable $ 96 $ 62 Prepaid insurance 1,897 1,728 Prepaid research studies 1,643 1,190 Prepaid other 838 561 Total $ 4,474 $ 3,541
Schedule of Prepaid Expenses, Net of Current Portion	Prepaid expenses, net of current portion, consisted of the following (dollar amounts in thousands): At September 30, At December 31, Prepaid clinical trial and other $ 3,810 $ 3,409 $ 3,810 $ 3,409
Schedule of Property and Equipment	Property and equipment consisted of the following (dollar amounts in thousands): At September 30, At December 31, Laboratory equipment and manufacturing equipment $ 806 $ 591 Furniture and fixtures 258 258 Computer equipment and software 571 440 Leasehold improvements 2,095 2,095 3,730 3,384 Less accumulated depreciation ( 1,533 ) ( 1,001 ) Total $ 2,197 $ 2,383
Schedule of Accrued Expenses	Accrued expenses consi sted of the following (dollar amounts in thousands): At September 30, At December 31, Payroll and related liabilities $ 2,263 $ 2,379 Professional fees 524 727 Research and development costs 7,649 5,066 Other 512 336 Total $ 10,948 $ 8,508

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Summary of Financial Assets Measured at Fair Value	The following tables represent the Company’s financial assets measured at fair value on a recurring basis and indicate the level of fair value hierarchy utilized to determine such fair values (in thousands): Fair Value Measurements at Reporting Date Description September 30, Quoted Significant Significant Assets: Money market funds (included in cash and cash $ 38,936 $ 38,936 $ — $ — Commercial paper (including amounts in cash and cash equivalents) 77,688 — 77,688 — U.S. Treasury securities 22,704 22,704 — — Total assets $ 139,328 $ 61,640 $ 77,688 $ — Fair Value Measurements at Reporting Date Description December 31, Quoted Significant Significant Assets: Money market funds (included in cash and cash $ 14,302 $ 14,302 $ — $ — Commercial paper 78,457 — 78,457 — U.S. Treasury securities 5,026 5,026 — — U.S. government agency debt securities 5,002 — 5,002 — Total assets $ 102,787 $ 19,328 $ 83,459 $ —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Lease Payments Under Non-Cancelable Leases	Future lease payments under non-cancelable leases as of September 30, 2022 are as follows (dollar amounts in thousands): Year Ending December 31, 2022 (remaining 3 months) $ 243 2023 992 2024 1,016 2025 944 Thereafter — $ 3,195

Convertible Debt (Tables)

Convertible Debt (Tables)	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Summarizes Of impact Term Loan	The following table summarizes the impact of the term loan, on the Company’s condensed consolidated balance sheet at September 30, 2022: September 30, (in thousands) Gross proceeds $ 5,000 Unamortized debt issuance costs ( 927 ) Carrying value $ 4,073
Future principal payment of Loan Agreement	Future principal payments, which include the Final Fee, in connection with the Loan Agreement as of September 30, 2022 are as follows (dollar amounts in thousands): Fiscal Year 2022 (remaining three months) $ — 2023 — 2024 — 2025 1,617 2026 3,695 Total $ 5,312

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2022
Summary of Stock Option Activity Under Equity Incentive Plans	The following table summarizes stock option activity under the Company’s equity incentive plans for the nine months ended September 30, 2022: Options Weighted- Weighted- Aggregate (in years) (in thousands) Outstanding at December 31, 2021 3,582,613 $ 10.63 8.32 $ 7,428 Granted 1,740,069 4.92 Exercised ( 210,977 ) 1.70 Forfeited ( 304,196 ) 10.28 Outstanding at September 30, 2022 4,807,509 $ 8.98 8.28 $ 831 Exercisable at September 30, 2022 1,967,985 $ 9.29 7.39 $ 741 Vested and expected to vest at September 30, 2022 4,807,509 $ 8.98 8.28 $ 831 (1) The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock.
Summary of Assumptions Used to Value Stock Options Granted Using Black-Scholes Option-Pricing	The underlying assumptions used to value stock options granted to participants using the Black-Scholes option-pricing were as follows: For the Three Months Ended September 30, For the Nine Months Ended September 30, 2022 2021 2022 2021 Risk-free interest rate range 2.63 % to 4.04 % 0.93 % to 0.98 % 1.58 % to 4.04 % 0.48 % to 1.15 % Dividend yield 0 % 0 % 0 % 0 % Expected term of options (years) 6.08 to 6.48 5.98 to 6.08 5.08 to 6.48 5.37 to 6.48 Volatility rate range 84.50 % to 86.40 % 88.57 % to 89.25 % 84.50 % to 87.15 % 88.57 % to 91.19 %
Summary of Total Compensation Cost Recognized in Statements of Operations	The total compensation cost recognized in the statements of operations associated with all the stock-based compensation awards granted by the Company is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Research and development $ 931 $ 798 $ 2,923 $ 2,495 General and administrative 918 954 2,863 2,647 Total $ 1,849 $ 1,752 $ 5,786 $ 5,142

