Larimar Therapeutics (LRMR) 10-Q 12 Aug 21 2021 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2021	Aug. 10, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Trading Symbol	LRMR
Entity Registrant Name	LARIMAR THERAPEUTICS, INC.
Entity Central Index Key	0001374690
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		17,710,450
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-36510
Entity Tax Identification Number	20-3857670
Entity Address, Address Line One	Three Bala Plaza East
Entity Address, Address Line Two	Suite 506
Entity Address, City or Town	Bala Cynwyd
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19004
City Area Code	844
Local Phone Number	511-9056
Title of 12(b) Security	Common Stock, par value $0.001 per share
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation State Country Code	DE

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 70,630	$ 68,148
Marketable debt securities	0	24,490
Prepaid expenses and other current assets	3,406	5,314
Total current assets	74,036	97,952
Property and equipment, net	1,211	1,040
Operating lease right-of-use assets	3,673	3,936
Restricted cash	1,339	1,339
Other assets	672	419
Total assets	80,931	104,686
Current liabilities:
Accounts payable	1,463	2,634
Accrued expenses	5,675	5,843
Operating lease liabilities, current	553	515
Total current liabilities	7,691	8,992
Operating lease liabilities	5,715	6,002
Total liabilities	13,406	14,994
Commitments and contingencies (See Note 9)
Stockholders’ equity:
Preferred stock; $0.001 par value per share; 5,000,000 shares authorized as of June 30, 2021 and December 31, 2020; no shares issued and outstanding as of June 30, 2021 and December 31, 2020
Common stock, $0.001 par value per share; 115,000,000 shares authorized as of June 30, 2021 and December 31, 2020; 15,367,730 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively	15	15
Additional paid-in capital	157,820	155,290
Accumulated deficit	(90,311)	(65,614)
Accumulated other comprehensive loss	1	1
Total stockholders’ equity	67,525	89,692
Total liabilities and stockholders’ equity	$ 80,931	$ 104,686

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Preferred stock, par value per share	$ 0.001	$ 0.001
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 per share	$ 0.001	$ 0.001
Common stock, shares authorized	115,000,000	115,000,000
Common stock, shares issued	15,367,730	15,367,730
Common stock, shares outstanding	15,367,730	15,367,730

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Operating expenses:
Research and development	$ 9,102	$ 8,907	$ 18,076	$ 13,914
General and administrative	3,441	2,492	6,573	4,159
Total operating expenses	12,543	11,399	24,649	18,073
Loss from operations	(12,543)	(11,399)	(24,649)	(18,073)
Other income (expense), net	(66)	69	(48)	69
Net loss	$ (12,609)	$ (11,330)	$ (24,697)	$ (18,004)
Net loss per share, basic	$ (0.79)	$ (1.21)	$ (1.54)	$ (2.33)
Net loss per share, diluted	$ (0.79)	$ (1.21)	$ (1.54)	$ (2.33)
Weighted average common shares outstanding, basic	15,996,133	9,381,412	15,996,133	7,736,331
Weighted average common shares outstanding, diluted	15,996,133	9,381,412	15,996,133	7,736,331
Comprehensive loss:
Net loss	$ (12,609)	$ (11,330)	$ (24,697)	$ (18,004)
Other comprehensive loss:
Unrealized gain (loss) on marketable debt securities	0	(3)	0	(3)
Total other comprehensive loss	0	(3)	0	(3)
Total comprehensive loss	$ (12,609)	$ (11,333)	$ (24,697)	$ (18,007)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning balance at Dec. 31, 2019	$ (694)	$ 6	$ 22,432	$ (23,132)
Beginning balance, shares at Dec. 31, 2019		6,091,250
Capital contributions from related party	9,595		9,595
Stock-based compensation expense	29		29
Net loss	(6,674)			(6,674)
Ending balance at Mar. 31, 2020	2,256	$ 6	32,056	(29,806)
Ending balance, shares at Mar. 31, 2020		6,091,250
Beginning balance at Dec. 31, 2019	(694)	$ 6	22,432	(23,132)
Beginning balance, shares at Dec. 31, 2019		6,091,250
Capital contributions from related party	17,995
Unrealized gain (loss) on marketable debt securities	(3)
Net loss	(18,004)
Ending balance at Jun. 30, 2020	112,544	$ 15	153,668	(41,136)	$ (3)
Ending balance, shares at Jun. 30, 2020		15,356,206
Beginning balance at Mar. 31, 2020	2,256	$ 6	32,056	(29,806)
Beginning balance, shares at Mar. 31, 2020		6,091,250
Capital contributions from related party	8,400		8,400
Merger with Zafgen Inc.	37,119	$ 3	37,116
Merger with Zafgen Inc., Shares		3,124,337
Private Placement of common shares and pre-funded warrants, net of transaction costs	75,350	$ 6	75,344
Shares issued to private placement, Shares		6,140,619
Stock-based compensation expense	752		752
Unrealized gain (loss) on marketable debt securities	(3)				(3)
Net loss	(11,330)			(11,330)
Ending balance at Jun. 30, 2020	112,544	$ 15	153,668	(41,136)	(3)
Ending balance, shares at Jun. 30, 2020		15,356,206
Beginning balance at Dec. 31, 2020	89,692	$ 15	155,290	(65,614)	1
Beginning balance, shares at Dec. 31, 2020		15,367,730
Stock-based compensation expense	1,180		1,180
Net loss	(12,088)			(12,088)
Ending balance at Mar. 31, 2021	78,784	$ 15	156,470	(77,702)	1
Ending balance, shares at Mar. 31, 2021		15,367,730
Beginning balance at Dec. 31, 2020	89,692	$ 15	155,290	(65,614)	1
Beginning balance, shares at Dec. 31, 2020		15,367,730
Unrealized gain (loss) on marketable debt securities	0
Net loss	(24,697)
Ending balance at Jun. 30, 2021	67,525	$ 15	157,820	(90,311)	1
Ending balance, shares at Jun. 30, 2021		15,367,730
Beginning balance at Mar. 31, 2021	78,784	$ 15	156,470	(77,702)	1
Beginning balance, shares at Mar. 31, 2021		15,367,730
Stock-based compensation expense	1,350		1,350
Unrealized gain (loss) on marketable debt securities	0
Net loss	(12,609)			(12,609)
Ending balance at Jun. 30, 2021	$ 67,525	$ 15	$ 157,820	$ (90,311)	$ 1
Ending balance, shares at Jun. 30, 2021		15,367,730

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net loss	$ (24,697)	$ (18,004)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	2,530	781
Loss on disposal of fixed asset	5
Depreciation expense	150	55
Amortization of premium on marketable securities	(11)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,908	(1,760)
Accounts payable	(1,466)	(3,284)
Accrued expenses	(168)	1,067
Right-of-use assets	263	89
Operating lease liabilities	(249)	(85)
Other assets	(253)	21
Net cash used in operating activities:	(21,988)	(21,120)
Cash flows from investing activities:
Purchase of property and equipment	(31)	(58)
Purchase of marketable securities	(1,749)
Maturities and sales of marketable securities	26,250
Cash, cash equivalents, and restricted cash acquired in connection with the Merger		41,934
Merger transaction costs		(1,233)
Net cash provided by investing activities	24,470	40,643
Cash flows from financing activities:
Capital contributions from related party		17,995
Proceeds from sale of common stock and prefunded warrants, net of issuance costs		75,485
Net cash provided by financing activities		93,480
Net increase in cash, cash equivalents and restricted cash	2,482	113,003
Cash, cash equivalents and restricted cash at beginning of period	69,487	1,009
Cash, cash equivalents and restricted cash at end of period	71,969	114,012
Supplemental disclosure of non-cash investing and financing activities:
Fair value of net assets acquired in the Merger, including $1.0 million of marketable debt securities and excluding cash acquired		(4,815)
Property and equipment included in accounts payable and accrued expenses	$ 295
Offering costs included in accounts payable and accrued expense		135
Merger transaction costs included in accounts payable and accrued expenses		65
Leased assets obtained in exchange for new operating lease liabilities		$ 448

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Parenthetical) $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)
Statement Of Cash Flows [Abstract]
Marketable debt securities acquired	$ 1

