Axcella Health (AXLA) 10-Q 5 May 22 2022 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2022	Apr. 29, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Document Transition Report	false
Entity File Number	001-38501
Entity Registrant Name	AXCELLA HEALTH INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-3321056
Entity Address, Address Line One	840 Memorial Drive
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02139
City Area Code	857
Local Phone Number	320-2200
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	AXLA
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		52,575,840
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Central Index Key	0001633070
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 45,190	$ 23,574
Marketable securities	18,029	31,474
Prepaid expenses and other current assets	963	1,598
Total current assets	64,182	56,646
Property and equipment, net	970	870
Operating lease right-of-use asset	3,017	0
Other assets	211	211
Total assets	68,380	57,727
Current liabilities:
Accounts payable	4,839	4,301
Accrued expenses and other current liabilities	4,920	5,849
Current portion of long-term debt	1,733	0
Operating lease liability	1,452	0
Total current liabilities	12,944	10,150
Long-term debt, net of current portion and discount	23,385	25,070
Operating lease liability, net of current portion	1,784	0
Other liabilities	375	499
Total liabilities	38,488	35,719
Commitments and contingencies (Note 10)	0	0
Stockholders' equity:
Common stock, $0.001 par value; 150,000,000 shares authorized, 52,994,821 and 39,605,701 shares issued and 52,575,840 and 39,186,720 shares outstanding at March 31, 2022 and December 31, 2021, respectively	53	40
Additional paid-in capital	386,189	359,261
Treasury stock, 418,981 shares at cost	0	0
Accumulated other comprehensive loss	(70)	(52)
Accumulated deficit	(356,280)	(337,241)
Total stockholders' equity	29,892	22,008
Total liabilities and stockholders' equity	$ 68,380	$ 57,727

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Common stock, par value (USD per share)	$ 0.001	$ 0.001
Common stock authorized (in shares)	150,000,000	150,000,000
Common stock issued (in shares)	52,994,821	39,605,701
Common stock outstanding (in shares)	52,575,840	39,186,720
Treasury stock at cost (in shares)	418,981	418,981

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating expenses:
Research and development	$ 13,544	$ 10,240
General and administrative	4,786	4,256
Total operating expenses	18,330	14,496
Loss from operations	(18,330)	(14,496)
Other income (expense):
Interest income	22	35
Interest expense	(704)	(728)
Other income (expense), net	(27)	0
Total other income (expense), net	(709)	(693)
Net loss	$ (19,039)	$ (15,189)
Net loss per share, basic (USD per share)	$ (0.46)	$ (0.40)
Net loss per share, diluted (USD per share)	$ (0.46)	$ (0.40)
Weighted average common shares outstanding, basic (in shares)	41,426,107	37,652,158
Weighted average common shares outstanding, diluted (in shares)	41,426,107	37,652,158
Comprehensive loss:
Net loss	$ (19,039)	$ (15,189)
Other comprehensive income (loss):
Unrealized (losses) gains on marketable securities	(18)	7
Comprehensive loss	$ (19,057)	$ (15,182)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net loss	$ (19,039)	$ (15,189)
Adjustment to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	77	64
Stock-based compensation	1,509	1,428
Non-cash interest expense	130	162
Non-cash lease expense	(9)	0
Other non-cash items	103	179
Changes in current assets and liabilities:
Prepaid expenses and other current assets	635	715
Accounts payable	596	(711)
Accrued expenses and other current liabilities	(864)	(793)
Net cash used in operating activities	(16,862)	(14,145)
Cash flows from investing activities:
Purchases of property and equipment	(164)	(50)
Purchases of marketable securities	0	(16,717)
Proceeds from sales and maturities of marketable securities	13,324	2,375
Net cash provided by (used in) investing activities	13,160	(14,392)
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance costs	25,426	0
Offering costs paid	(71)	(31)
Proceeds from exercise of common stock options and ESPP	6	27
Repayments of the principal portion of finance lease	(43)	0
Net cash provided by (used in) financing activities	25,318	(4)
Net increase (decrease) in cash and cash equivalents	21,616	(28,541)
Cash and cash equivalents, beginning of period	23,574	71,590
Cash and cash equivalents, end of period	45,190	43,049
Supplemental cash flow information:
Cash paid for interest	573	566
Supplemental disclosure of non-cash activities:
Obtaining a right-of-use asset in exchange for an operating lease liability	3,340	0
Purchases of property and equipment included in accounts payable	15	0
Offering costs incurred but unpaid at period end	$ 30	$ 0

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated other comprehensive income (loss)	Accumulated deficit
Balance at beginning of period (in shares) at Dec. 31, 2020		38,022,273
Balance at beginning of period at Dec. 31, 2020	$ 75,381	$ 38	$ 347,990	$ (34)	$ (272,613)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Costs incurred for the issuance of common stock	4		4
Exercise of common stock options (in shares)		27,143
Exercise of common stock options	27		27
Vesting of restricted stock units (in shares)		60,000
Stock-based compensation	1,428		1,428
Unrealized gain on marketable securities	7			7
Net loss	(15,189)				(15,189)
Balance at end of period (in shares) at Mar. 31, 2021		38,109,416
Balance at end of period at Mar. 31, 2021	61,658	$ 38	349,449	(27)	(287,802)
