ContextLogic (LOGC) 10-K 16 Mar 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Mar. 10, 2020	Jun. 28, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2019
Entity Registrant Name	LogicBio Therapeutics, Inc.
Entity Central Index Key	0001664106
Trading Symbol	LOGC
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity File Number	001-38707
Entity Tax Identification Number	47-1514975
Entity Address, Address Line One	99 Erie St.
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02139
City Area Code	(617)
Local Phone Number	245-0399
Entity Common Stock, Shares Outstanding		23,299,709
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Document Annual Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE
Entity Public Float			$ 137.8
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement for its 2020 Annual Meeting of Stockholders, which the registrant intends to file pursuant to Regulation 14A with the Securities and Exchange Commission not later than 120 days after the registrant’s fiscal year ended December 31, 2019, are incorporated by reference into Part III of this Annual Report on Form 10-K.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
CURRENT ASSETS:
Cash and cash equivalents	$ 33,107	$ 80,906
Short-term investments	17,540
Prepaid expenses and other current assets	2,045	1,268
Restricted cash	146
Total current assets	52,838	82,174
Property and equipment, net	1,696	590
Restricted cash	622	146
Operating lease right-of-use asset	504
TOTAL ASSETS	55,660	82,910
CURRENT LIABILITIES:
Accounts payable	624	1,168
Accrued expenses and other current liabilities	2,939	1,517
Total current liabilities	3,563	2,685
Long-term debt, net of issuance costs and discount	9,810
Total liabilities	13,373	2,685
COMMITMENTS AND CONTINGENCIES (Note 13)
STOCKHOLDERS’ EQUITY:
Preferred stock, par value of $0.0001 per share; 25,000,000 shares authorized; no shares issued and outstanding as of December 31, 2019 and 2018
Common stock, par value of $0.0001 per share; 175,000,000 shares authorized; 23,036,943 and 22,188,393 shares issued and outstanding as of December 31, 2019 and 2018, respectively	3	3
Additional paid-in capital	109,640	107,473
Accumulated other comprehensive income (loss)	14	(9)
Accumulated deficit	(67,370)	(27,242)
Total stockholders’ equity	42,287	80,225
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 55,660	$ 82,910

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	175,000,000	175,000,000
Common stock, shares issued	23,036,943	22,188,393
Common stock, shares outstanding	23,036,943	22,188,393
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
OPERATING EXPENSES:
Research and development	$ 30,656	$ 11,079
General and administrative	10,385	6,864
Total operating expenses	41,041	17,943
LOSS FROM OPERATIONS	(41,041)	(17,943)
OTHER INCOME (EXPENSE), NET:
Interest income	1,500	569
Interest expense	(546)	(2)
Other expense, net	(19)	(159)
Total other income, net	935	408
Loss before income taxes	(40,106)	(17,535)
Income tax provision	(22)	(86)
Net loss	$ (40,128)	$ (17,621)
Net loss per share—basic and diluted	$ (1.78)	$ (3.04)
Weighted-average common stock outstanding—basic and diluted	22,602,954	5,801,533

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (40,128)	$ (17,621)
Other comprehensive income:
Unrealized gain on investments	14
Foreign currency translation adjustment	9	5
Comprehensive loss	$ (40,105)	$ (17,616)

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Series A Convertible Preferred Stock [Member]	Series B Convertible Preferred Stock [Member]	Common Stock [Member]	Common Stock [Member]Stanford [Member]	Common Stock [Member]Series A Convertible Preferred Stock [Member]	Common Stock [Member]Series B Convertible Preferred Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]Series A Convertible Preferred Stock [Member]	Additional Paid-in Capital [Member]Series B Convertible Preferred Stock [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2017	$ (8,599)	$ 4,359	$ 28,703	$ 1				$ 1,035			$ (14)	$ (9,621)
Beginning Balance, Shares at Dec. 31, 2017		2,976,190	19,541,465	1,606,360
Vesting of restricted stock, Shares				656,944
Exercise of options	20							20
Exercise of options, Shares				29,217
Issuance of common stock	72,254			$ 1				72,253
Issuance of common stock, Shares				8,050,000	56,097
Conversion of preferred shares upon initial public offering		$ (4,359)	$ (28,703)
Conversion of preferred shares upon initial public offering, Shares		(2,976,190)	(19,541,465)
Convertible preferred shares upon initial public offering, Shares						1,558,271	10,231,504
Convertible preferred shares upon initial public offering		$ 4,359	$ 28,703				$ 1		$ 4,359	$ 28,702
Foreign currency translation adjustment	5										5
Stock-based compensation expense	1,104							1,104
Net loss	(17,621)											(17,621)
Ending Balance at Dec. 31, 2018	80,225			$ 3				107,473			(9)	(27,242)
Ending Balance, Shares at Dec. 31, 2018				22,188,393
Vesting of restricted stock, Shares				641,333
Exercise of options	224							224
Exercise of options, Shares				207,217
Issuance of common stock warrants related to loan and security agreement	136							136
Unrealized gain on investments	14										14
Foreign currency translation adjustment	9										9
Stock-based compensation expense	1,807							1,807
Net loss	(40,128)											(40,128)
Ending Balance at Dec. 31, 2019	$ 42,287			$ 3				$ 109,640			$ 14	$ (67,370)
Ending Balance, Shares at Dec. 31, 2019				23,036,943

Consolidated Statements of Co_2

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Statement Of Stockholders Equity [Abstract]
Issuance costs	$ 2,611

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (40,128)	$ (17,621)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	289	89
Loss on disposal of property and equipment		140
Net amortization of premiums and discounts on investments	(436)
Stock-based compensation expense	1,807	1,104
Non-cash interest expense	101
Non-cash lease expense	1,168
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(777)	(150)
Other assets		249
Accounts payable	(527)	35
Accrued expenses and other current liabilities	(247)	887
Net cash used in operating activities	(38,750)	(15,267)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of investments	(58,490)
Maturities of investments	41,400
Purchase of property and equipment	(1,415)	(614)
Disposal of property and equipment		35
Net cash used in investing activities	(18,505)	(579)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock from the initial public offering		74,865
Proceeds from borrowings under loan and security agreement, net of issuance costs	9,845
Proceeds from exercise of stock options	224	20
Payment of deferred initial public offering costs		(2,579)
Net cash provided by financing activities	10,069	72,306
Effect on foreign exchange rates on cash and cash equivalents	9	17
NET DECREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	(47,177)	56,477
Cash, cash equivalents and restricted cash at beginning of year	81,052	24,575
Cash, cash equivalents and restricted cash at end of period	33,875	81,052
RECONCILIATION OF CASH, CASH EQUIVALENTS AND RESTRICTED CASH
Cash and cash equivalents	33,107	80,906
Short-term restricted cash	146
Long-term restricted cash	622	146
Cash, cash equivalents and restricted cash at end of period	33,875	81,052
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for interest	445
Cash paid for income taxes	6	164
SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITIES:
Right-of-use assets obtained in exchange for operating lease obligation	1,461
Property and equipment purchases in accounts payable and accrued expenses		20
Deferred initial offering costs in accounts payable and accrued expenses		32
Conversion of preferred stock to common stock from the initial public offering		$ 33,062
Warrants issued in connection with loan and security agreement	$ 136

NATURE OF BUSINESS AND BASIS OF

NATURE OF BUSINESS AND BASIS OF PRESENTATION	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
NATURE OF BUSINESS AND BASIS OF PRESENTATION	1. NATURE OF BUSINESS AND BASIS OF PRESENTATION LogicBio Therapeutics, Inc. (“LogicBio” or the “Company”) was incorporated in 2014 as a Delaware corporation. Its principal offices are in Cambridge, Massachusetts. The Company is a genome editing company focused on developing medicines to durably treat rare diseases in pediatric patients with significant unmet medical need, using GeneRide ™ In January 2020, the Company announced the submission of an IND to support the initiation of a Phase 1/2 clinical trial in pediatric patients with MMA, which the FDA has placed on clinical hold. Subsequently, the Company received a letter from the FDA specifying its questions related to the clinical hold. The clinical hold was based on questions that were clinical and nonclinical in nature, including questions related to the studies conducted for the Company’s IND filing, but did not relate to chemistry, manufacturing, and controls. The Company expects to have interactions with the FDA regarding their questions through mid-2020, after which the Company plans to provide guidance on the anticipated timing for the initiation of the Phase 1/2 clinical trial for LB-001. Since its inception, the Company has devoted the majority of its efforts to business planning, research and development, developing markets, raising capital, recruiting management and technical staff. The Company is subject to a number of risks similar to those of other companies conducting high-risk, early-stage research and development of product candidates. Principal among these risks are a dependency on key individuals and intellectual property, competition from other products and companies, and the technical risks associated with the successful research, development and clinical manufacturing of its product candidates. The Company’s success is dependent upon its ability to continue to raise additional capital in order to fund ongoing research and development, meet its obligations and, ultimately, obtain regulatory approval of its products, successfully commercialize its products, generate revenue and attain profitable operations. During the years ended December 31, 2019 and 2018, the Company incurred net losses of $40.1 million and $17.6 million, respectively, and reported cash used in operations totaling $38.8 million and $15.3 million, respectively. In addition, as of December 31, 2019, the Company had an accumulated deficit of $67.4 million. The Company expects to continue to generate operating losses and use cash in operations for the foreseeable future. As of December 31, 2019, the Company had cash and cash equivalents of $33.1 million and short-term investments of $17.5 million which management believes will be sufficient to fund its operating expenses and capital expenditure requirements into the first quarter of 2021. However, based on the Company’s operating losses since inception, the expectation of continued operating losses for the foreseeable future, and the need to raise additional capital to finance its future operations, it has been deemed there is substantial doubt about the Company’s ability to continue as a going concern within one year from the date these consolidated financial statements are issued. The Company will require substantial additional capital to fund its research and development and ongoing operating expenses. Management’s plans to mitigate this risk include raising additional capital through equity or debt financings, or through strategic transactions. These plans may also include the possible deferral of certain operating expenses unless and until additional capital is received. There can be no assurance that the Company will be successful in raising additional capital or that such capital, if available, will be on terms that are acceptable to the Company, or that the Company will be successful in deferring certain operating expenses. The accompanying consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty. The accompanying consolidated financial statements have been prepared by the Company in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”).

