Inozyme Pharma (INZY) 10-Q 7 Nov 23 2023 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2023	Nov. 01, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
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		61,760,748

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 46,895	$ 32,915
Short-term investments	145,547	94,951
Prepaid expenses and other current assets	8,414	3,527
Total current assets	200,856	131,393
Property and equipment, net	1,584	2,018
Restricted cash	311	354
Right-of-use assets	1,256	1,620
Prepaid expenses, net of current portion	1,695	3,810
Total assets	205,702	139,195
Current liabilities:
Accounts payable	2,006	2,544
Accrued expenses	9,383	11,355
Operating lease liabilities	886	816
Total current liabilities	12,275	14,715
Operating lease liabilities, net of current portion	1,149	1,823
Long term debt, net	32,065	4,139
Other long-term liabilities	0	124
Total liabilities	45,489	20,801
Commitments and contingencies (Note 7)
Stockholders’ equity:
Preferred stock, $0.0001 par value - 5,000,000 shares authorized at September 30, 2023 and December 31, 2022; no shares issued and outstanding at September 30, 2023 or December 31, 2022	0	0
Common Stock, $0.0001 par value - 200,000,000 shares authorized at September 30, 2023 and December 31, 2022; 46,379,088 shares issued and outstanding at September 30, 2023 and 40,394,363 shares issued and outstanding at December 31, 2022	6	4
Additional paid in-capital	424,671	333,356
Accumulated other comprehensive income (loss)	(78)	(205)
Accumulated deficit	(264,386)	(214,761)
Total stockholders’ equity	160,213	118,394
Total liabilities and stockholders’ equity	$ 205,702	$ 139,195

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (Unaudited) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
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	61,760,748	40,394,363
Common stock, shares outstanding	61,760,748	40,394,363

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating expenses:
Research and development	$ 13,341	$ 12,191	$ 36,864	$ 34,012
General and administrative	4,733	4,721	15,973	15,130
Total operating expenses	18,074	16,912	52,837	49,142
Loss from operations	(18,074)	(16,912)	(52,837)	(49,142)
Other income (expense):
Interest income, net	1,416	737	3,254	1,118
Other income (expense), net	20	(197)	(42)	(493)
Other income, net	1,436	540	3,212	625
Net loss	(16,638)	(16,372)	(49,625)	(48,517)
Other comprehensive income (loss):
Unrealized gains (losses) on available-for-sale securities	53	(60)	279	(417)
Foreign currency translation adjustment	(182)	(20)	(152)	(78)
Total other comprehensive income (loss)	(129)	(80)	127	(495)
Comprehensive loss	(16,767)	(16,452)	(49,498)	(49,012)
Net loss attributable to common stockholders—basic and diluted	$ (16,638)	$ (16,372)	$ (49,625)	$ (48,517)
Net loss per share attributable to common stockholders- basic	$ (0.29)	$ (0.38)	$ (1.02)	$ (1.36)
Net loss per share attributable to common stockholders- diluted	$ (0.29)	$ (0.38)	$ (1.02)	$ (1.36)
Weighted-average common shares and pre-funded warrants outstanding - basic	56,758,395	43,657,718	48,494,175	35,755,695
Weighted-average common shares and pre-funded warrants outstanding - diluted	56,758,395	43,657,718	48,494,175	35,755,695

