Larimar Therapeutics (LRMR) 10-Q 14 Aug 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 31, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2020
Document Fiscal Year Focus	2020
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		15,356,206
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
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, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 112,673	$ 1,009
Marketable debt securities	1,011
Prepaid expenses and other current assets	5,427	3,741
Total current assets	119,111	4,750
Property and equipment, net	675	274
Operating lease right-of-use assets	4,252	87
Restricted cash	1,339
Other assets	80	90
Total assets	125,457	5,201
Current liabilities:
Accounts payable	2,258	3,539
Accrued expenses	3,796	2,259
Operating lease liabilities, current	591	97
Total current liabilities	6,645	5,895
Operating lease liabilities	6,268
Total liabilities	12,913	5,895
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, 2020 and December 31, 2019; no shares issued and outstanding as of June 30, 2020 and December 31, 2019
Common stock, $0.001 par value per share; 115,000,000 shares authorized as of June 30, 2020 and December 31, 2019; 15,356,206 and 6,091,250 shares issued and outstanding as of June 30, 2020 and December 31, 2019, respectively	15	6
Additional paid-in capital	153,668	22,432
Accumulated deficit	(41,136)	(23,132)
Accumulated other comprehensive loss	(3)
Total stockholders’ equity (deficit)	112,544	(694)
Total liabilities and stockholders’ equity (deficit)	$ 125,457	$ 5,201

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2020	Dec. 31, 2019
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	15,356,206	6,091,250
Common stock, shares outstanding	15,356,206	6,091,250

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating expenses:
Research and development	$ 8,907	$ 3,128	$ 13,914	$ 7,350
General and administrative	2,492	576	4,159	1,078
Total operating expenses	11,399	3,704	18,073	8,428
Loss from operations	(11,399)	(3,704)	(18,073)	(8,428)
Other income, net	69		69
Net loss	$ (11,330)	$ (3,704)	$ (18,004)	$ (8,428)
Net loss per share, basic and diluted	$ (1.21)	$ (0.61)	$ (2.33)	$ (1.38)
Weighted average common shares outstanding, basic and diluted	9,381,412	6,091,250	7,736,331	6,091,250
Comprehensive loss:
Net loss	$ (11,330)	$ (3,704)	$ (18,004)	$ (8,428)
Other comprehensive loss:
Unrealized loss on marketable debt securities	(3)		(3)
Total other comprehensive loss	(3)		(3)
Total comprehensive loss	$ (11,333)	$ (3,704)	$ (18,007)	$ (8,428)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Changes in Stockholders' Equity (Deficit) - 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, 2018	$ 2,914	$ 6	$ 2,908
Beginning balance, shares at Dec. 31, 2018		6,091,250
Capital contributions from related party	3,000		3,000
Stock-based compensation expense	34		34
Net loss	(4,724)			$ (4,724)
Ending balance at Mar. 31, 2019	1,224	$ 6	5,942	(4,724)
Ending balance, shares at Mar. 31, 2019		6,091,250
Beginning balance at Dec. 31, 2018	2,914	$ 6	2,908
Beginning balance, shares at Dec. 31, 2018		6,091,250
Capital contributions from related party	5,990
Net loss	(8,428)
Ending balance at Jun. 30, 2019	543	$ 6	8,965	(8,428)
Ending balance, shares at Jun. 30, 2019		6,091,250
Beginning balance at Dec. 31, 2018	2,914	$ 6	2,908
Beginning balance, shares at Dec. 31, 2018		6,091,250
Ending balance at Dec. 31, 2019	(694)	$ 6	22,432	(23,132)
Ending balance, shares at Dec. 31, 2019		6,091,250
Beginning balance at Mar. 31, 2019	1,224	$ 6	5,942	(4,724)
Beginning balance, shares at Mar. 31, 2019		6,091,250
Capital contributions from related party	2,990		2,990
Stock-based compensation expense	33		33
Net loss	(3,704)			(3,704)
Ending balance at Jun. 30, 2019	543	$ 6	8,965	(8,428)
Ending balance, shares at Jun. 30, 2019		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	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 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
Private Placement of common shares and pre-funded warrants, net of transaction costs, shares		6,140,619
Stock-based compensation expense	752		752
Unrealized 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

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Cash flows from operating activities:
Net loss					$ (18,004)	$ (8,428)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense					781	67
Depreciation expense					55	38
Changes in operating assets and liabilities:
Prepaid expenses and other current assets					(1,760)	(1,324)
Accounts payable					(3,284)	653
Accrued expenses					1,067	11
Right-of-use assets					89	39
Operating lease liabilities					(85)	(26)
Other assets					21	5
Net cash used in operating activities:					(21,120)	(8,965)
Cash flows from investing activities:
Purchase of property and equipment					(58)	(33)
Cash, cash equivalents, and restricted cash acquired in connection with the Merger					41,934
Merger transaction costs					(1,233)
Net cash provided by (used in) investing activities					40,643	(33)
Cash flows from financing activities:
Capital contributions from related party	$ 8,400	$ 9,595	$ 2,990	$ 3,000	17,995	5,990
Proceeds from sale of common stock and prefunded warrants, net of issuance costs					75,485
Net cash provided by financing activities					93,480	5,990
Net increase (decrease) in cash, cash equivalents and restricted cash					113,003	(3,008)
Cash, cash equivalents and restricted cash at beginning of period		$ 1,009		$ 4,396	1,009	4,396	$ 4,396
Cash, cash equivalents and restricted cash at end of period	$ 114,012		$ 1,388		114,012	$ 1,388	$ 1,009
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)
Leased assets obtained in exchange for new operating lease liabilities					448
Offering costs included in accounts payable and accrued expenses					135
Merger transaction costs included in accounts payable and accrued expenses					$ 65

