Applied Therapeutics (APLT) 10-Q 11 Aug 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Aug. 10, 2020
Document and Entity Information [Abstract]
Document Type	10-Q
Document Period End Date	Jun. 30, 2020
Entity Registrant Name	Applied Therapeutics Inc.
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		22,435,414
Entity Central Index Key	0001697532
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
CURRENT ASSETS:
Cash and cash equivalents	$ 100,854	$ 18,850
Investments	37,644	20,004
Prepaid expenses and other current assets	10,026	7,301
Total current assets	148,524	46,155
Operating lease right-of-use asset	1,849	2,035
Security deposits and leasehold improvements	199	199
TOTAL ASSETS	150,572	48,389
CURRENT LIABILITIES:
Current portion of operating lease liabilities	372	356
Accounts payable	5,649	8,793
Accrued expenses and other current liabilities	12,855	4,950
Total current liabilities	18,876	14,099
NONCURRENT LIABILITIES:
Noncurrent portion of operating lease liabilities	1,492	1,683
Total noncurrent liabilities	1,492	1,683
Total liabilities	20,368	15,782
STOCKHOLDERS’ EQUITY (DEFICIT):
Common stock, $0.0001 par value; 100,000,000 and 100,000,000 shares authorized as of June 30, 2020 and December 31, 2019, respectively; 22,331,142 shares and 18,531,560 shares issued and outstanding as of June 30, 2020 and December 31, 2019, respectively	2	1
Additional paid-in capital	237,429	99,378
Accumulated other comprehensive loss	(29)	(2)
Accumulated deficit	(107,198)	(66,770)
Total stockholders' equity	130,204	32,607
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 150,572	$ 48,389

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2020	Dec. 31, 2019
Balance Sheets
Common Stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common Stock, authorized (in shares)	100,000,000	100,000,000
Common Stock, issued (in shares)	22,331,142	18,531,560
Common stock, outstanding (in shares)	22,331,142	18,531,560

Statements of Operations

Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
OPERATING EXPENSES:
Research and development	$ 20,758	$ 4,254	$ 28,028	$ 11,128
General and administrative	7,522	4,183	12,725	6,037
Total operating expenses	28,280	8,437	40,753	17,165
LOSS FROM OPERATIONS	(28,280)	(8,437)	(40,753)	(17,165)
OTHER INCOME (EXPENSE), NET:
Interest income (expense), net	183		304	(1)
Other income (expense)	38		21
Total other income (expense), net	221		325	(1)
Net loss	(28,059)	(8,437)	(40,428)	(17,166)
Net loss attributable to common stockholders—basic	(28,059)	(8,437)	(40,428)	(17,166)
Net loss attributable to common stockholders— diluted	$ (28,059)	$ (8,437)	$ (40,428)	$ (17,166)
Net loss per share attributable to common stockholders—basic and diluted	$ (1.27)	$ (0.60)	$ (1.88)	$ (1.76)
Weighted-average common stock outstanding—basic and diluted	22,062,030	13,945,939	21,451,344	9,776,582

Statements of Comprehensive Los

Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statements of Comprehensive Loss
Net loss	$ (28,059)	$ (8,437)	$ (40,428)	$ (17,166)
Other comprehensive loss
Unrealized loss on marketable securities	(118)		(27)
Other comprehensive loss, net of tax	(118)		(27)
Comprehensive income (loss), net of tax	$ (28,177)	$ (8,437)	$ (40,455)	$ (17,166)

Statement of Convertible Prefer

Statement of Convertible Preferred Stock - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2019	Mar. 31, 2019
Series A Convertible Preferred Stock
Increase (Decrease) in Temporary Equity
Balance at beginning of period	$ 6,254	$ 6,254
Balance at beginning of period (in shares)	3,093,898	3,093,898
Conversion of convertible preferred stock into common stock upon closing of initial public offering	$ (6,254)
Conversion of convertible preferred stock into common stock upon closing of initial public offering (in shares)	(3,093,898)
Balance at end of period		$ 6,254
Balance at end of period (in shares)		3,093,898
Series B Convertible Preferred Stock
Increase (Decrease) in Temporary Equity
Balance at beginning of period	$ 32,207	$ 29,156
Balance at beginning of period (in shares)	4,444,773	4,001,848
Issuance of convertible preferred stock for cash, net of issuance costs		$ 3,051
Issuance of convertible preferred stock for cash, net of issuance costs (in shares)		442,925
Conversion of convertible preferred stock into common stock upon closing of initial public offering	$ (32,207)
Conversion of convertible preferred stock into common stock upon closing of initial public offering (in shares)	(4,444,773)
Balance at end of period		$ 32,207
Balance at end of period (in shares)		4,444,773

Statement of Convertible Pref_2

Statement of Convertible Preferred Stock (Parenthetical) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Series B Convertible Preferred Stock
Issuance of convertible preferred stock for cash, issuance costs	$ 266

Condensed Statement of Stockhol

Condensed Statement of Stockholders' (Deficit) Equity - USD ($) $ in Thousands	Common StockSeries A Convertible Preferred Stock	Common StockSeries B Convertible Preferred Stock	Common StockIPO	Common StockSecondary public offering	Common Stock	Additional Paid-in CapitalSeries A Convertible Preferred Stock	Additional Paid-in CapitalSeries B Convertible Preferred Stock	Additional Paid-in CapitalIPO	Additional Paid-in CapitalPrivate placement	Additional Paid-in CapitalSecondary public offering	Additional Paid-in CapitalRegistration of Form S-3 offering/Shelf Registration Statement	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Series A Convertible Preferred Stock	Series B Convertible Preferred Stock	IPO	Private placement	Secondary public offering	Registration of Form S-3 offering/Shelf Registration Statement	Total
Balance at Dec. 31, 2018												$ 1,665	$ (21,257)								$ (19,592)
Balance (in shares) at Dec. 31, 2018					5,513,531
Increase (Decrease) in Stockholders' Equity
Issuance of common stock warrants in connection with the issuance of convertible preferred stock												80									80
Stock-based compensation expense												325									325
Net loss													(8,730)								(8,730)
Balance at Mar. 31, 2019												2,070	(29,987)								(27,917)
Balance (in shares) at Mar. 31, 2019					5,513,531
Balance at Dec. 31, 2018												1,665	(21,257)								(19,592)
Balance (in shares) at Dec. 31, 2018					5,513,531
Increase (Decrease) in Stockholders' Equity
Net loss																					(17,166)
Balance at Jun. 30, 2019					$ 1							78,427	(38,424)								40,004
Balance (in shares) at Jun. 30, 2019					17,052,202
Balance at Mar. 31, 2019												2,070	(29,987)								(27,917)
Balance (in shares) at Mar. 31, 2019					5,513,531
Increase (Decrease) in Stockholders' Equity
Conversion of convertible preferred stock into common stock upon closing of the IPO		$ 1				$ 6,254	$ 32,207								$ 6,254	$ 32,208
Conversion of convertible preferred stock into common stock upon closing of the IPO (in shares)	3,093,898	4,444,773
Issuance of common stock								$ 34,617									$ 34,617
Issuance of common stock (in shares)			4,000,000
Stock-based compensation expense												3,279									3,279
Net loss													(8,437)								(8,437)
Balance at Jun. 30, 2019					$ 1							78,427	(38,424)								40,004
Balance (in shares) at Jun. 30, 2019					17,052,202
Balance at Dec. 31, 2019					$ 1							99,378	(66,770)	$ (2)							32,607
Balance (in shares) at Dec. 31, 2019					18,531,560
Increase (Decrease) in Stockholders' Equity
Issuance of common stock				$ 1						$ 134,127									$ 134,128
Issuance of common stock (in shares)				3,152,712
Exercise of options for common stock issued under equity incentive plan					$ 0							81									81
Exercise of options for common stock issued under equity incentive plan (in shares)					35,027
Issuance costs									$ (41)									$ (41)
Exercise of warrants of common stock (in shares)					249,978
Stock-based compensation expense												1,331									1,331
Net loss													(12,369)								(12,369)
Other comprehensive income (loss)														91							91
Balance at Mar. 31, 2020					$ 2							234,876	(79,139)	89							155,828
Balance (in shares) at Mar. 31, 2020					21,969,277
Balance at Dec. 31, 2019					$ 1							99,378	(66,770)	(2)							$ 32,607
Balance (in shares) at Dec. 31, 2019					18,531,560
Increase (Decrease) in Stockholders' Equity
Exercise of options for common stock issued under equity incentive plan (in shares)																					359,641
Net loss																					$ (40,428)
Balance at Jun. 30, 2020					$ 2							237,429	(107,198)	(29)							130,204
Balance (in shares) at Jun. 30, 2020					22,331,142
Balance at Mar. 31, 2020					$ 2							234,876	(79,139)	89							155,828
Balance (in shares) at Mar. 31, 2020					21,969,277
Increase (Decrease) in Stockholders' Equity
Exercise of options for common stock issued under equity incentive plan												1,342									1,342
Exercise of options for common stock issued under equity incentive plan (in shares)					324,614
Issuance costs									$ (6)	$ (25)	$ (495)							$ (6)	$ (25)	$ (495)
Exercise of warrants of common stock (in shares)					37,251
Stock-based compensation expense												1,737									1,737
Net loss													(28,059)								(28,059)
Other comprehensive income (loss)														(118)							(118)
Balance at Jun. 30, 2020					$ 2							$ 237,429	$ (107,198)	$ (29)							$ 130,204
Balance (in shares) at Jun. 30, 2020					22,331,142

Statement of Stockholders' (Def

Statement of Stockholders' (Deficit) Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Dec. 31, 2019
Increase (Decrease) in Stockholders' Equity
Common Stock, par value (in dollars per share)			$ 0.0001	$ 0.0001
IPO
Increase (Decrease) in Stockholders' Equity
Stock issuance cost		$ 5,383
Secondary public offering
Increase (Decrease) in Stockholders' Equity
Stock issuance cost	$ 714
Common Stock
Increase (Decrease) in Stockholders' Equity
Common Stock, par value (in dollars per share)			$ 0.0001	$ 0.0001

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (40,428)	$ (17,166)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	3,068	3,604
Amortization of operating lease right-of-use assets	186
Change in operating lease liability	(173)
Changes in operating assets and liabilities:
Prepaid expenses	762	(4,330)
Accounts payable	(3,150)	462
Accrued expenses and other current liabilities	4,441	1,369
Amortization of insurance premium	528
Net cash used in operating activities	(34,766)	(16,061)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of available-for-sale securities	(17,667)
Net cash used in investing activities	(17,667)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of Series B convertible preferred stock, net of cash issuance costs of $186		3,131
Proceeds from secondary public offering, net of cash issuance costs of $702	134,127
Proceeds from the IPO, net of underwriter commissions		37,200
Payment of deferred offering costs		(1,942)
Financed insurance premium down payment	(793)
Exercise of stock options for common stock under equity incentive plan	1,423
Net cash provided by financing activities	134,437	38,389
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	82,004	22,328
Cash and cash equivalents at beginning of period	18,850	18,748
Cash and cash equivalents at end of period	100,854	41,076
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Issuance of warrants in connection with Series B convertible preferred stock		80
Insurance premium obtained in exchange for a short-term loan	(4,015)
Unrealized gain (loss) on marketable securities	(27)
Conversion of preferred stock to equity following the IPO		38,461
IPO
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Stock issuance costs in accrued expenses		11
Stock issuance costs in accounts payable		$ 510
Private placement
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of offering costs	(152)
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Stock issuance costs in accrued expenses	43
Stock issuance costs in accounts payable	11
Secondary public offering
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Stock issuance costs in accrued expenses	25
Registration of Form S-3 offering/Shelf Registration Statement
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of offering costs	(168)
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Stock issuance costs in accrued expenses	224
Stock issuance costs in accounts payable	$ 103

Statements of Cash Flows (Paren

Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Statements of Cash Flows
Cash issuance costs, Convertible preferred stock		$ 186
Cash issuance costs, Secondary public offering	$ 702