Organization, Nature of the Bus

Organization, Nature of the Business, COVID-19 Risk and Basis of Presentation	6 Months Ended
	Jun. 30, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization, Nature of the Business, COVID-19 Risk and Basis of Presentation	1. Organization, Clinical Development, Nature of the Business, COVID-19 Risk and Basis of Presentation Larimar Therapeutics, Inc., together with its subsidiaries (the “Company” or “Larimar”), is a clinical-stage biotechnology company focused on developing treatments for patients suffering from complex rare diseases using its novel cell penetrating peptide technology platform. Larimar’s lead product candidate, CTI-1601, is a subcutaneously administered, recombinant fusion protein intended to deliver human frataxin, or FXN, an essential protein, to the mitochondria of patients with Friedreich’s ataxia. Friedreich’s ataxia is a rare, progressive, and fatal disease in which patients are unable to produce sufficient FXN due to a genetic abnormality. In May 2021, Larimar reported positive topline data from its Phase 1 Friedreich’s ataxia (FA) program after completing dosing of the single ascending dose (SAD) trial in December 2020 and of the multiple ascending dose (MAD) trial in March 2021. Data from these trials demonstrate proof-of-concept by showing that daily subcutaneous injections of CTI-1601 for up to 13 days resulted in dose-dependent increases in frataxin levels from baseline compared to placebo in all evaluated tissues (buccal cells, skin, and platelets). Frataxin levels achieved in peripheral tissues (buccal cells) following daily 50 mg and 100 mg subcutaneous injections of CTI-1601 were at or in excess of frataxin levels that would be expected in phenotypically normal heterozygous carriers. There were no serious adverse events (SAEs) associated with either the MAD or SAD trials. On May 25, 2021 the United States Food and Drug Administration (FDA) placed a clinical hold on the CTI-1601 clinical program following the Company’s notification to the FDA of mortalities which occurred at the highest dose levels in an ongoing 180-day non-human primate (NHP) toxicology study, which is designed to support extended dosing of patients with CTI-1601. In the clinical hold letter, the FDA stated that it needs a full study report from the ongoing NHP study and Larimar may not initiate additional clinical trials until the company has submitted the report and received notification from the FDA that additional clinical trials may commence. At the time of this notice, the Company had no interventional clinical trials with patients enrolled or enrolling. In July 2021, the Company completed dosing in the non-human primate toxicology study discussed above. The Company is currently collecting and analyzing data from the study. While there is no way to predict the FDA’s response or whether they will require additional data or testing before lifting the clinical hold on CTI-1601 in full or in part, the Company expects to initiate its Jive open-label extension and pediatric MAD trials in the first half of next year. The Company is subject to risks and uncertainties common to pre-commercialization companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with governmental regulations, failure to secure regulatory approval for its drug candidates or any other product candidates and the ability to secure additional capital to fund operations. Drug candidates currently under development will require extensive non-clinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel, and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s drug development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. In March 2020, the World Health Organization declared the outbreak of COVID-19, a novel strain of Coronavirus, a global pandemic. The pandemic resulted in the temporary stoppage of the Company’s CTI-1601 Phase 1 clinical trials in patients with Friedreich’s ataxia in March 2020. In July 2020, the Company resumed these clinical trials, and have since completed dosing of both its single ascending dose and multiple ascending dose clinical trials. Vaccines manufactured by Moderna, Pfizer and Johnson & Johnson were introduced late in the fourth quarter of 2020 and became widely available by the end of the first quarter of 2021. While the vaccines have proven effective in reducing the severity and mortality of COVID-19 including the variants that have evolved to date, the overall vaccination rate in the United States has not reached the level required for herd immunity in some states, particularly in some areas of the country. The incidence of variants of COVID-19, has been increasing particularly among unvaccinated individuals and the variant is proving to be more easily spread than earlier variants. The low vaccination rate, the spread of variants, the evolution of furthermore deadly mutations against which the current vaccines may prove ineffective could again result in major disruptions to businesses and markets worldwide. The Company’s business, results of operations, financial condition and cash flows could be materially and adversely affected. Specifically, the Company could experience additional delays in future clinical trial timelines as a result of additional travel and hospital restrictions related to the COVID-19 pandemic which may be imposed or experience supply shortages or manufacturer shutdowns impacting the manufacture of drug substance or drug product. The financial statements do not reflect any adjustments as a result of the pandemic. Merger with Zafgen On December 17, 2019, Zafgen, Inc. (“Zafgen”), Chondrial Therapeutics Inc. (“Chondrial”), Zordich Merger Sub, Inc. (“Merger Sub”) and Chondrial Holdings, LLC (“Holdings”), the sole stockholder of Chondrial, entered into an Agreement and Plan of Merger, as amended on March 9, 2020 (the “Merger Agreement”), pursuant to which Merger Sub merged with and into Chondrial, with Chondrial surviving as a wholly owned subsidiary of the Company and the surviving corporation of the merger (the “Merger”). The transaction was accounted for as a reverse acquisition in accordance with accounting principles generally accepted in the United States of America ("GAAP"). Under this method of accounting, Chondrial was deemed to be the accounting acquirer for financial reporting purposes. This determination was primarily based on the facts that, immediately following the Merger: (1) former shareholders of Chondrial own a substantial majority of the voting rights of the combined company; (2) the majority of the board of directors of the combined company is composed of directors designated by Chondrial under the terms of the Merger Agreement; and (3) existing members of Chondrial management constituted the management of the combined company. Because Chondrial has been determined to be the accounting acquirer in the Merger, but not the legal acquirer, the Merger is deemed a reverse acquisition under the guidance of the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 805, Business Combinations The Merger was completed on May 28, 2020 pursuant to the terms of the Merger Agreement. In addition, immediately prior to the closing of the Merger, Zafgen effected a 1-for-12 reverse stock split (the “Reverse Stock Split”) of Zafgen’s common stock, par value $0.001 per share (the “Zafgen Common Stock”). At the effective time of the Merger (the “Effective Time”), each share of Chondrial’s common stock, par value $0.001 per share (“Chondrial Common Stock”), outstanding immediately prior to the Effective Time was converted into the right to receive shares of Zafgen Common Stock based on an exchange ratio set forth in the Merger Agreement. At the Effective Time following the Reverse Stock Split, the exchange ratio was determined to be 60,912.5005 shares of Zafgen Common Stock for each share of Chondrial Common Stock (the “Exchange Ratio”). At the closing of the Merger on May 28, 2020, Zafgen issued an aggregate of 6,091,250 shares of its common stock to Holdings (the “Merger Shares”), based on the Exchange Ratio after giving effect to the Reverse Stock Split described below. Holdings subsequently distributed the Merger Shares to its members. In addition, all outstanding options exercisable for common units of Holdings became options exercisable for the shares of common stock of Zafgen based on the conversion factor discussed within the Merger Agreement. In connection with the Merger, Zafgen changed its name to Larimar Therapeutics, Inc. Following the closing of the Merger, Chondrial Therapeutics, Inc. became a wholly owned subsidiary of the Company. In December 2020, Chondrial Therapeutics was legally merged into Larimar Therapeutics, Inc. As used herein, the words “the Company” refers to, for periods following the Merger, Larimar, together with its subsidiaries, and for periods prior to the Merger, Chondrial Therapeutics Inc., and its direct and indirect subsidiaries, as applicable. Basis of Presentation The condensed consolidated financial statements include the accounts of Larimar and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated. The accompanying condensed consolidated financial statements have been prepared in conformity with GAAP. Unless otherwise noted, all references to common stock share and per share amounts have also been adjusted to reflect the Exchange Ratio. Reverse Stock Split On May 28, 2020, immediately prior to the closing of the Merger, Zafgen effected the Reverse Stock Split. Accordingly, all share and per share amounts for all periods presented in the accompanying condensed consolidated financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect the Reverse Stock Split. No fractional shares were issued in connection with the Reverse Stock Split. Unless otherwise noted, all references to common stock share and per share amounts have also been adjusted to reflect the Exchange Ratio. Going Concern Assessment In accordance with Accounting Standards Update (“ASU”) No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern , the Company has evaluated whether there are certain conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the condensed consolidated financial statements are issued. As of the issuance date of these condensed consolidated financial statements, the Company expects that its cash, cash equivalents and marketable debt securities will be sufficient to fund its forecasted operating expenses and capital expenditure requirements for at least the next twelve months from the issuance date of these financial statements. The Company has funded its operations to date primarily with proceeds from sales of common stock, prefunded warrants for the purchase of common stock and, prior to the merger with Zafgen described above, contributions from Holdings. In June 2020, the Company completed the Merger and acquired $42.9 million of cash, cash equivalents, restricted cash and marketable debt securities that were held by Zafgen immediately prior to the Merger. The Company also raised $75.4 million, net of offering costs, through a private offering of common stock and prefunded warrants to purchase shares of common stock in connection with and immediately after the closing of the Merger in June 2020. In August 2020, the Company entered into an Equity Distribution Agreement (the “ATM Agreement”) with an investment bank in connection with the establishment of an “at-the-market” offering program under which the Company may sell up to an aggregate of $50,000,000 of shares of its common stock from time to time through this investment bank as sales agent. In July 2021, the Company sold 2,342,720 shares pursuant to the ATM Agreement for gross proceeds of $20.5 million. As of August 10, 2021, the Company may sell up to $29.2 million of common stock under the ATM Agreement. Since its inception, the Company has incurred significant operating losses and negative cash flows from operations. The Company has not yet commercialized any products and does not expect to generate revenue from the commercial sale of any products for several years, if at all. The Company expects that its research and development and general and administrative expenses will continue to increase and, as a result, will need additional capital to fund its future operations, which it may raise through a combination of equity offerings, debt financings, other third-party funding, marketing and distribution arrangements, and other collaborations, strategic alliances and licensing arrangements. If the Company is unable to obtain future funding when needed, the Company may be forced to delay, reduce or eliminate some or all of its research and development programs, product portfolio expansion or pre‑commercialization efforts, which could adversely affect its business prospects, or the Company may be unable to continue operations. There is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Unaudited Interim Financial Information The condensed consolidated balance sheet as of December 31, 2020 was derived from the Company’s audited financial statements but does not include all disclosures required by GAAP. The accompanying unaudited condensed consolidated financial statements as of June 30, 2021 and for the three and six months ended June 30, 2021 and 2020, have been prepared by the Company, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”), for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. These condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2020 included in the Company’s Annual Report on Form 10-K filed on March 4, 2021. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair statement of the Company’s condensed consolidated financial position as of June 30, 2021 and condensed consolidated results of operations and cash flows for the three and six months ended June 30, 2021 and 2020 have been made. The results of operations for the three and six months ended June 30, 2021 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2021 . Use of Estimates The preparation of financial statements in conformity with GAAP 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. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, the accrual of research and development expense, valuation of stock-based awards and valuation of leases. Due to inherent uncertainty involved in making estimates, actual results reported in future periods may be affected by changes in these estimates. On an ongoing basis, the Company evaluates its estimates and assumptions. Concentrations of Credit Risk and Significant Suppliers Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents. The Company generally maintains cash balances in various operating accounts at financial institutions that management believes to be of high credit quality in amounts that may exceed federally insured limits. The Company has not experienced losses related to its cash and cash equivalents. The Company is highly dependent on third-party manufacturers to supply products for research and development activities in its programs. The Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for drug substance and formulated drugs related to these programs. The drug substance which is in frozen liquid form for CTI-1601 is currently manufactured for us by a third-party manufacturer, and the frozen liquid form of drug product is made at another manufacturer. The Company is undertaking a program with a third manufacturer to begin to produce a lyophilized version of the drug product from the same drug substance, that, once available, we intend to use in certain of our future planned clinical trials. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less at the date of purchase to be cash equivalents. At June 30, 2021 and December 31, 2020, cash equivalents consisted of commercial paper and corporate bonds with maturity dates of less than three months at the date of acquisition and money market funds. Marketable debt securities Marketable debt securities consist of debt investments with original maturities greater than ninety days. The Company classifies its marketable debt securities as available-for-sale. Accordingly, these investments are recorded at fair value, which is based on quoted market prices. When the fair value is below the amortized cost, the amount of the expected credit loss is estimated. The credit-related impairment amount is recognized in net income; the remaining impairment amount and unrealized gains are reported as a component of accumulated other comprehensive income in stockholders’ equity. Credit losses are recognized through the use of an allowance for credit losses account and subsequent improvements in expected credit losses are recognized as a reversal of the allowance account. If the Company has the intent to sell the security or it is more likely than not that the Company will be required to sell the security prior to recovery of its amortized cost basis, the allowance for credit loss is written off and the excess of the amortized cost basis of the asset over its fair value is recorded in net income. Property and Equipment Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over a five or seven-year Impairment of Long-Lived Assets Long-lived assets consist of property and equipment, net¸ and the net operating lease asset. Long-lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends, and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset for recoverability, the Company compares forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the long-lived asset to its carrying value. Any impairment loss, if indicated, is measured as the amount by which the carrying amount of the asset exceeds the estimated fair value of the asset. Segment Information The Company manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. The Company’s focus is on the research, development, and commercialization of novel therapeutics for the treatment of rare diseases. Research and Development Costs Costs associated with internal research and development and external research and development services, including drug development and non-clinical studies, are expensed as incurred. Research and development expenses include costs for salaries, employee benefits, subcontractors, facility-related expenses, depreciation, stock-based compensation, third-party license fees, laboratory supplies, and external costs of outside vendors engaged to conduct discovery, non-clinical and clinical development activities, and clinical trials as well as to manufacture clinical trial materials, and other costs. The Company recognizes external research and development costs based on an evaluation of the progress to completion of specific tasks using information provided to the Company by its service providers. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. Such prepaid expenses are recognized as an expense when the goods have been delivered or the related services have been performed, or when it is no longer expected that the goods will be delivered, or the services rendered. Upfront payments, milestone payments and annual maintenance fees under license agreements are currently expensed in the period in which they are incurred. Patent Costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses. Stock-Based Compensation The Company measures all stock-based awards granted to employees, non-employee consultants and directors based on the fair value on the date of grant using the Black-Scholes option-pricing model. Compensation expense of those awards is recognized over the requisite service period, which is the vesting period of the respective award. Typically, the Company issues awards with only service-based and market-based vesting conditions and records the expense for these awards using the straight-line method. The Company accounts for forfeitures as they occur. The Company classifies stock-based compensation expense in its condensed consolidated statements of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified or in which the award recipient’s service payments are classified. Prior to May 28, 2020, the Company had been a private company and lacked company-specific historical and implied volatility information for its common stock. Therefore, the Company estimates its expected common stock price volatility based on the historical volatility of publicly traded peer companies and expects to continue to do so until it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield considers the fact that the Company has never paid cash dividends on common stock and does not expect to pay any cash dividends in the foreseeable future. Income Taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the condensed consolidated financial statements or in the Company’s tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the consolidated financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties. Net Loss Per Share Basic net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding for the period. Basic shares outstanding includes the weighted average effect of the Company’s prefunded warrants issued in June 2020, the exercise of which requires little or no consideration for the delivery of shares of common stock. Basic and diluted weighted average shares of common stock outstanding for the three and six months ended June 30, 2021 and 2020 includes the weighted average effect of 628,403 prefunded warrants for the purchase of shares of common stock, which were issued in June 2020, and for which the remaining unfunded exercise price is $0.01 per share. Diluted net loss per share attributable to common stockholders is computed by dividing the diluted net loss attributable to common stockholders by the weighted average number of common shares, including potential dilutive common shares assuming the dilutive effect of outstanding stock options and unvested restricted common shares, as determined using the treasury stock method. For periods in which the Company has reported net losses, diluted net loss per common share attributable to common stockholders is the same as basic net loss per common share attributable to common stockholders, since dilutive common shares are not assumed to have been issued if their effect is antidilutive. The Company excluded Prior to the Merger the Company did not have options to purchase common stock or unvested restricted common stock to exclude from the calculation of earnings per share as all outstanding options were for common units of Holdings that upon the Merger converted into options exercisable for the shares of common stock of the Company. Recently Issued and Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In August 2018 , the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement . This standard modifies certain disclosure requirements on fair value measurements. This standard became effective for the Company on January 1, 2020. The adoption of this standard did not have a material impact on the Company’s disclosures.