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 and excluding cash acquired	$ 1

Organization, Nature of the Bus

Organization, Nature of the Business, COVID-19 Risk and Basis of Presentation	6 Months Ended
	Jun. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization, Nature of the Business, COVID-19 Risk and Basis of Presentation	1. Organization, 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 biopharmaceutical company leveraging its proprietary knowledge to develop a therapeutic treatment for mitochondrial disorders which currently have no cure. The Company has focused on Friedreich’s Ataxia, which is a progressive disease that affects multiple body systems, particularly the brain and heart. CTI-1601, the Company’s lead product candidate in Phase 1 clinical development, utilizes a cell penetrant peptide to deliver frataxin, the protein deficient in Friedreich’s Ataxia, to the mitochondria where it is believed to be processed into mature frataxin and becomes active in mitochondrial metabolism. 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 and the ability to secure additional capital to fund operations. Drug candidates currently under development will require extensive nonclinical 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. This outbreak is causing major disruptions to businesses and markets worldwide as the virus spreads. The extent of the effect on the Company’s operational and financial performance will depend on future developments, including the duration, spread and intensity of the pandemic, and governmental, regulatory and private sector responses, all of which are uncertain and difficult to predict. Although the Company is unable to estimate the financial effect of the pandemic at this time, if the pandemic continues to evolve into a severe worldwide crisis, it could have a material adverse effect on the Company’s business, results of operations, financial condition and cash flows. The financial statements do not reflect any adjustments as a result of the pandemic. The pandemic resulted in the temporary stoppage of the Company’s Phase 1 clinical trial studying CTI-1601 in patients with Friedreich’s Ataxia after the completion of two cohorts After dosing, patients remain in isolation in the clinical research unit for a period of time. 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) 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; and (3) existing members of Chondrial management will be 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 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. 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, Chondrial Therapeutics Inc., Chondrial Therapeutics IP LLC, Zafgen Securities Corporation, Zafgen Australia Pty Limited and Zafgen Animal Health, LLC. 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 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 consolidated financial statements are issued. As of the issuance date of these condensed consolidated financial statements, the Company expects that its cash and cash equivalents 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. 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, other collaborations, strategic alliances and licensing arrangements. 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 contributions from Holdings. In 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 addition, in 2020, prior to the Merger, the Company received $18.0 million in capital contributions from Holdings. 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, 2020
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, 2019 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, 2020 and for the three and six months ended June 30, 2020 and 2019, 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, 2019 included in the Company’s Current Report on Form 8-K/A filed on June 26, 2020. 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, 2020 and condensed consolidated results of operations and cash flows for the three and six months ended June 30, 2020 and 2019 have been made. The results of operations for the three and six months ended June 30, 2020 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2020. 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 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 the active pharmaceutical ingredients and formulated drugs related to these programs. These programs could be adversely affected by a significant interruption in these manufacturing services or in the supply of active pharmaceutical ingredients and formulated drugs. 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. Cash equivalents consisted of money market funds, U.S. government securities and corporate bonds as of June 30, 2020. As of December 31, 2019, the Company did not have cash equivalents. 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. 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 nonclinical 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, nonclinical 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 generally 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 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, 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 the following common stock equivalents, outstanding as of June 30, 2020 and 2019, from the computation of diluted net loss per share for the three and six months ended June 30, 2020 and 2019 because they had an anti-dilutive impact due to the net loss incurred for the periods: As of June 30, 2020 2019 Options to purchase common stock 720,067 — Unvested restricted common stock 6,957 — 727,024 — 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