ORGANIZATION AND SUMMARY OF SIG

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
	Jun. 30, 2020
ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	1. ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Operations and Business Applied Therapeutics, Inc. (the “Company”) is a clinical-stage biopharmaceutical company developing a pipeline of novel product candidates against validated molecular targets in indications of high unmet medical need. In particular, the Company is currently targeting treatments for rare metabolic diseases such as galactosemia, and diabetic complications including diabetic cardiomyopathy. The Company was incorporated in Delaware on January 20, 2016 and is headquartered in New York, New York. On May 16, 2019, the Company completed an initial public offering (the “IPO”) in which the Company issued and sold 4,000,000 shares of its common stock at a public offering price of $10.00 per share, for aggregate gross proceeds of $40.0 million. The Company received net of proceeds $34.6 million, after deducting underwriting discounts and commissions and offering costs. Prior to the completion of the IPO, the Company primarily funded its operations with proceeds from the sale of convertible preferred stock (see Note 8). In connection with the IPO, the Company effected a 55.2486-for-1 stock split of its issued and outstanding shares of common stock and convertible preferred stock. The stock split became effective on April 26, 2019. Stockholders entitled to fractional shares as a result of the forward stock split received cash payment in lieu of receiving fractional shares. All share and per share amounts for all periods presented in the accompanying condensed financial statements and notes thereto have been retroactively adjusted, where applicable, to reflect this stock split. Shares of common stock underlying outstanding stock options and other equity instruments were proportionately increased and the respective per share value and exercise prices, if applicable, were proportionately decreased in accordance with the terms of the agreements governing such securities. Upon the closing of the IPO on May 16, 2019, all of the then-outstanding shares of convertible preferred stock automatically converted into 7,538,671 shares of common stock on a one-for-one basis. Subsequent to the closing of the IPO, there were no shares of convertible preferred stock outstanding. On November 12, 2019, the Company completed a private placement (the “Private Placement”), pursuant to which it issued and sold 1,380,344 shares of the Company’s common stock at a price of $14.50 per share, for net proceeds of $18.4 million after deducting placement agent discounts and commissions and offering costs. On January 28, 2020, the Company completed its secondary public offering (the “Secondary Public Offering”), pursuant to which it issued and sold 2,741,489 shares of common stock at a public offering price of $45.50 per share, with an additional 411,223 shares sold pursuant to the underwriters’ full exercise of their option to purchase additional shares. The aggregate net proceeds received by the Company from the offering, after deducting underwriting discounts and commissions and offering costs, were $134.1 million. On June 4, 2020, the Company filed a shelf registration statement on Form S-3 (the “Shelf Registration Statement”) under which the Company may, from time to time, sell securities in one or more offerings having an aggregate offering price of up to $300.0 million. The Shelf Registration Statement was declared effective as of June 15, 2020. As of the filing date of this Quarterly Report on Form 10-Q, no securities have been sold under this shelf registration. On June 12, 2020, the Company entered into an equity distribution agreement (the “Equity Distribution Agreement”) with Goldman Sachs & Co. LLC (“Goldman”), as a sales agent to sell shares of the Company’s common stock, from time to time, having an aggregate offering price of up to $100 million. Goldman may act as an agent on the Company’s behalf or purchase shares of the Company’s common stock as a principal. As of June 30, 2020, the Company had no sold any shares of common stock pursuant to the Equity Distribution Agreement. The accompanying unaudited condensed financial statements as of June 30, 2020 and December 31, 2019 and for the three and six months ended June 30, 2020 and 2019 have been prepared by the Company in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. These condensed financial statements should be read in conjunction with the Company’s audited financial statements and the notes thereto for the year ended December 31, 2019 included in the Annual Report, filed with the SEC on March 13, 2020 (the “Annual Report”). The unaudited condensed financial statements have been prepared on the same basis as the audited financial statements. In the opinion of management, the accompanying unaudited condensed financial statements contain all adjustments which are necessary for a fair presentation of the Company’s financial position as of June 30, 2020, results of operations for the three and six months ended June 30, 2020 and 2019 and cash flows for the six months ended June 30, 2020 and 2019. Such adjustments are of a normal and recurring nature. The results of operations for the three and six months ended June 30, 2020 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2020. Liquidity The Company has incurred, and expects to continue to incur, significant operating losses and negative cash flows for at least the next several years as it continues to develop its drug candidates. To date, the Company has not generated any revenue, and it does not expect to generate revenue unless and until it successfully completes development and obtains regulatory approval for one of its product candidates. Management believes that the Company’s existing cash, cash equivalents, and investments will allow the Company to continue its operations for at least 12 months from the issuance date of these financial statements. After 12 months from the issuance of these financial statements, the Company may need to obtain additional funding. The Company may pursue additional cash resources through public or private financings. Risks and Uncertainties The Company is subject to risks common to companies in the biotechnology industry, including, but not limited to, risks of failure of preclinical studies and clinical trials, the need to obtain marketing approval for any product candidate that it may identify and develop, the need to successfully commercialize and gain market acceptance of its product candidates, dependence on key personnel, protection of proprietary technology, compliance with government regulations, development by competitors of technological innovations and reliance on third‑party manufacturers. 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 and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Significant Accounting Policies The significant accounting policies and estimates used in preparation of the condensed financial statements are described in the Company’s audited financial statements as of and for the year ended December 31, 2019, and the notes thereto, which are included in the Annual Report. Except as detailed below, there have been no material changes to the Company’s significant accounting policies during the three and six months ended June 30, 2020. Stock‑Based Compensation–Restricted Stock Units The Company accounts for restricted stock units in accordance with the authoritative guidance for stock-based compensation. The fair value of restricted stock units is measured at the grant date based on the closing market price of the Company’s common stock on the date of grant, and is recognized as expense on a straight-line basis over the period of vesting. Forfeitures are recognized as a reduction of stock-based compensation expense as they occur. Financed D&O Insurance Premium In June 2020, the Company financed their directors' and officers' insurance premium with a short-term note, the principal amount of which is approximately $3.2 million bearing interest at a rate of 3.2% per annum. The note payable balance was $3.2 million, which was included within accrued expense and other current liabilities on the Condensed Balance Sheets as of June 30, 2020 . Recent Accounting Pronouncements On January 1, 2020, the Company adopted ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which replaces the incurred loss methodology with an expected loss methodology that is referred to as the current expected credit loss (CECL) methodology. The measurement of expected credit losses under the CECL methodology applies to financial instruments measured at amortized cost, including loan receivables and held-to-maturity debt securities, off-balance sheet credit exposures and net investments in leases recognized by a lessor. ASC 326 also made changes to the accounting for available-for-sale debt securities, where credit losses are required to be presented as an allowance as opposed to a write-down. The FASB issued authoritative guidance that amends guidance on reporting credit losses for assets, including available-for-sale marketable securities and any other financial assets not excluded from the scope that have the contractual right to receive cash. For available-for-sale marketable securities, credit losses should be measured in a manner similar to current generally accepted accounting standards; however, ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , will require that credit losses be presented as an allowance rather than as a write-down. For available-for-sale debt securities in an unrealized position, the Company assesses whether a decline in fair value resulted from credit losses or other factors. Management considers the extent to which fair value is less than amortized cost, any changes to the credit rating of the security, and adverse conditions specifically related to the security. If the assessment indicates a credit loss exists, an allowance is recorded that is limited to the amount the amortized cost exceeds the fair value. Any impairment that is not recognized through the allowance for credit loss is recognized in other comprehensive income. The Company adopted ASC 326 using the modified retrospective method approach, where a cumulative-effect adjustment to credit loss allowance would be reflected in retained earnings. The adoption of this standard did not have an impact on the Company’s balance sheet as there were no credit losses identified. In August 2018, the FASB issued ASU No. 2018-13, “ Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement ,” which modifies the disclosure requirements on fair value measurements. The new guidance is effective for fiscal years beginning after December 15, 2019. Upon the effective date, certain provisions are to be applied prospectively, while others are to be applied retrospectively to all periods presented. The amendments eliminated certain disclosure requirements such as the elimination of disclosing the valuation process for Level 3 fair value measurements. Other amendments in the update did not impact the Company. The Company adopted the amendments on January 1, 2020 with no impact on our financial statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes. The new standard intended to simplify the accounting for income taxes by eliminating certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The new guidance also simplifies aspects of the accounting for franchise taxes and enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a step-up in the tax basis of goodwill. The standard is effective for annual periods beginning after December 15, 2020 and interim periods within, with early adoption permitted. Adoption of the standard requires certain changes to primarily be made prospectively, with some changes to be made retrospectively. The Company is currently evaluating the impact adoption of ASU 2019-12 will have on its financial statements.

LICENSE AGREEMENT

LICENSE AGREEMENT	6 Months Ended
	Jun. 30, 2020
LICENSE AGREEMENT
LICENSE AGREEMENT	2. LICENSE AGREEMENT Columbia University In October 2016, the Company entered into a license agreement (the “2016 Columbia Agreement”) with the Trustees of Columbia University (“Columbia University”) to obtain an exclusive royalty-bearing sublicensable license in respect to certain patents. As part of the consideration for entering into the 2016 Columbia Agreement, the Company issued to Columbia University shares equal to 5% of its outstanding common stock on a fully diluted basis at the time of issue. The common stock had a fair value of $0.5 million at the time of issuance. The Company will be required to make further payments to Columbia University of up to an aggregate of $1.3 million for the achievement of specified development and regulatory milestones, and up to an aggregate of $1.0 million for the achievement of a specified level of aggregate annual net sales, in each case in connection with products covered by the 2016 Columbia Agreement. The Company will also be required to pay tiered royalties to Columbia University in the low‑ to mid‑single digit percentages on the Company’s, its affiliates’ and its sublicensees’ net sales of licensed products, subject to specified offsets and reductions. In addition, the Company is required to make specified annual minimum royalty payments to Columbia University, which is contingent upon the approval of the licensed products, in the mid-six figures beginning on the 10th anniversary of the effective date of the 2016 Columbia Agreement. The Company has not granted any sublicenses under the 2016 Columbia Agreement. However, if the Company sublicenses the rights granted under the 2016 Columbia Agreement to one or more third parties, it will be required to pay Columbia University a portion of the net sublicensing revenue received from such third parties, at percentages between 10% and 20%, depending on the stage of development at the time such revenue is received from such third parties. The 2016 Columbia Agreement will terminate upon the expiration of all the Company’s royalty payment obligations in all countries. The Company may terminate the 2016 Columbia Agreement for convenience upon 90 days’ written notice to Columbia University. At its election, Columbia University may terminate the 2016 Columbia Agreement, or convert the licenses granted to the Company into non‑exclusive, non‑sublicensable licenses, in the case of (a) the Company’s uncured material breach upon 30 days’ written notice (which shall be extended to 90 days if the Company is diligently attempting to cure such material breach), (b) the Company’s failure to achieve the specified development and funding milestone events, or (c) the Company’s insolvency. In January 2019, the Company entered into a second license agreement with Columbia University (the “2019 Columbia Agreement”). Pursuant to the 2019 Columbia Agreement, Columbia University granted the Company a royalty-bearing, sublicensable license that is exclusive with respect to certain patents, and non-exclusive with respect to certain know-how, in each case to develop, manufacture and commercialize PI3k inhibitor products. The license grant is worldwide. Under the 2019 Columbia Agreement, the Company is obligated to use commercially reasonable efforts to research, discover, develop and market licensed products for commercial sale in the licensed territory, and to comply with certain obligations to meet specified development and funding milestones within defined time periods. Columbia University retains the right to conduct, and grant third parties the right to conduct, non-clinical academic research using the licensed technology; provided that such research is not funded by a commercial entity or for-profit entity or results in rights granted to a commercial or for-profit entity. As consideration for entering into the 2019 Columbia Agreement, the Company made a nominal upfront payment to Columbia University. The Company will be required to make further payments to Columbia University of up to an aggregate of $1.3 million for the achievement of specified development and regulatory milestones, and up to an aggregate of $1.0 million for the achievement of a specified level of aggregate annual net sales, in each case in connection with products covered by the 2019 Columbia Agreement. The Company will also be required to pay tiered royalties to Columbia University in the low- to mid-single digit percentages on the Company’s, its affiliates’ and its sublicensees’ net sales of licensed products, subject to specified offsets and reductions. In addition, the Company is required to make specified annual minimum royalty payments to Columbia University, which is contingent upon the approval of the licensed products, in the mid-six figures beginning on the tenth anniversary of the effective date of the 2019 Columbia Agreement. The Company has not granted any sublicenses under the 2019 Columbia Agreement. However, if the Company sublicenses the rights granted under the 2019 Columbia Agreement to one or more third parties, it will be required to pay Columbia University a portion of the net sublicensing revenue received from such third parties, at percentages between 10% and 50%, depending on the stage of development at the time such revenue is received from such third parties. The 2019 Columbia Agreement will terminate upon the expiration of all the Company’s royalty payment obligations in all countries. The Company may terminate the 2019 Columbia Agreement for convenience upon 90 days’ written notice to Columbia University. At its election, Columbia University may terminate the 2019 Columbia Agreement, or convert the licenses granted to the Company into non-exclusive, non-sublicensable licenses, in the case of (a) the Company’s uncured material breach upon 30 days’ written notice (which shall be extended to 90 days if the Company is diligently attempting to cure such material breach), (b) the Company’s failure to achieve the specified development and funding milestone events, or (c) the Company’s insolvency . In March 2019, and in connection with the 2016 Columbia Agreement, the Company entered into a research services agreement (the “2019 Columbia Research Agreement”) with Columbia University with the purpose of analyzing structural and functional changes in brain tissue in an animal model of galactosemia, and the effects of certain compounds whose intellectual property rights were licensed to the Company as part of the 2016 Columbia Agreement on any such structural and functional changes. The 2019 Columbia Research Agreement has a term of 12 months from its effective date; provided that the Company can terminate the 2019 Columbia Research Agreement without cause with at least 30 days’ prior written notice. The services covered by the 2019 Columbia Research Agreement will be performed by Columbia University in two parts consisting of six months. The decision to proceed with Part 2 of the 2019 Columbia Research Agreement shall be made solely by the Company and will be contingent on the success of the research performed in Part 1. In consideration for the services performed by Columbia University in Part 1, the Company will be required to pay $0.1 million to Columbia University for staffing, supplies and indirect costs. If the Company decides to continue the research defined in Part 2, the Company will be required to pay an additional $0.2 million to Columbia University. On October 3, 2019, and in connection with the 2019 Columbia Agreement, the Company entered into a research services agreement (the “PI3k Columbia Research Agreement” and collectively with the 2016 Columbia Agreement, 2019 Columbia Agreement and 2019 Columbia Research Agreement, the “Columbia Agreements”) with Columbia University with the purpose of analyzing PI3k inhibitors for the treatment of lymphoid malignancies. The research service agreement has a term of 18 months from is effective date; provided that the Company can terminate the research service agreement without cause with at least 30 days prior written notice. Midway through the study period, the Company and Columbia University will review the results of all completed and in progress research and determine whether the research will continue. In consideration for the services performed by Columbia University, the Company will be required to pay $0.4 million to Columbia University for staffing, supplies and indirect costs . During the three and six months ended June 30, 2020, the Company recorded $30,000, and $0.3 million, respectively, in research and development expense and $54,000 and $94,000, respectively, in general and administrative expense related to the Columbia Agreements. During the three and six months ended June 30, 2019, the Company recorded $24,000 and $25,000, respectively, in research and development expense and $0.1 million and $0.3 million, respectively, in general and administrative expense related to the Columbia Agreements. In aggregate, the Company has incurred $2.3 million in expense from the execution of the Columbia Agreements through June 30, 2020. As of June 30, 2020, the Company had $97,000 due to Columbia University included in accrued expenses and $0 included in accounts payable. As of December 31, 2019, the Company had $0.1 million due to Columbia University included in accrued expenses and $0.1 million included in accounts payable.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	6 Months Ended
	Jun. 30, 2020
FAIR VALUE MEASUREMENTS
FAIR VALUE MEASUREMENTS	3. FAIR VALUE MEASUREMENTS The following table summarizes, as of June 30, 2020, the Company's financial assets and liabilities that are measured at fair value on a recurring basis, according to the fair value hierarchy described in the significant accounting policies in the Company’s audited financial statements as of and for the year ended December 31, 2019, and the notes thereto, which are included in the Annual Report. As of June 30, 2020 (in thousands) Level 1 Level 2 Level 3 Total Cash $ 48,138 $ — $ — $ 48,138 Money market funds 52,716 — — 52,716 Total cash and cash equivalents $ 100,854 $ — $ — $ 100,854 Commercial paper and corporate bonds — 1,651 — 1,651 U.S. government agency debt securities — 35,993 — 35,993 Total marketable securities $ — $ 37,644 $ — $ 37,644 Total financial assets measured at fair value on a recurring basis $ 100,854 $ 37,644 $ — $ 138,498 Investments in commercial paper, corporate bonds, and U.S. government agency debt securities have been classified as Level 2 as they are valued using quoted prices in less active markets or other directly or indirectly observable inputs. Fair values of corporate bonds and U.S. government agency debt securities were derived from a consensus or weighted average price based on input of market prices from multiple sources at each reporting period. With regard to commercial paper, all of the securities had high credit ratings and one year or less to maturity; therefore, fair value was derived from accretion of purchase price to face value over the term of maturity or quoted market prices for similar instruments if available. During the six months ended June 30, 2020, there were no transfers of financial assets between Level 1 and Level 2.