Merger Accounting

Merger Accounting	6 Months Ended
	Jun. 30, 2021
Business Combinations [Abstract]
Merger Accounting	3. Merger Accounting On May 28, 2020, the Company completed its merger with Zafgen. Based on the Exchange Ratio, immediately following the Merger, former Zafgen stockholders, Zafgen option holders and other persons holding securities or other rights directly or indirectly convertible, exercisable or exchangeable for Zafgen Common Stock (collectively, the “Zafgen Securityholders”) owned approximately 34% of the outstanding capital stock of the combined company, and Holdings, the former Chondrial stockholder, owned approximately 66% of the outstanding capital stock of the combined company. At the closing of the Merger, all shares of Chondrial Common Stock were exchanged for an aggregate of 6,091,250 shares of Zafgen Common Stock, after giving effect to the Reverse Stock Split. In addition, pursuant to the terms of the Merger Agreement, the Company assumed all outstanding stock options to purchase shares of Zafgen common stock at the closing of the Merger. At the closing of the Merger, such stock options became options to purchase an aggregate of 328,770 shares of the Company’s common stock after giving effect to the Reverse Stock Split. The total purchase price paid in the Merger has been allocated to the tangible and intangible assets acquired and liabilities assumed of Zafgen based on their fair values as of the completion of the Merger. Number of shares of the combined organization owned by Zafgen stockholders ( 1) 3,124,337 Multiplied by the fair value per share of Zafgen common stock ( 2) $ 11.88 Fair value of consideration issued in effect of the Merger $ 37,119 Transaction costs $ 1,715 Purchase price: $ 38,834 (1) The number of shares of 3,124,337 represents the historical 37,492,044 shares of Zafgen common stock outstanding immediately prior to the closing of the Merger, adjusted for the Reverse Stock Split. (2) Based on the last reported sale price of Zafgen common stock on the Nasdaq Global Market on May 28, 2020, the closing date of the Merger, and after giving effect to the Reverse Stock Split. The allocation of the purchase price for the Merger was based on estimates of the fair value of the net assets acquired, which was then adjusted for the difference between the purchase price and the fair value of the assets acquired. The following summarizes the allocation of the purchase price to the net tangible and intangible assets acquired (in thousands): Cash and cash equivalents $ 40,595 Marketable debt securities 1,014 Other current and noncurrent assets 357 Property and equipment, net 398 Restricted cash 1,339 Right-of-use asset 3,806 Current liabi lities (2,685 ) Lease liability, net of current portion (5,990 ) Purchase price $ 38,834

Fair Value Measurements and Mar

Fair Value Measurements and Marketable Debt Securities	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements and Marketable Debt Securities	4 . Fair Value Measurements and Marketable Debt Securities Fair Value Measurements The Company’s assets and liabilities that are measured at fair value on a recurring basis as of June 30, 2021 and December 31, 2020 are measured in accordance with the standards of ASC 820, Fair Value Measurements and Disclosures Level – 1 Inputs to the valuation methodology are quoted prices (unadjusted) for identical assets or liabilities in active markets. Level – 2 Inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. Level – 3 Inputs to the valuation methodology are unobservable and significant to the fair value measurement. The Company’s financial instruments consist primarily of cash, cash equivalents, marketable debt securities, accounts payable and accrued liabilities. For accounts payable and accrued liabilities, the carrying amounts of these financial instruments as of June 30, 2021 and December 31, 2020 were considered representative of their fair values due to their short term to maturity. The following tables summarize the Company’s cash equivalents and marketable debt securities as of June 30, 2021 and December 31, 2020: Total Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) June 30, 2021 Cash equivalents: Money market funds $ 12,978 $ 12,978 $ — $ — Commercial paper 5,250 — 5,250 — Corporate bonds 1,921 — 1,921 — Total cash equivalents 20,149 12,978 7,171 — December 31, 2020 Cash equivalents: Money market funds $ 4,229 $ 4,229 $ — $ — Commercial paper 6,499 — 6,499 — Corporate bonds 1,907 — 1,907 — Total cash equivalents 12,635 4,229 8,406 — Marketable debt securities: U.S. Government securities 2,005 — 2,005 Commercial paper 22,485 — 22,485 — Total marketable debt securities 24,490 — 24,490 — Total cash equivalents and marketable debt securities $ 37,125 $ 4,229 $ 32,896 $ — Marketable Debt Securities The following tables summarize the Company’s marketable debt securities as of Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) December 31, 2020 Assets: U.S. Government securities $ 2,005 $ — $ — $ 2,005 Commercial paper 22,484 2 (1 ) 22,485 $ 24,489 $ 2 $ (1 ) $ 24,490

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	6 Months Ended
	Jun. 30, 2021
Prepaid Expense And Other Assets [Abstract]
Prepaid Expenses and Other Current Assets	5 . Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following: June 30, December 31, 2021 2020 (in thousands) Prepaid research and development expenses $ 2,945 $ 4,460 Prepaid insurance 201 571 Payroll tax receivable 67 32 Other prepaid expenses and other assets 193 251 $ 3,406 $ 5,314

Fixed Assets

Fixed Assets	6 Months Ended
	Jun. 30, 2021
Assets [Abstract]
Fixed Assets	6. Fixed Assets Fixed assets, net consisted of the following: June 30, December 31, Useful Life 2021 2020 (in thousands) Computer equipment 5 years $ 66 $ 66 Lab equipment 5 years 1,144 849 Furniture and fixtures 7 years 455 460 Leasehold Improvements lease term 31 — 1,696 1,375 Less: Accumulated depreciation (485 ) (335 ) $ 1,211 $ 1,040 Depreciation expense during the six months ended June 30, 2021 and 2020 was $0.2 million and less than $0.1 million, respectively.

Accrued Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2021
Payables And Accruals [Abstract]
Accrued Expenses	7 . Accrued Expenses June 30, December 31, 2021 2020 (in thousands) Accrued research and development expenses $ 4,183 $ 3,409 Accrued payroll and related expenses 852 1,350 Accrued professional fees 497 924 Accrued other 143 160 $ 5,675 $ 5,843