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Principles of Consolidation In January 2016, the Company formed LogicBio Research, LTD (“LogicBio Research”), a wholly owned Israeli subsidiary, for the purpose of conducting research and development activities on the Company’s behalf. In September 2018, all operations ceased for LogicBio Research and the subsidiary was formally liquidated in November 2019. In April 2018, the Company formed LogicBio Australia Pty Limited (“LogicBio Australia”), a wholly owned Australian subsidiary, for the purpose of conducting research and development activities on the Company’s behalf. In December 2018, the Company formed LogicBio Securities Corporation, which is a Delaware subsidiary created to buy, sell and hold securities. The accompanying consolidated financial statements include the accounts of the Company, LogicBio Research, LogicBio Australia and LogicBio Securities Corporation. All intercompany accounts and transactions have been eliminated in consolidation. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue, and expenses, and the disclosure of contingent assets and liabilities as of and during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, useful lives assigned to property and equipment, the fair values of common and convertible preferred stock, stock-based compensation and income taxes. The Company assesses estimates on an ongoing basis; however, actual results could materially differ from those estimates. Fair Value Measurements Certain assets and liabilities are reported on a recurring basis at fair value. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: Level 1—Quoted prices in active markets for identical assets or liabilities. Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. Cash and Cash Equivalents The Company considers all highly liquid investments purchased with a maturity date of 90 days or less at the date of purchase to be cash equivalents. Cash equivalents consist principally of money market funds and overnight repurchase agreements fully collateralized by government agency securities or U.S. Treasury securities The Company’s cash equivalents are measured at fair value on a recurring basis. As of December 31, 2019 and 2018, the carrying amount of cash equivalents was $31,094 and $80,043, respectively, which approximates fair value and was determined based upon both Level 1 and Level 2 inputs. Investments The Company determines the appropriate classification of its investments in debt securities at the time of purchase. All of the Company’s securities are classified as available-for-sale and are reported in short-term investments or long-term investments based on maturity dates and whether such assets are reasonably expected to be realized in cash or sold or consumed during the normal cycle of business. Available-for-sale investments are recorded at fair value, with unrealized gains or losses included in accumulated other comprehensive income (loss) on the Company’s Consolidated Balance Sheets, exclusive of other-than-temporary impairment losses, if any. Investments may be composed of corporate debt securities, commercial paper, U.S. government and agency securities and certificates of deposit. Concentrations of Credit Risk Financial instruments that potentially subject us to significant concentration of credit risk consist primarily of cash and cash equivalents. Periodically, the Company may maintain deposits in financial institutions in excess of government insured limits. The Company believes that it is not exposed to significant credit risk as our deposits are held at financial institutions that management believes to be of high credit quality and the Company has not experienced any losses on these deposits. As of December 31, 2019 and 2018, the Company’s cash and cash equivalents were held with one financial institution. The Company believes that the market risk arising from its holdings of these financial instruments is mitigated based on the fact that many of these securities are either government backed or of high credit rating. Restricted Cash As of December 31, 2019, the Company had restricted cash of $146 classified as a current asset and restricted cash of $622 classified as a non-current asset representing security deposits in the form of cash-collateralized letters of credit for the Cambridge, MA and Lexington, MA leases, respectively. As of December 31, 2018, the Company had restricted cash of $146 classified as a non-current asset representing a security deposit in the form of a cash-collateralized letter of credit for the Cambridge, MA lease. Deferred Offering Costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ (deficit) equity as a reduction of proceeds generated as a result of the offering. Should a planned equity financing be abandoned, the deferred offering costs would be expensed immediately as a charge to operating expenses in the consolidated statement of operations. Upon the closing of the IPO in October 2018, related deferred offering costs were recorded as a reduction to shareholders’ equity. As of December 31, 2019, the Company did not have any deferred offering costs recorded. Property and Equipment Property and equipment are recorded at cost. Expenditures for repairs and maintenance are expensed as incurred. When assets are retired or disposed of, the assets and related accumulated depreciation are derecognized from the accounts, and any resulting gain or loss is included in the determination of net loss. Depreciation is provided using the straight-line method over the estimated useful lives of the related assets as follows: Estimated Useful Life Computer equipment and software 3 years Laboratory equipment 5 years Furniture and fixtures 5 years Leasehold improvements lesser of useful life or remaining lease term Impairment of Long-Lived Assets The Company evaluates its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceed the fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell. To date, no impairments have been recognized for these assets. Leases In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update Leases (Topic 842) (“ASU ASU supersedes the lease guidance under FASB ASC Topic 840, Leases , (“ASC 840”) resulting in the creation of FASB Accounting Standards Codification (“ASC”) Topic 842, Leases . At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present in the arrangement. Most leases with a term greater than one year are recognized on the balance sheet as a right-of-use asset and a current and non-current lease liability, as applicable. The Company elected not to recognize on the balance sheet leases with terms of one year or less. The Company typically only includes an initial lease term in its assessment of a leasing arrangement. Options to renew a lease are not included in the Company’s assessment unless there is reasonable certainty that the Company will renew the lease. The Company remeasures and reallocates the consideration in a contract when there is a modification of a lease that is not accounted for as a separate contract. A lease modification that results in a separate contract, including when the modification grants the lessee an additional right of use that is not included in the original lease, is accounted for in the same manner as a new lease. The Company monitors its material leases on a quarterly basis. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the right-of-use asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate, which reflects the fixed rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. In transition to ASC 842, the Company utilized the remaining lease term of its leases in determining the appropriate incremental borrowing rates. In accordance with ASC 842, components of a lease should be split into three categories: lease components (e.g., land, building, etc.), non-lease components (e.g., common area maintenance, consumables, etc.) and non-components (e.g., property taxes, insurance, etc.). The fixed and in-substance fixed contract consideration, including any consideration related to non-components, must be allocated based on the respective relative fair values to the lease components and non-lease components. Although separation of lease and non-lease components is required, certain practical expedients are available. Entities may elect the practical expedient not to separate lease and non-lease components. Rather, entities would account for each lease component and the related non-lease component together as a single component. For new and amended leases beginning in 2019 and after, the Company has elected to account for the lease and non-lease components for leases for classes of all underlying assets together and allocate all of the contract consideration to the lease component only. Guarantees and Indemnifications As permitted under Delaware law, the Company indemnifies its officers, directors, consultants and employees for certain events or occurrences that happen by reason of the relationship with, or position held at, the Company. Through December 31, 2019, the Company had not experienced any losses related to these indemnification obligations, and no claims were outstanding. The Company does not expect significant claims related to these indemnification obligations and, consequently, concluded that the fair value of these obligations is negligible, and no related liabilities have been established. Research and Development Expenses Research and development expenses consist primarily of costs incurred for our research activities, including our discovery efforts and the development of our product candidates, and include: • salaries, benefits and other related costs, including stock-based compensation expense, for personnel engaged in research and development functions; • license maintenance fees and milestone fees incurred in connection with various license agreements; • the cost of laboratory supplies and acquiring, developing and manufacturing preclinical study and, eventually, clinical trial materials; • expenses incurred under agreements with contract research organizations, or CROs, contract manufacturing organizations, or CMOs, as well as academic institutions and consultants that conduct our preclinical studies and other scientific development services; • facility-related expenses, which include direct depreciation costs and allocated expenses for rent and maintenance of facilities and other operating costs; • costs of outside consultants, including their fees, stock-based compensation and related travel expenses; and • costs related to compliance with regulatory requirements. Costs for external development activities are recognized based on an evaluation of the progress to completion of specific tasks using information provided to the Company by its vendors. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the consolidated financial statements as prepaid expenses or accrued expenses and other current liabilities. Comprehensive Loss Comprehensive loss includes net loss as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders. The Company includes foreign currency translation adjustments and unrealized gains and losses on available-for-sale investments in other comprehensive loss. For the years ended December 31, 2019 and 2018, accumulated comprehensive loss included $0 and $9, respectively, of foreign currency translation adjustments. In addition, for the year ended December 31, 2019, accumulated comprehensive loss included $14 of unrealized gains on investments. Foreign Currency Transactions The functional currency for the Company’s wholly-owned foreign subsidiary, LogicBio Australia, is the U.S. Dollar. The functional currency for the Company’s wholly-owned foreign subsidiary, LogicBio Research, was the Israeli New Shekel. Assets and liabilities of LogicBio Research are translated into United States dollars at the exchange rate in effect on the consolidated balance sheet date. Income items and expenses are translated at the average exchange rate in effect during the period. Stockholders’ equity (deficit) amounts are translated based on historical exchange rates as of the date of each transaction. Unrealized translation gains and losses are recorded as a foreign currency translation adjustment, which is included in the consolidated statements of convertible preferred stock and stockholder’s equity (deficit) as a component of accumulated other comprehensive loss. Adjustments that arise from exchange rate changes on transactions denominated in a currency other than the local currency are included in other (expense) income, net in the consolidated statements of operations as incurred. Segment Information Operating segments are identified as components of an enterprise about which separate discrete financial information is made available for evaluation by the chief operating decision maker (“CODM”) in making decisions regarding resource allocation and assessing performance. The CODM is the Company’s Chief Executive Officer. The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular concentration is focused on the development and commercialization of specific genome editing and integration of the therapeutic transgene, utilizing the body’s own native processes to drive durable expression. Convertible Preferred Stock As of December 31, 2019 and 2018 the Company did not have any convertible preferred stock outstanding. Stock-Based Compensation The Company accounts for all stock-based payment awards granted to employees and non-employees as stock-based compensation expense at fair value. The Company’s stock-based payments include stock options and grants of common stock, including common stock subject to vesting. The measurement date for employee awards is the date of grant, and stock-based compensation costs are recognized as expense over the employees’ requisite service period, which is the vesting period, on a straight-line basis. The measurement date for non-employee awards is the date of grant and stock-based compensation costs for non-employees are recognized as expense over the vesting period on a straight-line basis. The Company has also issued restricted stock with performance-based vesting conditions and would have recorded the expense for these awards if the Company had concluded that it was probable that the performance condition would be achieved. Stock-based compensation is classified in the accompanying statements of operations based on the function to which the related services are provided. The Company recognizes stock-based compensation expense for the portion of awards that have vested. Forfeitures are accounted for as they occur. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. The Company has historically been a private company and lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options granted to employees has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The expected term of stock options granted to non-employees is determined in the same manner as stock options granted to employees. 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 is based on 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 recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the Company’s consolidated financial statements and tax returns. Deferred tax assets and liabilities are determined based upon the differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities and for loss and credit carryforwards, using enacted tax rates expected to be in effect in the year in which the differences are expected to reverse. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that these assets may not be realized. The Company determines whether it is more likely than not that a tax position will be sustained upon examination. If it is not more likely than not that a position will be sustained, none of the benefit attributable to the position is recognized. The tax benefit to be recognized for any tax position that meets the more-likely-than-not recognition threshold is calculated as the largest amount that is more than 50% likely of being realized upon resolution of the contingency. The Company accounts for interest and penalties related to uncertain tax positions as part of its provision for income taxes. Net Loss Per Share The Company’s potentially dilutive shares, which include any outstanding stock options, warrants and unvested restricted stock, are considered to be common stock equivalents and are only included in the calculation of diluted net loss when their effect is dilutive. The Company excluded the following potential common stock equivalents from the computation of diluted net loss per share attributable to common stockholders because including them would have had an anti-dilutive effect for the years ended December 31, 2019 and 2018. December 31, 2019 2018 Unvested restricted stock 243,387 884,720 Options to purchase common stock 2,247,753 2,702,747 Term A loan common stock warrants 15,686 — Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, “ Leases (Topic 842),” Leases (Topic 842): Codification Improvements In adopting ASC 842, the Company elected to utilize the available package of practical expedients permitted under the transition guidance within the new standard, which does not require the reassessment of the following: (i) whether existing or expired arrangements are or contain a lease, (ii) the lease classification of existing or expired leases, and (iii) whether previous initial direct costs would qualify for capitalization under the new lease standard. Additionally, the Company made an accounting policy election to keep leases with a term of 12 months or less off its balance sheet. Adoption of this standard resulted in the recording of $210 each of operating lease liabilities and a right-of-use asset on the Company’s consolidated balance sheet on the effective date. The adoption of the standard did not have a material effect on the Company’s consolidated statements of operations, comprehensive loss, cash flows or convertible preferred stock and stockholders’ equity (deficit). Refer to Note 13 for right-of-use asset and liabilities recorded during the year ended December 31, 2019. Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13 , "Measurement of Credit Losses on Financial Instruments" The guidance requires that credit losses be reported using an expected losses model rather than the incurred losses model that is currently used, and establishes additional disclosures related to credit risks. For available-for-sale debt securities with unrealized losses, the standard now requires allowances to be recorded instead of reducing the amortized cost of the investment. The adoption of this standard is not expected to have a material impact on the Company’s consolidated financial statements and related disclosures.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	3. FAIR VALUE MEASUREMENTS The following tables present information about the Company’s financial assets measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values: Description December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Other Observable Inputs (Level 3) Assets Overnight repurchase agreements $ 30,001 $ — $ 30,001 $ — U.S. Treasury securities 17,540 17,540 — — Money market funds and other cash equivalents 1,093 1,093 — — Total financial assets $ 48,634 $ 18,633 $ 30,001 $ — Description December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Other Observable Inputs (Level 3) Assets Money market funds and other cash equivalents $ 80,043 $ 80,043 $ — $ — Total financial assets $ 80,043 $ 80,043 $ — $ — When developing fair value estimates, the Company maximizes the use of observable inputs and minimizes the use of unobservable inputs. When available, the Company uses quoted market prices to measure fair value. The valuation technique used to measure fair value for the Company's Level 1 and Level 2 assets is a market approach, using prices and other relevant information generated by market transactions involving identical or comparable assets. If market prices are not available, the fair value measurement is based on models that use primarily market-based parameters including yield curves, volatilities, credit ratings and currency rates. In certain cases where market rate assumptions are not available, the Company is required to make judgments about assumptions market participants would use to estimate the fair value of a financial instrument. The Company did not have any transfers of assets between Level 1 and Level 2 of the fair value measurement hierarchy during the years ended December 31, 2019 and 2018.