Merger Accounting

Merger Accounting	6 Months Ended
	Jun. 30, 2020
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 liabilities (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, 2020
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, 2020 and December 31, 2019 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 and cash equivalents, accounts payable and accrued liabilities. For accounts payable and accrued liabilities, the carrying amounts of these financial instruments as of June 30, 2020 and December 31, 2019 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, 2020, there were no cash equivalents and marketable debt securities as of December 31, 2019: June 30, 2020 Total Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) Cash equivalents: Money market funds $ 33,546 $ 33,546 $ — $ — U.S. Government securities 902 — 902 — Corporate bonds 1,977 — 1,977 — Total cash equivalents 36,425 33,546 2,879 — Marketable securities: Corporate bonds 1,011 — 1,011 — Total marketable debt securities 1,011 — 1,011 — Total cash equivalents and marketable debt securities $ 37,436 $ 33,546 $ 3,890 $ — Marketable Debt Securities The following tables summarize the Company’s marketable debt securities as of June 30, 2020. There were no marketable debt securities as of December 31, 2019: June 30, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Assets: Corporate bonds (due within 1 year) $ 1,014 $ — $ (3 ) $ 1,011 $ 1,014 $ — $ (3 ) $ 1,011 As of June 30, 2020, the Company did not have an allowance for credit losses.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	6 Months Ended
	Jun. 30, 2020
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, 2020 2019 (in thousands) Prepaid research and development expenses $ 4,926 $ 3,099 Capitalized transaction costs — 419 Research and development tax credit sale receivable — 82 Payroll tax receivable 55 76 Other prepaid expenses and other assets 446 65 $ 5,427 $ 3,741 Capitalized transaction costs as of December 31, 2019 consists of capitalized legal and proxy fees incurred by the Company, related to the Merger. These costs were included in the purchase price allocation when accounting for the Merger.

Fixed Assets

Fixed Assets	6 Months Ended
	Jun. 30, 2020
Assets [Abstract]
Fixed Assets	6. Fixed Assets Fixed assets, net consisted of the following: June 30, December 31, Useful Life 2020 2019 (in thousands) Computer equipment 5 years $ 41 $ 14 Lab equipment 5 years 389 389 Furniture and fixtures 7 years 479 50 909 453 Less: Accumulated depreciation (234 ) (179 ) $ 675 $ 274 Depreciation expense during the three and six months ended June 30, 2020 and 2019 was less than $0.1 million.

Accrued Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2020
Payables And Accruals [Abstract]
Accrued Expenses	7 . Accrued Expenses Accrued expenses consisted of the following: June 30, December 31, 2020 2019 (in thousands) Accrued research and development expenses $ 2,290 $ 1,295 Accrued payroll and related expenses 516 119 Accrued professional fees 526 337 Accrued other 464 508 $ 3,796 $ 2,259

Stockholders_ Equity and Stock

Stockholders’ Equity and Stock Options	6 Months Ended
	Jun. 30, 2020
Stockholders Equity Note [Abstract]
Stockholders’ Equity and Stock Options	8 . Stockholders’ Equity and Stock Options Common Stock and Prefunded warrants As of June 30, 2020, 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. Restricted Common Units In November 2016, Holdings granted 123,853 Restricted Common Units of Holdings to Dr. Mark Payne (see Note 10) with an aggregate grant date fair value of approximately $0.5 million. Thirty percent (30%) of the award vested upon issuance with the remaining seventy percent (70%) vesting ratably over the next 48 months as long as services were continued to be provided as stipulated in the consulting agreement. The Company has recognized compensation expense of less than $0.1 million on a graded vesting basis in research and development expense during each of the three and six months ended June 30, 2020 and 2019. As of June 30, 2020, the Company expects to recognize less than $0.1 million over the remaining five-month vesting period. In accordance with ASC 718, Compensation—Stock Compensation 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”) were assumed by the Company. These plans are administered by the Board or, at the discretion of the Board, by a committee of the Board. 2014 Stock Option and Incentive Plan and 2006 Stock Option Plan In 2014, the Board and shareholders of Zafgen adopted the 2014 Plan. The 2014 Plan provides 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. The number of shares reserved for issuance may be increased by the number of shares under the previously authorized 2006 Plan that are not needed to fulfill the Company’s obligations for awards issued under the 2006 Plan as a result of forfeiture, expiration, cancellation, termination or net issuances of awards thereunder. The number of shares of common stock that may be issued under the 2014 Plan is also subject to increase on the first day of each fiscal year by the lesser of (i) 4% of the Company’s outstanding shares of common stock as of that date, or (ii) an amount determined by the Board. As of June 30, 2020, 505,893 shares of common stock were available for grant under the 2014 Plan, including 124,821 shares of common stock automatically added to the 2014 Plan on January 1, 2020. 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 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. During the three and six months ended June 30, 2020 Holdings did not issue options to purchase Common Units to employees of the Company. During the three and six months ended June 30, 2019 Holdings issued 59,236 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 was $12.14 per share were substituted for the 202,392 options to purchase Common Units, with a weighted average exercise price was $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 and the remaining $0.5 million will be 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: 2020 2019 Risk-free interest rate 0.47% 2.00% Expected term (in years) 6.25 6.25 Expected volatility 90% 77% 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, 2020: Weighted Average Average Remaining Aggregate Number of Exercise Contractual Intrinsic Shares Price Term Value Outstanding as of December 31, 2019 202,392 $ 10.36 7.5 $ — Assumed as part of the Merger with Zafgen 328,770 74.80 Modification of stock options 128,426 14.96 Granted 60,479 11.88 Outstanding as of June 30, 2020 720,067 $ 40.73 5.4 $ 0.4 Exercisable as of June 30, 2020 535,922 $ 50.34 4.2 $ 0.2 Vested and expected to vest as of June 30, 2020 720,067 $ 40.73 5.4 $ 0.4 July 2020 Option Grants On July 16, 2020, the Company granted options to purchase 489,295 shares of common stock to employees under the 2014 Plan. The options have an exercise price equal to $11.90, which was the closing stock price as of the grant date, and vest over four years, with 25% vesting on the first anniversary of the grant and the remainder vesting in equal monthly installments thereafter. In addition, on July 16, 2020 the Company granted options to purchase 735,100 shares of common stock to employees and directors under the Company’s 2020 Equity Incentive Plan (the “2020 Plan”). The 2020 Plan was approved by the Company’s Board of Directors, upon the recommendation of the Compensation Committee of the Board on July 16, 2020. The options granted to employees have an exercise price equal to $11.90, which was the closing stock price as of the grant date, and vest over four years, with 25% vesting on the first anniversary of the grant and the remainder vesting in equal monthly installments thereafter. The options granted to directors have an exercise price equal to $11.90, which was the closing stock price as of the grant date, and vest monthly in equal installments over three years. The Company plans to submit the 2020 Plan to the Company’s stockholders for approval. If the 2020 Plan is not approved by the stockholders of the Company by July 16, 2021, the 2020 Plan and the options granted thereunder will expire. Option Grants with market-based vesting conditions In October 2017, Zafgen granted 45,833 common stock options that vest on the third anniversary of the grant date upon achievement by the Company of minimum common stock prices for 20 consecutive days during the period between the first anniversary of the grant date and the third anniversary of the grant date. As of the Effective Time the options had not achieved the minimum common stock prices and remain unvested. 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, 2020 2019 2020 2019 (in thousands) Research and development $ 199 $ 17 $ 211 $ 36 General and administrative 553 16 570 31 $ 752 $ 33 $ 781 $ 67 As of June 30, 2020, total unrecognized compensation expense related to unvested stock options and restricted stock units was $1.1 million, which is expected to be recognized over a weighted average period of 3.08 years