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit
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
Other comprehensive income (loss):
Unrealized gain 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
Other comprehensive income (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
Proceeds from issuance of common stock	56,137	$ 2	56,135
Stock Issued During Period, Shares, New Issues		16,276,987
Stock Issued During Period, Value, New Issues	56,137	$ 2	56,135
Proceeds from issuance of common stock, 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
Other comprehensive income (loss):
Unrealized gain on investments	(225)			225
Foreign currency translation adjustment	(43)			(43)
Net loss					(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 pre-funded warrants, shares		197,240
Exercise of stock options	115		115
Exercise of stock options, shares		59,635
Shares purchased in Employee Stock Purchase Plan	92		92
Shares purchased in Employee Stock Purchase Plan, shares		40,412
Other comprehensive income (loss):
Unrealized gain 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
Balance at Dec. 31, 2022	118,394	$ 4	333,356	(205)	(214,761)
Balance, shares at Dec. 31, 2022		40,394,363
Stock-based compensation	2,092		2,092
Exercise of pre-funded warrants, shares		3,325,644
Shares purchased in Employee Stock Purchase Plan	96		96
Shares purchased in Employee Stock Purchase Plan, shares		45,478
Other comprehensive income (loss):
Unrealized gain on investments	150			150
Foreign currency translation adjustment	19			19
Net loss	(17,404)				(17,404)
Balance at Mar. 31, 2023	103,347	$ 4	335,544	(36)	(232,165)
Balance, shares at Mar. 31, 2023		43,765,485
Balance at Dec. 31, 2022	118,394	$ 4	333,356	(205)	(214,761)
Balance, shares at Dec. 31, 2022		40,394,363
Other comprehensive income (loss):
Net loss	(49,625)
Balance at Sep. 30, 2023	160,213	$ 6	424,671	(78)	(264,386)
Balance, shares at Sep. 30, 2023		61,760,748
Balance at Mar. 31, 2023	103,347	$ 4	335,544	(36)	(232,165)
Balance, shares at Mar. 31, 2023		43,765,485
Stock-based compensation	1,600		1,600
Shares issued in at-the-market offering, Shares		2,591,995
Shares issued in at-the-market offering	16,087	$ 1	16,086
Exercise of stock options	55		55
Exercise of stock options, shares		21,608
Other comprehensive income (loss):
Unrealized gain on investments	76			76
Foreign currency translation adjustment	11			11
Net loss	(15,583)				(15,583)
Balance at Jun. 30, 2023	105,593	$ 5	353,285	51	(247,748)
Balance, shares at Jun. 30, 2023		46,379,088
Stock-based compensation	1,672		1,672
Proceeds from issuance of common stock	64,413	$ 1	64,412
Stock Issued During Period, Shares, New Issues		14,375,000
Stock Issued During Period, Value, New Issues	64,413	$ 1	64,412
Shares issued in at-the-market offering, Shares		962,000
Shares issued in at-the-market offering	5,149		5,149
Proceeds from issuance of common stock, Shares		14,375,000
Exercise of stock options	43		43
Exercise of stock options, shares		13,578
Shares purchased in Employee Stock Purchase Plan	110		110
Shares purchased in Employee Stock Purchase Plan, shares		31,082
Other comprehensive income (loss):
Unrealized gain on investments	53			53
Foreign currency translation adjustment	(182)			(182)
Net loss	(16,638)				(16,638)
Balance at Sep. 30, 2023	$ 160,213	$ 6	$ 424,671	$ (78)	$ (264,386)
Balance, shares at Sep. 30, 2023		61,760,748

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating activities
Net loss	$ (49,625)	$ (48,517)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	624	546
Loss on Disposal of Fixed Assets	0	4
Stock-based compensation expense	5,364	5,786
Amortization of premiums and discounts on marketable securities	(3,334)	(1,082)
Reduction in the carrying value of right-of-use assets	364	319
Non-cash interest expense and amortization of debt issuance costs	426	27
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(4,887)	(933)
Accounts payable	(535)	(1,003)
Accrued expenses	(1,972)	2,435
Operating lease liabilities	(604)	(542)
Prepaid expenses, net of current portion	2,115	(401)
Other long-term liabilities	(124)
Net cash used in operating activities	(52,188)	(43,361)
Investing activities
Purchases of marketable securities	(211,465)	(126,007)
Maturities of marketable securities	164,482	117,750
Purchases of property and equipment	(193)	(364)
Net cash used in investing activities	(47,176)	(8,621)
Financing activities
Net proceeds from issuance of long-term debt	27,500	4,050
Proceeds from Issuance of Common Stock	85,649	56,137
Net proceeds from issuance of pre-funded warrants	0	12,150
Proceeds from exercise of stock options	98	359
Proceeds from issuance of common stock for cash under Employee Stock Purchase Plan	206	92
Net cash provided by financing activities	113,453	72,788
Net increase in cash, cash equivalents and restricted cash	14,089	20,806
Effect of foreign currency exchange rate in cash	(152)	(78)
Cash, cash equivalents and restricted cash at beginning of period	33,269	23,670
Cash, cash equivalents and restricted cash at end of period	47,206	44,398
Supplemental cash flow information:
Cash and cash equivalents	46,895	44,044
Restricted cash	311	354
Cash, cash equivalents and restricted cash at end of period	47,206	44,398
Property and equipment unpaid at end of period	$ 3	$ 0