INVESTMENTS

INVESTMENTS	12 Months Ended
	Dec. 31, 2019
Investments [Abstract]
INVESTMENTS	4. INVESTMENTS The following table summarizes the Company’s investments, which are considered available-for-sale and are included in short-term investments on the consolidated balance sheet as of December 31, 2019: December 31, 2019 Cost Basis Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury securities $ 17,526 $ 14 $ — $ 17,540 Total $ 17,526 $ 14 $ — $ 17,540 Certain short-term debt securities with original maturities of less than 90 days are included in cash and cash equivalents on the consolidated balance sheet and are not included in the table above. As of December 31, 2019, all investments have contractual maturities within one year. The Company had no short-term or long-term investments as of December 31, 2018.

PROPERTY AND EQUIPMENT, NET

PROPERTY AND EQUIPMENT, NET	12 Months Ended
	Dec. 31, 2019
Property Plant And Equipment [Abstract]
PROPERTY AND EQUIPMENT, NET	5. PROPERTY AND EQUIPMENT, NET Property and equipment, net consisted of the following: December 31, 2019 December 31, 2018 Computer equipment and software $ 108 $ 36 Laboratory equipment 1,798 582 Furniture and fixtures 123 21 Leasehold improvements 5 — Total 2,034 639 Less: Accumulated depreciation (338 ) (49 ) Property and equipment, net $ 1,696 $ 590 Depreciation expense for the years ended December 31, 2019 and 2018 was $289 and $89, respectively. Maintenance and repairs are charged to expense as incurred and any additions or improvements are capitalized.

ACCRUED EXPENSES AND OTHER CURR

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	12 Months Ended
	Dec. 31, 2019
Payables And Accruals [Abstract]
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	6. ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES Accrued expenses and other current liabilities at December 31, 2019 and 2018 consisted of the following: December 31, 2019 December 31, 2018 Accrued compensation and benefits 1,155 $ 709 Accrued professional services 1,004 585 Lease liabilities 504 — Other 276 223 Total accrued expenses and other current liabilities $ 2,939 $ 1,517 Accrued compensation and benefits consists primarily of accrued bonuses. Accrued professional services consists primarily of consulting services, legal services and services provided by contract research organizations (“CRO”) and contract manufacturing organizations (“CMO”).

DEBT

DEBT	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
DEBT	7. DEBT On July 2, 2019 (the “Closing Date”), the Company entered into a loan and security agreement (the “Loan Agreement”), for term loans with Oxford Finance LLC (“Oxford”) and Horizon Technology Finance Corporation (“Horizon,” and, together with Oxford, the “Lenders”). The Loan Agreement allows the Company to borrow up to $20,000 issuable in two equal tranches (the “Term Loans”). On the Closing Date, the first tranche of $10,000 was drawn down by the Company (the “Term A Loan”). The second tranche of $10,000 will be available to the Company through September 30, 2020, subject to the achievement of certain clinical milestones (the “Term B Loan”). The outstanding loan balance will accrue interest at the greater of (i) the rate of the one-month U.S. LIBOR rate plus 6.25% and (ii) 8.75%. The Loan Agreement provides for an interest only period until July 1, 2021, followed by thirty-six equal monthly payments of principal and interest continuing through June 1, 2024 (the “Maturity Date”). The Company has the option to prepay the outstanding balance prior to maturity, subject to a prepayment fee of 1.0% to 3.0% depending upon when the prepayment occurs. Upon repayment of the Term Loans, the Company is required to make a final payment to the Lenders equal to 4.5% of the original principal amount of the Term Loans funded which will be accrued by charges to interest expense over the term of the loans using the effective interest method. In conjunction with the Loan Agreement, the Company issued warrants to purchase 15,686 shares of common stock (“Warrants”) to the Lenders at a per share exercise price of $12.75, a maximum contractual term of 10 years and exercisable immediately. The fair value of the Warrants was accounted for as a debt discount and calculated to be approximately $136 using the Black-Scholes method. The Company determined the Warrants met the criteria for equity classification, and, as such, the fair value of the Warrants is recorded as additional paid-in capital on the condensed consolidated balance sheets. Finally, the Company incurred issuance costs of approximately $150. Both the debt discount and issuance costs will be accreted to Long-term debt, net of issuance costs and discount by charges to interest expense over the term of the Term A Loan using the effective interest method. The Loan Agreement contains customary representations, warranties and covenants and also includes customary events of default. Events of default include, among other things, the Company’s failure to pay amounts due, a breach of certain covenants, a material adverse change event, misrepresentations and judgements. Upon the occurrence of an event of default, a default interest rate of an additional 5.0% per annum may be applied to the outstanding loan balances, and the Lenders may declare all outstanding obligations immediately due and payable. Borrowings under the Loan Agreement are collateralized by substantially all the Company’s assets, other than its intellectual property. Interest expense was $546 for the year ended December 31, 2019. The effective rate on the Loan Agreement, including the amortization of the debt discount and issuance costs, and accretion of the final payment, was 9.7% at December 31, 2019. The components of the long-term debt balance are as follows: December 31, 2019 Notes payable, gross $ 10,000 Less: Unamortized debt discount and issuance costs (254 ) Accretion of final payment fee 64 Carrying value of notes payable 9,810 Less: Current portion of long-term debt — Long-term debt, net of issuance costs and discount $ 9,810 As of December 31, 2019, the estimated future principal payments due were as follows: As of December 31, 2019 2020 $ — 2021 1,945 2022 3,333 2023 3,333 Thereafter 1,389 Total principal payments $ 10,000

LICENSE AGREEMENTS

LICENSE AGREEMENTS	12 Months Ended
	Dec. 31, 2019
License Agreements [Abstract]
LICENSE AGREEMENTS	8. LICENSE AGREEMENTS In December 2015, as restated in January 2018, the Company entered into a license agreement (the “Stanford Agreement”) with The Board of Trustees of the Leland Stanford Junior University (“Stanford”), a private research university, pursuant to which the Company obtained an exclusive, worldwide license to make, have made, use, import, offer to sell and sell products covered by certain patent rights to the GeneRide technology owned by Stanford within certain fields of use. As consideration for the license, the Company paid a one-time, non-refundable license fee and issued shares of common stock. The Company also agreed to pay for certain patent expenses per the terms of the Stanford Agreement. The license term extends indefinitely, unless terminated earlier by either party under certain provisions. The Company is required to pay annual license fees. The Company is also required to reimburse Stanford for additional patent costs incurred, pay amounts up to approximately $1,300 upon achievement of certain development and commercialization milestones, pay royalties on future sales as a low single-digit percentage of net sales and royalties on sublicensing revenue as a low double-digit percentage of net sales, if any. The Company is required to pay Stanford a fee of $325 in the event of a change of control. The Company recorded research and development expense related to the Stanford Agreement of $145 and $131 in the years ended December 31, 2019 and 2018, respectively. In May 2018, the Company entered into a license agreement (the “UT Agreement”) with The University of Texas System (“UT”), pursuant to which the Company obtained an exclusive, worldwide license to manufacture, have manufactured, distribute, have distributed, use, offer for sale, sell, lease, loan or import products covered by certain patent rights to the GeneRide technology owned by UT (jointly with Stanford) within certain fields of use. As consideration for the license, the Company paid a one-time, non-refundable license fee of $25, which was be recorded as research and development expense. The Company also agreed to pay an annual license maintenance fee, which is creditable against royalties owed the same year the maintenance fee is paid. The Company is also obligated to reimburse UT for expenses associated with the prosecution and maintenance of the UT patent rights. UT is entitled to receive clinical and regulatory milestone payments upon the first occurrence of specified milestone events and the Company is obligated to make additional payments to UT of up to $3,000 upon the first occurrence of certain sales milestones. UT is also entitled to receive royalties on net sales of licensed products ranging from below single-digit to low single-digit percentage royalties on net sales. The Company recorded research and development expense of $25 for each of the years ended December 31, 2019 and 2018. In December 2018, the Company entered into a license agreement (the “NIH Agreement”) with the NIH (“the NIH”), pursuant to which the Company obtained a non-exclusive, worldwide license under certain specified patent rights relating to a synthetic codon-optimized MUT gene that is incorporated into the LB-001 GeneRide construct, to exploit products and practice processes that are covered by the licensed patent rights in the field of research, development, manufacture and commercialization of pharmaceutical products for the treatment or prevention of MMA using gene therapy constructs in humans. As consideration for the license, NIH received an upfront payment of $25 in 2019 and is entitled to payments of up to an aggregate of approximately $9,700 upon the achievement of certain specified development, regulatory and sales-based benchmarks as well as running royalties on annual net sales of licensed products at certain low- to mid-single digit royalty rates depending on the geographic market in which a sale occurs. During the years ended December 31, 2019 and 2018, the Company recorded research and development expense of $30 and $0 related to the NIH agreement, respectively. Any potential future milestone or royalty payment amounts have not been accrued at December 31, 2019 due to the uncertainty related to the successful achievement of these milestones.

