Inozyme Pharma (INZY) 10-Q 10 May 22 2022 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	May 06, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
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		40,097,076

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 31,943	$ 23,316
Short-term investments	65,830	88,485
Prepaid expenses and other current assets	2,810	3,541
Total current assets	100,583	115,342
Property and equipment, net	2,234	2,383
Right-of-use assets	1,950	2,053
Restricted cash	354	354
Prepaid expenses, net of current portion	3,810	3,409
Total assets	108,931	123,541
Current liabilities:
Accounts payable	2,200	2,394
Accrued expenses	9,308	8,508
Operating lease liabilities	752	731
Total current liabilities	12,260	11,633
Operating lease liabilities, net of current portion	2,442	2,640
Total liabilities	14,702	14,273
Commitments and Contingencies
Stockholders’ equity:
Preferred Stock, $0.0001 par value - 5,000,000 shares authorized at March 31, 2022 and December 31, 2021; No shares issued and outstanding at March 31, 2022 or December 31, 2021	0	0
Common Stock, $0.0001 par value - 200,000,000 shares authorized at March 31, 2022 and December 31, 2021; 23,818,411 shares issued and outstanding at March 31, 2022 and 23,668,747 shares issued and outstanding at December 31, 2021	2	2
Additional paid in-capital	258,940	256,948
Accumulated other comprehensive (loss) income	(129)	18
Accumulated deficit	(164,584)	(147,700)
Total stockholders’ equity	94,229	109,268
Total liabilities and stockholders’ equity	$ 108,931	$ 123,541

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (Unaudited) - $ / shares	Mar. 31, 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	23,818,411	23,668,747
Common stock, shares outstanding	23,818,411	23,668,747

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating expenses:
Research and development	$ 11,814	$ 6,603
General and administrative	5,025	4,369
Total operating expenses	16,839	10,972
Loss from operations	(16,839)	(10,972)
Other income (expense):
Interest income	60	63
Other expenses	(105)	(141)
Other expenses, net	(45)	(78)
Net loss	(16,884)	(11,050)
Other comprehensive (loss) income:
Unrealized (losses) gains on available-for-sale securities	(132)	10
Foreign currency translation adjustment	(15)
Total other comprehensive (loss) income	(147)	10
Comprehensive loss	(17,031)	(11,040)
Net loss attributable to common stockholders—basic and diluted	$ (16,884)	$ (11,050)
Net loss per share attributable to common stockholders—basic and diluted	$ (0.71)	$ (0.47)
Weighted-average common shares outstanding—basic and diluted	23,686,351	23,429,507

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	(56,600)
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	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