INVESTMENTS

INVESTMENTS	6 Months Ended
	Jun. 30, 2020
INVESTMENTS
INVESTMENTS	4. INVESTMENTS Marketable Securities Marketable securities, which the Company classifies as available-for-sale securities, primarily consist of high quality commercial paper, corporate bonds, and U.S. government debt obligations. The Company considers all available-for-sale securities, including those with maturity dates beyond 12 months, as available to support current operational liquidity needs. The Company classifies its investments as current based on the nature of the investments and their availability for use in current operations. The following tables provide the Company’s marketable securities by security type as of June 30, 2020 and December 31, 2019: As of June 30, 2020 As of December 31, 2019 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated (in thousands) Cost Gains Losses Fair Value Cost Gains Losses Fair Value Commercial paper and corporate bonds $ 1,653 $ 1 $ (3) $ 1,651 $ 7,540 $ — $ (20) $ 7,520 US government agency debt security 36,020 17 (44) 35,993 12,466 19 (1) 12,484 Total $ 37,673 $ 18 $ (47) $ 37,644 $ 20,006 $ 19 $ (21) $ 20,004 The Company adopted ASU No. 2016-13, “Financial Instruments–Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” on January 1, 2020 and applied the new modified credit impairment guidance related to available-for-sale debt securities prospectively. Under the new guidance, at each reporting date, entities must evaluate their individual available-for-sale debt securities that are in an unrealized loss position and determine whether the decline in fair value below the amortized cost basis from a credit loss or other factors. The amount of the decline related to credit losses are recorded as a credit loss expense in earnings with a corresponding allowance for credit losses and the amount of decline not related to credit losses are recorded through other comprehensive income, net of tax. As of June 30, 2020, our corporate bond portfolio reported an unrealized net loss of $29,000. Based on our evaluations, we determined that a credit loss allowance is not required since the decline was not related to underlying credit issues of the counterparties. The counterparties to these investments have high credit quality with investment grade ratings of at least A- or above, along with a history of no defaults. No single investment in the corporate bond portfolio had an individually material unrealized loss and in the aggregate. The total amount of unrealized losses of $47,000 as of June 30, 2020 was only 0.12% of the total amortized costs basis of the corporate bond portfolio. In addition, the Company does not intend to sell these investments and it is not more likely than not that the Company will be required to sell these investments before recovery of their amortized cost bases. Accordingly, based on the foregoing evaluation, the Company did not record any credit losses during the three and six months ended June 30, 2020 and the entire amount of the decline in fair value below the amortized cost basis was recorded as an unrealized loss, net of tax, in other comprehensive loss in the Statements of Comprehensive Loss. Unrealized gains are also reflected, net of tax, as other comprehensive income (loss) in the Statements of Comprehensive Loss. Contractual maturities of the Company’s marketable securities as of June 30, 2020 and December 31, 2019 are summarized as follows: As of June 30, 2020 As of December 31, 2019 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated (in thousands) Cost Gains Losses Fair Value Cost Gains Losses Fair Value Due in one year or less $ 36,156 $ 17 $ (45) $ 36,128 $ 20,006 $ 19 $ (21) $ 20,004 Due in one through two years 1,517 1 (2) 1,516 — — — — Total $ 37,673 $ 18 $ (47) $ 37,644 $ 20,006 $ 19 $ (21) $ 20,004 At June 30, 2020, the Company had $18,000 of gross unrealized gains and $47,000 of gross unrealized losses primarily due to fluctuations in the fair value of certain U.S. government agency debt securities. During the six months ended June 30, 2020, the Company recorded a net realized gains of $38,000 from the sale of marketable securities. The unrealized losses and fair values of available-for-sale securities that have been in an unrealized loss position for a period of less than and greater than 12 months as of June 30, 2020 are as follows: As of June 30, 2020 Securities in an unrealized loss position less than 12 months Securities in an unrealized loss position greater than 12 months Total Unrealized Estimated Unrealized Estimated Unrealized Estimated (in thousands) Losses Fair Value Losses Fair Value Losses Fair Value Commercial paper and corporate bonds $ (3) $ 902 $ — $ — $ (3) $ 902 US government agency debt security (42) 15,150 (2) 1,515 (44) 16,665 Total $ (45) $ 16,052 $ (2) $ 1,515 $ (47) $ 17,567 The unrealized losses and fair values of available-for-sale securities that have been in an unrealized loss position for a period of less than and greater than 12 months as of December 31, 2019 are as follows: As of December 31, 2019 Securities in an unrealized loss position less than 12 months Securities in an unrealized loss position greater than 12 months Total Unrealized Estimated Unrealized Estimated Unrealized Estimated (in thousands) Losses Fair Value Losses Fair Value Losses Fair Value Commercial paper and corporate bonds $ (20) $ 7,520 $ — $ — $ (20) $ 7,520 US government agency debt security (1) 3,497 — — (1) 3,497 Total $ (21) $ 11,017 $ — $ — $ (21) $ 11,017 As of June 30, 2020, we did not intend to sell and it was not likely that we would be required to sell these investments before recovery of their amortized cost basis, which may be at maturity. Unrealized losses related to these investments are primarily due to interest rate fluctuations as opposed to changes in credit quality.

PREPAID EXPENSES AND OTHER CURR

PREPAID EXPENSES AND OTHER CURRENT ASSETS	6 Months Ended
	Jun. 30, 2020
PREPAID EXPENSES AND OTHER CURRENT ASSETS
PREPAID EXPENSES AND OTHER CURRENT ASSETS	5. PREPAID EXPENSES AND OTHER CURRENT ASSETS Prepaid expenses and other current assets consisted of the following: June 30, December 31, (in thousands) 2020 2019 Prepaid research and development expenses 5,867 5,872 Insurance premium asset 3,487 — Prepaid rent expenses 98 142 Prepaid insurance expenses 101 1,196 Interest Receivable 33 10 Other prepaid expenses and current assets 440 81 Total prepaid expenses & other current assets $ 10,026 $ 7,301

ACCRUED EXPENSES AND OTHER CURR

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	6 Months Ended
	Jun. 30, 2020
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	6. ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES Accrued expenses and other current liabilities consisted of the following: June 30, December 31, (in thousands) 2020 2019 Accrued pre-clinical and clinical expenses $ 6,743 $ 4,287 Short-term insurance financing note 3,222 — Accrued professional fees 763 345 Accrued compensation and benefits 693 — Accrued commercial expenses 154 — Accrued patent expenses 497 54 Other 783 264 Total accrued expenses & other current liabilities $ 12,855 $ 4,950 In June 2020, the Company financed their directors' and officers' insurance premium with a short-term note, the principal amount of which is approximately $3.2 million bearing interest at a rate of 3.2% per annum. The note payable balance was $3.2 million, which was included within accrued expense and other current liabilities on the Condensed Balance Sheets at June 30, 2020 .