Stockholders' Equity and Stock

Stockholders' Equity and Stock Options	6 Months Ended
	Jun. 30, 2021
Stockholders Equity Note [Abstract]
Stockholders' Equity and Stock Options	8 . Stockholders’ Equity and Stock Options Common Stock and Prefunded warrants As of June 30, 2021, the Company’s Certificate of Incorporation, as amended and restated, authorized the Company to issue 115,000,000 of $0.001 par value common stock and 5,000,000 of $0.001 par value preferred stock. The voting, dividend, and liquidation rights of the holders of the Company’s common stock are subject to and qualified by the rights, powers, and preferences of the holders of the preferred stock. Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are entitled to receive dividends, as may be declared by the board of directors of the Company (the “Board”), if any. No cash dividends have been declared or paid to date. On May 28, 2020, the Company entered into a securities purchase agreement with certain accredited investors (the “Purchasers”) for the sale by the Company in a private placement of 6,105,359 shares of the Company’s common stock and prefunded warrants to purchase an aggregate of 628,403 shares of the Company’s common stock, for a price of $11.88 per share of the common stock and $11.87 per prefunded warrant. The prefunded warrants are exercisable at an exercise price of $0.01 and will be exercisable indefinitely. The Purchasers may exercise the prefunded warrants on a cashless basis in the event that there is no effective registration statement covering the resale of the shares of common stock underlying the prefunded warrants on the date in which the Company is required to deliver the shares. The private placement closed on June 1, 2020. The aggregate gross proceeds for the issuance and sale of the common stock and prefunded warrants were $80.0 million; transaction costs totaled $4.6 million and resulted in net proceeds of $75.4 million. The Company’s Registration Statement on Form S-3, filed with the SEC on June 26, 2020, registered the resale of 6,105,359 shares of common stock sold and the 628,403 shares of common stock underlying the prefunded warrants. Equity Distribution Agreement On August 14, 2020, the Company entered into the ATM Agreement with an investment bank in connection with the establishment of an “at-the-market” offering program under which the Company may sell up to an aggregate of $50,000,000 of shares of common stock (the “ATM Shares”) from time to time (the “Offering”). Under the ATM Agreement, the Company will set the parameters for the sale of ATM Shares, including the number of ATM Shares to be issued, the time period during which sales are requested to be made, limitations on the number of ATM Shares that may be sold in any one trading day and any minimum price below which sales may not be made. Sales of the ATM Shares, if any, under the ATM Agreement may be made in transactions that are deemed to be “at-the-market offerings” as defined in Rule 415 under the Securities Act. The Company will pay its investment bank a commission equal to 3.0% of the gross proceeds of any ATM Shares sold through its investment bank under the ATM Agreement and will reimburse the investment bank for certain specified expenses. The ATM Agreement contains customary representations, warranties and agreements by the Company, indemnification obligations of the Company and its investment bank, other customary obligations of the parties and termination provisions. The Company has no obligation to sell any of the ATM Shares and may at any time suspend offers under the ATM Agreement. In July 2021, the Company sold an additional 2,342,720 shares under the ATM Agreement for net proceeds of $19.9 million. As of August 10, 2021, the Company could sell up to $29.2 million under the ATM Agreement. Summary of Plans Upon completion of the Merger with Zafgen, Zafgen’s 2014 Stock Option and Incentive Plan (the “2014 Plan”) and Zafgen’s 2006 Stock Option Plan (the “2006 Plan” and together with the 2014 Plan the “Prior Plans”) were assumed by the Company. As described below, the Company adopted a new equity incentive plan in July 2020 that was approved by the stockholders in September 2020. These three plans are administered by the Board or, at the discretion of the Board, by a committee of the Board. 2020 Equity Incentive Plan The Company’s Board of Directors adopted the 2020 Equity Incentive Plan (the 2020 Plan) on July 16, 2020 and the stockholders of the Company approved the 2020 Plan on September 29, 2020. The 2020 Plan replaces the 2014 Plan. Option outstanding under the Prior Plans will remain outstanding, unchanged, and subject to the terms of the 2014 Plan and the respective award agreements, and no further awards will be made under the 2014 Plan. However, if any award previously granted under the Prior Plans, expires, terminates, is canceled, or is forfeited for any reason after the approval of the 2020 Plan, the shares subject to that award will be added to the 2020 Plan share pool so that they can be utilized for new grants under the 2020 Plan. The 2020 Plan provides for the grant of incentive stock options (“ISOs”), nonstatutory stock options (“NSOs”), stock appreciation rights, restricted stock awards, restricted stock unit awards, and cash or other stock-based awards. ISOs may be granted only to the Company’s employees, including the Company’s officers, and the employees of the Company’s affiliates. All other awards may be granted to the Company’s employees, including the Company’s officers, the Company’s non-employee directors and consultants, and the employees and consultants of the Company’s affiliates. As of June 30, 2021, 970,349 shares of common stock were available for grant under the 2020 Plan. The maximum number of shares that may be issued in respect of any awards under the 2020 Plan is the sum of: (i) 1,700,000 shares plus (ii) an annual increase on January 1, 2021 and each anniversary of such date thereafter through January 1, 2030, equal to the lesser of (A) 4% of the shares issued and outstanding on the last day of the immediately preceding fiscal year, and (B) such smaller number of shares as determined by the Board (collectively, the “Plan Limit”). ten-year 2014 Stock Option and Incentive Plan and 2006 Stock Option Plan In 2014, the Board and stockholders of Zafgen adopted the 2014 Plan. The 2014 Plan provided for the grant of stock options, stock appreciation rights, restricted stock awards, restricted stock units, unrestricted stock awards, performance-share awards, cash-based awards and dividend equivalent rights to employees, members of the Board and consultants of the Company. The number of shares initially reserved for issuance under the 2014 Plan was 180,685 shares of common stock. As the 2020 Plan was adopted by the Company and approved by the Company’s stockholders, no further awards will be made under the Prior Plans. 2016 Equity and Incentive Plan Under the 2016 Equity Plan adopted by Holdings on November 30, 2016, (the “2016 Equity Incentive Plan”), the Board of Managers of Holdings (the “Board of Managers”) or a committee thereof was authorized to issue 122,133 Common Units of Holdings or combination of Common Units, Common Unit options or profit interest units. On March 23, 2018, the Board of Managers increased the number of Common Units reserved for grant and issuance pursuant to the 2016 Plan from 122,133 to 138,133 and on April 29, 2019 increased the number of Common Units reserved for grant and issuance pursuant to the 2016 Plan by an additional 101,500 to 239,633. The Company has recorded costs incurred as stock-based compensation with a corresponding capital contribution from Holdings. From January 1, 2020 through the Merger date Holdings did not issue options to purchase Common Units to employees of the Company. The Company assumed all of the outstanding and unexercised options to purchase units of Holdings upon consummation of the Merger. Pursuant to the terms of the Merger Agreement, options to purchase 330,818 shares of the Company’s common stock at a weighted average exercise price of $12.14 per share were substituted for the 202,392 options to purchase Common Units, with a weighted average exercise price of $10.36 per Common Unit, that were outstanding immediately prior to the Merger. The Company treated the conversion as a modification pursuant to ASC 718, Compensation—Stock Compensation, calculated the pre- and post-modification value of the options. The increase in fair value of the options was calculated to be $1.2 million. As $0.7 million related to vested options the expense was recognized immediately on the Merger date, the remaining $0.5 million is recognized over the remaining vesting term with the original grant date fair value remaining of $0.1 million. Stock Valuation The following table presents, on a weighted average basis, the assumptions used in the Black-Scholes option-pricing model to determine the grant-date fair value of stock options granted to employees: June 30, December 31, 2021 2020 Risk-free interest rate 0.88% 0.37% Expected term (in years) 6.19 6.08 Expected volatility 91% 91% Dividend yield 0.00% 0.00% Stock Options The following table summarizes the Company’s stock option activity for the six months ended June 30, 2021 (amounts in millions, except for share and per share data): Weighted Weighted Average Aggregate Average Remaining Intrinsic Number of Exercise Contractual Value (a) Shares Price Term (in years) (in millions) Outstanding as of December 31, 2020 2,008,902 $ 22.31 7.9 Granted 603,050 15.74 Forfeited/Expired (64,990 ) 73.19 Outstanding as of June 30, 2021 2,546,962 $ 19.46 8.1 $ — Exercisable as of June 30, 2021 597,801 $ 39.35 4.3 $ — Vested and expected to vest as of June 30, 2021 2,546,962 $ 19.46 8.1 $ — (a) The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of the common stock for the options that were in the money at June 30, 2021. 2021 Option Grants During the six months ended June 30, 2021, the Company granted options to purchase 603,050 shares of common stock to employees and directors of the Company under the 2020 Plan. The options have an exercise price equal to the closing stock price as of the grant date. Of the 603,050 options granted in 2021, 553,250 vest over four years, with 25% vesting on the first anniversary of the grant and the remainder vesting in equal monthly installments thereafter, the remaining 49,800 options were annual grants to directors and vest one year from the grant date. Stock-Based Compensation Stock-based compensation expense was classified in the condensed consolidated statements of operations as follows: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (in thousands) Research and development $ 515 $ 199 $ 953 $ 211 General and administrative 835 553 1,577 570 $ 1,350 $ 752 $ 2,530 $ 781 As of June 30, 2021, total unrecognized compensation expense related to unvested stock options and restricted stock units was $17.7 million, which is expected to be recognized over a weighted average period of 3.12 years.

Commitments

Commitments	6 Months Ended
	Jun. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments	9. Commitments Intellectual Property Licenses The Company is party to an exclusive License Agreement (the “WFUHS License”), dated November 30, 2016 with Wake Forest University Health Sciences (“WFUHS”) and an exclusive License Agreement (the “IU License”), dated November 30, 2016, as amended, with Indiana University (“IU”). Such agreements provide for a transferable, worldwide license to certain patent rights regarding technology used by the Company with respect to the development of CTI-1601. In partial consideration for the right and license granted under these agreements, the Company will pay each of WFUHS and IU a royalty of a low single digit percentage of net sales of licensed products depending on whether there is a valid patent covering such products. As additional consideration for these agreements, the Company is obligated to pay each of WFUHS and IU certain milestone payments of up to $2.6 million in the aggregate upon the achievement of certain developmental milestones, commencing on the enrollment of the first patient in a Phase 1 clinical trial. The Company will also pay each of WFUHS and IU sublicensing fees ranging from a high-single digit to a low double-digit percentage of sublicense consideration depending on the Company’s achievement of certain regulatory milestones as of the time of receipt of the sublicense consideration. The Company is also obligated to reimburse WFUHS and IU for patent-related expenses. In the event that the Company disputes the validity of any of the licensed patents, the royalty rate would be tripled during such dispute. The Company is also obligated to pay to IU a minimum annual royalty of less than $0.1 million per annum starting in the 2020 calendar year for the term of the agreement. In the event that the Company is required to pay IU consideration, then the Company may deduct 20% of such IU consideration on a dollar-for-dollar basis from the consideration due to WFUHS. In the event that the Company is required to pay WFUHS consideration, then the Company may deduct 60% of such WFUHS consideration on a dollar-for-dollar basis from the consideration due to IU. During the three and six months ended June 30, 2021, no milestones were achieved and no expense was recognized. Both agreements continue from their effective date through the last to expire of the licensed patents unless earlier terminated by either party. Leases On August 8, 2019, the Company entered into an operating lease for office space in Bala Cynwyd, Pennsylvania, effective as of December 15, 2019, for a period of three years and six months with an option to extend the lease for three additional years. Due to required tenant improvements to be completed by the landlord, the Company did not take immediate possession of the leased property and the lease term commenced on February 15, 2020. In the quarter ended March 31, 2020, the Company recorded an operating lease right-of-use asset and operating lease liability of $0.4 million. On May 28, 2020, as part of the Merger with Zafgen, the Company acquired a non-cancellable operating lease for approximately 17,705 square feet of office space (the “Premises”). The lease expires on October 30, 2029. In addition to the base rent, the Company is also responsible for its share of operating expenses, electricity and real estate taxes, which costs are not included in the determination of the leases’ right-of-use assets or lease liabilities. The right-of-use asset is being amortized to rent expense over the remaining lease term. On October 27, 2020, the Company entered into a sublease agreement (the “Sublease”) with Massachusetts Municipal Association, Inc. (the “Subtenant”), whereby the Company subleased the entire Premises to the Subtenant. The initial term of the Sublease commenced on December 4, 2020 and continues until October 30, 2029. In connection with the Sublease, the Company evaluated the need for impairment under ASC 360 and determined there was no impairment. The Sublease provides for an initial annual base rent of $0.8 million, which increases annually up to a maximum annual base rent of $1.0 million. The Subtenant also is responsible for paying to the Company future increases in operating costs (commencing on January 1, 2022), future increases in annual tax costs (commencing July 1, 2021) and all utility costs (commencing March 1, 2021) attributable to the Premises during the term of the Sublease. As part of the Sublease, the subtenant deposited a letter of credit in the amount of $0.8 million to assure their performance under the sublease. If there are no uncured events of default under the sublease, the amount of this security deposit decreases over time to $0.4 million on the sixth anniversary of the Sublease. On November 5, 2018, the Company entered into an operating lease for office and lab space in Philadelphia, Pennsylvania, effective as of January 1, 2019, and expiring on December 31, 2020 with an option to extend the lease for two additional years On August 4, 2020, the Company executed the first option to extend the lease for an additional year, expiring on December 31, 2021. We have determined this lease extension qualifies as a short-term lease, as the remaining renewal option is not considered reasonably certain, for which we have applied the accounting policy election to not record the related right-of-use asset and lease liabilities Expense arising from operating leases was $0.1 million 11.0% Maturities of lease liabilities due under these lease agreements as of June 30, 2021 are as follows: Operating (in thousands) Leases Six months ending December 31, 2021 $ 590 Year ended December 31, 2022 1,197 Year ended December 31, 2023 1,146 Year ended December 31, 2024 1,065 Year ended December 31, 2025 1,083 Thereafter 4,314 Total lease payments 9,395 Less: imputed interest (3,127 ) Present value of lease liabilities $ 6,268