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities
Net loss	$ (16,884)	$ (11,050)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	178	158
Stock-based compensation expense	1,752	1,577
Amortization of premiums and discounts on marketable securities	(76)	58
Reduction in the carrying value of right-of-use assets	103	90
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	731	327
Accounts payable	(194)	(1,373)
Accrued expenses	808	(2,272)
Operating lease liabilities	(177)	(131)
Prepaid expenses - noncurrent	(401)	240
Net cash used in operating activities	(14,160)	(12,376)
Investing activities
Purchases of marketable securities	(30,421)	(38,549)
Maturities of marketable securities	53,000	39,210
Purchases of property and equipment	(17)	(88)
Net cash provided by investing activities	22,562	573
Financing activities
Proceeds from exercise of stock options	240	249
Net cash provided by financing activities	240	249
Net (decrease) increase in cash, cash equivalents and restricted cash	8,642	(11,554)
Effect of foreign currency exchange rate in cash	(15)	0
Cash, cash equivalents and restricted cash at beginning of period	23,670	28,394
Cash, cash equivalents and restricted cash at end of period	32,297	16,840
Supplemental cash flow information:
Cash and cash equivalents	31,943	16,486
Restricted cash	354	354
Cash, cash equivalents and restricted cash at end of period	32,297	16,840
Property and equipment unpaid at end of period	12	110
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	3 Months Ended
	Mar. 31, 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 of abnormal mineralization 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 mineralization pathway and that defects in these genes lead to abnormal mineralization. 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 a defect in the mineralization pathway caused by ENPP1 and ABCC6 Deficiencies. This pathway is central to the regulation of calcium deposition throughout the body and is further associated with neointimal proliferation, or the overgrowth of smooth muscle cells inside 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 months ended March 31, 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 March 31, 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 $ 16.9 million in the three months ended March 31, 2022 and $ 56.6 million in the year ended December 31, 2021 and had an accumulated deficit of $ 164.6 million as of March 31, 2022. The Company had cash, cash equivalents, and short-term investments of $ 97.8 million as of March 31, 2022. Subsequent to March 31, 2022, the Company entered into an underwriting agreement (the “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. Net proceeds from the offering were approximately $ 68.3 million, after deducting underwriting discounts and commissions and estimated offering expenses. 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 and offerings of common stock and pre-funded warrants. 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 March 31, 2022, together with the net proceeds from its sale of common stock and pre-funded warrants in April 2022, will be sufficient to fund its operating expenses and capital expenditure 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	3 Months Ended
	Mar. 31, 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. There have been no material changes in the Company’s significant accounting policies during the three months ended March 31, 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 consolidated balance sheets and within research and development expense in the accompanying 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 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 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.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 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 new standard is effective for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022 for non-public entities, with early adoption permitted. The Company adopted 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 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	3 Months Ended
	Mar. 31, 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): March 31, 2022 Description Maturity Amortized Gross Gross Estimated Commercial paper 1 year or less $ 44,213 $ — $ ( 87 ) $ 44,126 U.S. Treasury securities 1 year or less 21,747 — ( 43 ) 21,704 $ 65,960 $ — $ ( 130 ) $ 65,830 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 March 31, 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 March 31, At December 31, Interest receivable $ 48 $ 62 Prepaid insurance 1,029 1,728 Prepaid research studies 1,014 1,190 Prepaid other 719 561 Total $ 2,810 $ 3,541 Prepaid expenses, net of current portion, consisted of the following (dollar amounts in thousands): At March 31, 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 March 31, At December 31, Laboratory equipment and manufacturing equipment $ 591 $ 591 Furniture and fixtures 258 258 Computer equipment and software 469 440 Leasehold improvements 2,095 2,095 3,413 3,384 Less accumulated depreciation ( 1,179 ) ( 1,001 ) Total $ 2,234 $ 2,383 Depreciation expense for the three months ended March 31, 2022 and 2021 was $ 178 thousand and $ 158 thousand, respectively. Accrued expenses consi sted of the following (dollar amounts in thousands): At March 31, At December 31, Payroll and related liabilities $ 750 $ 2,379 Professional fees 590 727 Research and development costs 7,144 5,066 Other 824 336 Total $ 9,308 $ 8,508

Fair Value Measurement

Fair Value Measurement	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurement	5. Fair Value Measurement The following table represents 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 March 31, Quoted Significant Significant Assets: Money market funds (included in cash and cash $ 21,877 $ 21,877 $ — $ — Commercial paper 44,126 — 44,126 — U.S. Treasury securities 21,704 21,704 — — Total assets $ 87,707 $ 43,581 $ 44,126 $ — 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 months ended March 31, 2022 .

License and Sponsored Research

License and Sponsored Research Agreements	3 Months Ended
	Mar. 31, 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 approximately $ 0.1 million 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 March 31, 2022 , the Company incurred a total of $ 0.2 million in license maintenance fees to Yale. The Company is required to pay Yale $ 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 Company recorded research and development expenses associated with this arrangeme nt of $ 0.1 million an d $ 0.1 mil lion in the three months ended March 31, 2022 and 2021, respectively.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 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 March 31, 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 three months ended March 31, 2022 , cash paid for amounts included for the measurement of lease liabilities was $ 0.2 million and the Company recorded operating lease expense of $ 0.2 million. Future lease payments under non-cancelable leases as of March 31, 2022 are as follows (dollar amounts in thousands): Year Ending December 31, 2022 (remaining 9 months) $ 726 2023 992 2024 1,016 2025 944 Thereafter — $ 3,678 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 March 31, 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 months ended March 31, 2022 and 2021 .