STOCK BASED COMPENSATION

STOCK BASED COMPENSATION	6 Months Ended
	Jun. 30, 2020
STOCK BASED COMPENSATION
STOCK BASED COMPENSATION	7 . STOCK‑BASED COMPENSATION Equity Incentive Plans In May 2019, the Company's board of directors (the "Board") adopted its 2019 Equity Incentive Plan ("2019 Plan"), which was subsequently approved by its stockholders and became effective on May 13, 2019. As a result, no additional awards under the Company's 2016 Equity Incentive Plan, as amended (the "2016 Plan") will be granted and all outstanding stock awards granted under the 2016 Plan that are repurchased, forfeited, expired or are cancelled will become available for grant under the 2019 Plan in accordance with its terms. The 2016 Plan will continue to govern outstanding equity awards granted thereunder. The 2019 Plan provides for the issuance of incentive stock options ("ISOs") to employees, and for the grant of nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards, performance cash awards and other forms of stock awards to the Company's employees, officers and directors, as well as non- employees, consultants and affiliates to the Company. Under the terms of the 2019 Plan, stock options may not be granted at an exercise price less than fair market value of the Company's common stock on the date of the grant. The 2019 Plan will be administered by the Compensation Committee of the Company's Board. Initially, subject to adjustments as provided in the 2019 Plan, the maximum number of the Company's common stock that may be issued under the 2019 Plan is 4,530,000 shares, which is the sum of (i) 1,618,841 new shares, plus (ii) the number of shares (not to exceed 2,911,159 shares) that remained available for the issuance of awards under the 2016 Plan, at the time the 2019 Plan became effective, and (iii) any shares subject to outstanding stock options or other stock awards granted under the 2016 Plan that are forfeited, expired, or reacquired. The 2019 Plan provides that the number of shares reserved and available for issuance under the 2019 Plan will automatically increase each January 1, beginning on January 1, 2020, by 5% of the outstanding number of shares of common stock on the immediately preceding December 31 or such lesser number of shares as determined by the Board. Subject to certain changes in capitalization of the Company, the aggregate maximum number of shares of common stock that may be issued pursuant to the exercise of ISOs shall be equal to 13,000,000 shares of common stock. Stock options awarded under the 2019 Plan expire 10 years after grant and typically vest over four years. As of June 30, 2020, there were 2,675,770 shares reserved by the Company to grant under the 2016 and 2019 Plans and an aggregate of 801,395 shares remained available for future grants under the 2019 Plan. Stock-Based Compensation Expense Total stock-based compensation expense recorded for employees, directors and non-employees during the three and six months ended June 30, 2020 and 2019 was as follows: Three Months Ended Six Months Ended June 30, June 30, (in thousands) 2020 2019 2020 2019 Research and development $ 621 $ 1,445 $ 1,259 $ 1,592 General and administrative 952 1,833 1,623 2,012 Total stock-based compensation expense $ 1,573 $ 3,278 $ 2,882 $ 3,604 During the six months ended June 30, 2020, the Company granted options to purchase 481,488 shares of common stock. The Company recorded stock-based compensation expense for the three and six months ended June 30, 2020 of $1.6 million and $2.9 million, respectively. As of June 30, 2020 and December 31, 2019, there were 4,068,428 and 4,079,888 options outstanding, respectively. The weighted‑average fair value of options granted during the six months ended June 30, 2020 and 2019 was $24.74 and $4.79 per share, respectively. As of June 30, 2020, the total unrecognized stock‑based compensation balance for unvested options was $21.5 million which is expected to be recognized over a period of 1.6 years. The following table summarizes the information about options outstanding at June 30, 2020: Weighted-Average Weighted- Remaining Aggregate Options Average Contractual Intrinsic (in thousands, except for share data) Outstanding Exercise Price Term (in years) Value Outstanding at December 31, 2019 4,079,888 $ 5.11 8.26 $ 82,327 Options granted 481,488 40.56 Options exercised (359,641) 3.96 15,128 Forfeited (133,307) 12.37 Expired — — Outstanding at June 30, 2020 4,068,428 $ 10.88 8.73 $ 105,282 Exercisable at June 30, 2020 2,111,382 $ 4.18 8.34 $ 67,491 Nonvested at June 30, 2020 1,957,046 $ 18.10 9.16 $ 37,792 Valuation of Stock Options Granted to Employees that Contain Service Conditions Only The fair value of each option award granted with service-based vesting is estimated on the date of the grant using the Black-Scholes option valuation model based on the weighted average assumptions noted in the table below for those options granted in the six months ended June 30, 2020 and 2019. Six Months Ended June 30, 2020 2019 Expected term (in years) 6.0 6.0 Volatility 69.30 % 68.52 % Risk-free interest rate 0.54 % 2.26 % Dividend yield 0.00 % 0.00 % Stock Options Granted to Employees that Contain Service, Performance and Market Conditions Included in the stock options granted during the three and six months ended June 30, 2019 were 159,501 stock options that contain service-, performance- and market-based vesting conditions granted to the Company's interim Chief Financial Officer ("CFO") with a fair value at the grant date of $0.5 million, valued using the Monte-Carlo simulation model. The derived service period, calculated using the Monte-Carlo simulation model, ranged from one day to three years. The assumptions used in the Monte-Carlo simulation model were as follows: Six Months Ended June 30, 2020 Time to expiration (in years) 10.0 Volatility 68.54 % Risk-free interest rate 2.64 % Dividend yield 0.00 % Cost of equity 24.00 % Fair value of underlying common stock (as of valuation date) $ 5.85 The compensation expense for these awards is recognized over the derived service period, or, if earlier, until the vesting condition is met. The condition for the performance-based stock options was based on the Company's completion of its IPO and the condition for the market-based stock options was based on the future price of the Company's common stock trading at or above a specified threshold. During the six months ended June 30, 2019, 79,778 of the stock options containing service-, and performance-based vesting conditions were vested following the satisfaction of service- and performance-based conditions. In May 2019, the Company entered into a severance agreement, effective on May 31, 2019 ("Termination Date"), with the interim CFO. As part of this severance arrangement and as of the Termination Date, the Company accelerated the vesting of 79,723 unvested options, which were originally granted to the former CFO under the 2016 Plan. As a result of this modification, the Company recorded stock-based compensation expense of $0.6 million included in general and administrative expense for the three months and six months ended June 30, 2019. The Company accounted for this modification as a Type III modification since, at the modification date, the expectation of the award vesting changed from improbable to probable. As a result, the stock-based compensation expense recognized was based on the modification-date fair value. As of June 30, 2020, there were no outstanding stock options containing service-, performance-, and market-based vesting conditions. The Company recorded $0.7 million and $0.8 million, respectively in compensation expense related to these awards for the three and six months ended June 30, 2019. Issuance of Restricted Stock Units On March 9, 2020, the Board of Directors of the Company approved the grant of 36,464 restricted stock units (“RSUs”) to an employee of the Company, pursuant to the 2019 Equity Plan. One-fourth of the RSUs shall vest in four equal annual installments commencing one year after the date of grant, subject to the employee continuing to provide services through each such date. These shares were valued at $1.3 million, determined using price per share of $34.28, the closing price of the Company’s common stock on March 9, 2020, and will be amortized ratably over the term of the vesting periods of four years on a straight line basis. On June 4, 2020, the Board of Directors of the Company approved the grant of 108,662 RSUs to employees of the Company, pursuant to the 2019 Equity Plan. One-fourth of such RSUs vest in four equal annual installments commencing one year after the date of grant, subject to the respective employee continuing to provide services through each such date. These shares were valued at $4.8 million, determined using price per share of $44.02, the closing price of the Company’s common stock on June 4, 2020, and will be amortized ratably over the term of the vesting periods of four years on a straight line basis. For the three and six months ended June 30, 2020, amortization of stock compensation of RSUs amounted to $0.2 million and $0.2 million, respectively. As of June 30, 2020, the unamortized compensation costs associated with non-vested restricted stock awards were $5.9 million with a weighted-average remaining amortization period of 3.7 years. 2019 Employee Stock Purchase Plan In May 2019, the Company’s Board and its stockholders approved the 2019 Employee Stock Purchase Plan (the “ESPP”), which became effective as of May 13, 2019. The ESPP is intended to qualify as an “employee stock purchase plan” within the meaning of Section 423 of the U.S. Internal Revenue Code of 1986, as amended. The number of shares of common stock initially reserved for issuance under the ESPP was 180,000 shares. The ESPP provides for an annual increase on the first day of each year beginning in 2020 and ending in 2029, in each case subject to the approval of the Board, equal to the lesser of (i) 1% of the shares of common stock outstanding on the last day of the calendar month before the date of the automatic increase and (ii) 360,000 shares; provided that prior to the date of any such increase, the Board may determine that such increase will be less than the amount set forth in clauses (i) and (ii). As of June 30, 2020, no shares of common stock had been issued under the ESPP. The first offering period has not yet been decided by the Board.

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	6 Months Ended
	Jun. 30, 2020
STOCKHOLDERS’ EQUITY
STOCKHOLDERS’ EQUITY	8. STOCKHOLDERS’ EQUITY As of June 30, 2020, and December 31, 2019, the authorized capital stock of the Company consists of 100,000,000 shares of common stock, par value $0.0001 per share and 10,000,000 shares of preferred stock, par value $0.0001 per share. Common Stock Voting The holders of the common stock are entitled to one vote for each share of common stock held at all meetings of the stockholders. There are no cumulative voting rights. Equity Distribution Agreement In June 2020, we entered into the Equity Distribution Agreement with Goldman to sell shares of the Company’s common stock, from time to time, having and aggregate offering price of $100.0 million. The issuance and sale of shares of common stock by us pursuant to the Equity Distribution Agreement is deemed an “at-the-market” offering under the Securities Act of 1933, as amended, or the Securities Act. Goldman is entitled to compensation for its services equal to up to 3.0% of the gross offering proceeds of all shares of our common stock sold through it as a sales agent pursuant to the Equity Distribution Agreement. As of June 30, 2020, the Company had received no proceeds from the sale of shares of common stock pursuant to the Equity Distribution Agreement. Preferred Stock In February 2019, the Company issued 442,930 shares of Series B Preferred Stock at $7.49 per share for gross proceeds of approximately $3.3 million. Issuance costs were $0.3 million, which included the obligation to issue warrants to purchase common stock (see Note 10). Upon completion of the IPO, all 7,538,671 shares of outstanding Series A Preferred Stock (“Series A Preferred Stock”) and Series B Preferred Stock (collectively, "the Preferred Stock") were converted into common stock on a one-to-one basis. As of June 30, 2020 and December 31, 2019, there were no shares of preferred stock outstanding.

WARRANTS

WARRANTS	6 Months Ended
	Jun. 30, 2020
WARRANTS
WARRANTS	9. WARRANTS Warrants Issued with Series A Preferred Stock On January 26, 2017, in connection with the sale and issuance of the Series A Preferred Stock, the Company issued equity‑classified warrants to purchase 309,389 shares of common stock (the “2017 Warrants”), valued at $0.2 million, and included in the issuance costs of the Series A Preferred Stock. The warrants vested immediately and have an exercise price of $2.49 per share and expire on March 13, 2027. The fair value of warrants issued is estimated using the Black‑Scholes option pricing model with the following assumptions for the 2017 Warrants. Contractual term (in years) 10.0 Volatility 74.48 % Risk-free interest rate 3.20 % Dividend yield 0.00 % On February 21, 2020, two warrantholders exercised 185,634 options in a cashless exercise at net, and the Company issued 176,092 shares of common stock. On February 24, 2020, a warrantholder exercised 72,818 options in a cashless exercise at net, and the Company issued 69,094 shares of common stock. Warrants Issued with the 2018 Notes On January 18, 2018, the Company entered into a placement agent agreement through which it became obligated to issue common stock warrants in connection with the issuance of convertible notes, or the 2018 Notes. The obligation to issue the 2018 Notes Warrants was recorded as a liability at its fair value, which was initially $0.1 million, and was included in the issuance costs of the 2018 Notes. On November 5, 2018, in connection with the extinguishment of the 2018 Notes into shares of Series B Preferred Stock, the Company issued the 2018 Notes Warrants, which were equity‑classified warrants upon issuance, to purchase 76,847 shares of common stock, valued at $0.3 million. The 2018 Notes Warrants vested immediately upon issuance and have an exercise price of $6.59 per share and expire on November 4, 2028. On February 24, 2020, a warrantholder exercised 386 options in a cashless exercise at net, and the Company issued 333 shares of common stock. On June 24, 2020, a warrantholder exercised 20,331 options in a cashless exercise at net, and the Company issued 17,369 shares of common stock. Warrants Issued with Series B Preferred Stock In November and December 2018, in connection with the sale and issuance of the Series B Preferred Stock, the Company was obligated to issue warrants to purchase 72,261 shares of common stock (collectively the “2018 Warrants”), valued in the aggregate at $0.2 million, which was included in the issuance costs for the Series B Preferred Stock. The warrants vest immediately upon issuance, have an exercise price of $8.24 per share and expire 10 years from the date of issuance. The fair value of the 2018 Warrants was estimated using the Black‑Scholes option pricing model with the following assumptions: Contractual term (in years) 10.0 Volatility 73.22 % Risk-free interest rate 2.70 % Dividend yield 0.00 % In February 2019, in connection with the sale and issuance of the Series B Preferred Stock, the Company was obligated to issue warrants to purchase 23,867 shares of common stock (collectively the “2019 Warrants”), valued in the aggregate at $0.1 million, which was included in the issuance costs for the Series B Preferred Stock. The warrants vest immediately upon issuance, have an exercise price of $8.24 per share and expire 10 years from the date of issuance. The fair value of the 2019 Warrants was estimated using the Black-Scholes option pricing model with the following assumptions: Contractual term (in years) 10.0 Volatility 73.22 % Risk-free interest rate 2.70 % Dividend yield 0.00 % The inputs utilized by management to value the warrants are highly subjective. The assumptions used in calculating the fair value of the warrants represent the Company’s best estimates, but these estimates involve inherent uncertainties and the application of management judgment. As a result, if factors change and the Company uses different assumptions, the fair value of the warrants may be materially different in the future. On January 14, 2020, a warrantholder exercised 220 options in a cashless exercise at net, and the Company issued 146 shares of common stock. On February 24, 2020, a warrantholder exercised 5,193 options in a cashless exercise at net, and the Company issued 4,313 shares of common stock. On June 24, 2020, a warrantholder exercised 24,309 options in a cashless exercise at net, and the Company issued 19,882 shares of common stock. A summary of the Company’s outstanding common stock warrants as of June 30, 2020 is as follows: Warrants Outstanding as of December 31, 2019 462,364 Warrants granted and issued — Warrants exercised (308,891) Warrants exchanged — Balance as of June 30, 2020 153,473