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2023
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. Through the Company’s in-depth understanding of a key biological pathway, 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 this critical pathway and that defects in these genes lead to low levels of plasma pyrophosphate, which drives pathologic mineralization, and low levels of adenosine, which drives intimal proliferation. The Company is initially focused on developing a novel therapy to treat rare genetic diseases of ENPP1 and ABCC6 Deficiencies. The Company’s lead product candidate, INZ-701, is a soluble, recombinant, or genetically engineered, fusion protein that is designed to correct a defect 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 the inhibition of intimal proliferation, or narrowing and obstruction 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, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023, 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, 2022 . Liquidity, Capital Resources, and Going Concern Since the Company’s incorporation in 2017 and through September 30, 2023, 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 $ 49.6 million for the nine months ended September 30, 2023 and had an accumulated deficit of $ 264.4 million as of September 30, 2023. The Company had cash, cash equivalents, and short-term investments of $ 192.4 million as of September 30, 2023. 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 its loan and security agreement (the “Loan Agreement”) with K2 HealthVentures LLC (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, 2023 will be sufficient to fund its cash flow requirements for at least 12 months from the filing date of 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, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Principles of Consolidation The accompanying condensed 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 condensed consolidated financial statements are described in the Company’s audited consolidated financial statements for the year ended December 31, 2022 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. There have been no material changes in the Company’s significant accounting policies during the nine months ended September 30, 2023 . 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. 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 currently comprised of U.S. Treasury securities and U.S. government agency debt securities, and have also included commercial paper of corporations in prior periods. 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. Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents include cash in readily available checking accounts, money market accounts and certain marketable securities. Cash is carried at cost, which approximates its fair value. Cash equivalents are carried at fair market value. Restricted Cash Restricted cash is composed of amounts held to collateralize the letter of credit related to the Company’s lease arrangements. Restricted cash is classified as either current or non-current based on the terms of the underlying lease arrangement.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2023
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	3. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board ("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 Adopted Accounting Standards In June 2016, the FASB issued Accounting Standards Update ("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 Company adopted this standard effective January 1, 2023. There was no impact to the Company's financial statements upon adoption.

Short-Term Investments

Short-Term Investments	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Short-Term Investments	4. Short-Term Investments Short-term investments consisted of the following: September 30, 2023 Description Maturity Amortized Gross Gross Estimated U.S. Treasury securities 1 year or less $ 57,787 $ 2 $ ( 1 ) $ 57,788 U.S. government agency debt securities 1 year or less 87,679 82 ( 2 ) 87,759 $ 145,466 $ 84 $ ( 3 ) $ 145,547 December 31, 2022 Description Maturity Amortized Gross Gross Estimated Commercial paper 1 year or less $ 78,451 $ 4 $ ( 119 ) $ 78,336 U.S. Treasury securities 1 year or less 16,698 — ( 83 ) 16,615 $ 95,149 $ 4 $ ( 202 ) $ 94,951 The Company did no t have any investments in a continuous unrealized loss position for more than 12 months as of September 30, 2023. As of September 30, 2023 , the Company believes that the cost basis of its available-for-sale securities is recoverable and the Company has the intent and ability to hold its available-for-sale securities until recovery. Therefore, no allowance for credit losses was recorded.

Fair Value Measurement

Fair Value Measurement	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurement	5. Fair Value Measurement 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). 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: Fair Value Measurements at Reporting Date Description September 30, Level 1 Level 2 Level 3 Assets: Money market funds (included in cash and cash $ 41,289 $ 41,289 $ — $ — U.S. government agency debt securities 87,759 — 87,759 — U.S. Treasury securities (amounts included in either cash and cash 62,757 62,757 — — Total assets $ 191,805 $ 104,046 $ 87,759 $ — Fair Value Measurements at Reporting Date Description December 31, Level 1 Level 2 Level 3 Assets: Money market funds (included in cash and cash $ 26,587 $ 26,587 $ — $ — Commercial paper 78,336 — 78,336 — U.S. Treasury securities 16,615 16,615 — — Total assets $ 121,538 $ 43,202 $ 78,336 $ — There have been no transfers between fair value levels during the three or nine months ended September 30, 2023 .

License and Sponsored Research

License and Sponsored Research Agreements	9 Months Ended
	Sep. 30, 2023
Research and Development [Abstract]
License Agreement	6. License Agreement 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, 2023 , the Company incurred a life-to-date total of $ 0.7 million 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 the 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.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies Operating Leases The Company held the following significant operating leases as of September 30, 2023: • 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 • 6,244 square feet of laboratory space in Boston, Massachusetts that expires in 2025 . During the nine months ended September 30, 2023 , cash paid for amounts included in the measurement of lease liabilities was $ 0.7 million, and the Company recorded operating lease expense of $ 0.5 million. Future lease payments under non-cancelable leases as of September 30, 2023 are as follows: Year Ending December 31, 2023 (remaining 3 months) $ 249 2024 1,016 2025 944 $ 2,209 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, 2023 or December 31, 2022. 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, 2023 and 2022 .