Net Loss per Share (Tables)

Net Loss per Share (Tables)	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Schedule of Net Loss Per Share, Basic and Diluted	The following table sets forth the computation of basic and diluted net loss per share for the three months ended September 30, 2022 and 2021 (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Net loss attributable to common stockholders—basic $ ( 16,372 ) $ ( 14,280 ) $ ( 48,517 ) $ ( 37,870 ) Net loss per share attributable to common $ ( 0.38 ) $ ( 0.60 ) $ ( 1.36 ) $ ( 1.61 ) Weighted-average common shares and pre-funded warrants outstanding—basic 43,657,718 23,643,494 35,755,695 23,521,981
Schedule of Potential Dilutive Securities from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders	The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Options to purchase common stock 4,807,509 3,361,497 4,807,509 3,361,497 4,807,509 3,361,497 4,807,509 3,361,497

Organization and Basis of Pre_2

Organization and Basis of Presentation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended						9 Months Ended		12 Months Ended
	Jul. 25, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Subsidiary, Sale of Stock [Line Items]
Proceeds from issuance of common stock								$ 56,137
Net loss		$ 16,372	$ 15,261	$ 16,884	$ 14,280	$ 12,540	$ 11,050	48,517	$ 37,870	$ 56,600
Accumulated deficit		196,217						196,217		147,700
Cash and cash equivalents and short term investments		141,500						141,500
Loan amount		$ 4,073						$ 4,073
Payment Description for Debt	the Company is obligated to make interest only payments for the first 36 months and then interest and equal principal payments through the maturity date. The term loan bears a variable interest rate equal to the greater of (i) 7.85%, and (ii) the sum of (A) the prime rate last quoted in The Wall Street Journal (or a comparable replacement rate if The Wall Street Journal ceases to quote such rate) and (B) 3.85%; provided that the interest rate cannot exceed 9.60%
Annual rate of interest for the debt	7.85
Additional Interest rate for debt instrument	3.85%
K2HV [Member]
Subsidiary, Sale of Stock [Line Items]
Loan amount	$ 70,000
Debt instrument conversion price	$ 6.21
Customary percentage	9.99%
Beneficial ownership limitation percentage	19.99%
Loan Maturity Date	Aug. 01, 2026
K2HV [Member] | Maximum
Subsidiary, Sale of Stock [Line Items]
Annual rate of interest for the debt	9.60
Debt instrument, Amount converted to common stock upon lender's choice	$ 5,000
Future offerings of common stock	5,000
K2HV [Member] | Tranche One [Member]
Subsidiary, Sale of Stock [Line Items]
Loan amount	5,000
K2HV [Member] | Tranche Two [Member]
Subsidiary, Sale of Stock [Line Items]
Loan amount	20,000
K2HV [Member] | Tranche Four [Member]
Subsidiary, Sale of Stock [Line Items]
Loan amount	$ 25,000
Pre Funded Warrants [Member]
Subsidiary, Sale of Stock [Line Items]
Class of Warrant purchases		197,251						197,251

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Accounting Policies [Abstract]
Off-balance sheet concentrations of credit risk	$ 0