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Stockholders' Equity	8. Stockholders’ Equity 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 March 31, 2022 , 721,937 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 since December 31, 2021: Options Weighted- Weighted- Aggregate (in years) (in thousands) Outstanding at December 31, 2021 3,582,613 $ 10.63 8.32 $ 7,428 Granted 1,208,550 5.60 Exercised ( 149,664 ) 1.61 Forfeited ( 134,641 ) 10.16 Outstanding at March 31, 2022 4,506,858 $ 9.60 8.60 $ 2,746 Exercisable at March 31, 2022 1,487,970 $ 8.29 7.53 $ 1,964 Vested and expected to vest at March 31, 2022 4,506,858 $ 9.60 8.60 $ 2,746 (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 months ended March 31, 2022 was $ 4.34 per share. The aggregate intrinsic value of stock options exercised during the three months ended March 31, 2022 was immaterial. 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 March 31, 2022 2021 Risk-free interest rate range 1.59 % to 2.37 % 0.48 % to 1.05 % Dividend yield 0 % 0 % Expected term of options (years) 5.08 to 6.48 6.08 to 6.48 Volatility rate range 85.38 % to 86.64 % 88.70 % to 90.53 % 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 March 31, 2022 2021 Research and development $ 896 $ 641 General and administrative 856 936 Total $ 1,752 $ 1,577 The total unrecognized compensation cost related to outstanding employee awards as of March 31, 2022 wa s $ 19.5 million and is expected to be recognized over a weighted-average period of 2.90 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 March 31, 2022 , no 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 ends on September 30, 2022.

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Net Loss per Share	9. 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 March 31, 2022 and 2021 (in thousands, except share and per share amounts): Three Months Ended March 31, 2022 2021 Net loss attributable to common stockholders—basic $ ( 16,884 ) $ ( 11,050 ) Net loss per share attributable to common $ ( 0.71 ) $ ( 0.47 ) Weighted-average common shares outstanding—basic 23,686,351 23,429,507 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. 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 March 31, 2022 2021 Options to purchase common stock 4,506,858 3,523,586 4,506,858 3,523,586

Employee Benefit Plans

Employee Benefit Plans	3 Months Ended
	Mar. 31, 2022
Retirement Benefits [Abstract]
Employee Benefit Plans	10. 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 months ended March 31, 2022 , the Company made employer contributions to the 401(k) plan totaling $ 82 thousand.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2022
Related Party Transactions [Abstract]
Related Party Transaction	11. Related Party Transactions On May 6, 2021, the Company entered into an amended and restated consulting agreement (the “Consulting Agreement”) with Danforth Advisors, LLC (“Danforth”), pursuant to which Danforth, in addition to providing finance, accounting and administrative functions, provided interim chief financial officer services provided to the Company by Stephen J. DiPalma, managing director of Danforth. The Company pays Danforth an agreed upon hourly rate for such services and reimburses Danforth for expenses. The Consulting Agreement may be terminated by the Company or Danforth with cause, upon 30 days prior written notice, and without cause, upon 60 days prior written notice. Mr. DiPalma ceased serving as the Company's interim chief financial officer on March 21, 2022 in connection with the appointment of Sanjay S. Subramanian as the Company's Chief Financial Officer. The Company has incurred $ 0.4 million of expense for services provided by Danforth in the three months ended March 31, 2022 .

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 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 months ended March 31, 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. There have been no material changes in the Company’s significant accounting policies during the three months ended March 31, 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 consolidated balance sheets and within research and development expense in the accompanying 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 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 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.
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 new standard is effective for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022 for non-public entities, with early adoption permitted. The Company adopted 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 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)	3 Months Ended
	Mar. 31, 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): March 31, 2022 Description Maturity Amortized Gross Gross Estimated Commercial paper 1 year or less $ 44,213 $ — $ ( 87 ) $ 44,126 U.S. Treasury securities 1 year or less 21,747 — ( 43 ) 21,704 $ 65,960 $ — $ ( 130 ) $ 65,830 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 March 31, At December 31, Interest receivable $ 48 $ 62 Prepaid insurance 1,029 1,728 Prepaid research studies 1,014 1,190 Prepaid other 719 561 Total $ 2,810 $ 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 March 31, 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 March 31, At December 31, Laboratory equipment and manufacturing equipment $ 591 $ 591 Furniture and fixtures 258 258 Computer equipment and software 469 440 Leasehold improvements 2,095 2,095 3,413 3,384 Less accumulated depreciation ( 1,179 ) ( 1,001 ) Total $ 2,234 $ 2,383
Schedule of Accrued Expenses	Accrued expenses consi sted of the following (dollar amounts in thousands): At March 31, At December 31, Payroll and related liabilities $ 750 $ 2,379 Professional fees 590 727 Research and development costs 7,144 5,066 Other 824 336 Total $ 9,308 $ 8,508