Convertible Debt

Convertible Debt	9 Months Ended
	Sep. 30, 2023
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 the Loan Agreement with K2 HealthVentures LLC (“K2HV”, together with any other lender from time to time, the “Lenders”), 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 contained an additional $ 20.0 million available to be drawn at the Company’s option through March 31, 2023. The Company elected to borrow the remaining $ 20.0 million in February 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. The Company elected to borrow $ 7.5 million under the second tranche commitment in June 2023. 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 at its discretion. The fourth tranche commitment is subject to an additional 0.75 % facility fee. As of September 30, 2023, a total of $ 37.5 million of borrowing capacity remained available under the Loan Agreement, subject to the terms and conditions set forth therein. 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, 2023 was 9.60 %. 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 to 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, 2023, 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 $ 1.0 million and $ 2.1 million during the three and nine months ended September 30, 2023, respectively. At September 30, 2023, the carrying value of the Loan Agreement approximated 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, 2023: September 30, Gross proceeds $ 32,500 Unamortized debt issuance costs ( 435 ) Carrying value $ 32,065 Future principal payments, which include the Final Fee, in connection with the Loan Agreement as of September 30, 2023 are as follows: Fiscal Year 2023 $ — 2024 — 2025 10,479 2026 24,052 Total $ 34,531

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Stockholders' Equity	9. Stockholders’ Equity July 2023 Underwritten Offering On July 27, 2023, the Company entered into an underwriting agreement with BofA Securities, Inc., Cowen and Company, LLC and Piper Sandler & Co., as representatives of the several underwriters named therein (collectively, the “Underwriters”), relating to an underwritten public offering of 14,375,000 shares of the Company's common stock, which included 1,875,000 shares issued upon the exercise in full by the underwriters of their option to purchase additional shares (the "July 2023 Shares"). The closing of the offering took place on August 1, 2023. All of the July 2023 Shares were sold by the Company. The offering price of the July 2023 Shares was $ 4.80 per share. Net proceeds from the sale and issuance of the July 2023 Shares were approximately $ 64.4 million, after deducting underwriting discounts and commissions and offering expenses. 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 under the Company's registration statement on Form S-3 of 16,276,987 shares of the Company’s common stock (the "April 2022 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 April 2022 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. 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 were 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 were equity classified because they were freestanding financial instruments that were legally detachable and separately exercisable from the equity instruments, were immediately exercisable, did not embody an obligation for the Company to repurchase its shares, and permitted the holders to receive a fixed number of shares of common stock upon exercise. In addition, such pre-funded warrants did not provide any guarantee of value or return. As of March 31, 2023, all 3,523,013 pre-funded warrants had been exercised by means of cashless exercise in exchange for the issuance of 3,522,884 shares of the Company's common stock. Open Market Sale Agreement On August 11, 2021, the Company filed a universal shelf registration statement on Form S-3, which was declared effective on August 23, 2021 (the "Registration Statement"). Under the Registration Statement, the Company may offer and sell up to $ 200.0 million of a variety of securities, including common stock, preferred stock, depositary shares, debt securities, warrants, subscription rights or units from time to time pursuant to one or more offerings at prices and terms to be determined at the time of the sale. In connection with the filing of the Registration Statement, the Company entered into an Open Market Sale Agreement (the “Sales Agreement”) with Jefferies LLC (“Jefferies”) , as sales agent, pursuant to which the Company may offer and sell shares of its common stock with an aggregate offering price of up to $ 50.0 million under an “at-the-market” offering program. For the three months ended September 30, 2023, the Company sold 962,000 shares of its common stock pursuant to the Sales Agreement for aggregate net proceeds of $ 5.1 million. As of September 30, 2023, the Company had sold 3,553,995 shares of its common stock pursuant to the Sales Agreement for aggregate net proceeds of $ 21.2 million . Equity Incentive Plans 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. On February 27, 2023, the Company's board of directors adopted the 2023 Inducement Stock Incentive Plan (the "Inducement Plan"). The Inducement Plan provides for the grant of non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards to persons who (a) were not previously an employee or director or (b) are commencing employment with the Company following a bona fide period of non-employment, in either case, as an inducement material to such person’s entry into employment with the Company and in accordance with the requirements of the Nasdaq Stock Market Rule 5635(c)(4). Stock Options The Company estimates the fair value of stock options using the Black-Scholes option-pricing model. The underlying assumptions used to value stock options granted to participants using the Black-Scholes option-pricing model were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Risk-free interest rate range 4.15 % to 4.23 % 2.63 % to 4.04 % 3.36 % to 4.23 % 1.58 % to 4.04 % Dividend yield — — — — Expected term of options (years) 6.08 6.08 to 6.48 5.50 to 6.48 5.08 to 6.48 Volatility rate range 88.39 % to 88.96 % 84.50 % to 86.40 % 87.68 % to 89.67 % 84.50 % to 87.15 % The weighted-average grant date fair value of options granted in the three and nine months ended September 30, 2023 was $ 3.79 per share and $ 4.50 per share, respectively. The total unrecognized compensation cost related to outstanding option awards as of September 30, 2023 was $ 15.0 million and is expected to be recognized over a weighted-average period of 2.6 years. Restricted Stock Units Activity related to restricted stock units ("RSUs") for the nine months ended September 30, 2023 is summarized in the table below: Number of Shares Outstanding as of January 1, 2023 — Granted 100,000 Canceled / Forfeited — Vested / Settled — Outstanding as of September 30, 2023 100,000 The weighted-average grant date fair value of RSUs granted in both the three and nine months ended September 30, 2023 was $ 5.73 per share. The total unrecognized compensation cost related to outstanding RSUs as of September 30, 2023 was $ 0.5 million and is expected to be recognized over a weighted-average period of 3.5 years. The total compensation cost recognized in the condensed consolidated statements of operations associated with all the stock-based compensation awards granted by the Company is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development $ 839 $ 931 $ 2,546 $ 2,923 General and administrative 833 918 2,817 2,863 Total $ 1,672 $ 1,849 $ 5,363 $ 5,786