CONVERTIBLE PREFERRED STOCK

CONVERTIBLE PREFERRED STOCK	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
CONVERTIBLE PREFERRED STOCK	9. CONVERTIBLE PREFERRED STOCK The Company’s Series A Convertible Preferred Stock and Series B Convertible Preferred Stock is collectively referred to as “Preferred Stock.” On October 23, 2018, upon the closing of the Company’s IPO, all outstanding shares of Preferred Stock converted into 11,789,775 shares of the Company’s common stock. As such, there were no outstanding shares of Preferred Stock as of December 31, 2019 and 2018.

COMMON STOCK

COMMON STOCK	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
COMMON STOCK	10. COMMON STOCK As of December 31, 2019, and 2018, the Company’s certificate of incorporation authorized the Company to issue 175,000,000 shares of $0.0001 par value common stock. In July 2018, the Company issued 56,097 shares of common stock to Stanford, pursuant to the anti-dilution right under the Stanford Agreement. In October 2018, the Company completed an IPO in which the Company issued and sold 8,050,000 shares of its common stock, including 1,050,000 shares pursuant to the full exercise of the underwriters’ option to purchase additional shares, at a public offering price of $10.00 per share, for aggregate gross proceeds of $80,500. The Company received approximately $72,300 in net proceeds after deducting underwriting discounts and commissions and offering costs. In connection with this financing, all outstanding shares of Preferred Stock converted into 11,789,775 shares of the Company’s common stock. Open Market Sale Agreement On November 15, 2019, the Company entered into an Open Market Sale Agreement (the “Open Market Sale Agreement”) with Jefferies LLC, as agent (“Jefferies”), pursuant to which the Company may issue and sell shares of its common stock having an aggregate offering price of up to $50,000 (the “Open Market Shares”) from time to time through Jefferies (the “Open Market Offering”). Under the Open Market Sale Agreement, Jefferies may sell the Open Market Shares by methods deemed to be an “at the market offering” as defined in Rule 415(a)(4) promulgated under the Securities Exchange Act of 1934, as amended. The Company may sell the Open Market Shares in amounts and at times to be determined by the Company from time to time subject to the terms and conditions of the Open Market Sale Agreement, but it has no obligation to sell any of the Open Market Shares in the Open Market Offering. The Company or Jefferies may suspend or terminate the offering of Open Market Shares upon notice to the other party and subject to other conditions. The Company has agreed to pay Jefferies commissions for its services in acting as agent in the sale of the Open Market Shares in the amount of up to 3.0% of gross proceeds from the sale of the Open Market Shares pursuant to the Open Market Sale Agreement. The Company has also agreed to provide Jefferies with customary indemnification and contribution rights. The Company has not sold any shares to date under the Open Market Sale Agreement.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
STOCK-BASED COMPENSATION	11. STOCK-BASED COMPENSATION Equity Incentive Plans In December 2014, the Company adopted the LogicBio Therapeutics, Inc. 2014 Equity Incentive Plan, as amended (the “2014 Plan”), for the issuance of stock options and other stock-based awards. In October 2018, the Company’s 2018 Equity Incentive Plan (the “2018 Plan”) became effective and as a result, no further awards will be made under the 2014 Plan. The 2018 Plan was established to provide equity-based ownership opportunities for employees and directors, as well as outside consultants and advisors. The 2018 Plan authorized up to 1,183,214 of shares of the Company’s common stock to be issued. In addition, any previously granted awards under the 2014 Plan will remain outstanding in accordance with their respective terms. Under the 2018 Plan, there is an annual increase on January 1 of each year from 2019 until 2028, by the lesser of (i) 4% of the number of shares of common stock outstanding on December 31 of the prior year and (ii) an amount determined by the Board. On January 1, 2019, the Company increased the number of shares available for future grant under the 2018 Plan by 887,535 shares. At December 31, 2019, there were 1,085,312 shares available for future grant under the 2018 Plan. The 2014 Plan and the 2018 Plan are collectively referred to as the “Plans”. The 2018 Plan is administered by the Board. The exercise prices, vesting and other restrictions are determined at the discretion of the Board, except that the exercise price per share of stock options may not be less than 100% of the fair market value of the common stock on the date of grant. Stock options awarded under the 2018 Plan expire 10 years after the grant date, unless the Board sets a shorter term. Vesting periods for awards under the 2018 Plan are determined at the discretion of the Board. Incentive stock options granted to employees and shares of restricted stock granted to employees, officers, members of the Board, advisors, and consultants of the Company typically vest over four years. Non-statutory options and shares of restricted stock granted to employees, officers, members of the Board, advisors, and consultants of the Company typically vest over three or four years. The Company recorded stock-based compensation expense for options granted of $1,542 and $801 during the years ended December 31, 2019 and 2018, respectively. The Company recorded stock-based compensation expense for restricted stock granted of $265 and $303 during the years ended December 31, 2019 and 2018, respectively. Stock Option Valuation The assumptions that the Company used in Black-Scholes options pricing model to determine the grant-date fair value of stock options granted to employees and non-employees for the years ended December 31, 2019 and 2018 were as follows: Year Ended December 31, 2019 2018 Weighted-average risk-free interest rate 1.99% 2.91% Expected term (in years) 5.25 - 6.08 5.92 Expected volatility 71.50% - 75.85% 70.03% Expected dividend yield 0.00% 0.00% Stock Options A summary of option activity under the Plans during the year ended December 31, 2019 is as follows: Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding as of December 31, 2018 2,702,747 $ 3.16 9.21 $ 19,591 Granted 431,769 10.15 - Exercised (207,217 ) 1.09 1,586 Cancelled or forfeited (679,546 ) 2.82 3,417 Outstanding as of December 31, 2019 2,247,753 $ 4.80 8.42 $ 8,220 Options exercisable as of December 31, 2019 1,129,076 $ 2.26 8.01 $ 6,107 Options unvested as of December 31, 2019 1,118,677 $ 7.37 8.83 $ 2,113 The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock. The weighted-average grant date fair value per share of options granted during the years ended December 31, 2019 and 2018 was $5.94 and $5.46, respectively. As of December 31, 2019, there was $4,720 of unrecognized stock-based compensation expense related to unvested employee and non-employee stock options estimated to be recognized over a period of 2.7 years. The total fair value of options vested during the years ended December 31, 2019 and 2018 was $1,708 and $232, respectively. Shares of Restricted Common Stock The Company has granted shares of restricted common stock with time-based and performance-based vesting conditions. A summary of restricted stock activity under the Plans during the year ended December 31, 2019 is as follows: Restricted Stock Weighted- Average Grant Date Fair Value Unvested as of December 31, 2018 884,720 $ 0.63 Granted — — Vested or Released (641,333 ) 0.41 Unvested as of December 31, 2019 243,387 $ 1.21 No shares of restricted common stock were granted during the year ended December 31, 2019. The weighted-average grant date fair value per share of restricted stock granted during the year ended December 31, 2018 was $4.02. As of December 31, 2019, there was $260 of unrecognized stock-based compensation expense related to unvested employee and non-employee restricted stock estimated to be recognized over a period of 1.9 years. The total fair value of restricted stock vested during the years ended December 31, 2019 and 2018 was $266 and $160, respectively. Stock-Based Compensation Expense Total stock-based compensation expense recorded as research and development and general and administrative expenses, respectively, for employees, directors and non-employees during the years ended December 31, 2019 and 2018 is as follows: Year Ended December 31, 2019 2018 Research and development $ 760 $ 284 General and administrative 1,047 820 Total stock-based compensation expense $ 1,807 $ 1,104