Balance at beginning of period (in shares) at Dec. 31, 2021		39,605,701
Balance at beginning of period at Dec. 31, 2021	22,008	$ 40	359,261	(52)	(337,241)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of issuance costs (in shares)		13,321,602
Issuance of common stock, net of issuance costs	$ 25,426	$ 13	25,413
Exercise of common stock options (in shares)	8,499	8,499
Exercise of common stock options	$ 6		6
Vesting of restricted stock units (in shares)		59,019
Stock-based compensation	1,509		1,509
Unrealized gain on marketable securities	(18)			(18)
Net loss	(19,039)				(19,039)
Balance at end of period (in shares) at Mar. 31, 2022		52,994,821
Balance at end of period at Mar. 31, 2022	$ 29,892	$ 53	$ 386,189	$ (70)	$ (356,280)

NATURE OF BUSINESS

NATURE OF BUSINESS	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
NATURE OF BUSINESS	NATURE OF BUSINESS Company Overview Axcella Health Inc., doing business as “Axcella Therapeutics,” and subsidiaries ("Axcella," the "Company," "we" or "us") is a clinical-stage biotechnology company that was incorporated in Delaware on August 27, 2008 and has a principal place of business in Cambridge, Massachusetts. The Company is focused on pioneering a new approach to treat complex diseases using compositions of endogenous metabolic modulators, or EMMs. The Company's product candidates are comprised of multiple EMMs that are engineered in distinct combinations and ratios with the goal of simultaneously impacting multiple biological pathways. The Company's pipeline includes lead therapeutic candidates for the treatment of non-alcoholic steatohepatitis, or NASH, for the treatment of Long COVID (also known as Post COVID-19 Condition and Post-Acute Sequelae of COVID-19, or “PASC”) associated fatigue, and for the reduction in risk of recurrent overt hepatic encephalopathy, or OHE. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, successful development of technology, obtaining additional funding, protection of proprietary technology, compliance with government regulations, risks of failure of preclinical studies, Clinical Studies and Clinical Trials, the need to obtain marketing approval for its product candidates, if required, and successfully market products, fluctuations in operating results, economic pressure impacting therapeutic pricing, dependence on key personnel, risks associated with changes in technologies, development by competitors of technological innovations and the ability to scale manufacturing to large scale production. Product candidates currently under development will require significant additional research and development efforts, including preclinical and clinical testing and any necessary regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. Going Concern The accompanying condensed consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. Consequently, management has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within 12 months after the date the annual financial statements herein are issued. Historically, the Company has funded its operations with proceeds from sales of preferred and common stock and borrowings under a loan and security agreement. The Company may never commercialize a product and achieve profitability, and unless and until it does, the Company will need to raise additional capital. The Company has had recurring losses since inception and incurred a loss of $19.0 million during the three months ended March 31, 2022 and an accumulated deficit of $356.3 million. Net cash used in operations for the three months ended March 31, 2022 was $16.9 million. The Company has spent, and expects to continue to spend, significant funds to continue development of its current and potential future pipeline candidates and continue to generate operating losses for the foreseeable future. As of March 31, 2022, the Company had cash, cash equivalents and marketable securities of $63.2 million and is required to comply with an unrestricted minimum cash level in accordance with its Loan and Security Agreement with SLR Investment Corp. until certain clinical trial data conditions are met, and there is a risk that the Company may be unable to remain in compliance with those financial covenants in the future in which case the debt may become immediately due and payable. Accordingly, the foregoing conditions, taken together, raise substantial doubt about the Company’s ability to continue as a going concern for one year from the issuance of these condensed consolidated financial statements. These condensed consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty. In response to these conditions, on March 16, 2022, the Company secured approximately $24.8 million in net proceeds through a registered direct offering of common stock. The Company will also be seeking additional financing options to raise additional capital going forward. However, there is no assurance the Company will be successful in obtaining such additional financing on terms acceptable to it, if at all, and it may not be able to enter into other arrangements to obtain additional financing, and therefore cannot be deemed probable. As a result the Company has concluded that these plans do not alleviate substantial doubt about the Company’s ability to continue as a going concern.