Net Loss per Share

Net Loss per Share	9 Months Ended
	Sep. 30, 2023
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: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Net loss attributable to common stockholders—basic $ ( 16,638 ) $ ( 16,372 ) $ ( 49,625 ) $ ( 48,517 ) Net loss per share attributable to common $ ( 0.29 ) $ ( 0.38 ) $ ( 1.02 ) $ ( 1.36 ) Weighted-average common shares and pre-funded 56,758,395 43,657,718 48,494,175 35,755,695 The Company 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 were issuable for little or no consideration, they were considered outstanding for both basic and diluted loss per share from the date of issuance. The Company excluded the following potential shares of common stock, 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, 2023 2022 2023 2022 Stock options 6,520,878 4,807,509 6,520,878 4,807,509 Unvested RSUs 100,000 — 100,000 — Total 6,620,878 4,807,509 6,620,878 4,807,509

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
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, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023, 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, 2022 .
Principles of Consolidation	Principles of Consolidation The accompanying condensed 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 condensed consolidated financial statements are described in the Company’s audited consolidated financial statements for the year ended December 31, 2022 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. There have been no material changes in the Company’s significant accounting policies during the nine months ended September 30, 2023 .
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.
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 currently comprised of U.S. Treasury securities and U.S. government agency debt securities, and have also included commercial paper of corporations in prior periods. 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.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents include cash in readily available checking accounts, money market accounts and certain marketable securities. Cash is carried at cost, which approximates its fair value. Cash equivalents are carried at fair market value.
Restricted Cash	Restricted Cash Restricted cash is composed of amounts held to collateralize the letter of credit related to the Company’s lease arrangements. Restricted cash is classified as either current or non-current based on the terms of the underlying lease arrangement.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards In June 2016, the FASB issued Accounting Standards Update ("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 Company adopted this standard effective January 1, 2023. There was no impact to the Company's financial statements upon adoption.