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
INCOME TAXES	12. INCOME TAXES During the years ended December 31, 2019 and 2018, the Company recorded full valuation allowance on federal and state deferred balances since management does not forecast the Company to be in a profitable position in the near future. Loss before the provision for income taxes for the years ended December 31, 2019 and 2018 consisted of the following: Year Ended December 31, 2019 2018 United States $ (39,063 ) $ (17,284 ) Foreign (1,043 ) (337 ) $ (40,106 ) $ (17,621 ) A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate is as follows: Year Ended December 31, 2019 2018 U.S. federal statutory income tax rate 21.0 % 21.0 % State taxes, net of federal benefit 9.4 2.4 Foreign rate differential 0.2 0.1 Research and development tax credits 3.4 2.4 Stock based compensation 0.1 (0.7 ) Valuation allowances (33.8 ) (25.2 ) Rate changes - (0.1 ) Other (0.3 ) 0.1 Effective income tax rate — % — % Net deferred tax assets as of December 31, 2019 and 2018 consisted of the following: December 31, 2019 2018 Net operating loss carryforwards $ 16,768 $ 6,089 Reserves & accruals not currently deductible 932 324 Federal & state credit carryforwards 2,697 433 Total deferred tax assets 20,397 6,846 Valuation allowance (20,397 ) (6,846 ) Net deferred tax assets $ — $ — At December 31, 2019, the Company had available net operating loss carryforwards for federal and state income tax purposes of approximately $62,973 and $55,852, respectively, which if not utilized earlier, will begin to expire in 2035. The Company had federal research credits of approximately $1,854, which, if not utilized earlier, will begin to expire in 2036, and state research credits of approximately $1,068. At December 31, 2018, the Company had available net operating loss carryforwards for federal and state income tax purposes of approximately $25,854 and $9,324, respectively, which if not utilized earlier, will begin to expire in 2035. The Company had federal research credits of approximately $204, which, if not utilized earlier, will begin to expire in 2035, and state research credits of approximately $290. Changes in the valuation allowance for deferred tax assets during the years ended December 31, 2019 and 2018 related primarily to the increases in net operating loss carryforwards and research and development tax credit carryforwards and were as follows: Year Ended December 31, 2019 2018 Valuation allowance at beginning of year $ (6,846 ) $ (2,412 ) Increases recorded to income tax provision (13,683 ) (4,443 ) Decreases recorded to income tax provision 132 9 Valuation allowance at end of year $ (20,397 ) $ (6,846 ) The Company’s U.S. federal and state income tax returns are generally subject to tax examinations for the tax years ended December 31, 2014 through December 31, 2017 . There are currently no pending income tax examinations. To the extent the Company has tax attribute carryforwards, the tax years in which the attribute was generated may still be adjusted upon examination by the Internal Revenue Service and state tax authorities to the extent utilized in a future period. The Company’s policy is to record interest and penalties related to income taxes as part of its income tax provision.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	13. COMMITMENTS AND CONTINGENCIES Operating Leases The Company has historically entered into lease arrangements for its facilities and certain equipment. As of December 31, 2019, the Company had three operating leases with required future minimum payments. In applying the transition guidance under ASC 842, the Company determined the classification of these leases to be operating leases and recorded a right-of-use asset and lease liabilities as of the effective date. The Company’s leases generally do not include termination or purchase options. From time to time, leases may include options to renew the lease after the expiration of the initial lease term. A renewal period is included in the lease term only when it reasonably certain that the Company will exercise such renewal options. As of December 31, 2019, no renewal options existed that the Company felt were reasonably certain of being exercised. In November 2019, the Company entered into a lease agreement for office, laboratory and vivarium space located at 65 Hayden Avenue Lexington, Massachusetts (“65 Hayden Ave Lease”) to replace the Company’s current headquarters located at 99 Erie Street Cambridge, Massachusetts. Under the terms of the 65 Hayden Ave Lease, the Company will lease approximately 23,901 square feet of space and pay an initial annual base rent of approximately $1,494, which is subject to scheduled annual increases, plus certain operating expenses and taxes. The Company anticipates it will take possession of the space on April 1, 2020 (“Lease Commencement Date”) and continue through July 1, 2025 (“Lease Termination Date”). The Company has one option to extend the lease for a term of 5 years. Upon execution of the lease, the Company executed a $622 cash-collateralized letter of credit. Lease payments are anticipated to begin three months after the Lease Commencement Date and will continue in monthly installments through the Lease Termination Date. The Company will assess the lease classification of the 65 Hayden Ave Lease and commence recognition of the associated rent expense upon the Lease Commencement Date. The following table contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company’s operating leases for the year ended December 31, 2019. Note that rent expense under the Company’s operating leases was $880 for the year ended December 31, 2018. Year Ended December 31, 2019 Operating leases Lease cost Operating lease cost $ 1,208 Variable lease cost 330 Total lease cost $ 1,538 Other year-to-date lease information Operating cash flows used for operating leases $ 1,143 Operating lease liabilities arising from obtaining right-of-use assets $ 1,461 As of December 31, 2019 Other operating lease information Operating lease liabilities — short term $ 504 Operating lease liabilities — long term $ — Weighted average remaining lease term 0.7 years Weighted average discount rate 7.04 % The variable lease costs for the year ended December 31, 2019 include common area maintenance and other operating charges. As the Company’s leases do not provide an implicit rate, the Company utilized its incremental borrowing rate based on what it would normally pay to borrow on a collateralized basis over a similar term for an amount equal to the lease payments at the commencement date in determining the present value of lease payments. As of December 31, 2019, the Company classified its short-term operating lease liabilities within accrued expenses and other current liabilities. Future minimum lease payments under the Company’s operating leases as of December 31, 2019 and 2018, respectively, were as follows: 2019 2018 Maturity of lease liabilities 2019 $ — $ 1,028 2020 523 223 Thereafter — — Total lease payments $ 523 $ 1,251 Less: imputed interest (19 ) Total operating lease liabilities $ 504 Research Agreements Refer to Note 8, License Agreements Litigation The Company is not a party to any litigation and does not have contingency reserves established for any litigation liabilities.