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule of Short-Term Investments (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Amortized Costs	$ 97,822	$ 88,483
Gross Unrealized Gains	0	5
Gross Unrealized Losses	(414)	(3)
Estimated Fair Value	$ 97,408	$ 88,485
Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Maturity	1 year or less	1 year or less
Amortized Costs	$ 74,935	$ 78,456
Gross Unrealized Gains	0	5
Gross Unrealized Losses	(231)	(3)
Estimated Fair Value	$ 74,704	$ 78,458
U.S. Treasury Securities
Schedule Of Available For Sale Securities [Line Items]
Maturity	1 year or less	1 year or less
Amortized Costs	$ 22,887	$ 5,025
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(183)	0
Estimated Fair Value	$ 22,704	$ 5,025
U.S. Government Agency Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Maturity		1 year or less
Amortized Costs		$ 5,002
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Estimated Fair Value		$ 5,002

Balance Sheet Details - Additio

Balance Sheet Details - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Depreciation expense	$ 189	$ 167	$ 546	$ 492
Restricted cash	$ 400	$ 400	$ 400	$ 400

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Interest receivable	$ 96	$ 62
Prepaid insurance	1,897	1,728
Prepaid research studies	1,643	1,190
Prepaid other	838	561
Total	$ 4,474	$ 3,541

Balance Sheet Details - Sched_3

Balance Sheet Details - Schedule of Prepaid Expenses, Net of Current Portion (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Prepaid clinical trial and other	$ 3,810	$ 3,409
Prepaid expenses, net of current portion	$ 3,810	$ 3,409

Balance Sheet Details - Sched_4

Balance Sheet Details - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 3,730	$ 3,384
Less accumulated depreciation	(1,533)	(1,001)
Total	2,197	2,383
Laboratory Equipment and Manufacturing Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	806	591
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	258	258
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	571	440
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 2,095	$ 2,095

Balance Sheet Details - Sched_5

Balance Sheet Details - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Payroll and related liabilities	$ 2,263	$ 2,379
Professional fees	524	727
Research and development costs	7,649	5,066
Other	512	336
Total	$ 10,948	$ 8,508

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Financial Assets Measured at Fair Value (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	$ 139,328	$ 102,787
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents fair value disclosure	38,936	14,302
Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents fair value disclosure	77,688
Assets fair value disclosure		78,457
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	61,640	19,328
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents fair value disclosure	38,936	14,302
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents fair value disclosure	0
Assets fair value disclosure		0
Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	77,688	83,459
Significant Other Observable Inputs (Level 2) | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents fair value disclosure	0	0
Significant Other Observable Inputs (Level 2) | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents fair value disclosure	77,688
Assets fair value disclosure		78,457
Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	0	0
Significant Unobservable Inputs (Level 3) | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents fair value disclosure	0	0
Significant Unobservable Inputs (Level 3) | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents fair value disclosure	0
Assets fair value disclosure		0
U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	22,704	5,026
U.S. Treasury Securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	22,704	5,026
U.S. Treasury Securities | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	0	0
U.S. Treasury Securities | Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	$ 0	0
U.S. Government Agency Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure		5,002
U.S. Government Agency Debt Securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure		0
U.S. Government Agency Debt Securities | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure		5,002
U.S. Government Agency Debt Securities | Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure		$ 0

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Jun. 30, 2022	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Assets Level 1 To Level 2		$ 0	$ 0
Fair Value Assets Level 2 To Level 1		$ 0	$ 0
Fair value measurement with unobservable inputs reconciliation recurring basis asset transfers into level 3	$ 0			$ 0

License and Sponsored Researc_2

License and Sponsored Research Agreements - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Feb. 28, 2019	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	May 31, 2022	Mar. 31, 2022	Nov. 30, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research support funding expiration year	2021-12
Research and development expenses		$ 12,191	$ 9,346	$ 34,012	$ 24,169
Yale
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Partial upfront consideration payment under license agreement				100
Milestone payment upon achievement of certain milestones		3,000		3,000			$ 300	$ 300
Yale | Sponsored Research Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research support funding amount	$ 2,400					$ 100
Research support funding period	5 years
Research and development expenses			$ 100	100	$ 400
Yale | Sponsored Research Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development expenses		$ 100
Yale | License
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Maintenance fees				$ 200