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Short-Term Investments	Short-term investments consisted of the following: September 30, 2023 Description Maturity Amortized Gross Gross Estimated U.S. Treasury securities 1 year or less $ 57,787 $ 2 $ ( 1 ) $ 57,788 U.S. government agency debt securities 1 year or less 87,679 82 ( 2 ) 87,759 $ 145,466 $ 84 $ ( 3 ) $ 145,547 December 31, 2022 Description Maturity Amortized Gross Gross Estimated Commercial paper 1 year or less $ 78,451 $ 4 $ ( 119 ) $ 78,336 U.S. Treasury securities 1 year or less 16,698 — ( 83 ) 16,615 $ 95,149 $ 4 $ ( 202 ) $ 94,951

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	9 Months Ended
	Sep. 30, 2023
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: Fair Value Measurements at Reporting Date Description September 30, Level 1 Level 2 Level 3 Assets: Money market funds (included in cash and cash $ 41,289 $ 41,289 $ — $ — U.S. government agency debt securities 87,759 — 87,759 — U.S. Treasury securities (amounts included in either cash and cash 62,757 62,757 — — Total assets $ 191,805 $ 104,046 $ 87,759 $ — Fair Value Measurements at Reporting Date Description December 31, Level 1 Level 2 Level 3 Assets: Money market funds (included in cash and cash $ 26,587 $ 26,587 $ — $ — Commercial paper 78,336 — 78,336 — U.S. Treasury securities 16,615 16,615 — — Total assets $ 121,538 $ 43,202 $ 78,336 $ —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2023
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, 2023 are as follows: Year Ending December 31, 2023 (remaining 3 months) $ 249 2024 1,016 2025 944 $ 2,209

Convertible Debt (Tables)

Convertible Debt (Tables)	9 Months Ended
	Sep. 30, 2023
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, 2023: September 30, Gross proceeds $ 32,500 Unamortized debt issuance costs ( 435 ) Carrying value $ 32,065
Future principal payment of Loan Agreement	Future principal payments, which include the Final Fee, in connection with the Loan Agreement as of September 30, 2023 are as follows: Fiscal Year 2023 $ — 2024 — 2025 10,479 2026 24,052 Total $ 34,531

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2023
Summary of Stock Option Activity Under Equity Incentive Plans	Activity related to restricted stock units ("RSUs") for the nine months ended September 30, 2023 is summarized in the table below: Number of Shares Outstanding as of January 1, 2023 — Granted 100,000 Canceled / Forfeited — Vested / Settled — Outstanding as of September 30, 2023 100,000
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 model were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Risk-free interest rate range 4.15 % to 4.23 % 2.63 % to 4.04 % 3.36 % to 4.23 % 1.58 % to 4.04 % Dividend yield — — — — Expected term of options (years) 6.08 6.08 to 6.48 5.50 to 6.48 5.08 to 6.48 Volatility rate range 88.39 % to 88.96 % 84.50 % to 86.40 % 87.68 % to 89.67 % 84.50 % to 87.15 %
Summary of Total Compensation Cost Recognized in Statements of Operations	The total compensation cost recognized in the condensed consolidated statements of operations associated with all the stock-based compensation awards granted by the Company is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development $ 839 $ 931 $ 2,546 $ 2,923 General and administrative 833 918 2,817 2,863 Total $ 1,672 $ 1,849 $ 5,363 $ 5,786

Net Loss per Share (Tables)

Net Loss per Share (Tables)	9 Months Ended
	Sep. 30, 2023
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: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Net loss attributable to common stockholders—basic $ ( 16,638 ) $ ( 16,372 ) $ ( 49,625 ) $ ( 48,517 ) Net loss per share attributable to common $ ( 0.29 ) $ ( 0.38 ) $ ( 1.02 ) $ ( 1.36 ) Weighted-average common shares and pre-funded 56,758,395 43,657,718 48,494,175 35,755,695
Schedule of Potential Dilutive Securities Excluded from Computation of Earning Per Share	The Company excluded the following potential shares of common stock, 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, 2023 2022 2023 2022 Stock options 6,520,878 4,807,509 6,520,878 4,807,509 Unvested RSUs 100,000 — 100,000 — Total 6,620,878 4,807,509 6,620,878 4,807,509

Organization and Basis of Pre_2

Organization and Basis of Presentation - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended					9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Subsidiary, Sale of Stock [Line Items]
Net loss	$ (16,638)	$ (15,583)	$ (17,404)	$ (16,372)	$ (16,884)	$ (49,625)	$ (48,517)
Accumulated deficit	(264,386)					(264,386)		$ (214,761)
Cash and cash equivalents and short term investments	$ 192,400					$ 192,400