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Summary of Financial Assets Measured at Fair Value	The following table represents 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 March 31, Quoted Significant Significant Assets: Money market funds (included in cash and cash $ 21,877 $ 21,877 $ — $ — Commercial paper 44,126 — 44,126 — U.S. Treasury securities 21,704 21,704 — — Total assets $ 87,707 $ 43,581 $ 44,126 $ — 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)	3 Months Ended
	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Lease Payments Under Non-Cancelable Leases	Future lease payments under non-cancelable leases as of March 31, 2022 are as follows (dollar amounts in thousands): Year Ending December 31, 2022 (remaining 9 months) $ 726 2023 992 2024 1,016 2025 944 Thereafter — $ 3,678

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2022
Summary of Stock Option Activity Under Equity Incentive Plans	The following table summarizes stock option activity under the Company’s equity incentive plans since December 31, 2021: Options Weighted- Weighted- Aggregate (in years) (in thousands) Outstanding at December 31, 2021 3,582,613 $ 10.63 8.32 $ 7,428 Granted 1,208,550 5.60 Exercised ( 149,664 ) 1.61 Forfeited ( 134,641 ) 10.16 Outstanding at March 31, 2022 4,506,858 $ 9.60 8.60 $ 2,746 Exercisable at March 31, 2022 1,487,970 $ 8.29 7.53 $ 1,964 Vested and expected to vest at March 31, 2022 4,506,858 $ 9.60 8.60 $ 2,746 (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 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 March 31, 2022 2021 Research and development $ 896 $ 641 General and administrative 856 936 Total $ 1,752 $ 1,577
Employees
Summary of Assumptions Used to Value Stock Options Granted Using Black-Scholes Option-Pricing	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 March 31, 2022 2021 Risk-free interest rate range 1.59 % to 2.37 % 0.48 % to 1.05 % Dividend yield 0 % 0 % Expected term of options (years) 5.08 to 6.48 6.08 to 6.48 Volatility rate range 85.38 % to 86.64 % 88.70 % to 90.53 %

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2022 and 2021 (in thousands, except share and per share amounts): Three Months Ended March 31, 2022 2021 Net loss attributable to common stockholders—basic $ ( 16,884 ) $ ( 11,050 ) Net loss per share attributable to common $ ( 0.71 ) $ ( 0.47 ) Weighted-average common shares outstanding—basic 23,686,351 23,429,507
Schedule of Potential Dilutive Securities from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders	Three Months Ended March 31, 2022 2021 Options to purchase common stock 4,506,858 3,523,586 4,506,858 3,523,586

Organization and Basis of Pre_2

Organization and Basis of Presentation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Apr. 19, 2022	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Subsidiary, Sale of Stock [Line Items]
Net loss		$ 16,884	$ 11,050	$ 56,600
Accumulated deficit		164,584		$ 147,700
Cash and cash equivalents and short term investments		$ 97,800
Subsequent Event [Member]
Subsidiary, Sale of Stock [Line Items]
Offering price	$ 3.69
Proceeds from issuance of common stock	$ 68,300
Jefferies LLC and Cowen and Company LLC [Member] | Subsequent Event [Member]
Subsidiary, Sale of Stock [Line Items]
Underwritten offering	16,276,987
Pre Funded Warrants [Member] | Subsequent Event [Member]
Subsidiary, Sale of Stock [Line Items]
Class of Warrant purchases	3,523,013
Offering price	$ 3.6899