LEASES

LEASES	6 Months Ended
	Jun. 30, 2020
LEASES
LEASES	10. LEASES The following table summarizes the Company’s lease assets and liabilities as of June 30, 2020: ROU Assets and Liabilities Balance Sheet Location Operating (in thousands) ROU - Asset Right-of-use assets $ 1,849 Lease liabilities (current) Operating lease liabilities, current 372 Lease liabilities (non-current) Operating lease liabilities, non-current 1,492 The following table summarizes the Company’s lease related costs for the three months ended June 30, 2020: Lease Cost Statement of Operations Location Operating (in thousands) Operating Lease Cost General and administrative $ 121 Total Lease Cost $ 121 Average lease terms and discount rates for the Company’s operating leases were as follows: Six Months Ended June 30, Other Information 2020 Weighted-average remaining lease term Operating leases 4.34 years Weighted-average discount rate Operating leases The following table summarizes the maturities of lease liabilities as of June 30, 2020: Operating Year (in thousands) 2020 $ 232 2021 474 2022 486 2023 497 2024 423 Thereafter — Total lease payments 2,112 Less: interest 248 Total lease liabilities $ 1,864

INCOME TAXES

INCOME TAXES	6 Months Ended
	Jun. 30, 2020
INCOME TAXES
INCOME TAXES	11. INCOME TAXES On March 27, 2020, Congress enacted the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) to provide certain relief as a result of the Covid-19 pandemic. The CARES Act provides numerous tax provisions and other stimulus measures, including temporary changes regarding the prior and future utilization of net operating losses, temporary changes to the prior and future limitations on interest deductions, temporary suspension of certain payment requirements for the employer portion of social security taxes, technical corrections from prior tax legislation for tax depreciation of certain qualified improvement property and the creation of certain refundable employee retention credits . The CARES Act did not have a material impact on our financial statements for the six months ended June 30, 2020. We continue to monitor any effects that may result from the CARES Act. During the six months ended June 30, 2020 and the year ended December 31, 2019, the Company recorded a full valuation allowance on federal and state deferred tax assets since management does not forecast the Company to be in a profitable position in the near future.

BENEFIT PLANS

BENEFIT PLANS	6 Months Ended
	Jun. 30, 2020
BENEFIT PLANS
BENEFIT PLANS	12. BENEFIT PLANS The Company established a defined contribution savings plan under Section 401(k) of the Internal Revenue Code in 2018. This plan covers substantially all employees who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre‑tax basis. Matching contributions to the plan may be made at the discretion of the Company’s board of directors. The Company made approximately $43,000 and $35,000 in matching contributions to the plan during the six months ended June 30, 2020 and 2019, respectively.

NET LOSS PER COMMON SHARE

NET LOSS PER COMMON SHARE	6 Months Ended
	Jun. 30, 2020
NET LOSS PER COMMON SHARE
NET LOSS PER COMMON SHARE	13. NET LOSS PER COMMON SHARE Basic net loss per common share is computed by dividing the net loss available to common stockholders by the weighted‑average number of shares of common stock outstanding during the period. Diluted net loss per common share is computed by giving the effect of all potential shares of common stock, including stock options, preferred shares, warrants and instruments convertible into common stock, to the extent dilutive. Basic and diluted net loss per common share was the same for the three and six months ended June 30, 2020 and 2019, as the inclusion of all potential common shares outstanding would have been anti‑dilutive. The following tables sets forth the computation of basic and diluted net loss per common share for the three and six months ended June 30, 2020 and 2019: Three Months Ended June 30, (in thousands, except for share data) 2020 2019 Numerator: Net loss $ (28,059) $ (8,437) Denominator: Weighted-average common stock outstanding 22,062,030 13,945,939 Net loss per share attributable to common stockholders - basic and diluted $ (1.27) $ (0.60) Six Months Ended June 30, 2020 2019 Numerator: Net loss $ (40,428) $ (17,166) Denominator: Weighted-average common stock outstanding 21,451,344 9,776,582 Net loss per share attributable to common stockholders - basic and diluted $ (1.88) $ (1.76) The Company’s potentially dilutive securities, which include Preferred Stock, stock options, and warrants, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted‑average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding for the three and six months ended June 30, 2020 and 2019, from the computation of diluted net loss per share attributable to common stockholders because including them would have had an anti‑dilutive effect: As of June 30, 2020 2019 Options to purchase common stock 4,068,428 3,855,083 Restricted stock units 145,126 — Warrants to purchase common stock 153,473 482,364

RELATED PARTIES

RELATED PARTIES	6 Months Ended
	Jun. 30, 2020
RELATED PARTIES
RELATED PARTIES	14. RELATED PARTIES In December 2018, the Company entered into an agreement (the “LaunchLabs Agreement”) with ARE‑LaunchLabs NYC LLC (“Alexandria LaunchLabs”), a subsidiary of Alexandria Real Estate Equities, Inc. for use of specified premises within the Alexandria LaunchLabs space. A member of the Company’s board of directors is the founder and executive chairman of Alexandria Real Estate Equities, Inc. During the three and six months ended June 30, 2020 and 2019, the Company made payments to Alexandria LaunchLabs of approximately $12,000,$36,000, $28,000, and $50,000, respectively under the LaunchLabs Agreement, which was recognized in research and development expenses. As of June 30, 2020, there were no amounts due to Alexandria LaunchLabs under the LaunchLabs Agreement.

ORGANIZATION AND SUMMARY OF S_2

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 2020
ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Basis of Accounting	Operations and Business Applied Therapeutics, Inc. (the “Company”) is a clinical-stage biopharmaceutical company developing a pipeline of novel product candidates against validated molecular targets in indications of high unmet medical need. In particular, the Company is currently targeting treatments for rare metabolic diseases such as galactosemia, and diabetic complications including diabetic cardiomyopathy. The Company was incorporated in Delaware on January 20, 2016 and is headquartered in New York, New York. On May 16, 2019, the Company completed an initial public offering (the “IPO”) in which the Company issued and sold 4,000,000 shares of its common stock at a public offering price of $10.00 per share, for aggregate gross proceeds of $40.0 million. The Company received net of proceeds $34.6 million, after deducting underwriting discounts and commissions and offering costs. Prior to the completion of the IPO, the Company primarily funded its operations with proceeds from the sale of convertible preferred stock (see Note 8). In connection with the IPO, the Company effected a 55.2486-for-1 stock split of its issued and outstanding shares of common stock and convertible preferred stock. The stock split became effective on April 26, 2019. Stockholders entitled to fractional shares as a result of the forward stock split received cash payment in lieu of receiving fractional shares. All share and per share amounts for all periods presented in the accompanying condensed financial statements and notes thereto have been retroactively adjusted, where applicable, to reflect this stock split. Shares of common stock underlying outstanding stock options and other equity instruments were proportionately increased and the respective per share value and exercise prices, if applicable, were proportionately decreased in accordance with the terms of the agreements governing such securities. Upon the closing of the IPO on May 16, 2019, all of the then-outstanding shares of convertible preferred stock automatically converted into 7,538,671 shares of common stock on a one-for-one basis. Subsequent to the closing of the IPO, there were no shares of convertible preferred stock outstanding. On November 12, 2019, the Company completed a private placement (the “Private Placement”), pursuant to which it issued and sold 1,380,344 shares of the Company’s common stock at a price of $14.50 per share, for net proceeds of $18.4 million after deducting placement agent discounts and commissions and offering costs. On January 28, 2020, the Company completed its secondary public offering (the “Secondary Public Offering”), pursuant to which it issued and sold 2,741,489 shares of common stock at a public offering price of $45.50 per share, with an additional 411,223 shares sold pursuant to the underwriters’ full exercise of their option to purchase additional shares. The aggregate net proceeds received by the Company from the offering, after deducting underwriting discounts and commissions and offering costs, were $134.1 million. On June 4, 2020, the Company filed a shelf registration statement on Form S-3 (the “Shelf Registration Statement”) under which the Company may, from time to time, sell securities in one or more offerings having an aggregate offering price of up to $300.0 million. The Shelf Registration Statement was declared effective as of June 15, 2020. As of the filing date of this Quarterly Report on Form 10-Q, no securities have been sold under this shelf registration. On June 12, 2020, the Company entered into an equity distribution agreement (the “Equity Distribution Agreement”) with Goldman Sachs & Co. LLC (“Goldman”), as a sales agent to sell shares of the Company’s common stock, from time to time, having an aggregate offering price of up to $100 million. Goldman may act as an agent on the Company’s behalf or purchase shares of the Company’s common stock as a principal. As of June 30, 2020, the Company had no sold any shares of common stock pursuant to the Equity Distribution Agreement. The accompanying unaudited condensed financial statements as of June 30, 2020 and December 31, 2019 and for the three and six months ended June 30, 2020 and 2019 have been prepared by the Company in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. These condensed financial statements should be read in conjunction with the Company’s audited financial statements and the notes thereto for the year ended December 31, 2019 included in the Annual Report, filed with the SEC on March 13, 2020 (the “Annual Report”). The unaudited condensed financial statements have been prepared on the same basis as the audited financial statements. In the opinion of management, the accompanying unaudited condensed financial statements contain all adjustments which are necessary for a fair presentation of the Company’s financial position as of June 30, 2020, results of operations for the three and six months ended June 30, 2020 and 2019 and cash flows for the six months ended June 30, 2020 and 2019. Such adjustments are of a normal and recurring nature. The results of operations for the three and six months ended June 30, 2020 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2020.
Liquidity	Liquidity The Company has incurred, and expects to continue to incur, significant operating losses and negative cash flows for at least the next several years as it continues to develop its drug candidates. To date, the Company has not generated any revenue, and it does not expect to generate revenue unless and until it successfully completes development and obtains regulatory approval for one of its product candidates. Management believes that the Company’s existing cash, cash equivalents, and investments will allow the Company to continue its operations for at least 12 months from the issuance date of these financial statements. After 12 months from the issuance of these financial statements, the Company may need to obtain additional funding. The Company may pursue additional cash resources through public or private financings.
Risk and Uncertainties	Risks and Uncertainties The Company is subject to risks common to companies in the biotechnology industry, including, but not limited to, risks of failure of preclinical studies and clinical trials, the need to obtain marketing approval for any product candidate that it may identify and develop, the need to successfully commercialize and gain market acceptance of its product candidates, dependence on key personnel, protection of proprietary technology, compliance with government regulations, development by competitors of technological innovations and reliance on third‑party manufacturers.
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 and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates.
Stock Based Compensation–Restricted Stock Units	Stock‑Based Compensation–Restricted Stock Units The Company accounts for restricted stock units in accordance with the authoritative guidance for stock-based compensation. The fair value of restricted stock units is measured at the grant date based on the closing market price of the Company’s common stock on the date of grant, and is recognized as expense on a straight-line basis over the period of vesting. Forfeitures are recognized as a reduction of stock-based compensation expense as they occur.
Financed D&O Insurance Premium	Financed D&O Insurance Premium In June 2020, the Company financed their directors' and officers' insurance premium with a short-term note, the principal amount of which is approximately $3.2 million bearing interest at a rate of 3.2% per annum. The note payable balance was $3.2 million, which was included within accrued expense and other current liabilities on the Condensed Balance Sheets as of June 30, 2020 .
Recent Accounting Pronouncements	Recent Accounting Pronouncements On January 1, 2020, the Company adopted ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which replaces the incurred loss methodology with an expected loss methodology that is referred to as the current expected credit loss (CECL) methodology. The measurement of expected credit losses under the CECL methodology applies to financial instruments measured at amortized cost, including loan receivables and held-to-maturity debt securities, off-balance sheet credit exposures and net investments in leases recognized by a lessor. ASC 326 also made changes to the accounting for available-for-sale debt securities, where credit losses are required to be presented as an allowance as opposed to a write-down. The FASB issued authoritative guidance that amends guidance on reporting credit losses for assets, including available-for-sale marketable securities and any other financial assets not excluded from the scope that have the contractual right to receive cash. For available-for-sale marketable securities, credit losses should be measured in a manner similar to current generally accepted accounting standards; however, ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , will require that credit losses be presented as an allowance rather than as a write-down. For available-for-sale debt securities in an unrealized position, the Company assesses whether a decline in fair value resulted from credit losses or other factors. Management considers the extent to which fair value is less than amortized cost, any changes to the credit rating of the security, and adverse conditions specifically related to the security. If the assessment indicates a credit loss exists, an allowance is recorded that is limited to the amount the amortized cost exceeds the fair value. Any impairment that is not recognized through the allowance for credit loss is recognized in other comprehensive income. The Company adopted ASC 326 using the modified retrospective method approach, where a cumulative-effect adjustment to credit loss allowance would be reflected in retained earnings. The adoption of this standard did not have an impact on the Company’s balance sheet as there were no credit losses identified. In August 2018, the FASB issued ASU No. 2018-13, “ Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement ,” which modifies the disclosure requirements on fair value measurements. The new guidance is effective for fiscal years beginning after December 15, 2019. Upon the effective date, certain provisions are to be applied prospectively, while others are to be applied retrospectively to all periods presented. The amendments eliminated certain disclosure requirements such as the elimination of disclosing the valuation process for Level 3 fair value measurements. Other amendments in the update did not impact the Company. The Company adopted the amendments on January 1, 2020 with no impact on our financial statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes. The new standard intended to simplify the accounting for income taxes by eliminating certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The new guidance also simplifies aspects of the accounting for franchise taxes and enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a step-up in the tax basis of goodwill. The standard is effective for annual periods beginning after December 15, 2020 and interim periods within, with early adoption permitted. Adoption of the standard requires certain changes to primarily be made prospectively, with some changes to be made retrospectively. The Company is currently evaluating the impact adoption of ASU 2019-12 will have on its financial statements.