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Thousands		3 Months Ended		9 Months Ended
	Jan. 01, 2021	Sep. 30, 2022 USD ($) ft²	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) ft²	Sep. 30, 2021 USD ($)
Lessee Lease Description [Line Items]
Operating lease liabilities		$ 600		$ 600
Operating lease expense				500
Costs related to legal proceedings		$ 0	$ 0	$ 0	$ 0
Office Space | Boston, Massachusetts
Lessee Lease Description [Line Items]
Area of leased space | ft²		8,499		8,499
Lessee operating lease expiration year				2025
Lessee, Operating Lease, Existence of Option to Extend [true false]	true	true
Lessee operating lease option to extend description				option to extend the term for five years
Operating lease renewal term		5 years		5 years
Laboratory Space | Boston, Massachusetts
Lessee Lease Description [Line Items]
Area of leased space | ft²		6,244		6,244
Lessee operating lease expiration year				2025

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Future Lease Payments Under Non-Cancelable Leases (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2022 (remaining 3 months)	$ 243
2023	992
2024	1,016
2025	944
Thereafter	0
Operating lease liability	$ 3,195

Convertible Debt (Additional In

Convertible Debt (Additional Information) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	9 Months Ended
	Jul. 25, 2022	Sep. 30, 2022	Sep. 30, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Loan amount		$ 4,073	$ 4,073
Annual rate of interest for the debt	7.85
Additional Interest rate for debt instrument	3.85%
Payment Description for Debt	the Company is obligated to make interest only payments for the first 36 months and then interest and equal principal payments through the maturity date. The term loan bears a variable interest rate equal to the greater of (i) 7.85%, and (ii) the sum of (A) the prime rate last quoted in The Wall Street Journal (or a comparable replacement rate if The Wall Street Journal ceases to quote such rate) and (B) 3.85%; provided that the interest rate cannot exceed 9.60%
Prepayment of Loans	6.25%
Additional facility fee			5%
K2HV [Member]
Debt Instrument [Line Items]
Loan amount	$ 70,000
Loan Maturity Date	Aug. 01, 2026
Debt instrument conversion price	$ 6.21
Customary percentage	9.99%
Beneficial ownership limitation percentage	19.99%
Maximum | K2HV [Member]
Debt Instrument [Line Items]
Annual rate of interest for the debt	9.60
Debt instrument, Amount converted to common stock upon lender's choice	$ 5,000
Future offerings of common stock	$ 5,000
Tranche One [Member]
Debt Instrument [Line Items]
Prepayment fee percentage	3%
Tranche One [Member] | K2HV [Member]
Debt Instrument [Line Items]
Loan amount	$ 5,000
Additional loan amount	$ 20,000
Tranche Two [Member]
Debt Instrument [Line Items]
Prepayment fee percentage	2%
Tranche Two [Member] | K2HV [Member]
Debt Instrument [Line Items]
Loan amount	$ 20,000
Tranche Four [Member]
Debt Instrument [Line Items]
Prepayment fee percentage	1%
Tranche Four [Member] | K2HV [Member]
Debt Instrument [Line Items]
Loan amount	$ 25,000
Additional facility fee	0.75%
Term Loan [Member]
Debt Instrument [Line Items]
Debt issuance cost	$ 500
Lenders facility fee	400
Lenders reimbursed amount	$ 100
Debt interest expenses		$ 100	$ 100

Convertible Debt - Summarizes o

Convertible Debt - Summarizes of impact Term Loan (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
Gross Proceeds	$ 5,000
Unamortized debt issuance costs	(927)
Long-Term Debt, Total	$ 4,073

Convertible Debt - Future princ

Convertible Debt - Future principal payments (Details) - K2 Loan Agreement [Member] $ in Thousands	Sep. 30, 2022 USD ($)
Fiscal Year
2022 (remaining three months)	$ 0
2023	0
2024	0
2025	1,617
2026	3,695
Total	$ 5,312