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)
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	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Amortized Costs	$ 65,960	$ 88,483
Gross Unrealized Gains	0	5
Gross Unrealized Losses	(130)	(3)
Estimated Fair Value	$ 65,830	$ 88,485
Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Maturity	1 year or less	1 year or less
Amortized Costs	$ 44,213	$ 78,456
Gross Unrealized Gains	0	5
Gross Unrealized Losses	(87)	(3)
Estimated Fair Value	$ 44,126	$ 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	$ 21,747	$ 5,025
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(43)	0
Estimated Fair Value	$ 21,704	$ 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
	Mar. 31, 2022	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Depreciation expense	$ 178	$ 158

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Long-Term Investments (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Amortized Costs	$ 65,960	$ 88,483
Gross Unrealized Gains	0	5
Gross Unrealized Losses	(130)	(3)
Estimated Fair Value	$ 65,830	$ 88,485
U.S. Treasury Securities
Schedule Of Available For Sale Securities [Line Items]
Maturity	1 year or less	1 year or less
Amortized Costs	$ 21,747	$ 5,025
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(43)	0
Estimated Fair Value	$ 21,704	$ 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 - Sched_3

Balance Sheet Details - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Interest receivable	$ 48	$ 62
Prepaid insurance	1,029	1,728
Prepaid research studies	1,014	1,190
Prepaid other	719	561
Total	$ 2,810	$ 3,541

Balance Sheet Details - Sched_4

Balance Sheet Details - Schedule of Prepaid Expenses, Net of Current Portion (Details) - USD ($) $ in Thousands	Mar. 31, 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_5

Balance Sheet Details - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 3,413	$ 3,384
Less accumulated depreciation	(1,179)	(1,001)
Total	2,234	2,383
Laboratory Equipment and Manufacturing Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	591	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	469	440
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 2,095	$ 2,095

Balance Sheet Details - Sched_6

Balance Sheet Details - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Payroll and related liabilities	$ 750	$ 2,379
Professional fees	590	727
Research and development costs	7,144	5,066
Other	824	336
Total	$ 9,308	$ 8,508

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Financial Assets Measured at Fair Value (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	$ 87,707	$ 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	21,877	14,302
Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	44,126	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	43,581	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	21,877	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]
Assets fair value disclosure	0	0
Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	44,126	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]
Assets fair value disclosure	44,126	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]
Assets fair value disclosure	0	0
U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	21,704	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	21,704	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) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)
Fair Value Disclosures [Abstract]
Fair value assets level 1 to level 2 transfers amount	$ 0
Fair value assets level 2 to level 1 transfers amount	0
Fair value measurement with unobservable inputs reconciliation recurring basis asset transfers into level 3	0
Fair value measurement with unobservable inputs reconciliation recurring basis asset transfers out of level 3	$ 0

License and Sponsored Researc_2

License and Sponsored Research Agreements - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 28, 2019	Mar. 31, 2022	Mar. 31, 2021	Jan. 31, 2022	Nov. 30, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research support funding expiration year	2021-12
Research and development expenses		$ 11,814	$ 6,603
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		$ 300	$ 300
Yale | Sponsored Research Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research support funding amount	$ 2,400
Research support funding period	5 years
Research and development expenses		100	$ 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	Jan. 01, 2021	Mar. 31, 2022USD ($)ft²	Mar. 31, 2021USD ($)
Lessee Lease Description [Line Items]
Operating lease liabilities		$ 200
Operating lease expense		200
Costs related to legal proceedings		$ 0	$ 0
Office Space | Boston, Massachusetts
Lessee Lease Description [Line Items]
Area of leased space | ft²		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
Laboratory Space | Boston, Massachusetts
Lessee Lease Description [Line Items]
Area of leased space | ft²		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	Mar. 31, 2022USD ($)
Commitments and Contingencies Disclosure [Abstract]
2022 (remaining 9 months)	$ 726
2023	992
2024	1,016
2025	944
Thereafter	0
Operating lease liability	$ 3,678