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2021
Related Party Transactions [Abstract]
Related Party Transactions	10. Related Party Transactions In November 2016, the Company entered into a consulting agreement with Mark Payne, M.D (the “Consulting Engagement”). Dr. Payne was a director of Chondrial at that time, a full-time employee of IU and one of the inventors of the licensed IU intellectual property, and as such is entitled to a certain share of the revenues received by IU under the IU License. Pursuant to the terms of his consulting agreement the Company agreed to pay Dr. Payne $0.1 million per year over the term of the agreement and granted Dr. Payne 123,853 restricted Common Units in Holdings. On November 30, 2016, 30% immediately vested and was associated with Chondrial Therapeutics IP, LLC (“IP LLC”) becoming a subsidiary of Holdings, which subsequently contributed to the Company on December 31, 2018. The remaining 70% vested ratably over 48 months beginning on December 1, 2016 and were fully vested as of December 31, 2020. The consulting agreement has a four-year On November 30, 2020, The Company entered into a 1-month extension of the Consulting Engagement, expiring on December 31, 2020 and on January 1, 2021, the Company entered into a new consulting agreement with Mark Payne, M.D. which extended the term of the Consulting Engagement for a four-year The funding to the Company originated from Holdings’ sale of Series A Preferred Units and Series B convertible preferred units (the “Units”) with Deerfield Private Design Fund IV, L.P., Deerfield Private Design Fund III, L.P. and Deerfield Health Innovations Fund, L.P. (together, the “Deerfield Funds”), and certain other purchasers, from inception through May 28, 2020 and the contribution of the proceeds received by Holdings on such sales to the Company in order to fund the Company’s operations Under a November 30, 2016 Series A Preferred Unit Purchase Agreement, as amended on September 8, 2017, November 15, 2017, November 14, 2018 and April 29, 2019, Holdings sold Series A Preferred Units for gross proceeds of $35.6 million. The gross proceeds of $35.6 million were contributed to the Company. On November 21, 2019 (as amended on December 20, 2019), Holdings entered into a Second Amended and Restated LLC Agreement and entered into a Series B Bridge Unit Purchase Agreement with the Deerfield Funds and certain other purchasers to sell Series B convertible preferred units (“Series B Bridge Units”) for gross proceeds of up to $10.0 million. The gross proceeds of $10.0 million were contributed to the Company. On January 16, 2020, Holdings entered into a Third Amended and Restated LLC Agreement and entered into a Second Series B Bridge Unit Purchase Agreement with the Deerfield Funds and certain other purchasers to sell Second Series B convertible preferred units (“Second Series B Bridge Units”) for gross proceeds of up to $15.0 million. The gross proceeds of $11.4 million were contributed to the Company. During the six months ended June 30, 2020, Holdings provided the Company non-interest bearing, permanent funding from the above Series A and Series B preferred unit transactions, totaling $18.0 million, which were recorded as capital contributions with the balance of combined equity and additional paid in capital on the condensed consolidated balance sheets and condensed consolidated statements of changes in stockholders’ equity for each respective period.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Merger with Zafgen	Merger with Zafgen On December 17, 2019, Zafgen, Inc. (“Zafgen”), Chondrial Therapeutics Inc. (“Chondrial”), Zordich Merger Sub, Inc. (“Merger Sub”) and Chondrial Holdings, LLC (“Holdings”), the sole stockholder of Chondrial, entered into an Agreement and Plan of Merger, as amended on March 9, 2020 (the “Merger Agreement”), pursuant to which Merger Sub merged with and into Chondrial, with Chondrial surviving as a wholly owned subsidiary of the Company and the surviving corporation of the merger (the “Merger”). The transaction was accounted for as a reverse acquisition in accordance with accounting principles generally accepted in the United States of America ("GAAP"). Under this method of accounting, Chondrial was deemed to be the accounting acquirer for financial reporting purposes. This determination was primarily based on the facts that, immediately following the Merger: (1) former shareholders of Chondrial own a substantial majority of the voting rights of the combined company; (2) the majority of the board of directors of the combined company is composed of directors designated by Chondrial under the terms of the Merger Agreement; and (3) existing members of Chondrial management constituted the management of the combined company. Because Chondrial has been determined to be the accounting acquirer in the Merger, but not the legal acquirer, the Merger is deemed a reverse acquisition under the guidance of the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 805, Business Combinations The Merger was completed on May 28, 2020 pursuant to the terms of the Merger Agreement. In addition, immediately prior to the closing of the Merger, Zafgen effected a 1-for-12 reverse stock split (the “Reverse Stock Split”) of Zafgen’s common stock, par value $0.001 per share (the “Zafgen Common Stock”). At the effective time of the Merger (the “Effective Time”), each share of Chondrial’s common stock, par value $0.001 per share (“Chondrial Common Stock”), outstanding immediately prior to the Effective Time was converted into the right to receive shares of Zafgen Common Stock based on an exchange ratio set forth in the Merger Agreement. At the Effective Time following the Reverse Stock Split, the exchange ratio was determined to be 60,912.5005 shares of Zafgen Common Stock for each share of Chondrial Common Stock (the “Exchange Ratio”). At the closing of the Merger on May 28, 2020, Zafgen issued an aggregate of 6,091,250 shares of its common stock to Holdings (the “Merger Shares”), based on the Exchange Ratio after giving effect to the Reverse Stock Split described below. Holdings subsequently distributed the Merger Shares to its members. In addition, all outstanding options exercisable for common units of Holdings became options exercisable for the shares of common stock of Zafgen based on the conversion factor discussed within the Merger Agreement. In connection with the Merger, Zafgen changed its name to Larimar Therapeutics, Inc. Following the closing of the Merger, Chondrial Therapeutics, Inc. became a wholly owned subsidiary of the Company. In December 2020, Chondrial Therapeutics was legally merged into Larimar Therapeutics, Inc. As used herein, the words “the Company” refers to, for periods following the Merger, Larimar, together with its subsidiaries, and for periods prior to the Merger, Chondrial Therapeutics Inc., and its direct and indirect subsidiaries, as applicable.
Basis of Presentation	Basis of Presentation The condensed consolidated financial statements include the accounts of Larimar and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated. The accompanying condensed consolidated financial statements have been prepared in conformity with GAAP. Unless otherwise noted, all references to common stock share and per share amounts have also been adjusted to reflect the Exchange Ratio. Unaudited Interim Financial Information The condensed consolidated balance sheet as of December 31, 2020 was derived from the Company’s audited financial statements but does not include all disclosures required by GAAP. The accompanying unaudited condensed consolidated financial statements as of June 30, 2021 and for the three and six months ended June 30, 2021 and 2020, have been prepared by the Company, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”), for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. These condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2020 included in the Company’s Annual Report on Form 10-K filed on March 4, 2021. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair statement of the Company’s condensed consolidated financial position as of June 30, 2021 and condensed consolidated results of operations and cash flows for the three and six months ended June 30, 2021 and 2020 have been made. The results of operations for the three and six months ended June 30, 2021 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2021 .
Reverse Stock Split	Reverse Stock Split On May 28, 2020, immediately prior to the closing of the Merger, Zafgen effected the Reverse Stock Split. Accordingly, all share and per share amounts for all periods presented in the accompanying condensed consolidated financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect the Reverse Stock Split. No fractional shares were issued in connection with the Reverse Stock Split. Unless otherwise noted, all references to common stock share and per share amounts have also been adjusted to reflect the Exchange Ratio.
Going Concern Assessment	Going Concern Assessment In accordance with Accounting Standards Update (“ASU”) No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern , the Company has evaluated whether there are certain conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the condensed consolidated financial statements are issued. As of the issuance date of these condensed consolidated financial statements, the Company expects that its cash, cash equivalents and marketable debt securities will be sufficient to fund its forecasted operating expenses and capital expenditure requirements for at least the next twelve months from the issuance date of these financial statements. The Company has funded its operations to date primarily with proceeds from sales of common stock, prefunded warrants for the purchase of common stock and, prior to the merger with Zafgen described above, contributions from Holdings. In June 2020, the Company completed the Merger and acquired $42.9 million of cash, cash equivalents, restricted cash and marketable debt securities that were held by Zafgen immediately prior to the Merger. The Company also raised $75.4 million, net of offering costs, through a private offering of common stock and prefunded warrants to purchase shares of common stock in connection with and immediately after the closing of the Merger in June 2020. In August 2020, the Company entered into an Equity Distribution Agreement (the “ATM Agreement”) with an investment bank in connection with the establishment of an “at-the-market” offering program under which the Company may sell up to an aggregate of $50,000,000 of shares of its common stock from time to time through this investment bank as sales agent. In July 2021, the Company sold 2,342,720 shares pursuant to the ATM Agreement for gross proceeds of $20.5 million. As of August 10, 2021, the Company may sell up to $29.2 million of common stock under the ATM Agreement. Since its inception, the Company has incurred significant operating losses and negative cash flows from operations. The Company has not yet commercialized any products and does not expect to generate revenue from the commercial sale of any products for several years, if at all. The Company expects that its research and development and general and administrative expenses will continue to increase and, as a result, will need additional capital to fund its future operations, which it may raise through a combination of equity offerings, debt financings, other third-party funding, marketing and distribution arrangements, and other collaborations, strategic alliances and licensing arrangements. If the Company is unable to obtain future funding when needed, the Company may be forced to delay, reduce or eliminate some or all of its research and development programs, product portfolio expansion or pre‑commercialization efforts, which could adversely affect its business prospects, or the Company may be unable to continue operations. There is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP 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. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, the accrual of research and development expense, valuation of stock-based awards and valuation of leases. Due to inherent uncertainty involved in making estimates, actual results reported in future periods may be affected by changes in these estimates. On an ongoing basis, the Company evaluates its estimates and assumptions.
Concentrations of Credit Risk and Significant Suppliers	Concentrations of Credit Risk and Significant Suppliers Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents. The Company generally maintains cash balances in various operating accounts at financial institutions that management believes to be of high credit quality in amounts that may exceed federally insured limits. The Company has not experienced losses related to its cash and cash equivalents. The Company is highly dependent on third-party manufacturers to supply products for research and development activities in its programs. The Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for drug substance and formulated drugs related to these programs. The drug substance which is in frozen liquid form for CTI-1601 is currently manufactured for us by a third-party manufacturer, and the frozen liquid form of drug product is made at another manufacturer. The Company is undertaking a program with a third manufacturer to begin to produce a lyophilized version of the drug product from the same drug substance, that, once available, we intend to use in certain of our future planned clinical trials.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less at the date of purchase to be cash equivalents. At June 30, 2021 and December 31, 2020, cash equivalents consisted of commercial paper and corporate bonds with maturity dates of less than three months at the date of acquisition and money market funds.
Marketable Debt Securities	Marketable debt securities Marketable debt securities consist of debt investments with original maturities greater than ninety days. The Company classifies its marketable debt securities as available-for-sale. Accordingly, these investments are recorded at fair value, which is based on quoted market prices. When the fair value is below the amortized cost, the amount of the expected credit loss is estimated. The credit-related impairment amount is recognized in net income; the remaining impairment amount and unrealized gains are reported as a component of accumulated other comprehensive income in stockholders’ equity. Credit losses are recognized through the use of an allowance for credit losses account and subsequent improvements in expected credit losses are recognized as a reversal of the allowance account. If the Company has the intent to sell the security or it is more likely than not that the Company will be required to sell the security prior to recovery of its amortized cost basis, the allowance for credit loss is written off and the excess of the amortized cost basis of the asset over its fair value is recorded in net income.
Property and Equipment	Property and Equipment Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over a five or seven-year
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets consist of property and equipment, net¸ and the net operating lease asset. Long-lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends, and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset for recoverability, the Company compares forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the long-lived asset to its carrying value. Any impairment loss, if indicated, is measured as the amount by which the carrying amount of the asset exceeds the estimated fair value of the asset.
Segment Information	Segment Information The Company manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. The Company’s focus is on the research, development, and commercialization of novel therapeutics for the treatment of rare diseases.
Research and Development Costs	Research and Development Costs Costs associated with internal research and development and external research and development services, including drug development and non-clinical studies, are expensed as incurred. Research and development expenses include costs for salaries, employee benefits, subcontractors, facility-related expenses, depreciation, stock-based compensation, third-party license fees, laboratory supplies, and external costs of outside vendors engaged to conduct discovery, non-clinical and clinical development activities, and clinical trials as well as to manufacture clinical trial materials, and other costs. The Company recognizes external research and development costs based on an evaluation of the progress to completion of specific tasks using information provided to the Company by its service providers. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. Such prepaid expenses are recognized as an expense when the goods have been delivered or the related services have been performed, or when it is no longer expected that the goods will be delivered, or the services rendered. Upfront payments, milestone payments and annual maintenance fees under license agreements are currently expensed in the period in which they are incurred.
Patent Costs	Patent Costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses.
Stock-Based Compensation	Stock-Based Compensation The Company measures all stock-based awards granted to employees, non-employee consultants and directors based on the fair value on the date of grant using the Black-Scholes option-pricing model. Compensation expense of those awards is recognized over the requisite service period, which is the vesting period of the respective award. Typically, the Company issues awards with only service-based and market-based vesting conditions and records the expense for these awards using the straight-line method. The Company accounts for forfeitures as they occur. The Company classifies stock-based compensation expense in its condensed consolidated statements of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified or in which the award recipient’s service payments are classified. Prior to May 28, 2020, the Company had been a private company and lacked company-specific historical and implied volatility information for its common stock. Therefore, the Company estimates its expected common stock price volatility based on the historical volatility of publicly traded peer companies and expects to continue to do so until it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield considers the fact that the Company has never paid cash dividends on common stock and does not expect to pay any cash dividends in the foreseeable future.
Income Taxes	Income Taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the condensed consolidated financial statements or in the Company’s tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the consolidated financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding for the period. Basic shares outstanding includes the weighted average effect of the Company’s prefunded warrants issued in June 2020, the exercise of which requires little or no consideration for the delivery of shares of common stock. Basic and diluted weighted average shares of common stock outstanding for the three and six months ended June 30, 2021 and 2020 includes the weighted average effect of 628,403 prefunded warrants for the purchase of shares of common stock, which were issued in June 2020, and for which the remaining unfunded exercise price is $0.01 per share. Diluted net loss per share attributable to common stockholders is computed by dividing the diluted net loss attributable to common stockholders by the weighted average number of common shares, including potential dilutive common shares assuming the dilutive effect of outstanding stock options and unvested restricted common shares, as determined using the treasury stock method. For periods in which the Company has reported net losses, diluted net loss per common share attributable to common stockholders is the same as basic net loss per common share attributable to common stockholders, since dilutive common shares are not assumed to have been issued if their effect is antidilutive. The Company excluded Prior to the Merger the Company did not have options to purchase common stock or unvested restricted common stock to exclude from the calculation of earnings per share as all outstanding options were for common units of Holdings that upon the Merger converted into options exercisable for the shares of common stock of the Company.
Recently Issued and Adopted Accounting Pronouncements	Recently Issued and Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In August 2018 , the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement . This standard modifies certain disclosure requirements on fair value measurements. This standard became effective for the Company on January 1, 2020. The adoption of this standard did not have a material impact on the Company’s disclosures.