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
	Jun. 30, 2020
FAIR VALUE MEASUREMENTS
Schedule of financial assets or liabilities measured at fair value on a recurring basis	As of June 30, 2020 (in thousands) Level 1 Level 2 Level 3 Total Cash $ 48,138 $ — $ — $ 48,138 Money market funds 52,716 — — 52,716 Total cash and cash equivalents $ 100,854 $ — $ — $ 100,854 Commercial paper and corporate bonds — 1,651 — 1,651 U.S. government agency debt securities — 35,993 — 35,993 Total marketable securities $ — $ 37,644 $ — $ 37,644 Total financial assets measured at fair value on a recurring basis $ 100,854 $ 37,644 $ — $ 138,498

INVESTMENTS (Tables)

INVESTMENTS (Tables)	6 Months Ended
	Jun. 30, 2020
INVESTMENTS
Schedule of marketable securities by security type	As of June 30, 2020 As of December 31, 2019 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated (in thousands) Cost Gains Losses Fair Value Cost Gains Losses Fair Value Commercial paper and corporate bonds $ 1,653 $ 1 $ (3) $ 1,651 $ 7,540 $ — $ (20) $ 7,520 US government agency debt security 36,020 17 (44) 35,993 12,466 19 (1) 12,484 Total $ 37,673 $ 18 $ (47) $ 37,644 $ 20,006 $ 19 $ (21) $ 20,004
Schedule of contractual maturities	As of June 30, 2020 As of December 31, 2019 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated (in thousands) Cost Gains Losses Fair Value Cost Gains Losses Fair Value Due in one year or less $ 36,156 $ 17 $ (45) $ 36,128 $ 20,006 $ 19 $ (21) $ 20,004 Due in one through two years 1,517 1 (2) 1,516 — — — — Total $ 37,673 $ 18 $ (47) $ 37,644 $ 20,006 $ 19 $ (21) $ 20,004
Unrealized Gain (Loss) on Investments	As of June 30, 2020 Securities in an unrealized loss position less than 12 months Securities in an unrealized loss position greater than 12 months Total Unrealized Estimated Unrealized Estimated Unrealized Estimated (in thousands) Losses Fair Value Losses Fair Value Losses Fair Value Commercial paper and corporate bonds $ (3) $ 902 $ — $ — $ (3) $ 902 US government agency debt security (42) 15,150 (2) 1,515 (44) 16,665 Total $ (45) $ 16,052 $ (2) $ 1,515 $ (47) $ 17,567 As of December 31, 2019 Securities in an unrealized loss position less than 12 months Securities in an unrealized loss position greater than 12 months Total Unrealized Estimated Unrealized Estimated Unrealized Estimated (in thousands) Losses Fair Value Losses Fair Value Losses Fair Value Commercial paper and corporate bonds $ (20) $ 7,520 $ — $ — $ (20) $ 7,520 US government agency debt security (1) 3,497 — — (1) 3,497 Total $ (21) $ 11,017 $ — $ — $ (21) $ 11,017

PREPAID EXPENSES AND OTHER CU_2

PREPAID EXPENSES AND OTHER CURRENT ASSETS (Tables)	6 Months Ended
	Jun. 30, 2020
PREPAID EXPENSES AND OTHER CURRENT ASSETS
Summary of prepaid expenses and other current assets	June 30, December 31, (in thousands) 2020 2019 Prepaid research and development expenses 5,867 5,872 Insurance premium asset 3,487 — Prepaid rent expenses 98 142 Prepaid insurance expenses 101 1,196 Interest Receivable 33 10 Other prepaid expenses and current assets 440 81 Total prepaid expenses & other current assets $ 10,026 $ 7,301

ACCRUED EXPENSES AND OTHER CU_2

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)	6 Months Ended
	Jun. 30, 2020
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES
Summary of accrued expenses and other current liabilities	June 30, December 31, (in thousands) 2020 2019 Accrued pre-clinical and clinical expenses $ 6,743 $ 4,287 Short-term insurance financing note 3,222 — Accrued professional fees 763 345 Accrued compensation and benefits 693 — Accrued commercial expenses 154 — Accrued patent expenses 497 54 Other 783 264 Total accrued expenses & other current liabilities $ 12,855 $ 4,950

STOCK BASED COMPENSATION (Table

STOCK BASED COMPENSATION (Tables)	6 Months Ended
	Jun. 30, 2020
Stock-based compensation
Schedule of stock-based compensation expenses	Three Months Ended Six Months Ended June 30, June 30, (in thousands) 2020 2019 2020 2019 Research and development $ 621 $ 1,445 $ 1,259 $ 1,592 General and administrative 952 1,833 1,623 2,012 Total stock-based compensation expense $ 1,573 $ 3,278 $ 2,882 $ 3,604
Schedule of options outstanding	Weighted-Average Weighted- Remaining Aggregate Options Average Contractual Intrinsic (in thousands, except for share data) Outstanding Exercise Price Term (in years) Value Outstanding at December 31, 2019 4,079,888 $ 5.11 8.26 $ 82,327 Options granted 481,488 40.56 Options exercised (359,641) 3.96 15,128 Forfeited (133,307) 12.37 Expired — — Outstanding at June 30, 2020 4,068,428 $ 10.88 8.73 $ 105,282 Exercisable at June 30, 2020 2,111,382 $ 4.18 8.34 $ 67,491 Nonvested at June 30, 2020 1,957,046 $ 18.10 9.16 $ 37,792
Stock options - Service conditions only
Stock-based compensation
Schedule of valuation assumptions	Six Months Ended June 30, 2020 2019 Expected term (in years) 6.0 6.0 Volatility 69.30 % 68.52 % Risk-free interest rate 0.54 % 2.26 % Dividend yield 0.00 % 0.00 %
Stock options - Service, performance and market conditions
Stock-based compensation
Schedule of valuation assumptions	Six Months Ended June 30, 2020 Time to expiration (in years) 10.0 Volatility 68.54 % Risk-free interest rate 2.64 % Dividend yield 0.00 % Cost of equity 24.00 % Fair value of underlying common stock (as of valuation date) $ 5.85

WARRANTS (Tables)

WARRANTS (Tables)	6 Months Ended
	Jun. 30, 2020
Warrants
Schedule of warrants outstanding	Warrants Outstanding as of December 31, 2019 462,364 Warrants granted and issued — Warrants exercised (308,891) Warrants exchanged — Balance as of June 30, 2020 153,473
Warrants Issued with Series A Preferred Stock | 2017 Warrants
Warrants
Schedule of fair value of warrants using the Black Scholes option pricing model	Contractual term (in years) 10.0 Volatility 74.48 % Risk-free interest rate 3.20 % Dividend yield 0.00 %
Warrants Issued with Series B Preferred Stock | 2018 Warrants
Warrants
Schedule of fair value of warrants using the Black Scholes option pricing model	Contractual term (in years) 10.0 Volatility 73.22 % Risk-free interest rate 2.70 % Dividend yield 0.00 %
Warrants Issued with Series B Preferred Stock | 2019 Warrants
Warrants
Schedule of fair value of warrants using the Black Scholes option pricing model	Contractual term (in years) 10.0 Volatility 73.22 % Risk-free interest rate 2.70 % Dividend yield 0.00 %

LEASES (Tables)

LEASES (Tables)	6 Months Ended
	Jun. 30, 2020
LEASES
Summary of lease assets and liabilities	ROU Assets and Liabilities Balance Sheet Location Operating (in thousands) ROU - Asset Right-of-use assets $ 1,849 Lease liabilities (current) Operating lease liabilities, current 372 Lease liabilities (non-current) Operating lease liabilities, non-current 1,492
Summary of lease related costs	Lease Cost Statement of Operations Location Operating (in thousands) Operating Lease Cost General and administrative $ 121 Total Lease Cost $ 121
Summary of lease terms and discount rates	Six Months Ended June 30, Other Information 2020 Weighted-average remaining lease term Operating leases 4.34 years Weighted-average discount rate Operating leases
Summary of maturities of lease liabilities	Operating Year (in thousands) 2020 $ 232 2021 474 2022 486 2023 497 2024 423 Thereafter — Total lease payments 2,112 Less: interest 248 Total lease liabilities $ 1,864

NET LOSS PER COMMON SHARE (Tabl

NET LOSS PER COMMON SHARE (Tables)	6 Months Ended
	Jun. 30, 2020
NET LOSS PER COMMON SHARE
Schedule of computation of basic and diluted net loss per common share	Three Months Ended June 30, (in thousands, except for share data) 2020 2019 Numerator: Net loss $ (28,059) $ (8,437) Denominator: Weighted-average common stock outstanding 22,062,030 13,945,939 Net loss per share attributable to common stockholders - basic and diluted $ (1.27) $ (0.60) Six Months Ended June 30, 2020 2019 Numerator: Net loss $ (40,428) $ (17,166) Denominator: Weighted-average common stock outstanding 21,451,344 9,776,582 Net loss per share attributable to common stockholders - basic and diluted $ (1.88) $ (1.76)
Schedule of potential dilutive securities excluded from the computation of diluted net loss per share attributable to common stockholders	As of June 30, 2020 2019 Options to purchase common stock 4,068,428 3,855,083 Restricted stock units 145,126 — Warrants to purchase common stock 153,473 482,364

ORGANIZATION AND SUMMARY OF S_3

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Stock issued (Details) $ / shares in Units, $ in Millions	Jun. 12, 2020USD ($)	Jun. 04, 2020USD ($)shares	Jan. 28, 2020USD ($)$ / sharesshares	Nov. 12, 2019USD ($)$ / sharesshares	May 16, 2019USD ($)$ / sharesshares	Apr. 26, 2019	Jun. 30, 2020shares	Dec. 31, 2019shares
IPO
Convertible preferred stock, outstanding (in shares)					0		0	0
IPO
IPO
Issuance of common stock (in shares)					4,000,000
Issue price (in dollars per share) | $ / shares					$ 10
Aggregate gross proceeds from issuance | $					$ 40
Net proceeds after deducting underwriting discounts and commissions and offering costs | $					$ 34.6
Stock split ratio						55.2486
Conversion of convertible preferred stock into common stock upon closing of the IPO (in shares)					7,538,671
Number of shares issued for each share of convertible preferred stock converted					1
Private placement
IPO
Issuance of common stock (in shares)				1,380,344
Issue price (in dollars per share) | $ / shares				$ 14.50
Net proceeds after deducting underwriting discounts and commissions and offering costs | $				$ 18.4
Secondary public offering
IPO
Issue price (in dollars per share) | $ / shares			$ 45.50
Net proceeds from issuance of common stock | $			$ 134.1
Secondary public offering, excluding underwriters' option
IPO
Issuance of common stock (in shares)			2,741,489
Underwriters' option
IPO
Issuance of common stock (in shares)			411,223
Registration of Form S-3 offering/Shelf Registration Statement
IPO
Issuance of common stock (in shares)		0
Maximum value of shares authorized to be sold in stock offering. | $		$ 300
Equity Distribution Agreement
IPO
Issuance of common stock (in shares)							0
Maximum value of shares authorized to be sold in stock offering. | $	$ 100

ORGANIZATION AND SUMMARY OF S_4

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - D&O Insurance (Details) - Notes For Financing Directors and Officers Insurance Premium $ in Millions	Jun. 30, 2020USD ($)
Short-term debt
Aggregate principal amount	$ 3.2
Interest rate (as a percent)	3.20%
Note payable	$ 3.2

ORGANIZATION AND SUMMARY OF S_5

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Recently Adopted Accounting Pronouncements (Details)	Jan. 01, 2020
ASU 2016-13, Financial Instruments
Recently Adopted Accounting Pronouncements
Change in Accounting Principle, Accounting Standards Update, Adopted	true
ASU 2018-13, Fair Value Measurement
Recently Adopted Accounting Pronouncements
Change in Accounting Principle, Accounting Standards Update, Adopted	true

LICENSE AGREEMENT (Details)