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Accounting Policies [Abstract]
Off-balance sheet concentrations of credit risk description	The Company has no significant off-balance sheet risk such as foreign exchange contracts, option contracts, or other foreign hedging arrangements.
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, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Amortized Costs	$ 145,466	$ 95,149
Gross Unrealized Gains	84	4
Gross Unrealized Losses	(3)	(202)
Estimated Fair Value	$ 145,547	$ 94,951
Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Maturity		1 year or less
Amortized Costs		$ 78,451
Gross Unrealized Gains		4
Gross Unrealized Losses		(119)
Estimated Fair Value		$ 78,336
U.S. Treasury Securities
Schedule Of Available For Sale Securities [Line Items]
Maturity	1 year or less	1 year or less
Amortized Costs	$ 57,787	$ 16,698
Gross Unrealized Gains	2	0
Gross Unrealized Losses	(1)	(83)
Estimated Fair Value	$ 57,788	$ 16,615
U.S. government agency debt securities
Schedule Of Available For Sale Securities [Line Items]
Maturity	1 year or less
Amortized Costs	$ 87,679
Gross Unrealized Gains	82
Gross Unrealized Losses	(2)
Estimated Fair Value	$ 87,759

Balance Sheet Details - Additio

Balance Sheet Details - Additional Information (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Investments in a continuous unrealized loss position, 12 months or longer	$ 0
Debt securities, available for sale, allowance for credit loss	$ 0

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Total	$ 9,383	$ 11,355

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Financial Assets Measured at Fair Value (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	$ 191,805	$ 121,538
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents fair value disclosure	41,289	26,587
Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure		78,336
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	104,046	43,202
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	41,289	26,587
Level 1 | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure		0
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	87,759	78,336
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
Level 2 | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure		78,336
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	0	0
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
Level 3 | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
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		16,615
U.S. Treasury Securities | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure		16,615
U.S. Treasury Securities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure		0
U.S. Treasury Securities | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure		$ 0
U.S. Government Agency Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents fair value disclosure	87,759
U.S. Government Agency Debt Securities | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents fair value disclosure	0
U.S. Government Agency Debt Securities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents fair value disclosure	87,759
U.S. Government Agency Debt Securities | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents fair value disclosure	0
U.S. Government agency debt securities Included in Cash and Cash equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	62,757
U.S. Government agency debt securities Included in Cash and Cash equivalents | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	62,757
U.S. Government agency debt securities Included in Cash and Cash equivalents | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	0
U.S. Government agency debt securities Included in Cash and Cash equivalents | 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	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
Fair Value Disclosures [Abstract]
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) - Yale University [Member] - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Mar. 31, 2022	Nov. 30, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Partial upfront consideration payment under license agreement	$ 0.1
Milestone payment upon achievement of certain milestones	3	$ 0.3	$ 0.3
License [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Maintenance fees	$ 0.7

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2023 USD ($) ft²	Mar. 31, 2023	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) ft²	Sep. 30, 2022 USD ($)
Lessee Lease Description [Line Items]
Operating lease liabilities	$ 700			$ 700
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, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2023 (remaining 3 months)	$ 249
2024	1,016
2025	944
Operating lease liability	$ 2,209

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, 2023	Sep. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Loan amount		$ 32,065	$ 32,065	$ 4,139
Annual rate of interest for the debt	7.85		9.60
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	37,500	$ 37,500
Loan Maturity Date	Aug. 01, 2026
Debt instrument conversion price	$ 6.21
Customary percentage	9.99%
Beneficial ownership limitation percentage	19.99%
Maximum [Member] | K2HV [Member]
Debt Instrument [Line Items]
Debt instrument, Amount converted to common stock upon lender's choice	$ 5,000
Future offerings of common stock	$ 5,000
Share Based Compensation Award Tranche One [Member]
Debt Instrument [Line Items]
Prepayment fee percentage	3%
Share Based Compensation Award Tranche One [Member] | K2HV [Member]
Debt Instrument [Line Items]
Loan amount	$ 5,000
Additional loan amount	$ 20,000
Share Based Compensation Award Tranche Two [Member]
Debt Instrument [Line Items]
Prepayment fee percentage	2%
Share Based Compensation Award Tranche Two [Member] | K2HV [Member]
Debt Instrument [Line Items]
Loan amount	$ 20,000	7,500	7,500
Share Based Compensation Award Tranche Four [Member]
Debt Instrument [Line Items]
Prepayment fee percentage	1%
Share Based Compensation Award 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		$ 1,000	$ 2,100

Convertible Debt - Summarizes o

Convertible Debt - Summarizes of impact Term Loan (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
Gross Proceeds	$ 32,500
Unamortized debt issuance costs	(435)
Total	$ 32,065	$ 4,139