Merger Accounting (Tables)

Merger Accounting (Tables)	6 Months Ended
	Jun. 30, 2021
Business Combinations [Abstract]
Summary of Purchase Price Paid in Merger	The following summarizes the purchase price paid in the Merger (in thousands, except share and per share amounts): Number of shares of the combined organization owned by Zafgen stockholders ( 1) 3,124,337 Multiplied by the fair value per share of Zafgen common stock ( 2) $ 11.88 Fair value of consideration issued in effect of the Merger $ 37,119 Transaction costs $ 1,715 Purchase price: $ 38,834 (1) The number of shares of 3,124,337 represents the historical 37,492,044 shares of Zafgen common stock outstanding immediately prior to the closing of the Merger, adjusted for the Reverse Stock Split. (2) Based on the last reported sale price of Zafgen common stock on the Nasdaq Global Market on May 28, 2020, the closing date of the Merger, and after giving effect to the Reverse Stock Split.
Summary of Allocation of Purchase Price to Net Tangible and Intangible Assets Acquired	The allocation of the purchase price for the Merger was based on estimates of the fair value of the net assets acquired, which was then adjusted for the difference between the purchase price and the fair value of the assets acquired. The following summarizes the allocation of the purchase price to the net tangible and intangible assets acquired (in thousands): Cash and cash equivalents $ 40,595 Marketable debt securities 1,014 Other current and noncurrent assets 357 Property and equipment, net 398 Restricted cash 1,339 Right-of-use asset 3,806 Current liabi lities (2,685 ) Lease liability, net of current portion (5,990 ) Purchase price $ 38,834

Fair Value Measurements and M_2

Fair Value Measurements and Marketable Debt Securities (Tables)	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Summary of Cash Equivalents and Marketable Debt Securities	The following tables summarize the Company’s cash equivalents and marketable debt securities as of June 30, 2021 and December 31, 2020: Total Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) June 30, 2021 Cash equivalents: Money market funds $ 12,978 $ 12,978 $ — $ — Commercial paper 5,250 — 5,250 — Corporate bonds 1,921 — 1,921 — Total cash equivalents 20,149 12,978 7,171 — December 31, 2020 Cash equivalents: Money market funds $ 4,229 $ 4,229 $ — $ — Commercial paper 6,499 — 6,499 — Corporate bonds 1,907 — 1,907 — Total cash equivalents 12,635 4,229 8,406 — Marketable debt securities: U.S. Government securities 2,005 — 2,005 Commercial paper 22,485 — 22,485 — Total marketable debt securities 24,490 — 24,490 — Total cash equivalents and marketable debt securities $ 37,125 $ 4,229 $ 32,896 $ —
Summary of Marketable Debt Securities	The following tables summarize the Company’s marketable debt securities as of Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) December 31, 2020 Assets: U.S. Government securities $ 2,005 $ — $ — $ 2,005 Commercial paper 22,484 2 (1 ) 22,485 $ 24,489 $ 2 $ (1 ) $ 24,490

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	6 Months Ended
	Jun. 30, 2021
Prepaid Expense And Other Assets [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following: June 30, December 31, 2021 2020 (in thousands) Prepaid research and development expenses $ 2,945 $ 4,460 Prepaid insurance 201 571 Payroll tax receivable 67 32 Other prepaid expenses and other assets 193 251 $ 3,406 $ 5,314

Fixed Assets (Tables)

Fixed Assets (Tables)	6 Months Ended
	Jun. 30, 2021
Assets [Abstract]
Schedule of Fixed Assets, Net	Fixed assets, net consisted of the following: June 30, December 31, Useful Life 2021 2020 (in thousands) Computer equipment 5 years $ 66 $ 66 Lab equipment 5 years 1,144 849 Furniture and fixtures 7 years 455 460 Leasehold Improvements lease term 31 — 1,696 1,375 Less: Accumulated depreciation (485 ) (335 ) $ 1,211 $ 1,040

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2021
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	June 30, December 31, 2021 2020 (in thousands) Accrued research and development expenses $ 4,183 $ 3,409 Accrued payroll and related expenses 852 1,350 Accrued professional fees 497 924 Accrued other 143 160 $ 5,675 $ 5,843

Stockholders' Equity and Stoc_2

Stockholders' Equity and Stock Options (Tables)	6 Months Ended
	Jun. 30, 2021
Stockholders Equity Note [Abstract]
Assumptions used to Determine Fair Value of Stock Options Granted	The following table presents, on a weighted average basis, the assumptions used in the Black-Scholes option-pricing model to determine the grant-date fair value of stock options granted to employees: June 30, December 31, 2021 2020 Risk-free interest rate 0.88% 0.37% Expected term (in years) 6.19 6.08 Expected volatility 91% 91% Dividend yield 0.00% 0.00%
Summary of Stock Option Activity	The following table summarizes the Company’s stock option activity for the six months ended June 30, 2021 (amounts in millions, except for share and per share data): Weighted Weighted Average Aggregate Average Remaining Intrinsic Number of Exercise Contractual Value (a) Shares Price Term (in years) (in millions) Outstanding as of December 31, 2020 2,008,902 $ 22.31 7.9 Granted 603,050 15.74 Forfeited/Expired (64,990 ) 73.19 Outstanding as of June 30, 2021 2,546,962 $ 19.46 8.1 $ — Exercisable as of June 30, 2021 597,801 $ 39.35 4.3 $ — Vested and expected to vest as of June 30, 2021 2,546,962 $ 19.46 8.1 $ —
Summary of Stock-Based Compensation Expense	Stock-based compensation expense was classified in the condensed consolidated statements of operations as follows: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (in thousands) Research and development $ 515 $ 199 $ 953 $ 211 General and administrative 835 553 1,577 570 $ 1,350 $ 752 $ 2,530 $ 781