LICENSE AGREEMENT (Details) $ in Thousands	Oct. 03, 2019USD ($)	Mar. 31, 2019USD ($)Part	Jan. 31, 2019USD ($)	Oct. 31, 2016USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Agreements
Research and development					$ 20,758	$ 4,254	$ 28,028	$ 11,128
General and administrative					7,522	4,183	12,725	6,037
Operating expenses					28,280	8,437	40,753	17,165
Accrued expenses and other current liabilities					12,855		12,855		$ 12,855	$ 4,950
Accounts payable					5,649		5,649		5,649	8,793
Columbia University
Agreements
Research and development					30	24	300	25
General and administrative					54	$ 100	94	$ 300
Operating expenses									2,300
Accrued expenses and other current liabilities					97		97		97	100
Accounts payable					$ 0		$ 0		$ 0	$ 100
2016 license agreement | Columbia University
Agreements
Percentage of outstanding common stock issued				5.00%
Fair value of stock issued				$ 500
Written notice period for termination of agreement				90 days
Written notice period for termination of agreement, uncured material breach				30 days
Extended written notice period for termination of agreement, attempt to cure material breach				90 days
2016 license agreement | Columbia University | Minimum
Agreements
Percentage of sublicensing revenue, if sublicenses rights granted				10.00%
2016 license agreement | Columbia University | Maximum
Agreements
Payment on achievement of specified development and regulatory milestones				$ 1,300
Payment on achievement of specified level of aggregate annual net sales				$ 1,000
Percentage of sublicensing revenue, if sublicenses rights granted				20.00%
2019 license agreement | Columbia University
Agreements
Written notice period for termination of agreement			90 days
Written notice period for termination of agreement, uncured material breach			30 days
Extended written notice period for termination of agreement, attempt to cure material breach			90 days
2019 license agreement | Columbia University | Minimum
Agreements
Percentage of sublicensing revenue, if sublicenses rights granted			10.00%
2019 license agreement | Columbia University | Maximum
Agreements
Payment on achievement of specified development and regulatory milestones			$ 1,300
Payment on achievement of specified level of aggregate annual net sales			$ 1,000
Percentage of sublicensing revenue, if sublicenses rights granted			50.00%
2019 research agreement | Columbia University
Agreements
Agreement term		12 months
Written notice period for termination of agreement		30 days
Number of parts | Part		2
2019 research agreement - Part I | Columbia University
Agreements
Agreement term		6 months
Payment to be made		$ 100
2019 research agreement - Part II | Columbia University
Agreements
Agreement term		6 months
Payment to be made		$ 200
P13k Research agreement | Columbia University
Agreements
Agreement term	18 months
Written notice period for termination of agreement	30 days
Payment to be made	$ 400

FAIR VALUE MEASUREMENTS - FV hi

FAIR VALUE MEASUREMENTS - FV hierarchy (Details) - Fair Value, Recurring $ in Thousands	Jun. 30, 2020USD ($)
Financial assets or liabilities measured at fair value on a recurring basis
Cash and cash equivalents	$ 100,854
Marketable securities	37,644
Total financial assets measured at fair value on a recurring basis	138,498
Level 1
Financial assets or liabilities measured at fair value on a recurring basis
Cash and cash equivalents	100,854
Total financial assets measured at fair value on a recurring basis	100,854
Level 2
Financial assets or liabilities measured at fair value on a recurring basis
Marketable securities	37,644
Total financial assets measured at fair value on a recurring basis	37,644
Cash
Financial assets or liabilities measured at fair value on a recurring basis
Cash and cash equivalents	48,138
Cash | Level 1
Financial assets or liabilities measured at fair value on a recurring basis
Cash and cash equivalents	48,138
Money market funds
Financial assets or liabilities measured at fair value on a recurring basis
Cash and cash equivalents	52,716
Money market funds | Level 1
Financial assets or liabilities measured at fair value on a recurring basis
Cash and cash equivalents	52,716
Commercial paper and corporate bonds
Financial assets or liabilities measured at fair value on a recurring basis
Marketable securities	1,651
Commercial paper and corporate bonds | Level 2
Financial assets or liabilities measured at fair value on a recurring basis
Marketable securities	1,651
U.S. government agency debt securities
Financial assets or liabilities measured at fair value on a recurring basis
Marketable securities	35,993
U.S. government agency debt securities | Level 2
Financial assets or liabilities measured at fair value on a recurring basis
Marketable securities	$ 35,993

FAIR VALUE MEASUREMENTS - Trans

FAIR VALUE MEASUREMENTS - Transfers (Details) $ in Thousands	Jun. 30, 2020USD ($)
FAIR VALUE MEASUREMENTS
Assets, transfer from level 1 to level 2	$ 0
Assets, transfer from level 2 to level 1	$ 0

INVESTMENTS - By type (Details)

INVESTMENTS - By type (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Marketable securities by type
Cost	$ 37,673	$ 20,006
Gross Unrealized Gains	18	19
Gross Unrealized Losses	(47)	(21)
Estimated Fair Value	37,644	20,004
Commercial paper and corporate bonds
Marketable securities by type
Cost	1,653	7,540
Gross Unrealized Gains	1
Gross Unrealized Losses	(3)	(20)
Estimated Fair Value	1,651	7,520
U.S. government agency debt securities
Marketable securities by type
Cost	36,020	12,466
Gross Unrealized Gains	17	19
Gross Unrealized Losses	(44)	(1)
Estimated Fair Value	$ 35,993	$ 12,484

INVESTMENTS - Additional Inform

INVESTMENTS - Additional Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
INVESTMENTS
Net unrealized loss	$ (29)
Gross Unrealized Losses	$ 47	$ 21
Unrealized loss as a percentage of total amortized costs basis of corporate bond portfolio	0.12%

INVESTMENTS - By contractual ma

INVESTMENTS - By contractual maturity (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
INVESTMENTS
Due in one year or less - Cost	$ 36,156	$ 20,006
Due in one year or less - Gross Unrealized Gains	17	19
Due in one year or less - Gross Unrealized Losses	(45)	(21)
Due in one year or less - Estimated Fair Value	36,128	20,004
Due in one through two years - Cost	1,517
Due in one through two years - Gross Unrealized Gains	1
Due in one through two years - Gross Unrealized Losses	(2)
Due in one through two years - Estimated Fair Value	1,516
Cost	37,673	20,006
Gross Unrealized Gains	18	19
Gross Unrealized Losses	(47)	(21)
Estimated Fair Value	37,644	$ 20,004
Net unrealized gains	(29)
Marketable securities realized gain (loss) recorded
Net realized gain from sale of marketable securities	$ 38

INVESTMENTS - Unrealized losses

INVESTMENTS - Unrealized losses and fair values of available-for-sale securities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Securities in an unrealized loss position less than 12 months
Unrealized Losses Less Than 12 months	$ (45)	$ (21)
Estimated Fair Value Less Than 12 Months	16,052	11,017
Unrealized Losses Greater Than 12 months	(2)
Estimated Fair Value Greater Than 12 Months	1,515
Total Unrealized Losses	(47)	(21)
Total Estimated Fair Value	17,567	11,017
Commercial paper and corporate bonds
Securities in an unrealized loss position less than 12 months
Unrealized Losses Less Than 12 months	(3)	(20)
Estimated Fair Value Less Than 12 Months	902	7,520
Total Unrealized Losses	(3)	(20)
Total Estimated Fair Value	902	7,520
U.S. government agency debt securities
Securities in an unrealized loss position less than 12 months
Unrealized Losses Less Than 12 months	(42)	(1)
Estimated Fair Value Less Than 12 Months	15,150	3,497
Unrealized Losses Greater Than 12 months	(2)
Estimated Fair Value Greater Than 12 Months	1,515
Total Unrealized Losses	(44)	(1)
Total Estimated Fair Value	$ 16,665	$ 3,497

PREPAID EXPENSES AND OTHER CU_3

PREPAID EXPENSES AND OTHER CURRENT ASSETS (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
PREPAID EXPENSES AND OTHER CURRENT ASSETS
Prepaid research and development expenses	$ 5,867	$ 5,872
Insurance premium asset	3,487
Prepaid rent expenses	98	142
Prepaid insurance expenses	101	1,196
Interest Receivable	33	10
Other prepaid expenses and current assets	440	81
Total prepaid expenses & other current assets	$ 10,026	$ 7,301

ACCRUED EXPENSES AND OTHER CU_3

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Short-term debt
Accrued pre-clinical and clinical expenses	$ 6,743	$ 4,287
Short-term insurance financing note	3,222
Accrued professional fees	763	345
Accrued compensation and benefits	693
Accrued commercial expenses	154
Accrued patent expenses	497	54
Other	783	264
Total accrued expenses & other current liabilities	12,855	$ 4,950
Notes For Financing Directors and Officers Insurance Premium
Short-term debt
Debt Instrument, Face Amount	$ 3,200
Debt Instrument, Interest Rate, Stated Percentage	3.20%
Notes Payable	$ 3,200

STOCK BASED COMPENSATION - Plan

STOCK BASED COMPENSATION - Plans (Details) - shares	1 Months Ended
	May 31, 2019	Jun. 30, 2020	Dec. 31, 2019
Stock-based compensation
Options outstanding (in shares)		4,068,428	4,079,888
Equity Incentive Plan 2016 and 2019
Stock-based compensation
Shares reserved (in shares)		2,675,770
2019 Plan
Stock-based compensation
New shares reserved (in shares)	1,618,841
Reserved shares available from 2016 Plan (in shares)	2,911,159
Increase in number of shares reserved and available for issuance (as a percent)	5.00%
Expiration period	10 years
Vesting period	4 years
Number of shares available for future issuance		801,395
2019 Plan | Maximum
Stock-based compensation
Shares reserved (in shares)	4,530,000
2019 Plan | Options
Stock-based compensation
Maximum number of shares authorized for issuance	13,000,000

STOCK BASED COMPENSATION - Stoc

STOCK BASED COMPENSATION - Stock-based compensation expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Stock-based compensation
Total stock-based compensation expense	$ 1,573	$ 3,278	$ 2,882	$ 3,604
Research and development
Stock-based compensation
Total stock-based compensation expense	621	1,445	1,259	1,592
General and administrative
Stock-based compensation
Total stock-based compensation expense	$ 952	$ 1,833	$ 1,623	$ 2,012

STOCK BASED COMPENSATION - Opti

STOCK BASED COMPENSATION - Options (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
STOCK BASED COMPENSATION
Options granted (in shares)			481,488
Stock-based compensation expense	$ 1,573	$ 3,278	$ 2,882	$ 3,604
Options outstanding (in shares)	4,068,428		4,068,428		4,079,888
Weighted-average fair value of options granted (in dollars per share)			$ 24.74	$ 4.79
Unrecognized stock-based compensation balance for unvested options	$ 21,500		$ 21,500
Unrecognized stock-based compensation balance for unvested options expected to be recognized (in years)			1 year 7 months 6 days

STOCK BASED COMPENSATION - Op_2

STOCK BASED COMPENSATION - Options outstanding (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares
Options Outstanding
Outstanding at beginning of period (in shares) | shares	4,079,888
Options granted (in shares) | shares	481,488
Options exercised (in shares) | shares	(359,641)
Forfeited (in shares) | shares	(133,307)
Outstanding at end of period (in shares) | shares	4,068,428	4,079,888
Exercisable at end of period (in shares) | shares	2,111,382
Nonvested at end of period (in shares) | shares	1,957,046
Weighted-Average Exercise Price
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 5.11
Options granted (in dollars per share) | $ / shares	40.56
Options exercised (in dollars per share) | $ / shares	3.96
Options forfeited (in dollars per share) | $ / shares	12.37
Outstanding at end of period (in dollars per share) | $ / shares	10.88	$ 5.11
Exercisable at end of period (in dollars per share) | $ / shares	4.18
Nonvested at end of period (in dollars per share) | $ / shares	$ 18.10
Weighted-Average Remaining Contractual Term-in years
Outstanding	8 years 8 months 23 days	8 years 3 months 4 days
Exercisable	8 years 4 months 2 days
Nonvested	9 years 1 month 28 days
Aggregate Intrinsic Value
Options exercised (in dollars) | $	$ 15,128
Outstanding (in dollars) | $	105,282	$ 82,327
Exercisable (in dollars) | $	67,491
Nonvested (in dollars) | $	$ 37,792

STOCK BASED COMPENSATION - Valu

STOCK BASED COMPENSATION - Valuation assumptions (Details) - $ / shares	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Stock options - Service conditions only
Valuation Assumptions
Expected term/Time to expiration (in years)	6 years	6 years
Volatility	69.30%	68.52%
Risk-free interest rate	0.54%	2.26%
Dividend yield (as a percent)	0.00%	0.00%
Stock options - Service, performance and market conditions
Valuation Assumptions
Expected term/Time to expiration (in years)	10 years
Volatility	68.54%
Risk-free interest rate	2.64%
Dividend yield (as a percent)	0.00%
Cost of equity	24.00%
Fair value of underlying common stock (as of valuation date)	$ 5.85