Convertible Debt - Future princ

Convertible Debt - Future principal payments (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fiscal Year
Total	$ 32,065	$ 4,139
K2 Loan Agreement [Member]
Fiscal Year
2023	0
2024	0
2025	10,479
2026	24,052
Total	$ 34,531,000

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($)				3 Months Ended	9 Months Ended
	Jul. 27, 2023	Apr. 14, 2022	Aug. 11, 2021	Sep. 30, 2023	Sep. 30, 2023	Dec. 31, 2022	Jun. 10, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common Stock, Par or Stated Value Per Share				$ 0.0001	$ 0.0001	$ 0.0001
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.
Total unrecognized compensation cost related to outstanding employee awards				$ 15,000,000	$ 15,000,000
Total unrecognized compensation cost related to outstanding employee awards, expected to be recognized over a weighted-average period					2 years 7 months 6 days
Pre-funded warrant exercisable price							$ 0.0001
Additional shares issued	1,875,000
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of options granted				$ 3.79	$ 4.5
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of options granted				$ 5.73	$ 5.73
Total unrecognized compensation cost related to outstanding employee awards				$ 500,000	$ 500,000
Employee Service ShareBased Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period ForRecognition 2					3 years 6 months
Pre Funded Warrants [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized for issuance				3,522,884	3,522,884
Pre-funded warrant exercisable price				$ 3,523,013	$ 3,523,013
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		$ 68,300,000
Proceeds from issuance or sale of equity			$ 21,200	$ 5,100,000
Sale of Stock, Number of Shares Issued in Transaction			3,553,995	962,000
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
BofA Securities, Inc [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Offering price	$ 4.8
Net proceeds from the offering	$ 64,400
Underwriting Agreement [Member] | BofA Securities, Inc [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from issuance of common stock, Shares	14,375,000
Maximum [Member] | Jefferies LLC
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Offer and sell			$ 50,000,000
Aggregate offering price			$ 200,000,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Option Activity Under Equity Incentive Plans (Details)	9 Months Ended
	Sep. 30, 2023 shares
Equity [Abstract]
Options Outstanding, Beginning Balance	0
Options Outstanding, Granted	100,000
Options Outstanding, Forfeited	0
Options Outstanding, vested	0
Options Outstanding, Ending Balance	100,000

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, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate range, minimum	4.15%	2.63%	3.36%	1.58%
Risk-free interest rate range, maximum	4.23%	4.04%	4.23%	4.04%
Dividend yield	0%	0%	0%	0%
Expected term of options (years)	6 years 29 days
Volatility rate range, minimum	88.39%	84.50%	87.68%	84.50%
Volatility rate range, maximum	88.96%	86.40%	89.67%	87.15%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term of options (years)		6 years 29 days	5 years 6 months	5 years 29 days
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term of options (years)		6 years 5 months 23 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, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	$ 1,672	$ 1,849	$ 5,363	$ 5,786
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	839	931	2,546	2,923
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	$ 833	$ 918	$ 2,817	$ 2,863

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
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Net loss attributable to common stockholders—basic and diluted	$ (16,638)	$ (15,583)	$ (17,404)	$ (16,372)	$ (16,884)	$ (49,625)	$ (48,517)
Net loss per share attributable to common stockholders- basic	$ (0.29)			$ (0.38)		$ (1.02)	$ (1.36)
Net loss per share attributable to common stockholders- diluted	$ (0.29)			$ (0.38)		$ (1.02)	$ (1.36)
Weighted-average common shares and pre-funded warrants outstanding - basic	56,758,395			43,657,718		48,494,175	35,755,695
Weighted-average common shares and pre-funded warrants outstanding - diluted	56,758,395			43,657,718		48,494,175	35,755,695

Net Loss per Share - Schedule_2

Net Loss per Share - Schedule of Potential Dilutive Securities Excluded from Computation of Earning Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	6,620,878	4,807,509	6,620,878	4,807,509
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	6,520,878	4,807,509	6,520,878	4,807,509
Unvested RSUs [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	100,000	0	100,000	0

Subsequent Event (Additional In

Subsequent Event (Additional Information) (Details) - Jefferies, LLC [Member] - USD ($)			3 Months Ended
	Apr. 14, 2022	Aug. 11, 2021	Sep. 30, 2023
Subsequent Event [Line Items]
Number of shares issued or sold		3,553,995	962,000
Proceeds from issuance or sale of equity		$ 21,200	$ 5,100,000
Net proceeds from the offering	$ 68,300,000