Commitments

Commitments	6 Months Ended
	Jun. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments	9. Commitments Intellectual Property Licenses The Company is party to a License Agreement (the “WFUHS License”), dated November 30, 2016 with Wake Forest University Health Sciences (“WFUHS”) and a 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 $2.2 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 months and six months ended June 30, 2020 and 2019, 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 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 at 3 Center Plaza, Boston, Massachusetts. The lease commenced on June 21, 2019 and expires after a term of approximately 124 months and the Company has an option to extend the lease for 60 additional months. As part of the agreement, the Company is required to maintain a letter of credit, which upon signing was $1.3 million and is classified as restricted cash within the consolidated financial statements. 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 Company has ceased using the leased space and is actively seeking to obtain a subtenant. The right-of-use asset is being amortized to rent expense over the remaining lease term. 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. Expense arising from operating leases was $0.1 million during the three and six months ended June 30, 2020 and less than $0.1 million during the three and six months ended June 30, 2019. For operating leases, the weighted-average remaining lease term for leases at June 30, 2020 and December 31, 2019 was 9.0 and 3.3 years, respectively. For operating leases, the weighted average discount rate for leases at June 30, 2020 and December 31, 2019 was 11.0% and 12.0%, respectively. The Company has not entered into any financing leases. Maturities of lease liabilities due under these lease agreements as of June 30, 2020 are as follows: Year Ending December 31, Operating (in thousands) Leases 2020 (July - December) $ 588 2021 1,177 2022 1,197 2023 1,146 2024 1,065 Thereafter 5,397 Total lease payments 10,570 Less: Imputed interest (3,711 ) Present value of lease liabilities $ 6,859