STOCK BASED COMPENSATION - Op_3

STOCK BASED COMPENSATION - Options that Contain Service, Performance and Market Conditions - Grants (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Stock-based compensation
Options granted (in shares)		481,488
Stock options - Service, performance and market conditions
Stock-based compensation
Options granted (in shares)	159,501		159,501
Fair value at grant date	$ 0.5		$ 0.5
Stock options - Service, performance and market conditions | Minimum
Stock-based compensation
Derived service period	P1D		P1D
Stock options - Service, performance and market conditions | Maximum
Stock-based compensation
Derived service period	P3Y		P3Y

STOCK BASED COMPENSATION - Op_4

STOCK BASED COMPENSATION - Options that Contain, Service, Performance and Market Conditions - Expense (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	May 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Stock-based compensation
Stock-based compensation expense		$ 1,573	$ 3,278	$ 2,882	$ 3,604
Options outstanding (in shares)		4,068,428		4,068,428		4,079,888
Stock options - Service, performance and market conditions
Stock-based compensation
Options vested (in shares)					79,778
Stock-based compensation expense			700		$ 800
Options outstanding (in shares)		0		0
Former Interim Chief Financial Officer | Stock options - Service, performance and market conditions
Stock-based compensation
Options vested (in shares)	79,723
General and administrative
Stock-based compensation
Stock-based compensation expense		$ 952	1,833	$ 1,623	2,012
General and administrative | Former Interim Chief Financial Officer | Stock options - Service, performance and market conditions
Stock-based compensation
Stock-based compensation expense			$ 600		$ 600

STOCK BASED COMPENSATION - RSUs

STOCK BASED COMPENSATION - RSUs (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 04, 2020	Mar. 09, 2020	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Stock-based compensation
Stock-based compensation expense			$ 1,573	$ 3,278	$ 2,882	$ 3,604
Unrecognized stock-based compensation balance for unvested options expected to be recognized (in years)					1 year 7 months 6 days
Restricted Stock Units (RSUs)
Stock-based compensation
Awards granted (in shares)	108,662	36,464
Vesting period	4 years	4 years
Fair value of awards (in dollars)	$ 4,800	$ 1,300
Fair value of awards (in dollars per share)	$ 44.02	$ 34.28
Stock-based compensation expense			200		$ 200
Unrecognized stock-based compensation balance for unvested awards			$ 5,900		$ 5,900
Unrecognized stock-based compensation balance for unvested options expected to be recognized (in years)					3 years 8 months 12 days
Restricted Stock Units (RSUs) | Tranche one
Stock-based compensation
Vesting percentage	25.00%	25.00%
Vesting period	1 year	1 year
Restricted Stock Units (RSUs) | Tranche two
Stock-based compensation
Vesting percentage	25.00%	25.00%
Vesting period	1 year	1 year
Restricted Stock Units (RSUs) | Tranche three
Stock-based compensation
Vesting percentage	25.00%	25.00%
Vesting period	1 year	1 year
Restricted Stock Units (RSUs) | Tranche four
Stock-based compensation
Vesting percentage	25.00%	25.00%
Vesting period	1 year	1 year

STOCK BASED COMPENSATION - 2019

STOCK BASED COMPENSATION - 2019 Employee Stock Purchase Plan (Details) - 2019 ESPP - shares	1 Months Ended	6 Months Ended
	May 31, 2019	Jun. 30, 2020
Stock-based compensation
Shares issued under ESPP		0
Maximum
Stock-based compensation
Shares authorized (in shares)	180,000
Increase in number of shares reserved and available for issuance (as a percent)	1.00%
Increase in number of shares reserved and available for issuance (in shares)	360,000

STOCKHOLDERS' EQUITY - Authoriz

STOCKHOLDERS' EQUITY - Authorized stock (Details) - $ / shares	Jun. 30, 2020	Dec. 31, 2019
STOCKHOLDERS’ EQUITY
Common Stock, authorized (in shares)	100,000,000	100,000,000
Common Stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred Stock, authorized (in shares)	10,000,000	10,000,000
Preferred Stock, par value (in dollars per share)	$ 0.0001	$ 0.0001

STOCKHOLDERS' EQUITY - Common S

STOCKHOLDERS' EQUITY - Common Stock (Details) $ in Millions	1 Months Ended	6 Months Ended
	Jun. 30, 2020USD ($)	Jun. 30, 2020USD ($)Vote
STOCKHOLDERS' EQUITY
Number of votes per common stock | Vote		1
Equity Distribution Agreement
STOCKHOLDERS' EQUITY
Offering price	$ 100
Maximum amount paid to Goldman (as a percent)	3.00%
Proceeds from stock issuance		$ 0

STOCKHOLDERS' EQUITY - Preferre

STOCKHOLDERS' EQUITY - Preferred stock issued (Details) - USD ($) $ / shares in Units, $ in Millions	May 16, 2019	Feb. 28, 2019	Mar. 31, 2019	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Preferred Stock
Convertible preferred stock, outstanding (in shares)	0			0	0
IPO
Preferred Stock
Issue price (in dollars per share)	$ 10
Conversion of convertible preferred stock into common stock upon closing of the IPO (in shares)	7,538,671
Number of shares issued for each share of convertible preferred stock converted	1
Series B Convertible Preferred Stock
Preferred Stock
Issuance of convertible preferred stock (in shares)		442,930	442,925
Issue price (in dollars per share)		$ 7.49
Gross proceeds from issuance of convertible preferred stock		$ 3.3
Issuance costs		$ 0.3
Convertible preferred stock, outstanding (in shares)			4,444,773			4,001,848

WARRANTS - Issued with Series A

WARRANTS - Issued with Series A Preferred Stock (Details) - 2017 Warrants - Warrants Issued with Series A Preferred Stock $ / shares in Units, $ in Millions	Jan. 26, 2017USD ($)$ / sharesshares	Jun. 30, 2020Y
Warrants
Warrants to purchase common stock (in shares) | shares	309,389
Warrants to purchase common stock (in dollars) | $	$ 0.2
Exercise price (in dollars per share) | $ / shares	$ 2.49
Contractual term (in years)
Warrants
Measurement input | Y		10
Volatility
Warrants
Measurement input		0.7448
Risk-free interest rate
Warrants
Measurement input		0.0320
Dividend yield
Warrants
Measurement input		0

WARRANTS - 2017 Warrants (Detai

WARRANTS - 2017 Warrants (Details)	Feb. 24, 2020shares	Feb. 21, 2020itemshares	Jun. 30, 2020shares
Warrants
Warrants exercised (in shares)			308,891
2017 Warrants | Warrants Issued with Series A Preferred Stock
Warrants
Number of warrant holders that exercised options | item		2
Warrants exercised (in shares)	72,818	185,634
Stock issued in exercise of warrants (in shares)	69,094	176,092

WARRANTS - Issued with the 2018

WARRANTS - Issued with the 2018 Notes (Details) - USD ($) $ / shares in Units, $ in Millions	Jun. 24, 2020	Feb. 24, 2020	Nov. 05, 2018	Jun. 30, 2020	Jan. 18, 2018
Warrants
Warrants exercised (in shares)				308,891
Warrants Issued with the 2018 Notes
Warrants
Initial fair value recorded as debt discount (in dollars)					$ 0.1
Warrants to purchase common stock (in shares)			76,847
Warrants to purchase common stock (in dollars)			$ 0.3
Exercise price (in dollars per share)			$ 6.59
Warrants exercised (in shares)	20,331	386
Stock issued in exercise of warrants (in shares)	17,369	333

WARRANTS - Issued with Series B

WARRANTS - Issued with Series B Preferred Stock (Details) $ / shares in Units, $ in Millions	Jun. 24, 2020shares	Feb. 24, 2020shares	Jan. 14, 2020shares	Feb. 28, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Jun. 30, 2020YRateshares
Warrants
Warrants exercised (in shares) | shares						308,891
Warrants Issued with Series B Preferred Stock
Warrants
Warrants exercised (in shares) | shares	24,309	5,193	220
Stock issued in exercise of warrants (in shares) | shares	19,882	4,313	146
2018 Warrants | Warrants Issued with Series B Preferred Stock
Warrants
Warrants to purchase common stock (in shares) | shares					72,261
Warrants to purchase common stock (in dollars) | $					$ 0.2
Exercise price (in dollars per share) | $ / shares					$ 8.24
Expiration term					10 years
2018 Warrants | Warrants Issued with Series B Preferred Stock | Contractual term (in years)
Warrants
Measurement input | Y						10
2018 Warrants | Warrants Issued with Series B Preferred Stock | Volatility
Warrants
Measurement input						0.7322
2018 Warrants | Warrants Issued with Series B Preferred Stock | Risk-free interest rate
Warrants
Measurement input | Rate						0.0270
2018 Warrants | Warrants Issued with Series B Preferred Stock | Dividend yield
Warrants
Measurement input | Rate						0
2019 Warrants | Warrants Issued with Series B Preferred Stock
Warrants
Warrants to purchase common stock (in shares) | shares				23,867
Warrants to purchase common stock (in dollars) | $				$ 0.1
Exercise price (in dollars per share) | $ / shares				$ 8.24
Expiration term				10 years
2019 Warrants | Warrants Issued with Series B Preferred Stock | Contractual term (in years)
Warrants
Measurement input | Y						10
2019 Warrants | Warrants Issued with Series B Preferred Stock | Volatility
Warrants
Measurement input | Rate						0.7322
2019 Warrants | Warrants Issued with Series B Preferred Stock | Risk-free interest rate
Warrants
Measurement input | Rate						0.0270
2019 Warrants | Warrants Issued with Series B Preferred Stock | Dividend yield
Warrants
Measurement input | Rate						0

WARRANTS - Warrant Activity (De

WARRANTS - Warrant Activity (Details)	6 Months Ended
	Jun. 30, 2020shares
WARRANTS
Outstanding as of beginning of period	462,364
Warrants exercised	(308,891)
Outstanding as of end of period	153,473

LEASES - ROU Assets and Liabili

LEASES - ROU Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
ROU Assets and Liabilities
ROU - Asset	$ 1,849	$ 2,035
Lease liabilities (current)	372	356
Lease liabilities (non-current)	$ 1,492	$ 1,683

LEASES - Lease Cost (Details)

LEASES - Lease Cost (Details) $ in Thousands	3 Months Ended
	Jun. 30, 2020USD ($)
Leases
Operating Lease Cost	$ 121
General and administrative
Leases
Operating Lease Cost	$ 121

LEASES - Lease terms and discou

LEASES - Lease terms and discount rates (Details)	Jun. 30, 2020
LEASES
Weighted-average remaining lease term - operating leases	4 years 4 months 2 days
Weighted-average discount rate — operating leases	5.69%

LEASES - Maturities of Lease Li

LEASES - Maturities of Lease Liabilities (Details) $ in Thousands	Jun. 30, 2020USD ($)
LEASES
2020	$ 232
2021	474
2022	486
2023	497
2024	423
Total lease payments	2,112
Less: interest	248
Total lease liabilities	$ 1,864

BENEFIT PLANS (Details)

BENEFIT PLANS (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
BENEFIT PLANS
Employer matching contributions to the plan	$ 43	$ 35

NET LOSS PER COMMON SHARE - EPS

NET LOSS PER COMMON SHARE - EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net loss attributable to common stockholders—basic	$ (28,059)	$ (8,437)	$ (40,428)	$ (17,166)
Net loss attributable to common stockholders— diluted	$ (28,059)	$ (8,437)	$ (40,428)	$ (17,166)
Denominator:
Weighted-average common stock outstanding	22,062,030	13,945,939	21,451,344	9,776,582
Net loss per share attributable to common stockholders—basic and diluted	$ (1.27)	$ (0.60)	$ (1.88)	$ (1.76)

NET LOSS PER COMMON SHARE - Ant

NET LOSS PER COMMON SHARE - Anti-dilutive securities (Details) - shares	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Options
Antidilutive securities excluded from computation of loss per share
Potential dilutive securities excluded from the computation of diluted net loss per share attributable to common stockholders	4,068,428	3,855,083
Restricted Stock Units (RSUs)
Antidilutive securities excluded from computation of loss per share
Potential dilutive securities excluded from the computation of diluted net loss per share attributable to common stockholders	145,126
Warrants Liability
Antidilutive securities excluded from computation of loss per share
Potential dilutive securities excluded from the computation of diluted net loss per share attributable to common stockholders	153,473	482,364

RELATED PARTIES (Details)

RELATED PARTIES (Details) - LaunchLabs Agreement - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Related Party Transaction [Line Items]
Payments to related party	$ 12	$ 28	$ 36	$ 50
Due to related parties	$ 0		$ 0