RELATED PARTIES

RELATED PARTIES	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
RELATED PARTIES	14. RELATED PARTIES From time to time, the Company is or has been party to consulting service agreements with each of its three founders. Under the terms of each agreement, the Company pays an annual fee of $68 for research and development consulting services. For the years ended December 31, 2019 and 2018, the Company charged $152 and $118, respectively, to research and development expenses under these consulting service agreements. In addition, beginning in 2018, each founder receives $5 annually for their participation on the Scientific Advisory Board. Each founder has also received stock options for their services as either a board member or member of the Scientific Advisory Board. In March 2017, the Company subleased to an affiliate certain space in Tel Aviv, Israel, through June 2018. For the year ended December 31, 2018, the Company recognized income of $21 in other income related to this arrangement.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	15. SUBSEQUENT EVENTS LB-301 for the Crigler-Najjar Syndrome (CN) In January 2020, we announced a research collaboration with Takeda Pharmaceutical Company Limited to further develop LB-301 in CN the second indication to be pursued using the GeneRide platform. Takeda will provide funding for the research program under the collaboration agreement and will have an exclusive option to negotiate an exclusive, worldwide license to LogicBio’s LB-301 program.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation In January 2016, the Company formed LogicBio Research, LTD (“LogicBio Research”), a wholly owned Israeli subsidiary, for the purpose of conducting research and development activities on the Company’s behalf. In September 2018, all operations ceased for LogicBio Research and the subsidiary was formally liquidated in November 2019. In April 2018, the Company formed LogicBio Australia Pty Limited (“LogicBio Australia”), a wholly owned Australian subsidiary, for the purpose of conducting research and development activities on the Company’s behalf. In December 2018, the Company formed LogicBio Securities Corporation, which is a Delaware subsidiary created to buy, sell and hold securities. The accompanying consolidated financial statements include the accounts of the Company, LogicBio Research, LogicBio Australia and LogicBio Securities Corporation. All intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue, and expenses, and the disclosure of contingent assets and liabilities as of and during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, useful lives assigned to property and equipment, the fair values of common and convertible preferred stock, stock-based compensation and income taxes. The Company assesses estimates on an ongoing basis; however, actual results could materially differ from those estimates.
Fair Value Measurements	Fair Value Measurements Certain assets and liabilities are reported on a recurring basis at fair value. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: Level 1—Quoted prices in active markets for identical assets or liabilities. Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments purchased with a maturity date of 90 days or less at the date of purchase to be cash equivalents. Cash equivalents consist principally of money market funds and overnight repurchase agreements fully collateralized by government agency securities or U.S. Treasury securities The Company’s cash equivalents are measured at fair value on a recurring basis. As of December 31, 2019 and 2018, the carrying amount of cash equivalents was $31,094 and $80,043, respectively, which approximates fair value and was determined based upon both Level 1 and Level 2 inputs.
Investments	Investments The Company determines the appropriate classification of its investments in debt securities at the time of purchase. All of the Company’s securities are classified as available-for-sale and are reported in short-term investments or long-term investments based on maturity dates and whether such assets are reasonably expected to be realized in cash or sold or consumed during the normal cycle of business. Available-for-sale investments are recorded at fair value, with unrealized gains or losses included in accumulated other comprehensive income (loss) on the Company’s Consolidated Balance Sheets, exclusive of other-than-temporary impairment losses, if any. Investments may be composed of corporate debt securities, commercial paper, U.S. government and agency securities and certificates of deposit.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject us to significant concentration of credit risk consist primarily of cash and cash equivalents. Periodically, the Company may maintain deposits in financial institutions in excess of government insured limits. The Company believes that it is not exposed to significant credit risk as our deposits are held at financial institutions that management believes to be of high credit quality and the Company has not experienced any losses on these deposits. As of December 31, 2019 and 2018, the Company’s cash and cash equivalents were held with one financial institution. The Company believes that the market risk arising from its holdings of these financial instruments is mitigated based on the fact that many of these securities are either government backed or of high credit rating.
Restricted Cash	Restricted Cash As of December 31, 2019, the Company had restricted cash of $146 classified as a current asset and restricted cash of $622 classified as a non-current asset representing security deposits in the form of cash-collateralized letters of credit for the Cambridge, MA and Lexington, MA leases, respectively. As of December 31, 2018, the Company had restricted cash of $146 classified as a non-current asset representing a security deposit in the form of a cash-collateralized letter of credit for the Cambridge, MA lease.
Deferred Offering Costs	Deferred Offering Costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ (deficit) equity as a reduction of proceeds generated as a result of the offering. Should a planned equity financing be abandoned, the deferred offering costs would be expensed immediately as a charge to operating expenses in the consolidated statement of operations. Upon the closing of the IPO in October 2018, related deferred offering costs were recorded as a reduction to shareholders’ equity. As of December 31, 2019, the Company did not have any deferred offering costs recorded.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost. Expenditures for repairs and maintenance are expensed as incurred. When assets are retired or disposed of, the assets and related accumulated depreciation are derecognized from the accounts, and any resulting gain or loss is included in the determination of net loss. Depreciation is provided using the straight-line method over the estimated useful lives of the related assets as follows: Estimated Useful Life Computer equipment and software 3 years Laboratory equipment 5 years Furniture and fixtures 5 years Leasehold improvements lesser of useful life or remaining lease term
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company evaluates its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceed the fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell. To date, no impairments have been recognized for these assets.
Leases	Leases In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update Leases (Topic 842) (“ASU ASU supersedes the lease guidance under FASB ASC Topic 840, Leases , (“ASC 840”) resulting in the creation of FASB Accounting Standards Codification (“ASC”) Topic 842, Leases . At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present in the arrangement. Most leases with a term greater than one year are recognized on the balance sheet as a right-of-use asset and a current and non-current lease liability, as applicable. The Company elected not to recognize on the balance sheet leases with terms of one year or less. The Company typically only includes an initial lease term in its assessment of a leasing arrangement. Options to renew a lease are not included in the Company’s assessment unless there is reasonable certainty that the Company will renew the lease. The Company remeasures and reallocates the consideration in a contract when there is a modification of a lease that is not accounted for as a separate contract. A lease modification that results in a separate contract, including when the modification grants the lessee an additional right of use that is not included in the original lease, is accounted for in the same manner as a new lease. The Company monitors its material leases on a quarterly basis. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the right-of-use asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate, which reflects the fixed rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. In transition to ASC 842, the Company utilized the remaining lease term of its leases in determining the appropriate incremental borrowing rates. In accordance with ASC 842, components of a lease should be split into three categories: lease components (e.g., land, building, etc.), non-lease components (e.g., common area maintenance, consumables, etc.) and non-components (e.g., property taxes, insurance, etc.). The fixed and in-substance fixed contract consideration, including any consideration related to non-components, must be allocated based on the respective relative fair values to the lease components and non-lease components. Although separation of lease and non-lease components is required, certain practical expedients are available. Entities may elect the practical expedient not to separate lease and non-lease components. Rather, entities would account for each lease component and the related non-lease component together as a single component. For new and amended leases beginning in 2019 and after, the Company has elected to account for the lease and non-lease components for leases for classes of all underlying assets together and allocate all of the contract consideration to the lease component only.
Guarantees and Indemnifications	Guarantees and Indemnifications As permitted under Delaware law, the Company indemnifies its officers, directors, consultants and employees for certain events or occurrences that happen by reason of the relationship with, or position held at, the Company. Through December 31, 2019, the Company had not experienced any losses related to these indemnification obligations, and no claims were outstanding. The Company does not expect significant claims related to these indemnification obligations and, consequently, concluded that the fair value of these obligations is negligible, and no related liabilities have been established.
Research and Development Expenses	Research and Development Expenses Research and development expenses consist primarily of costs incurred for our research activities, including our discovery efforts and the development of our product candidates, and include: • salaries, benefits and other related costs, including stock-based compensation expense, for personnel engaged in research and development functions; • license maintenance fees and milestone fees incurred in connection with various license agreements; • the cost of laboratory supplies and acquiring, developing and manufacturing preclinical study and, eventually, clinical trial materials; • expenses incurred under agreements with contract research organizations, or CROs, contract manufacturing organizations, or CMOs, as well as academic institutions and consultants that conduct our preclinical studies and other scientific development services; • facility-related expenses, which include direct depreciation costs and allocated expenses for rent and maintenance of facilities and other operating costs; • costs of outside consultants, including their fees, stock-based compensation and related travel expenses; and • costs related to compliance with regulatory requirements. Costs for external development activities are recognized based on an evaluation of the progress to completion of specific tasks using information provided to the Company by its vendors. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the consolidated financial statements as prepaid expenses or accrued expenses and other current liabilities.
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes net loss as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders. The Company includes foreign currency translation adjustments and unrealized gains and losses on available-for-sale investments in other comprehensive loss. For the years ended December 31, 2019 and 2018, accumulated comprehensive loss included $0 and $9, respectively, of foreign currency translation adjustments. In addition, for the year ended December 31, 2019, accumulated comprehensive loss included $14 of unrealized gains on investments.
Foreign Currency Transactions	Foreign Currency Transactions The functional currency for the Company’s wholly-owned foreign subsidiary, LogicBio Australia, is the U.S. Dollar. The functional currency for the Company’s wholly-owned foreign subsidiary, LogicBio Research, was the Israeli New Shekel. Assets and liabilities of LogicBio Research are translated into United States dollars at the exchange rate in effect on the consolidated balance sheet date. Income items and expenses are translated at the average exchange rate in effect during the period. Stockholders’ equity (deficit) amounts are translated based on historical exchange rates as of the date of each transaction. Unrealized translation gains and losses are recorded as a foreign currency translation adjustment, which is included in the consolidated statements of convertible preferred stock and stockholder’s equity (deficit) as a component of accumulated other comprehensive loss. Adjustments that arise from exchange rate changes on transactions denominated in a currency other than the local currency are included in other (expense) income, net in the consolidated statements of operations as incurred.
Segment Information	Segment Information Operating segments are identified as components of an enterprise about which separate discrete financial information is made available for evaluation by the chief operating decision maker (“CODM”) in making decisions regarding resource allocation and assessing performance. The CODM is the Company’s Chief Executive Officer. The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular concentration is focused on the development and commercialization of specific genome editing and integration of the therapeutic transgene, utilizing the body’s own native processes to drive durable expression.
Convertible Preferred Stock	Convertible Preferred Stock As of December 31, 2019 and 2018 the Company did not have any convertible preferred stock outstanding.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for all stock-based payment awards granted to employees and non-employees as stock-based compensation expense at fair value. The Company’s stock-based payments include stock options and grants of common stock, including common stock subject to vesting. The measurement date for employee awards is the date of grant, and stock-based compensation costs are recognized as expense over the employees’ requisite service period, which is the vesting period, on a straight-line basis. The measurement date for non-employee awards is the date of grant and stock-based compensation costs for non-employees are recognized as expense over the vesting period on a straight-line basis. The Company has also issued restricted stock with performance-based vesting conditions and would have recorded the expense for these awards if the Company had concluded that it was probable that the performance condition would be achieved. Stock-based compensation is classified in the accompanying statements of operations based on the function to which the related services are provided. The Company recognizes stock-based compensation expense for the portion of awards that have vested. Forfeitures are accounted for as they occur. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. The Company has historically been a private company and lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options granted to employees has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The expected term of stock options granted to non-employees is determined in the same manner as stock options granted to employees. 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 is based on 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 recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the Company’s consolidated financial statements and tax returns. Deferred tax assets and liabilities are determined based upon the differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities and for loss and credit carryforwards, using enacted tax rates expected to be in effect in the year in which the differences are expected to reverse. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that these assets may not be realized. The Company determines whether it is more likely than not that a tax position will be sustained upon examination. If it is not more likely than not that a position will be sustained, none of the benefit attributable to the position is recognized. The tax benefit to be recognized for any tax position that meets the more-likely-than-not recognition threshold is calculated as the largest amount that is more than 50% likely of being realized upon resolution of the contingency. The Company accounts for interest and penalties related to uncertain tax positions as part of its provision for income taxes.
Net Loss Per Share	Net Loss Per Share The Company’s potentially dilutive shares, which include any outstanding stock options, warrants and unvested restricted stock, are considered to be common stock equivalents and are only included in the calculation of diluted net loss when their effect is dilutive. The Company excluded the following potential common stock equivalents from the computation of diluted net loss per share attributable to common stockholders because including them would have had an anti-dilutive effect for the years ended December 31, 2019 and 2018. December 31, 2019 2018 Unvested restricted stock 243,387 884,720 Options to purchase common stock 2,247,753 2,702,747 Term A loan common stock warrants 15,686 —
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, “ Leases (Topic 842),” Leases (Topic 842): Codification Improvements In adopting ASC 842, the Company elected to utilize the available package of practical expedients permitted under the transition guidance within the new standard, which does not require the reassessment of the following: (i) whether existing or expired arrangements are or contain a lease, (ii) the lease classification of existing or expired leases, and (iii) whether previous initial direct costs would qualify for capitalization under the new lease standard. Additionally, the Company made an accounting policy election to keep leases with a term of 12 months or less off its balance sheet. Adoption of this standard resulted in the recording of $210 each of operating lease liabilities and a right-of-use asset on the Company’s consolidated balance sheet on the effective date. The adoption of the standard did not have a material effect on the Company’s consolidated statements of operations, comprehensive loss, cash flows or convertible preferred stock and stockholders’ equity (deficit). Refer to Note 13 for right-of-use asset and liabilities recorded during the year ended December 31, 2019.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13 , "Measurement of Credit Losses on Financial Instruments" The guidance requires that credit losses be reported using an expected losses model rather than the incurred losses model that is currently used, and establishes additional disclosures related to credit risks. For available-for-sale debt securities with unrealized losses, the standard now requires allowances to be recorded instead of reducing the amortized cost of the investment. The adoption of this standard is not expected to have a material impact on the Company’s consolidated financial statements and related disclosures.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Estimated Useful Lives	Depreciation is provided using the straight-line method over the estimated useful lives of the related assets as follows: Estimated Useful Life Computer equipment and software 3 years Laboratory equipment 5 years Furniture and fixtures 5 years Leasehold improvements lesser of useful life or remaining lease term
Computation of Potentially Anti-Dilutive Securities	The Company excluded the following potential common stock equivalents from the computation of diluted net loss per share attributable to common stockholders because including them would have had an anti-dilutive effect for the years ended December 31, 2019 and 2018. December 31, 2019 2018 Unvested restricted stock 243,387 884,720 Options to purchase common stock 2,247,753 2,702,747 Term A loan common stock warrants 15,686 —

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Financial Assets Measured at Fair Value on Recurring Basis	The following tables present information about the Company’s financial assets measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values: Description December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Other Observable Inputs (Level 3) Assets Overnight repurchase agreements $ 30,001 $ — $ 30,001 $ — U.S. Treasury securities 17,540 17,540 — — Money market funds and other cash equivalents 1,093 1,093 — — Total financial assets $ 48,634 $ 18,633 $ 30,001 $ — Description December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Other Observable Inputs (Level 3) Assets Money market funds and other cash equivalents $ 80,043 $ 80,043 $ — $ — Total financial assets $ 80,043 $ 80,043 $ — $ —

INVESTMENTS (Tables)

INVESTMENTS (Tables)	12 Months Ended
	Dec. 31, 2019
Investments [Abstract]
Summary of Investments	The following table summarizes the Company’s investments, which are considered available-for-sale and are included in short-term investments on the consolidated balance sheet as of December 31, 2019: December 31, 2019 Cost Basis Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury securities $ 17,526 $ 14 $ — $ 17,540 Total $ 17,526 $ 14 $ — $ 17,540

PROPERTY AND EQUIPMENT, NET (Ta

PROPERTY AND EQUIPMENT, NET (Tables)	12 Months Ended
	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Components of Property and Equipment	Property and equipment, net consisted of the following: December 31, 2019 December 31, 2018 Computer equipment and software $ 108 $ 36 Laboratory equipment 1,798 582 Furniture and fixtures 123 21 Leasehold improvements 5 — Total 2,034 639 Less: Accumulated depreciation (338 ) (49 ) Property and equipment, net $ 1,696 $ 590

ACCRUED EXPENSES AND OTHER CU_2

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2019
Payables And Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities at December 31, 2019 and 2018 consisted of the following: December 31, 2019 December 31, 2018 Accrued compensation and benefits 1,155 $ 709 Accrued professional services 1,004 585 Lease liabilities 504 — Other 276 223 Total accrued expenses and other current liabilities $ 2,939 $ 1,517

DEBT (Tables)