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2020
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% 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% is associated with future services (see Note 8) vesting ratably over 48 months beginning on December 1, 2016. The consulting agreement has a four-year term, subject to earlier termination. During the three and six months ended June 30, 2020 and 2019, the Company recognized less than $0.1 million, related to this consulting agreement, recorded as research and development expense in the Statement of Operations. The funding to the Company originated from Holdings’ sale of Series A Preferred Units and Series B convertible preferred 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 and the year December 31, 2019, Holdings provided the Company non-interest bearing, permanent funding from the above Series A and Series B preferred unit transactions, totaling $18.0 million and $19.4 million, respectively, which has been 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. No contributions were made by Holdings subsequent to the Merger.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	1 1 . Subsequent Events The Company has entered into an Equity Distribution Agreement (the “ATM Program”) with an investment banking firm, pursuant to which the Company may sell shares of its common stock through the investment banker as sales agent for aggregate proceeds of up to $50.0 million. The Company has not sold any shares under the ATM Program.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2020
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) 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; and (3) existing members of Chondrial management will be 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 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. 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, Chondrial Therapeutics Inc., Chondrial Therapeutics IP LLC, Zafgen Securities Corporation, Zafgen Australia Pty Limited and Zafgen Animal Health, LLC. 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, 2019 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, 2020 and for the three and six months ended June 30, 2020 and 2019, 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, 2019 included in the Company’s Current Report on Form 8-K/A filed on June 26, 2020. 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, 2020 and condensed consolidated results of operations and cash flows for the three and six months ended June 30, 2020 and 2019 have been made. The results of operations for the three and six months ended June 30, 2020 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2020.
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 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 consolidated financial statements are issued. As of the issuance date of these condensed consolidated financial statements, the Company expects that its cash and cash equivalents 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. 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, other collaborations, strategic alliances and licensing arrangements. 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 contributions from Holdings. In 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 addition, in 2020, prior to the Merger, the Company received $18.0 million in capital contributions from Holdings. 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 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 the active pharmaceutical ingredients and formulated drugs related to these programs. These programs could be adversely affected by a significant interruption in these manufacturing services or in the supply of active pharmaceutical ingredients and formulated drugs.
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. Cash equivalents consisted of money market funds, U.S. government securities and corporate bonds as of June 30, 2020. As of December 31, 2019, the Company did not have cash equivalents.
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.
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 nonclinical 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, nonclinical 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 generally 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 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, 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 the following common stock equivalents, outstanding as of June 30, 2020 and 2019, from the computation of diluted net loss per share for the three and six months ended June 30, 2020 and 2019 because they had an anti-dilutive impact due to the net loss incurred for the periods: As of June 30, 2020 2019 Options to purchase common stock 720,067 — Unvested restricted common stock 6,957 — 727,024 — 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

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Summary of Common Stock Equivalents Outstanding	The Company excluded the following common stock equivalents, outstanding as of June 30, 2020 and 2019, from the computation of diluted net loss per share for the three and six months ended June 30, 2020 and 2019 because they had an anti-dilutive impact due to the net loss incurred for the periods: As of June 30, 2020 2019 Options to purchase common stock 720,067 — Unvested restricted common stock 6,957 — 727,024 —

Merger Accounting (Tables)

Merger Accounting (Tables)	6 Months Ended
	Jun. 30, 2020
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 liabilities (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, 2020
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, 2020, there were no cash equivalents and marketable debt securities as of December 31, 2019: June 30, 2020 Total Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) Cash equivalents: Money market funds $ 33,546 $ 33,546 $ — $ — U.S. Government securities 902 — 902 — Corporate bonds 1,977 — 1,977 — Total cash equivalents 36,425 33,546 2,879 — Marketable securities: Corporate bonds 1,011 — 1,011 — Total marketable debt securities 1,011 — 1,011 — Total cash equivalents and marketable debt securities $ 37,436 $ 33,546 $ 3,890 $ —
Summary of Marketable Debt Securities	The following tables summarize the Company’s marketable debt securities as of June 30, 2020. There were no marketable debt securities as of December 31, 2019: June 30, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Assets: Corporate bonds (due within 1 year) $ 1,014 $ — $ (3 ) $ 1,011 $ 1,014 $ — $ (3 ) $ 1,011

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	6 Months Ended
	Jun. 30, 2020
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, 2020 2019 (in thousands) Prepaid research and development expenses $ 4,926 $ 3,099 Capitalized transaction costs — 419 Research and development tax credit sale receivable — 82 Payroll tax receivable 55 76 Other prepaid expenses and other assets 446 65 $ 5,427 $ 3,741

Fixed Assets (Tables)

Fixed Assets (Tables)	6 Months Ended
	Jun. 30, 2020
Assets [Abstract]
Schedule of Fixed Assets, Net	Fixed assets, net consisted of the following: June 30, December 31, Useful Life 2020 2019 (in thousands) Computer equipment 5 years $ 41 $ 14 Lab equipment 5 years 389 389 Furniture and fixtures 7 years 479 50 909 453 Less: Accumulated depreciation (234 ) (179 ) $ 675 $ 274

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2020
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following: June 30, December 31, 2020 2019 (in thousands) Accrued research and development expenses $ 2,290 $ 1,295 Accrued payroll and related expenses 516 119 Accrued professional fees 526 337 Accrued other 464 508 $ 3,796 $ 2,259

Stockholders_ Equity and Stoc_2

Stockholders’ Equity and Stock Options (Tables)	6 Months Ended
	Jun. 30, 2020
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: 2020 2019 Risk-free interest rate 0.47% 2.00% Expected term (in years) 6.25 6.25 Expected volatility 90% 77% 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, 2020: Weighted Average Average Remaining Aggregate Number of Exercise Contractual Intrinsic Shares Price Term Value Outstanding as of December 31, 2019 202,392 $ 10.36 7.5 $ — Assumed as part of the Merger with Zafgen 328,770 74.80 Modification of stock options 128,426 14.96 Granted 60,479 11.88 Outstanding as of June 30, 2020 720,067 $ 40.73 5.4 $ 0.4 Exercisable as of June 30, 2020 535,922 $ 50.34 4.2 $ 0.2 Vested and expected to vest as of June 30, 2020 720,067 $ 40.73 5.4 $ 0.4
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, 2020 2019 2020 2019 (in thousands) Research and development $ 199 $ 17 $ 211 $ 36 General and administrative 553 16 570 31 $ 752 $ 33 $ 781 $ 67