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended		9 Months Ended
	Apr. 14, 2022	Jul. 23, 2020	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Jun. 10, 2022	Jan. 01, 2022	Dec. 31, 2021	Jul. 31, 2020	Jul. 17, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense					$ 5,786	$ 5,142
Common stock, shares issued			40,394,363		40,394,363				23,668,747
Preferred stock, shares outstanding			0		0				0
Common stock, shares authorized			200,000,000		200,000,000				200,000,000
Preferred stock, shares authorized			5,000,000		5,000,000				5,000,000
Plan description					On July 17, 2020, the Company’s stockholders approved the 2020 Stock Incentive Plan (the “2020 Plan”), which became effective on July 23, 2020. The 2020 Plan provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards. The number of shares of the Company’s common stock reserved for issuance under the 2020 Plan
Granted options					1,740,069
Weighted-average exercise price of options granted					$ 4.92
Weighted-average grant date fair value of options granted			$ 2.28		$ 3.62
Aggregate intrinsic value of stock options exercised			$ 100		$ 500
Total unrecognized compensation cost related to outstanding employee awards			$ 14,900		$ 14,900
Total unrecognized compensation cost related to outstanding employee awards, expected to be recognized over a weighted-average period					2 years 7 months 6 days
Share based compensation options to purchase number of common stock			4,807,509		4,807,509				3,582,613
Pre-funded warrant exercisable price							$ 0.0001
Pre Funded Warrants [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Class of Warrant purchases			197,251		197,251
Common stock, shares issued			197,240		197,240
2020 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance		1,588,315	333,216		333,216			946,749
Number of common stock reserved for issuance increase percentage on stock outstanding		4%
2017 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance		426,065
2017 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized for issuance										2,730,496
Number of awards available for issuance											0
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance								236,687
Number of common stock reserved for issuance increase percentage on stock outstanding		1%
Plan description		The number of shares of common stock reserved for issuance under the ESPP will automatically increase on each January 1 through January 1, 2031, in an amount equal to the lowest of (1) 397,079 shares of the Company’s common stock, (2) 1% of the number of shares of the Company’s common stock outstanding on the first day of such fiscal year and (3) an amount determined by the Company’s board of directors
Share based compensation options to purchase number of common stock		198,539
Increase in additional number of shares to be issued		397,079
Number of shares purchased			40,412
ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense			$ 100	$ 0	$ 100	$ 0
Jefferies LLC
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Underwritten offering	16,276,987
Offering price	$ 3.69
Net proceeds from the offering	$ 68,300
Jefferies LLC | Pre Funded Warrants [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Class of Warrant purchases	3,523,013
Offering price	$ 3.6899

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Option Activity Under Equity Incentive Plans (Details) $ / shares in Units, $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2022 USD ($) $ / shares shares		Dec. 31, 2021 USD ($) $ / shares shares
Equity [Abstract]
Options Outstanding, Beginning Balance | shares	3,582,613
Options Outstanding, Granted | shares	1,740,069
Options Outstanding, Exercised | shares	(210,977)
Options Outstanding, Forfeited | shares	(304,196)
Options Outstanding, Ending Balance | shares	4,807,509		3,582,613
Options Outstanding, Exercisable | shares	1,967,985
Options Outstanding, Vested and expected to vest | shares	4,807,509
Weighted Average Exercise Price, Outstanding, Beginning Balance | $ / shares	$ 10.63
Weighted Average Exercise Price, Granted | $ / shares	4.92
Weighted Average Exercise Price, Exercised | $ / shares	1.70
Weighted Average Exercise Price, Forfeited | $ / shares	10.28
Weighted Average Exercise Price, Outstanding, Ending Balance | $ / shares	8.98		$ 10.63
Weighted Average Exercise Price, Exercisable | $ / shares	9.29
Weighted Average Exercise Price, Vested and expected to vest | $ / shares	$ 8.98
Weighted Average Remaining Contractual Term (in years), Outstanding	8 years 3 months 10 days		8 years 3 months 25 days
Weighted Average Remaining Contractual Term (in years), Exercisable	7 years 4 months 20 days
Weighted Average Remaining Contractual Term (in years), Vested and expected to vest	8 years 3 months 10 days
Aggregate Intrinsic Value, Outstanding | $	$ 831	[1]	$ 7,428	[1]
Aggregate Intrinsic Value, Exercisable | $	741	[1]
Aggregate Intrinsic Value, Vested and expected to vest | $	$ 831	[1]
[1] (1) The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock.