DEBT (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Long-term Debt	The components of the long-term debt balance are as follows: December 31, 2019 Notes payable, gross $ 10,000 Less: Unamortized debt discount and issuance costs (254 ) Accretion of final payment fee 64 Carrying value of notes payable 9,810 Less: Current portion of long-term debt — Long-term debt, net of issuance costs and discount $ 9,810
Schedule of Estimated Future Principal Payments	As of December 31, 2019, the estimated future principal payments due were as follows: As of December 31, 2019 2020 $ — 2021 1,945 2022 3,333 2023 3,333 Thereafter 1,389 Total principal payments $ 10,000

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Assumptions Used to Determine the Fair Value of Option Grants	The assumptions that the Company used in Black-Scholes options pricing model to determine the grant-date fair value of stock options granted to employees and non-employees for the years ended December 31, 2019 and 2018 were as follows: Year Ended December 31, 2019 2018 Weighted-average risk-free interest rate 1.99% 2.91% Expected term (in years) 5.25 - 6.08 5.92 Expected volatility 71.50% - 75.85% 70.03% Expected dividend yield 0.00% 0.00%
Schedule of Common Stock Option Activity	A summary of option activity under the Plans during the year ended December 31, 2019 is as follows: Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding as of December 31, 2018 2,702,747 $ 3.16 9.21 $ 19,591 Granted 431,769 10.15 - Exercised (207,217 ) 1.09 1,586 Cancelled or forfeited (679,546 ) 2.82 3,417 Outstanding as of December 31, 2019 2,247,753 $ 4.80 8.42 $ 8,220 Options exercisable as of December 31, 2019 1,129,076 $ 2.26 8.01 $ 6,107 Options unvested as of December 31, 2019 1,118,677 $ 7.37 8.83 $ 2,113
Schedule of Activity Relating to Restricted Stock Units	A summary of restricted stock activity under the Plans during the year ended December 31, 2019 is as follows: Restricted Stock Weighted- Average Grant Date Fair Value Unvested as of December 31, 2018 884,720 $ 0.63 Granted — — Vested or Released (641,333 ) 0.41 Unvested as of December 31, 2019 243,387 $ 1.21
Schedule of Stock-Based Compensation Expense	Total stock-based compensation expense recorded as research and development and general and administrative expenses, respectively, for employees, directors and non-employees during the years ended December 31, 2019 and 2018 is as follows: Year Ended December 31, 2019 2018 Research and development $ 760 $ 284 General and administrative 1,047 820 Total stock-based compensation expense $ 1,807 $ 1,104

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Summary of Loss Before the Provision for Income Taxes	Loss before the provision for income taxes for the years ended December 31, 2019 and 2018 consisted of the following: Year Ended December 31, 2019 2018 United States $ (39,063 ) $ (17,284 ) Foreign (1,043 ) (337 ) $ (40,106 ) $ (17,621 )
Reconciliation of the Federal Statutory Income Tax Rate	A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate is as follows: Year Ended December 31, 2019 2018 U.S. federal statutory income tax rate 21.0 % 21.0 % State taxes, net of federal benefit 9.4 2.4 Foreign rate differential 0.2 0.1 Research and development tax credits 3.4 2.4 Stock based compensation 0.1 (0.7 ) Valuation allowances (33.8 ) (25.2 ) Rate changes - (0.1 ) Other (0.3 ) 0.1 Effective income tax rate — % — %
Summary of Net Deferred Tax Assets	Net deferred tax assets as of December 31, 2019 and 2018 consisted of the following: December 31, 2019 2018 Net operating loss carryforwards $ 16,768 $ 6,089 Reserves & accruals not currently deductible 932 324 Federal & state credit carryforwards 2,697 433 Total deferred tax assets 20,397 6,846 Valuation allowance (20,397 ) (6,846 ) Net deferred tax assets $ — $ —
Summary of Valuation Allowance	Changes in the valuation allowance for deferred tax assets during the years ended December 31, 2019 and 2018 related primarily to the increases in net operating loss carryforwards and research and development tax credit carryforwards and were as follows: Year Ended December 31, 2019 2018 Valuation allowance at beginning of year $ (6,846 ) $ (2,412 ) Increases recorded to income tax provision (13,683 ) (4,443 ) Decreases recorded to income tax provision 132 9 Valuation allowance at end of year $ (20,397 ) $ (6,846 )

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Summary of Lease Costs	The following table contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company’s operating leases for the year ended December 31, 2019. Note that rent expense under the Company’s operating leases was $880 for the year ended December 31, 2018. Year Ended December 31, 2019 Operating leases Lease cost Operating lease cost $ 1,208 Variable lease cost 330 Total lease cost $ 1,538 Other year-to-date lease information Operating cash flows used for operating leases $ 1,143 Operating lease liabilities arising from obtaining right-of-use assets $ 1,461 As of December 31, 2019 Other operating lease information Operating lease liabilities — short term $ 504 Operating lease liabilities — long term $ — Weighted average remaining lease term 0.7 years Weighted average discount rate 7.04 %
Schedule of Future Minimum Rental Payments for Operating Leases	Future minimum lease payments under the Company’s operating leases as of December 31, 2019 and 2018, respectively, were as follows: 2019 2018 Maturity of lease liabilities 2019 $ — $ 1,028 2020 523 223 Thereafter — — Total lease payments $ 523 $ 1,251 Less: imputed interest (19 ) Total operating lease liabilities $ 504

Nature of Business and Basis _2

Nature of Business and Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Organization And Nature Of Business Textual [Abstract]
Net loss	$ 40,128	$ 17,621
Net cash used in operating activities	38,750	15,267
Accumulated deficit	67,370	27,242
Cash and cash equivalents	33,107	$ 80,906
Short-term investments	$ 17,540

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Cash equivalents at carrying value	$ 31,094	$ 80,043
Restricted cash, non-current	622	146
Restricted cash, current	146
Accumulated other comprehensive loss	0	$ 9
Unrealized gain (loss) on investments	$ 14
Preferred stock, shares outstanding	0	0
Operating lease, liability	$ 504
Operating lease right-of-use asset	504
Accounting Standards Update 2016-02 [Member]
Significant Accounting Policies [Line Items]
Operating lease, liability	210
Operating lease right-of-use asset	$ 210
Minimum [Member]
Significant Accounting Policies [Line Items]
Income tax expense benefit recognition of tax position threshold percentage	50.00%

Summary of Significant accoun_5

Summary of Significant accounting Policies - Summary of Estimated Useful Lives (Detail)	12 Months Ended
	Dec. 31, 2019
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	3 years
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	5 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	5 years
Leaseholds Improvements [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	lesser of useful life or remaining lease term

Summary of Significant accoun_6

Summary of Significant accounting Policies - Computation of Potentially Anti-Dilutive Securities (Detail) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Unvested Restricted Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from computation of diluted net loss per common share	243,387	884,720
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from computation of diluted net loss per common share	2,247,753	2,702,747
Term A Loan Common Stock Warrants [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from computation of diluted net loss per common share	15,686

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Total financial assets	$ 48,634	$ 80,043
Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Total financial assets	18,633	80,043
Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Total financial assets	30,001
U.S. Treasury Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Total financial assets	17,540
U.S. Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Total financial assets	17,540
Overnight Repurchase Agreements [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Total financial assets	30,001
Overnight Repurchase Agreements [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Total financial assets	30,001
Money Market Funds And Other Cash Equivalents [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Total financial assets	1,093	80,043
Money Market Funds And Other Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Total financial assets	$ 1,093	$ 80,043

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Transfers between fair value measure levels	$ 0	$ 0
Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Transfers between fair value measure levels	$ 0	$ 0

Investments - Summary of Invest

Investments - Summary of Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Investments [Line Items]
Cost Basis	$ 17,526
Gross Unrealized Gains	14
Fair Value	17,540	$ 0
U.S. Treasury Securities [Member]
Schedule Of Investments [Line Items]
Cost Basis	17,526
Gross Unrealized Gains	14
Fair Value	$ 17,540

Investments - Additional Inform

Investments - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Investments [Abstract]
Short term Investments	$ 17,540	$ 0
Long term Investments		$ 0

Property and Equipment - Compon

Property and Equipment - Components of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,034	$ 639
Less: Accumulated depreciation	(338)	(49)
Property and equipment, net	1,696	590
Computer Equipment And Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	108	36
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,798	582
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	123	$ 21
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 5

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Abstract]
Depreciation expense	$ 289	$ 89

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Accrued compensation and benefits	$ 1,155	$ 709
Accrued professional services	1,004	585
Lease liabilities	504
Other	276	223
Total accrued expenses and other current liabilities	$ 2,939	$ 1,517

Debt - Additional Information (

Debt - Additional Information (Detail)	Jul. 02, 2019USD ($)$ / sharesshares	Dec. 31, 2019USD ($)Payment
Debt Instrument [Line Items]
Interest expense		$ 546,000
Effective interest percentage		9.70%
Oxford Finance LLC And Technology Finance Corporation [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 20,000,000
Interest rate description		The outstanding loan balance will accrue interest at the greater of (i) the rate of the one-month U.S. LIBOR rate plus 6.25% and (ii) 8.75%. The Loan Agreement provides for an interest only period until July 1, 2021, followed by thirty-six equal monthly payments of principal and interest continuing through June 1, 2024 (the “Maturity Date”).
Number of monthly payments | Payment		36
Debt instruments maturity date		Jun. 1, 2024
Debt instrument interest rate final payment fee percentage	4.50%
Debt instrument, interest rate, stated percentage	8.75%
Debt Issuance Costs	$ 150,000
Term loan event of default description		Events of default include, among other things, the Company’s failure to pay amounts due, a breach of certain covenants, a material adverse change event, misrepresentations and judgements.
Term loan default interest rate	5.00%
Oxford Finance LLC And Technology Finance Corporation [Member] | Term Loan [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, percentage of pre payment fees	1.00%
Oxford Finance LLC And Technology Finance Corporation [Member] | Term Loan [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, percentage of pre payment fees	3.00%
Oxford Finance LLC And Technology Finance Corporation [Member] | Term Loan [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	6.25%
Oxford Finance LLC And Technology Finance Corporation [Member] | Term A Loan [Member]
Debt Instrument [Line Items]
Proceeds from term loan	$ 10,000,000
Number of securities called by warrants | shares	15,686
Exercise price of warrants | $ / shares	$ 12.75
Warrants maximum contractual term	10 years
Warrant, fair value	$ 136,000
Oxford Finance LLC And Technology Finance Corporation [Member] | Term B Loan [Member]
Debt Instrument [Line Items]
Remaining borrowing capacity	$ 10,000,000

Debt - Schedule of Long-term De

Debt - Schedule of Long-term Debt (Detail) $ in Thousands	Dec. 31, 2019USD ($)
Debt Disclosure [Abstract]
Notes payable, gross	$ 10,000
Less: Unamortized debt discount and issuance costs	(254)
Accretion of final payment fee	64
Carrying value of notes payable	9,810
Long-term debt, net of issuance costs and discount	$ 9,810