Commitments (Tables)

Commitments (Tables)	6 Months Ended
	Jun. 30, 2020
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, 2020 are as follows: Year Ending December 31, Operating (in thousands) Leases 2020 (July - December) $ 588 2021 1,177 2022 1,197 2023 1,146 2024 1,065 Thereafter 5,397 Total lease payments 10,570 Less: Imputed interest (3,711 ) Present value of lease liabilities $ 6,859

Organization, Nature of the B_2

Organization, Nature of the Business, COVID-19 Risk and Basis of Presentation - Additional Information (Detail) $ / shares in Units, $ in Thousands	May 28, 2020$ / sharesshares	Jun. 30, 2020USD ($)$ / sharesshares	Mar. 31, 2020USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Jun. 30, 2020USD ($)$ / sharesshares	Jun. 30, 2019USD ($)	Dec. 31, 2019$ / sharesshares
Phase 1 clinical trial resume period						2020-07
Common stock, par value per share | $ / shares		$ 0.001				$ 0.001		$ 0.001
Common stock, shares issued | shares		15,356,206				15,356,206		6,091,250
Cash, cash equivalents, restricted cash and marketable debt securities acquired merger | $						$ 42,900
Capital contributions from related party | $		$ 8,400	$ 9,595	$ 2,990	$ 3,000	17,995	$ 5,990
Private Offering [Member]
Proceeds from issuance common stock and warrants net offering costs | $						$ 75,400
Zafgen [Member]
Reverse stock split of common stock	1-for-12
Common stock, par value per share | $ / shares	$ 0.001
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_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Cash equivalents		$ 0
Percentage of likelihood to be realized upon ultimate settlement, description	50.00%
Warrant issued	628,403
Warrant Excercise Price	$ 0.01

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Common Stock Equivalents Outstanding (Detail)	6 Months Ended
	Jun. 30, 2020shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potentially dilutive shares	727,024
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potentially dilutive shares	720,067
Unvested Restricted Common Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potentially dilutive shares	6,957

Merger Accounting - Additional

Merger Accounting - Additional Information (Detail) - shares	May 28, 2020	Jun. 30, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Common stock, shares issued		15,356,206	6,091,250
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, 2020	May 27, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Purchase price:		$ 38,834
Common stock outstanding			15,356,206		6,091,250
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 - Additional Information (Detail) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Cash equivalents and marketable debt securities	$ 37,436,000	$ 0
Marketable debt securities		$ 0
Allowance for credit losses	$ 0

Fair Value Measurements and M_4

Fair Value Measurements and Marketable Debt Securities - Summary of Cash Equivalents and Marketable Debt Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 36,425
Marketable debt securities	1,011
Total cash equivalents and marketable debt securities	37,436	$ 0
Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	33,546
Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	1,977
Marketable debt securities	1,011
U.S. Government Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	902
Quoted Prices in Active Markets, (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	33,546
Total cash equivalents and marketable debt securities	33,546
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	33,546
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	2,879
Marketable debt securities	1,011
Total cash equivalents and marketable debt securities	3,890
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	1,977
Marketable debt securities	1,011
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]
Cash equivalents	$ 902

Fair Value Measurements and M_5

Fair Value Measurements and Marketable Debt Securities - Summary of Marketable Debt Securities (Detail) $ in Thousands	Jun. 30, 2020USD ($)
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 1,014
Gross Unrealized Losses	(3)
Fair Value	1,011
Corporate Bonds (Due within 1 Year) [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	1,014
Gross Unrealized Losses	(3)
Fair Value	$ 1,011

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, 2020	Dec. 31, 2019
Prepaid Expense And Other Assets [Abstract]
Prepaid research and development expenses	$ 4,926	$ 3,099
Capitalized transaction costs		419
Research and development tax credit sale receivable		82
Payroll tax receivable	55	76
Other prepaid expenses and other assets	446	65
Total prepaid expenses and other current assets	$ 5,427	$ 3,741

Fixed Assets - Schedule of Fixe

Fixed Assets - Schedule of Fixed Assets, Net (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Fixed assets, gross	$ 909	$ 453
Less: Accumulated depreciation	(234)	(179)
Fixed assets, net	675	274
Computer Equipment [Member]
Fixed assets, gross	$ 41	14
Fixed assets, useful life	5 years
Lab Equipment [Member]
Fixed assets, gross	$ 389	389
Fixed assets, useful life	5 years
Furniture and Fixtures [Member]
Fixed assets, gross	$ 479	$ 50
Fixed assets, useful life	7 years

Fixed Assets - Additional Infor

Fixed Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Depreciation expense			$ 55	$ 38
Maximum [Member]
Depreciation expense	$ 100	$ 100	$ 100	$ 100

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued research and development expenses	$ 2,290	$ 1,295
Accrued payroll and related expenses	516	119
Accrued professional fees	526	337
Accrued other	464	508
Total accrued expenses	$ 3,796	$ 2,259