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Assumptions Used to Value Stock Options Granted to Employees using Black-Scholes Option-Pricing (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate range, minimum	2.63%	0.93%	1.58%	0.48%
Risk-free interest rate range, maximum	4.04%	0.98%	4.04%	1.15%
Dividend yield	0%	0%	0%	0%
Volatility rate range, minimum	84.50%	88.57%	84.50%	88.57%
Volatility rate range, maximum	86.40%	89.25%	87.15%	91.19%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term of options (years)	6 years 29 days	5 years 11 months 23 days	5 years 29 days	5 years 4 months 13 days
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term of options (years)	6 years 5 months 23 days	6 years 29 days	6 years 5 months 23 days	6 years 5 months 23 days

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of Total Compensation Cost Recognized in Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	$ 1,849	$ 1,752	$ 5,786	$ 5,142
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	931	798	2,923	2,495
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	$ 918	$ 954	$ 2,863	$ 2,647

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Earnings Per Share [Abstract]
Net loss attributable to common stockholders—basic and diluted	$ (16,372)	$ (15,261)	$ (16,884)	$ (14,280)	$ (12,540)	$ (11,050)	$ (48,517)	$ (37,870)	$ (56,600)
Net loss per share attributable to common stockholders- basic	$ (0.38)			$ (0.60)			$ (1.36)	$ (1.61)
Net loss per share attributable to common stockholders- diluted	$ (0.38)			$ (0.60)			$ (1.36)	$ (1.61)
Weighted-average common shares and pre-funded warrants outstanding - basic	43,657,718			23,643,494			35,755,695	23,521,981
Weighted-average common shares and pre-funded warrants outstanding - diluted	43,657,718			23,643,494			35,755,695	23,521,981

Net Loss per Share - Schedule_2

Net Loss per Share - Schedule of Potential Dilutive Securities from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of earnings per share	4,807,509	3,361,497	4,807,509	3,361,497
Options to Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of earnings per share	4,807,509	3,361,497	4,807,509	3,361,497

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
	Jan. 01, 2021	Sep. 30, 2022	Sep. 30, 2022
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution, percentage of match	50%
Employer contribution amount		$ 60	$ 202
Maximum
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution, percentage of employees base salary and bonus paid	6%

Subsequent Events (Additional I

Subsequent Events (Additional Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 25, 2022	Sep. 30, 2022	Dec. 31, 2021
Subsequent Event [Line Items]
Loan amount		$ 4,073
Payment Description for Debt	the Company is obligated to make interest only payments for the first 36 months and then interest and equal principal payments through the maturity date. The term loan bears a variable interest rate equal to the greater of (i) 7.85%, and (ii) the sum of (A) the prime rate last quoted in The Wall Street Journal (or a comparable replacement rate if The Wall Street Journal ceases to quote such rate) and (B) 3.85%; provided that the interest rate cannot exceed 9.60%
Annual rate of interest for the debt	7.85
Additional Interest rate for debt instrument	3.85%
Common Stock, Par or Stated Value Per Share		$ 0.0001	$ 0.0001
K2HV [Member]
Subsequent Event [Line Items]
Loan amount	$ 70,000
Loan Maturity Date	Aug. 01, 2026
Debt instrument conversion price	$ 6.21
Customary percentage	9.99%
Beneficial ownership limitation percentage	19.99%
K2HV [Member] | Tranche One [Member]
Subsequent Event [Line Items]
Loan amount	$ 5,000
Additional loan amount	20,000
K2HV [Member] | Tranche Two [Member]
Subsequent Event [Line Items]
Loan amount	20,000
K2HV [Member] | Tranche Four [Member]
Subsequent Event [Line Items]
Loan amount	$ 25,000
Maximum [Member] | K2HV [Member]
Subsequent Event [Line Items]
Annual rate of interest for the debt	9.60
Debt instrument, Amount converted to common stock upon lender's choice	$ 5,000
Future offerings of common stock	$ 5,000
Pre Funded Warrants [Member]
Subsequent Event [Line Items]
Class of Warrant purchases		197,251