Commitments (Tables)

Commitments (Tables)	6 Months Ended
	Jun. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Schedule of Maturities of Lease Liabilities Due Under Lease Agreements	Maturities of lease liabilities due under these lease agreements as of June 30, 2021 are as follows: Operating (in thousands) Leases Six months ending December 31, 2021 $ 590 Year ended December 31, 2022 1,197 Year ended December 31, 2023 1,146 Year ended December 31, 2024 1,065 Year ended December 31, 2025 1,083 Thereafter 4,314 Total lease payments 9,395 Less: imputed interest (3,127 ) Present value of lease liabilities $ 6,268

Organization, Nature of the B_2

Organization, Nature of the Business, COVID-19 Risk and Basis of Presentation - Additional Information (Detail)	Aug. 10, 2021USD ($)	Aug. 14, 2020USD ($)	May 28, 2020$ / sharesshares	Jul. 31, 2021USD ($)shares	Jun. 30, 2020USD ($)	Jun. 30, 2021USD ($)$ / sharesshares	Mar. 31, 2021USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Jun. 30, 2021USD ($)$ / sharesshares	Jun. 30, 2020USD ($)	Dec. 31, 2020USD ($)$ / sharesshares
Common stock, par value per share | $ / shares						$ 0.001				$ 0.001		$ 0.001
Common stock, shares issued | shares						15,367,730				15,367,730		15,367,730
Proceeds from issuance of common stock											$ 75,485,000
Net loss						$ 12,609,000	$ 12,088,000	$ 11,330,000	$ 6,674,000	$ 24,697,000	$ 18,004,000
Accumulated deficit						(90,311,000)				(90,311,000)		$ (65,614,000)
Cash, cash equivalents and marketable securities						$ 70,600,000				$ 70,600,000
Private Offering [Member]
Proceeds from issuance common stock and warrants net offering costs					$ 75,400,000
ATM Offering [Member] | Common Stock [Member]
Aggregate sale of shares of our common stock	$ 29,200,000
Issuance of common stock | shares | shares				2,342,720
Proceeds from issuance of common stock				$ 20,500,000
ATM Offering [Member] | Common Stock [Member] | Maximum [Member]
Aggregate sale of shares of our common stock		$ 50,000,000
Zafgen [Member]
Reverse stock split of common stock			1-for-12
Common stock, par value per share | $ / shares			$ 0.001
Cash, cash equivalents, restricted cash and marketable debt securities acquired merger					$ 42,900,000
Zafgen [Member] | Merger Agreement [Member]
Exchange rate of shares issued per share			60,912.5005
Common stock, shares issued | shares			6,091,250
Chondrial [Member] | Merger Agreement [Member]
Common stock, par value per share | $ / shares			$ 0.001

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Summary Of Significant Accounting Policies [Line Items]
Percentage of likelihood to be realized upon ultimate settlement, description			50.00%
Warrant issued	628,403	628,403	628,403	628,403
Warrant Exercise Price	$ 0.01		$ 0.01
Common Stock Equivalents [Member]
Summary Of Significant Accounting Policies [Line Items]
Total potentially dilutive shares	2,546,962	727,024	2,546,962	727,024
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property Plant And Equipment Useful Life			7 years
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property Plant And Equipment Useful Life			5 years

Merger Accounting - Additional

Merger Accounting - Additional Information (Detail) - shares	May 28, 2020	Jun. 30, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Common stock, shares issued		15,367,730	15,367,730
Zafgen [Member]
Business Acquisition [Line Items]
Capital stock ownership percentage	34.00%
Zafgen [Member] | Options to Purchase Common Stock [Member]
Business Acquisition [Line Items]
Options to purchase stock	328,770
Chondrial Therapeutics Inc. [Member]
Business Acquisition [Line Items]
Capital stock ownership percentage	66.00%
Merger Agreement [Member] | Zafgen [Member]
Business Acquisition [Line Items]
Common stock, shares issued	6,091,250

Merger Accounting - Summary of

Merger Accounting - Summary of Purchase Price Paid in Merger (Detail) - USD ($) $ / shares in Units, $ in Thousands		May 28, 2020	Jun. 30, 2021	Dec. 31, 2020	May 27, 2020
Business Acquisition [Line Items]
Purchase price:		$ 38,834
Common stock outstanding			15,367,730	15,367,730
Zafgen [Member]
Business Acquisition [Line Items]
Number of shares of the combined organization owned by Zafgen stockholders	[1]	3,124,337
Multiplied by the fair value per share of Zafgen common stock	[2]	$ 11.88
Fair value of consideration issued in effect of the Merger		$ 37,119
Transaction costs		1,715
Purchase price:		$ 38,834
Common stock outstanding					37,492,044
[1]	The number of shares of 3,124,337 represents the historical 37,492,044 shares of Zafgen common stock outstanding immediately prior to the closing of the Merger, adjusted for the Reverse Stock Split.
[2]	Based on the last reported sale price of Zafgen common stock on the Nasdaq Global Market on May 28, 2020, the closing date of the Merger, and after giving effect to the Reverse Stock Split.

Merger Accounting - Summary o_2

Merger Accounting - Summary of Allocation of Purchase Price to Net Tangible and Intangible Assets Acquired (Detail) $ in Thousands	May 28, 2020USD ($)
Business Combinations [Abstract]
Cash and cash equivalents	$ 40,595
Marketable debt securities	1,014
Other current and noncurrent assets	357
Property and equipment, net	398
Restricted cash	1,339
Right-of-use asset	3,806
Current liabilities	(2,685)
Lease liability, net of current portion	(5,990)
Purchase price	$ 38,834

Fair Value Measurements and M_3

Fair Value Measurements and Marketable Debt Securities - Summary of Cash Equivalents and Marketable Debt Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 20,149	$ 12,635
Marketable debt securities	0	24,490
Total cash equivalents and marketable debt securities		37,125
Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	12,978	4,229
Commercial Paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	5,250	6,499
Marketable debt securities		22,485
Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	1,921	1,907
U.S. Government Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable debt securities		2,005
Quoted Prices in Active Markets, (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	12,978	4,229
Total cash equivalents and marketable debt securities		4,229
Quoted Prices in Active Markets, (Level 1) [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	12,978	4,229
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	7,171	8,406
Marketable debt securities		24,490
Total cash equivalents and marketable debt securities		32,896
Significant Other Observable Inputs (Level 2) [Member] | Commercial Paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	5,250	6,499
Marketable debt securities		22,485
Significant Other Observable Inputs (Level 2) [Member] | Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 1,921	1,907
Significant Other Observable Inputs (Level 2) [Member] | U.S. Government Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable debt securities		$ 2,005

Fair Value Measurements and M_4

Fair Value Measurements and Marketable Debt Securities - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Marketable debt securities	$ 0	$ 24,490

Fair Value Measurements and M_5

Fair Value Measurements and Marketable Debt Securities - Summary of Marketable Debt Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		$ 24,489
Gross Unrealized Gains		2
Gross Unrealized Losses		(1)
Fair Value	$ 0	24,490
U.S. Government Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		2,005
Fair Value		2,005
Commercial Paper [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		22,484
Gross Unrealized Gains		2
Gross Unrealized Losses		(1)
Fair Value		$ 22,485

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Prepaid Expense And Other Assets [Abstract]
Prepaid research and development expenses	$ 2,945	$ 4,460
Prepaid insurance	201	571
Payroll tax receivable	67	32
Other prepaid expenses and other assets	193	251
Total prepaid expenses and other current assets	$ 3,406	$ 5,314

Fixed Assets - Schedule of Fixe

Fixed Assets - Schedule of Fixed Assets, Net (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Fixed assets, gross	$ 1,696		$ 1,375
Less: Accumulated depreciation	(485)		(335)
Fixed assets, net	1,211	$ 1,211	1,040
Computer Equipment [Member]
Fixed assets, gross	$ 66		66
Fixed assets, useful life	5 years
Lab Equipment [Member]
Fixed assets, gross	$ 1,144		849
Fixed assets, useful life	5 years
Furniture and Fixtures [Member]
Fixed assets, gross	$ 455		$ 460
Fixed assets, useful life	7 years
Lease hold Improvements [Member]
Fixed assets, gross	$ 31
Fixed assets, useful life	lease term

Fixed Assets - Additional Infor

Fixed Assets - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Depreciation expense	$ 150	$ 55
Maximum [Member]
Depreciation expense		$ 100

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued research and development expenses	$ 4,183	$ 3,409
Accrued payroll and related expenses	852	1,350
Accrued professional fees	497	924
Accrued other	143	160
Total accrued expenses	$ 5,675	$ 5,843