Stockholders Equity and Stock O

Stockholders Equity and Stock Options - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Jul. 16, 2020	May 28, 2020	Jan. 01, 2020	Apr. 29, 2019	Oct. 31, 2017	Nov. 30, 2016	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Mar. 23, 2018
Preferred stock, shares authorized							5,000,000		5,000,000		5,000,000
Preferred stock, par value							$ 0.001		$ 0.001		$ 0.001
Common stock, shares authorized							115,000,000		115,000,000		115,000,000
Common stock, par value							$ 0.001		$ 0.001		$ 0.001
Dividend paid							$ 0		$ 0
Number of units granted									60,479
Stock-based compensation expense									$ 781	$ 67
Shares added to plan									328,770
Weighted average exercise price, Granted									$ 11.88
Unrecognized compensation expense							$ 1,100		$ 1,100
Unrecognized compensation expense recognized period									3 years 29 days
2014 Stock Option and Incentive Plan and 2006 Stock Option Plan [Member]
Shares reserved for future issuance							180,685		180,685
Shares available for grant							505,893		505,893
Shares added to plan			124,821
Percentage of outstanding shares									4.00%
2016 Equity and Incentive Plan [Member]
Aggregate grant fair value									$ 100
Shares reserved for future issuance				239,633		122,133						138,133
Increase in shares reserved for future issuance				101,500
Issuance of options							0	59,236	0	59,236
Number of options to purchase common unit prior to conversion							330,818		330,818
Number of options to purchase common unit post conversion							202,392		202,392
Weighted average exercise price post conversion							$ 12.14		$ 12.14
Weighted average exercise price prior to conversion							$ 10.36		$ 10.36
Increase in fair value									$ 1,200
2016 Equity and Incentive Plan [Member] | Vested Recognized Immediately [Member]
Increase in fair value									700
2016 Equity and Incentive Plan [Member] | Nonvested Recognize Over Remaining Term [Member]
Increase in fair value									$ 500
2014 Stock Option and Incentive Plan [Member] | Subsequent Event [Member]
Number of units granted	489,295
Vesting period of stock option	4 years
Weighted average exercise price, Granted	$ 11.90
2020 Equity Incentive Plan [Member] | Subsequent Event [Member]
Number of units granted	735,100
Vesting period of stock option	4 years
Weighted average exercise price, Granted	$ 11.90
2020 Equity Incentive Plan [Member] | Subsequent Event [Member] | Director
Vesting period of stock option	3 years
Weighted average exercise price, Granted	$ 11.90
First Anniversary [Member] | 2014 Stock Option and Incentive Plan [Member] | Subsequent Event [Member]
Award vesting	25.00%
First Anniversary [Member] | 2020 Equity Incentive Plan [Member] | Subsequent Event [Member]
Award vesting	25.00%
Restricted Common Units [Member]
Number of units granted						123,853
Aggregate grant fair value						$ 500
Award vesting						30.00%
Restricted Common Units [Member] | Ratably Over Forty Eight Months [Member]
Award vesting									70.00%
Restricted Common Units [Member] | Maximum [Member]
Stock-based compensation expense							$ 100	$ 100	$ 100	$ 100
Restricted Common Units [Member] | Maximum [Member] | Expected Five Month Remaining Vesting [Member]
Stock-based compensation expense									$ 100
Market-Based Vesting Conditions [Member]
Number of units granted					45,833
Stock option vesting description					Zafgen granted 45,833 common stock options that vest on the third anniversary of the grant date upon achievement by the Company of minimum common stock prices for 20 consecutive days during the period between the first anniversary of the grant date and the third anniversary of the grant date
Private Placement [Member]
Issuance of common stock		6,105,359
Share price per share		$ 11.88
Issuance of warrants		628,403
Warrants price per share		$ 11.87
Gross proceeds		$ 80,000
Warrants exercise price		$ 0.01
Transaction cost		$ 4,600
Proceeds from issuance common stock and warrants net offering costs		$ 75,400
Private Placement [Member] | MTS Health Partners [Member]
Issuance of common stock									35,260

Stockholders Equity and Stock_2

Stockholders Equity and Stock Options - Assumptions used to Determine Fair Value of Stock Options Granted (Details)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Stockholders Equity Note [Abstract]
Risk-free interest rate	0.47%	2.00%
Expected term (in years)	6 years 3 months	6 years 3 months
Expected volatility	90.00%	77.00%
Dividend yield	0.00%	0.00%