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 23, 2020	Mar. 31, 2022	Jan. 01, 2022	Dec. 31, 2021	Jul. 31, 2020	Jul. 17, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Preferred stock, shares outstanding		0		0
Common stock, shares authorized		200,000,000		200,000,000
Preferred stock, shares authorized		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		1,208,550
Weighted-average exercise price of options granted		$ 5.60
Weighted-average grant date fair value of options granted		$ 4.34
Total unrecognized compensation cost related to outstanding employee awards		$ 19.5
Total unrecognized compensation cost related to outstanding employee awards, expected to be recognized over a weighted-average period		2 years 10 months 24 days
Share based compensation options to purchase number of common stock		4,506,858		3,582,613
2020 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	1,588,315	721,937	946,749
Number of common stock reserved for issuance increase percentage on stock outstanding	4.00%
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	1.00%
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		0

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Option Activity Under Equity Incentive Plans (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2022	Dec. 31, 2021
Equity [Abstract]
Options Outstanding, Beginning Balance		3,582,613
Options Outstanding, Granted		1,208,550
Options Outstanding, Exercised		(149,664)
Options Outstanding, Forfeited		(134,641)
Options Outstanding, Ending Balance		4,506,858	3,582,613
Options Outstanding, Exercisable		1,487,970
Options Outstanding, Vested and expected to vest		4,506,858
Weighted Average Exercise Price, Outstanding, Beginning Balance		$ 10.63
Weighted Average Exercise Price, Granted		5.60
Weighted Average Exercise Price, Exercised		1.61
Weighted Average Exercise Price, Forfeited		10.16
Weighted Average Exercise Price, Outstanding, Ending Balance		9.60	$ 10.63
Weighted Average Exercise Price, Exercisable		8.29
Weighted Average Exercise Price, Vested and expected to vest		$ 9.60
Weighted Average Remaining Contractual Term (in years), Outstanding		8 years 7 months 6 days	8 years 3 months 25 days
Weighted Average Remaining Contractual Term (in years), Exercisable		7 years 6 months 10 days
Weighted Average Remaining Contractual Term (in years), Vested and expected to vest		8 years 7 months 6 days
Aggregate Intrinsic Value, Outstanding	[1]	$ 2,746	$ 7,428
Aggregate Intrinsic Value, Exercisable	[1]	1,964
Aggregate Intrinsic Value, Vested and expected to vest	[1]	$ 2,746
[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
	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate range, minimum	1.59%	0.48%
Risk-free interest rate range, maximum	2.37%	1.05%
Dividend yield	0.00%	0.00%
Volatility rate range, minimum	85.38%	88.70%
Volatility rate range, maximum	86.64%	90.53%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term of options (years)	5 years 29 days	6 years 29 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 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
	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	$ 1,752	$ 1,577
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	896	641
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	$ 856	$ 936

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		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Earnings Per Share [Abstract]
Net loss attributable to common stockholders—basic and diluted	$ (16,884)	$ (11,050)	$ (56,600)
Net loss per share attributable to common stockholders—basic and diluted	$ (0.71)	$ (0.47)
Weighted-average common shares outstanding—basic and diluted	23,686,351	23,429,507

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
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options to purchase common stock	4,506,858	3,523,586
Options to Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options to purchase common stock	4,506,858	3,523,586

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Details) - USD ($) $ in Thousands	Jan. 01, 2021	Mar. 31, 2022
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution, percentage of match	50.00%
Employer contribution amount		$ 82
Maximum
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution, percentage of employees base salary and bonus paid	6.00%

Related Party Transactions (Add

Related Party Transactions (Additional Information) (Details) - USD ($) $ in Millions	May 06, 2021	Mar. 31, 2021
Related Party Transaction [Line Items]
Management Fee Expense		$ 0.4
30 Days prior written notice
Related Party Transaction [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	30 days
60 Days prior written notice
Related Party Transaction [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	60 days

Subsequent Events (Additional I

Subsequent Events (Additional Information) (Details) - $ / shares	Apr. 19, 2022	Mar. 31, 2022	Dec. 31, 2021
Subsequent Event [Line Items]
Common Stock, Par or Stated Value Per Share		$ 0.0001	$ 0.0001
Subsequent Event [Member]
Subsequent Event [Line Items]
Offering price	$ 3.69
Jefferies LLC and Cowen and Company LLC [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Underwritten offering	16,276,987
Pre Funded Warrants [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Class of Warrant purchases	3,523,013
Offering price	$ 3.6899