Stockholders Equity and Stock O

Stockholders Equity and Stock Options - Additional Information (Detail) - USD ($)	Aug. 10, 2021	May 28, 2021	Jan. 01, 2021	Aug. 14, 2020	May 28, 2020	May 28, 2020	Apr. 29, 2019	Jul. 31, 2021	Nov. 30, 2016	Mar. 31, 2021	May 28, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Mar. 23, 2018	Dec. 31, 2014
Preferred stock, shares authorized												5,000,000		5,000,000
Preferred stock, par value												$ 0.001		$ 0.001
Common stock, shares authorized												115,000,000		115,000,000
Common stock, par value												$ 0.001		$ 0.001
Common stock voting rights												Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders
Dividend paid												$ 0
Warrant issued												628,403	628,403
Warrant Exercise Price												$ 0.01
Common stock, shares issued												15,367,730		15,367,730
Proceeds from issuance of common stock													$ 75,485,000
Options to purchase shares of common stock granted												603,050
Unrecognized compensation expense												$ 17,700,000
Unrecognized compensation expense recognized period												3 years 1 month 13 days
2014 Stock Option and Incentive Plan [Member]
Shares reserved for future issuance																180,685
2016 Equity and Incentive Plan [Member]
Increase in shares reserved for future issuance							101,500		122,133
Shares reserved for future issuance							239,633		122,133						138,133
Issuance of options											0
Number of options to purchase common unit prior to conversion					202,392	202,392					202,392
Number of options to purchase common unit post conversion					330,818	330,818					330,818
Weighted average exercise price post conversion					$ 12.14	$ 12.14					$ 12.14
Weighted average exercise price prior to conversion					$ 10.36	$ 10.36					10.36
Increase in fair value						$ 1,200,000
Aggregate grant fair value						100,000
2016 Equity and Incentive Plan [Member] | Vested Recognized Immediately [Member]
Increase in fair value						700,000
2016 Equity and Incentive Plan [Member] | Nonvested Recognize Over Remaining Term [Member]
Increase in fair value						$ 500,000
Common Stock [Member] | 2020 Equity Incentive Plan [Member]
Share-based compensation arrangement by share-based payment award, description										As of June 30, 2021, 970,349 shares of common stock were available for grant under the 2020 Plan. The maximum number of shares that may be issued in respect of any awards under the 2020 Plan is the sum of: (i) 1,700,000 shares plus (ii) an annual increase on January 1, 2021 and each anniversary of such date thereafter through January 1, 2030, equal to the lesser of (A) 4% of the shares issued and outstanding on the last day of the immediately preceding fiscal year, and (B) such smaller number of shares as determined by the Board (collectively, the “Plan Limit”).
Shares available for grant												970,349
Minimum level of maximum number of shares allowed to be issued												1,700,000
Increase in shares reserved for future issuance			614,709
Maximum number of shares that may be issued under stock option incentive plan			2,314,709
Maximum aggregate shares issuable over plan term												8,000,000
Percentage of outstanding shares												4.00%
Term of the 2020 plan												10 years
Options to purchase shares of common stock granted												603,050
Common Stock [Member] | 2020 Equity Incentive Plan [Member] | Director [Member]
Vesting period of stock option												1 year
Options to purchase shares of common stock vested												49,800
Common Stock [Member] | 2020 Equity Incentive Plan [Member] | Vest Over 4 Years [Member]
Vesting period of stock option												4 years
Stock option vesting percentage												25.00%
Options to purchase shares of common stock vested												553,250
Common Stock [Member] | 2020 Equity Incentive Plan [Member] | Merger [Member]
Increase in shares reserved for future issuance		38,090
Private Placement [Member]
Issuance of common stock | shares					6,105,359
Share price per share					$ 11.88	$ 11.88					$ 11.88
Warrant issued					628,403	628,403					628,403
Warrants price per share					$ 11.87	$ 11.87					$ 11.87
Gross proceeds					$ 80,000,000
Warrant Exercise Price					$ 0.01	$ 0.01					$ 0.01
Transaction cost					$ 4,600,000
Proceeds from issuance common stock and warrants net offering costs					$ 75,400,000
Private Placement [Member] | MTS Health Partners [Member] | Common Stock [Member]
Issuance of common stock as compensation to placement agency					35,260
ATM Offering Program [Member] | Common Stock [Member]
Percentage of compensation for services equal to gross proceeds				3.00%
Sales agreement, description				The Company has no obligation to sell any of the ATM Shares and may at any time suspend offers under the ATM Agreement.
Common stock, shares issued								2,342,720				11,524
Proceeds from issuance of common stock	$ 29,200,000							$ 19,900,000				$ 200,000
Average price per share												$ 21.89
ATM Offering Program [Member] | Common Stock [Member] | Maximum [Member]
Aggregate sale of shares of our common stock				$ 50,000,000

Stockholders Equity and Stock_2

Stockholders Equity and Stock Options - Assumptions used to Determine Fair Value of Stock Options Granted (Detail)	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Stockholders Equity Note [Abstract]
Risk-free interest rate	0.88%	0.37%
Expected term (in years)	6 years 2 months 8 days	6 years 29 days
Expected volatility	91.00%	91.00%
Dividend yield	0.00%	0.00%

Stockholders Equity and Stock_3

Stockholders Equity and Stock Options - Summary of Stock Option Activity (Detail) - $ / shares	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Stockholders Equity Note [Abstract]
Number of shares, Outstanding	2,008,902
Number of shares, Granted	603,050
Number of shares, Forfeited	(64,990)
Number of shares, Outstanding	2,546,962	2,008,902
Number of shares, Exercisable as of March 31, 2021	597,801
Number of shares, Vested and expected to vest as of March 31, 2021	2,546,962
Weighted average exercise price, balance	$ 22.31
Weighted average exercise price, Granted	15.74
Weighted average exercise price, Forfeited	73.19
Weighted average exercise price, balance	19.46	$ 22.31
Weighted average exercise price, Exercisable as of March 31, 2021	39.35
Weighted average exercise price, Vested and expected to vest as of March 31, 2021	$ 19.46
Weighted average remaining contractual term, outstanding	8 years 1 month 6 days	7 years 10 months 24 days
Weighted average remaining contractual term, Exercisable as of March 31, 2021	4 years 3 months 18 days
Weighted average remaining contractual term, Vested and expected to vest as of March 31, 2021	8 years 1 month 6 days

Stockholders Equity and Stock_4

Stockholders Equity and Stock Options - Summary of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,350	$ 752	$ 2,530	$ 781
Research and Development [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	515	199	953	211
General and Administrative [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 835	$ 553	$ 1,577	$ 570

Commitments - Additional Inform

Commitments - Additional Information (Detail)	Oct. 27, 2020	Aug. 04, 2020	May 28, 2020USD ($)ft²	Aug. 08, 2019	Nov. 05, 2018	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Dec. 31, 2020USD ($)	Mar. 31, 2020USD ($)
Other Commitments [Line Items]
Milestone expenses						$ 0		$ 0
Milestone payments due						0		0
Operating lease right-of-use assets						3,673,000		3,673,000		$ 3,936,000
Operating lease liability						$ 6,268,000		$ 6,268,000
Weighted average remaining lease term in years						8 years 1 month 6 days		8 years 1 month 6 days		8 years 7 months 6 days
Weighted average discount rate						11.00%		11.00%		11.00%
Lease expenses						$ 100,000	$ 100,000	$ 100,000	$ 100,000
Pennsylvania [Member] | Office and Lab [Member]
Other Commitments [Line Items]
Lease extension period					2 years
Lease term commencement date					Jan. 1, 2019
Lease term expiration date		Dec. 31, 2021			Dec. 31, 2020
Pennsylvania [Member] | Office [Member]
Other Commitments [Line Items]
Operating lease term				3 years 6 months
Lease extension period				3 years
Operating lease right-of-use assets											$ 400,000
Operating lease liability											$ 400,000
Lease term commencement date				Feb. 15, 2020
Massachusetts [Member] | Office [Member]
Other Commitments [Line Items]
Area of office space | ft²			17,705
Massachusetts [Member] | Office [Member] | Letter of Credit
Other Commitments [Line Items]
Letter of credit			$ 1,300,000
Massachusetts [Member] | Office Sublease [Member]
Other Commitments [Line Items]
Lease term expiration date	Oct. 30, 2029
Massachusetts [Member] | First Sublease Year [Member] | Office Sublease [Member]
Other Commitments [Line Items]
Annual base rent						800,000		800,000
Massachusetts [Member] | First Sublease Year [Member] | Office Sublease [Member] | Letter of Credit
Other Commitments [Line Items]
Lease security deposits letters of credit						800,000		800,000
Massachusetts [Member] | Final Sublease Year [Member] | Office Sublease [Member]
Other Commitments [Line Items]
Annual base rent						1,000,000		1,000,000
Massachusetts [Member] | Sixth Sublease Year | Office Sublease [Member] | Letter of Credit
Other Commitments [Line Items]
Lease security deposits letters of credit						$ 400,000		$ 400,000
WFUHS [Member]
Other Commitments [Line Items]
License agreement consideration deduction percentage						60.00%		60.00%
WFUHS [Member] | Maximum [Member]
Other Commitments [Line Items]
Milestone payments						$ 2,600,000		$ 2,600,000
IU [Member]
Other Commitments [Line Items]
License agreement consideration deduction percentage						20.00%		20.00%
IU [Member] | Maximum [Member]
Other Commitments [Line Items]
Milestone payments						$ 2,600,000		$ 2,600,000
Annual royalty pay obligation						$ 100,000		$ 100,000

Commitments - Schedule of Matur

Commitments - Schedule of Maturities of Lease Liabilities Due Under Lease Agreements (Detail) $ in Thousands	Jun. 30, 2021USD ($)
Leases [Abstract]
Six months ending December 31, 2021	$ 590
Year ended December 31, 2022	1,197
Year ended December 31, 2023	1,146
Year ended December 31, 2024	1,065
Year ended December 31, 2025	1,083
Thereafter	4,314
Total lease payments	9,395
Less: imputed interest	(3,127)
Present value of lease liabilities	$ 6,268

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($) $ in Thousands	Jan. 01, 2021	Jan. 16, 2020	Nov. 21, 2019	Nov. 30, 2016	Nov. 30, 2020	Nov. 30, 2016	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Related Party Transaction [Line Items]
Research and development expense							$ 9,102	$ 8,907		$ 18,076	$ 13,914
Capital contributions from related party								8,400	$ 9,595		17,995
Holdings [Member] | Series A Preferred Unit Purchase Agreement [Member]
Related Party Transaction [Line Items]
Gross proceeds from sale of equity						$ 35,600
Capital contributions from related party						35,600
Holdings [Member] | Series B Bridge Unit Purchase Agreement [Member]
Related Party Transaction [Line Items]
Capital contributions from related party			$ 10,000
Holdings [Member] | Second Series B Bridge Unit Purchase Agreement [Member]
Related Party Transaction [Line Items]
Capital contributions from related party		$ 11,400
Holdings [Member] | Series A and Series B [Member]
Related Party Transaction [Line Items]
Capital contributions from related party											18,000
Maximum [Member] | Holdings [Member] | Series B Bridge Unit Purchase Agreement [Member]
Related Party Transaction [Line Items]
Gross proceeds from sale of equity			$ 10,000
Maximum [Member] | Holdings [Member] | Second Series B Bridge Unit Purchase Agreement [Member]
Related Party Transaction [Line Items]
Gross proceeds from sale of equity		$ 15,000
Consulting Agreement [Member]
Related Party Transaction [Line Items]
Amount to be paid for consulting services						$ 100
Research and development expense										$ 100	$ 100
Period of agreement				4 years
Extented period of agreement					1 month
Agreement expiration date					Dec. 31, 2020
Consulting Agreement [Member] | Holdings [Member]
Related Party Transaction [Line Items]
Restricted common units granted						123,853
Award vesting				30.00%
Consulting Agreement [Member] | Future Services [Member] | Vests Over Forty Eight Months [Member]
Related Party Transaction [Line Items]
Award vesting				70.00%
Consulting Agreement [Member] | Future Services [Member] | Remaining Restricted Common Units [Member]
Related Party Transaction [Line Items]
Vesting period of stock option				48 months
Consulting Agreement [Member] | Maximum [Member]
Related Party Transaction [Line Items]
Research and development expense							$ 100	$ 100
New Consulting Agreement [Member]
Related Party Transaction [Line Items]
Period of agreement	4 years