Stockholders Equity and Stock_3

Stockholders Equity and Stock Options - Summary of Stock Option Activity (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Stockholders Equity Note [Abstract]
Number of shares, Outstanding	202,392
Number of shares, Assumed as part of the Merger with Zafgen	328,770
Number of shares, Modification of stock options	128,426
Number of shares, Granted	60,479
Number of shares, Outstanding	720,067	202,392
Number of shares, Exercisable as of June 30, 2020	535,922
Number of shares, Vested and expected to vest as of June 30, 2020	720,067
Weighted average exercise price, balance	$ 10.36
Weighted average exercise price, Assumed as part of the Merger with Zafgen	74.80
Weighted average exercise price, Modification of stock options	14.96
Weighted average exercise price, Granted	11.88
Weighted average exercise price, balance	40.73	$ 10.36
Weighted average exercise price, Exercisable as of June 30, 2020	50.34
Weighted average exercise price, Vested and expected to vest as of June 30, 2020	$ 40.73
Average remaining contractual term, outstanding	5 years 4 months 24 days	7 years 6 months
Average remaining contractual term, Exercisable as of June 30, 2020	4 years 2 months 12 days
Average remaining contractual term, Vested and expected to vest as of June 30, 2020	5 years 4 months 24 days
Aggregate intrinsic value, outstanding	$ 400
Aggregate intrinsic value, exercisable as of June 30, 2020	200
Aggregate intrinsic value, Vested and expected to vest as of June 30, 2020	$ 400

Stockholders Equity and Stock_4

Stockholders Equity and Stock Options - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 752	$ 33	$ 781	$ 67
Research and Development [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	199	17	211	36
General and Administrative [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 553	$ 16	$ 570	$ 31

Commitments - Additional Inform

Commitments - Additional Information (Detail) $ in Thousands	May 28, 2020USD ($)ft²	Aug. 08, 2019	Nov. 05, 2018	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Other Commitments [Line Items]
Milestone expenses				$ 0	$ 0	$ 0	$ 0
Milestone payments due				0	0	0	0
Operating lease right-of-use assets				4,252		4,252			$ 87
Operating lease liability				$ 6,859		$ 6,859
Weighted average remaining lease term in years				9 years		9 years			3 years 3 months 18 days
Weighted average discount rate				11.00%		11.00%			12.00%
Lease expenses				$ 100		$ 100
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
Operating lease liability								$ 400
Lease term commencement date		Feb. 15, 2020
Pennsylvania [Member] | Office and Lab [Member]
Other Commitments [Line Items]
Lease extension period			2 years
Lease term commencement date			Jan. 1, 2019
Lease expiration date			Dec. 31, 2020
Massachusetts [Member]
Other Commitments [Line Items]
Operating lease term	124 months
Lease extension period	60 months
Lease term commencement date	Jun. 21, 2019
Letter of credit	$ 1,300
Area of office space | ft²	17,705
Maximum [Member]
Other Commitments [Line Items]
Lease expenses					$ 100		$ 100
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				$ 2,200		$ 2,200
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				$ 2,200		$ 2,200
Annual royalty pay obligation				$ 100		$ 100

Commitments - Schedule of Matur

Commitments - Schedule of Maturities of Lease Liabilities Due Under Lease Agreements (Detail) $ in Thousands	Jun. 30, 2020USD ($)
Leases [Abstract]
2020 (July - December)	$ 588
2021	1,177
2022	1,197
2023	1,146
2024	1,065
Thereafter	5,397
Total lease payments	10,570
Less: Imputed interest	(3,711)
Present value of lease liabilities	$ 6,859

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	Jan. 16, 2020	Nov. 21, 2019	Nov. 30, 2016	Nov. 30, 2016	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Related Party Transaction [Line Items]
Research and development expense					$ 8,907		$ 3,128		$ 13,914	$ 7,350
Capital contributions from related party					8,400	$ 9,595	2,990	$ 3,000	17,995	5,990
Holdings
Related Party Transaction [Line Items]
Capital contributions from related party									$ 18,000		$ 19,400
Holdings | 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 | Series B Bridge Unit Purchase Agreement [Member]
Related Party Transaction [Line Items]
Capital contributions from related party		$ 10,000
Holdings | Second Series B Bridge Unit Purchase Agreement [Member]
Related Party Transaction [Line Items]
Capital contributions from related party	$ 11,400
Chondrial [Member]
Related Party Transaction [Line Items]
Award vesting			30.00%
Chondrial [Member] | Vests Over Forty Eight Months
Related Party Transaction [Line Items]
Award vesting			70.00%
Chondrial [Member] | Remaining Restricted Common Units
Related Party Transaction [Line Items]
Vesting period of stock option			48 months
Maximum [Member] | Holdings | Series B Bridge Unit Purchase Agreement [Member]
Related Party Transaction [Line Items]
Gross proceeds from sale of equity		$ 10,000
Maximum [Member] | Holdings | Second Series B Bridge Unit Purchase Agreement [Member]
Related Party Transaction [Line Items]
Gross proceeds from sale of equity	$ 15,000
Consulting Agreement [Member] | Holdings
Related Party Transaction [Line Items]
Amount to be paid for consulting services				$ 100
Restricted common units granted				123,853
Period of agreement									4 years
Consulting Agreement [Member] | Maximum [Member]
Related Party Transaction [Line Items]
Research and development expense					$ 100		$ 100		$ 100	$ 100

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - ATM Program [Member] $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)shares
Subsequent Event [Line Items]
Stock issuance program, authorized amount | $	$ 50
Issuance of common stock | shares	0