Debt - Schedule of Estimated Fu

Debt - Schedule of Estimated Future Principal Payments (Detail) $ in Thousands	Dec. 31, 2019USD ($)
Debt Disclosure [Abstract]
2020
2021	1,945
2022	3,333
2023	3,333
Thereafter	1,389
Total principal payments	$ 10,000

License Agreements - Additional

License Agreements - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	May 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2015
Offsetting Assets [Line Items]
Research and development expense		$ 30,656	$ 11,079
License Agreement With Stanford [Member] | Stanford [Member]
Offsetting Assets [Line Items]
Milestone contingent consideration maximum liability				$ 1,300
Amount payable in event of change of control				$ 325
Research and development expense		145	131
University of Texas System Agreement [Member]
Offsetting Assets [Line Items]
Milestone contingent consideration maximum liability	$ 3,000
Research and development expense	$ 25	25	25
National Institute of Health Agreement [Member]
Offsetting Assets [Line Items]
Milestone contingent consideration maximum liability		9,700
Research and development expense		30	$ 0
Upfront payment upon achievement of milestone		$ 25

Convertible Preferred Stock - A

Convertible Preferred Stock - Additional Information (Detail) - IPO [Member] - shares	Dec. 31, 2019	Dec. 31, 2018	Oct. 23, 2018
Class Of Stock [Line Items]
Conversion of preferred stock shares into common stock shares			11,789,775
Convertible preferred stock shares outstanding	0	0

Common Stock - Additional Infor

Common Stock - Additional Information (Detail) - USD ($)	Nov. 15, 2019	Oct. 31, 2018	Jul. 31, 2018	Dec. 31, 2018	Dec. 31, 2019
Common stock, shares authorized				175,000,000	175,000,000
Common stock, par value				$ 0.0001	$ 0.0001
Issuance of common stock, Shares		1,050,000
Convertible preferred shares upon initial public offering, Shares		11,789,775
Number of shares sold under open market sale agreement	0
Jefferies LLC [Member]
Common stock, aggregate offering price	$ 50,000,000
Jefferies LLC [Member] | Maximum [Member]
Percentage of accrued brokerage commissions and fees	3.00%
IPO [Member]
Issuance of common stock, Shares		8,050,000
Stock issued, price per share | $ / shares		$ 10
Proceeds from issuance of common stock | $		$ 80,500,000
Proceeds after underwriting discounts and commissions and offering costs | $		$ 72,300,000
Common Stock [Member]
Issuance of common stock, Shares				8,050,000
Standford [Member] | Common Stock [Member]
Issuance of common stock, Shares			56,097	56,097

Stock-Based Compensation - Comp

Stock-Based Compensation - Compensation Related Costs Share based Payments - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019
2018 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	1,183,214
Number of shares available for future grant	1,085,312		887,535
Percentage of shares issued on common stock outstanding		4.00%
Stock option expiration period	10 years
2018 Plan | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price per share of stock options as percentage of fair market value of common stock	100.00%
Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option outstanding	2,247,753	2,702,747
Stock option vesting period	4 years
Stock- based compensation expense	$ 1,807	$ 1,104
Plans | Options to Purchase Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock- based compensation expense	$ 1,542	$ 801
Weighted-average grant-date fair values of options granted	$ 5.94	$ 5.46
Unrecognized compensation cost	$ 4,720
Unrecognized compensation cost, recognized cost	2 years 8 months 12 days
Total fair value of options vested	$ 1,708	$ 232
Plans | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock- based compensation expense	$ 265	$ 303
Unrecognized compensation cost, recognized cost	1 year 10 months 24 days
Weighted-average grant-date fair values of restricted stock granted		$ 4.02
Unrecognized compensation cost	$ 260
Total fair value restricted stock vested	$ 266	$ 160
Plans | Maximum [Member] | Non Statutory Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period	4 years
Plans | Minimum [Member] | Non Statutory Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period	3 years

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Assumptions Used to Determine the Fair Value of Option Grants (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted-average risk-free interest rate	1.99%	2.91%
Expected dividend yield	0.00%	0.00%
Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected term (in years)	5 years 3 months	5 years 11 months 1 day
Expected volatility	71.50%	70.03%
Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected term (in years)	6 years 29 days
Expected volatility	75.85%

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of Common Stock Option Activity (Detail) - Plans - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Outstanding Beginning Balance	2,702,747
Shares, Granted	431,769
Shares, Exercised	(207,217)
Shares, Cancelled or forfeited	(679,546)
Shares, Outstanding Ending Balance	2,247,753	2,702,747
Shares, Options exercisable	1,129,076
Shares, Options unvested	1,118,677
Weighted Average Exercise Price, Outstanding Beginning Balance	$ 4.80	$ 3.16
Weighted Average Exercise Price, Granted	10.15
Weighted Average Exercise Price, Exercised	1.09
Weighted Average Exercise Price, Cancelled or forfeited	2.82
Weighted Average Exercise Price, Options Exercisable	2.26
Weighted Average Exercise Price, Options Unvested	$ 7.37
Weighted Average Remaining Contractual Term Outstanding	8 years 5 months 1 day	9 years 2 months 15 days
Weighted Average Remaining Contractual Term, Options exercisable	8 years 3 days
Weighted Average Remaining Contractual Term, Options unvested	8 years 9 months 29 days
Aggregate Intrinsic Value Beginning Balance	$ 19,591
Aggregate Intrinsic Value, Exercised	1,586
Aggregate Intrinsic Value, Cancelled or forfeited	3,417
Aggregate Intrinsic Value, Ending Balance	8,220	$ 19,591
Aggregate Intrinsic Value, Options exercisable	6,107
Aggregate Intrinsic Value, Options unvested	$ 2,113

Stock-Based Compensation - Sc_3

Stock-Based Compensation - Schedule of Activity Relating to Restricted Stock Units (Detail) - Restricted Stock - Plans - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Unvested Beginning Balance	243,387	884,720
Shares Vested or Released	(641,333)
Weighted-Average Grant Date Fair Value, Beginning Balance	$ 0.63
Weighted-Average Grant Date Fair Value, Granted		$ 4.02
Weighted-Average Grant Date Fair Value, Vested or Released	0.41
Weighted-Average Grant Date Fair Value, Ending Balance	$ 1.21	$ 0.63

Stock-Based Compensation - Sc_4

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Detail) - Plans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,807	$ 1,104
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	760	284
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,047	$ 820

Income Taxes - Summary of Loss

Income Taxes - Summary of Loss Before the Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
United States	$ (39,063)	$ (17,284)
Foreign	(1,043)	(337)
Total (Loss from) before provision for income taxes	$ (40,106)	$ (17,621)

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the Federal Statutory Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	21.00%	21.00%
State taxes, net of federal benefit	9.40%	2.40%
Foreign rate differential	0.20%	0.10%
Research and development tax credits	3.40%	2.40%
Stock based compensation	0.10%	(0.70%)
Valuation allowances	(33.80%)	(25.20%)
Rate changes		(0.10%)
Other	(0.30%)	0.10%
Effective income tax rate	0.00%	0.00%

Income Taxes - Summary of Net D

Income Taxes - Summary of Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 16,768	$ 6,089
Reserves & accruals not currently deductible	932	324
Federal & state credit carryforwards	2,697	433
Total deferred tax assets	20,397	6,846
Valuation allowance	(20,397)	(6,846)	$ (2,412)
Net deferred tax assets	$ 0	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Line Items]
Federal net operating loss carryforwards	$ 62,973	$ 25,854
State net operating loss carryforwards	$ 55,852	$ 9,324
Federal operating loss carryforwards, beginning expiry year	2035	2035
Federal research and development credits, utilized year	2036	2035
Income tax examination description	December 31, 2014 through December 31, 2017
Domestic Tax Authority [Member]
Income Taxes [Line Items]
Research and development credit	$ 1,854	$ 204
State and Local Jurisdiction [Member]
Income Taxes [Line Items]
Research and development credit	$ 1,068	$ 290

Income Taxes - Summary of Valua

Income Taxes - Summary of Valuation Allowance (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Valuation allowance at beginning of year	$ (6,846)	$ (2,412)
Increases recorded to income tax provision	(13,683)	(4,443)
Decreases recorded to income tax provision	132	9
Valuation allowance at end of year	$ (20,397)	$ (6,846)

Commitments and Contingencies-A

Commitments and Contingencies-Additional Information (Detail) $ in Thousands	1 Months Ended	12 Months Ended
	Nov. 30, 2019USD ($)ft²	Dec. 31, 2018USD ($)	Dec. 31, 2019OperatingLease
Commitments And Contingencies Disclosure [Abstract]
Number of operating leases | OperatingLease			3
Rentable space | ft²	23,901
Operating leases initial annual base rent	$ 1,494
Lease commencement date	Apr. 1, 2020
Lease termination date	Jul. 1, 2025
Lease extended term	5 years
Cash collateral for letters of credit	$ 622
Rent expense under operating lease		$ 880

Commitments and Contingencies -

Commitments and Contingencies - Summary of Lease Costs (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Lease cost
Operating lease cost	$ 1,208
Variable lease cost	330
Total lease cost	1,538
Other year-to-date lease information
Operating cash flows used for operating leases	1,143
Operating lease liabilities arising from obtaining right-of-use assets	1,461
Other operating lease information
Operating lease liabilities — short term	$ 504
Weighted average remaining lease term	8 months 12 days
Weighted average discount rate	7.04%

Commitments and Contingencies-

Commitments and Contingencies- Summary of Future Minimum Lease Payments (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
2019		$ 1,028
2020	$ 523	223
Total lease payments	523	$ 1,251
Less: imputed interest	(19)
Total operating lease liabilities	$ 504

Related Parties - Additional In

Related Parties - Additional Information (Detail) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2019USD ($)Founder	Dec. 31, 2018USD ($)
Israel
Related Party Transaction [Line Items]
Subleases expiration month	2018-06
Sublease income			$ 21
Consulting Agreements [Member]
Related Party Transaction [Line Items]
Number of founders | Founder		3
Consulting agreement annual fee		$ 68
Consulting fee		$ 152	118
Consulting Agreements [Member] | Founder One [Member] | Scientific Advisory Board [Member]
Related Party Transaction [Line Items]
Consulting fee			5
Consulting Agreements [Member] | Founder Two [Member] | Scientific Advisory Board [Member]
Related Party Transaction [Line Items]
Consulting fee			5
Consulting Agreements [Member] | Founder Three [Member] | Scientific Advisory Board [Member]
Related Party Transaction [Line Items]
Consulting fee			$ 5