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). Furthermore, the accompanying condensed consolidated financial statements are unaudited and certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. During the three months ended March 31, 2022, we adopted ASU No. 2016-02, Leases (Topic 842) and the related accounting policies. Other than the adoption of Topic 842 , there were no material changes to the Company's significant accounting policies and estimates as reported in it's Annual Report on Form 10-K for the year ended December 31, 2021, which was filed with the SEC on March 30, 2022. The unaudited interim financial statements have been prepared on the same basis as the audited annual financial statements as of and for the year ended December 31, 2021. The accompanying interim condensed consolidated financial statements reflect all adjustments, consisting of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of March 31, 2022, the results of its operations for the three months ended March 31, 2022 and 2021, its cash flows for the three months ended March 31, 2022 and 2021, and its statements of stockholders’ equity for the three months ended March 31, 2022 and 2021. The results for the three months ended March 31, 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022, any other interim periods, or any future year or period. These interim financial statements should be read in conjunction with the audited financial statements as of and for the year ended December 31, 2021, and the notes thereto, together with Management’s Discussion and Analysis of Financial Condition and Results of Operations, contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021. Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of Axcella Health Inc. and its wholly owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. Segment Information Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the CEO, who is the chief operating decision maker, in making decisions on how to allocate resources and assess performance. The Company operates in one reportable business segment. Use of Estimates The preparation of the condensed consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, expenses and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the Company’s ability to continue as a going concern. The Company bases its estimates on historical experience, known trends and other market-specific or relevant factors that it believes to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates as there are changes in circumstances, facts and experience. Actual results may differ from those estimates or assumptions. Cash and Cash Equivalents Cash and cash equivalents include cash held in banks and amounts held in interest-bearing money market accounts. Cash equivalents are carried at cost, which approximates their fair market value. The Company considers all highly liquid investments with a remaining maturity when purchased of three months or less to also be cash equivalents. Marketable Securities The Company’s marketable securities, which consisted of corporate debt obligations as of March 31, 2022, are classified as available-for-sale and are reported at fair value. Unrealized gains and losses on available-for-sale securities are reported as a component of accumulated other comprehensive income (loss) in stockholders’ equity. Realized gains and losses and declines in value determined to be other than temporary are based on the specific identification method and are included as a component of other income (expense), net in the condensed consolidated statements of operations and comprehensive loss. The Company evaluates its marketable securities with unrealized losses for other-than-temporary impairment. When assessing marketable securities for other-than-temporary declines in value, the Company considers such factors as, among other things, how significant the decline in value is as a percentage of the original cost, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions in general. If any adjustment to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the condensed consolidated statements of operations and comprehensive loss. No such adjustments were necessary during the periods presented. Concentrations of Credit Risk The Company has no off-balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company’s cash equivalents and marketable securities as of March 31, 2022 consisted of bank deposits, money market funds that invest in U.S. treasury securities, and corporate obligations. The Company invests in high-quality financial instruments and it's portfolio does not consist of any instrument with a maturity duration in excess of twenty-four months, which the Company believes limits it's credit risk. In addition, the Company's investment policy includes guidelines on the quality of the institutions and financial instruments and defines the allowable investments that the Company believes minimizes the exposure to concentrations of credit risk. The Company has not experienced any credit losses and does not believe that it is subject to significant credit risk. Fair Value Measurements Certain assets and liabilities of the Company are carried at fair value. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1 — Quoted prices in active markets for identical assets or liabilities. • Level 2 — Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3 — Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The Company’s cash equivalents and marketable securities are carried at fair value, determined according to the fair value hierarchy described above. The carrying values of the Company’s accounts payable and accrued expenses approximate their fair values due to the short-term nature of these liabilities. The carrying value of the long-term debt approximates fair value as evidenced by the recent amendment to the Company's debt facility. Comprehensive loss Comprehensive loss includes net loss as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders. For the three months ended March 31, 2022, the Company’s only element of other comprehensive loss was unrealized gains (losses) on marketable securities. Net Loss Per Share Basic net loss per share attributable to common stockholders is calculated by dividing net loss by the weighted average shares outstanding during the period. Diluted net income (loss) per share is calculated by adjusting weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period. All common stock equivalents have been excluded from the calculation of diluted net loss per share, as their effect would be anti-dilutive for all periods presented. Newly Adopted Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) , as amended by various subsequently issued ASUs. The standard requires lessees to recognize an operating lease with a term greater than one year on their balance sheets as a right-of-use asset and corresponding lease liability, measured at the present value of the lease payments. Under the standard, disclosures are required to enable financial statement users to assess the amount, timing, and uncertainty of cash flows arising from the leases. Companies are also required to recognize and measure leases existing at, or entered into after, the adoption date using a modified retrospective approach, with certain practical expedients available. Comparative periods prior to adoption have not been retrospectively adjusted. Effective January 1, 2022, the Company adopted ASU 2016-02, using the required modified retrospective approach and utilizing January 1, 2022 as its date of initial application. As a result, prior periods are presented in accordance with the previous guidance in ASC 840, Leases (Topic 840) . At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present in the arrangement. Leases with a term greater than one year are recognized on the balance sheet as right-of-use assets and short-term and long-term lease liabilities, as applicable. The Company does not have material financing leases. Operating lease liabilities and their corresponding right-of-use assets are initially recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the right-of-use asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate to discount lease payments, which reflects an internally developed rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. Prospectively, the Company will adjust the right-of-use assets for straight-line rent expense or any incentives received and remeasure the lease liability at the net present value using the same incremental borrowing rate that was in effect as of the lease commencement or transition date. The Company has elected not to recognize leases with an original term of one year or less on the balance sheet. The Company typically only includes an initial lease term in its assessment of a lease arrangement. Options to renew a lease are not included in the Company’s assessment unless there is reasonable certainty that the Company will renew. ASC 842 transition practical expedients and application of transition provisions to leases at the transition date The Company elected the following practical expedients, which must be elected as a package and applied consistently to all of its leases at the transition date (including those for which the entity is a lessee or a lessor): i) the Company did not reassess whether any expired or existing contracts are or contain leases; ii) the Company did not reassess the lease classification for any expired or existing leases (that is, all existing leases that were classified as operating leases in accordance with ASC 840 are classified as operating leases, and all existing leases that were classified as capital leases in accordance with ASC 840 are classified as finance leases); and iii) the Company did not reassess initial direct costs for any existing leases. For leases that existed prior to the date of initial application of ASC 842 (which were previously classified as operating leases), a lessee may elect to use either the total lease term measured at lease inception under ASC 840 or the remaining lease term as of the date of initial application of ASC 842 in determining the period for which to measure its incremental borrowing rate. In transition to ASC 842, the Company utilized the remaining lease term of its leases in determining the appropriate incremental borrowing rates. Application of ASC 842 policy elections to leases post adoption The Company has made certain policy elections to apply to its leases executed post adoption, or subsequent to January 1, 2022, as further described below. In accordance with ASC 842, components of a lease should be split into three categories: lease components, non-lease components, and non-components. The fixed and in-substance fixed contract consideration (including any consideration related to non-components) must be allocated based on the respective relative fair values to the lease components and non-lease components. Entities may elect not to separate lease and non-lease components. Rather, entities would account for each lease component and related non-lease component together as a single lease component. The Company has elected to account for lease and non-lease components together as a single lease component for all underlying assets and allocate all of the contract consideration to the lease component only. ASC 842 allows for the use of judgment in determining whether the assumed lease term is for a major part of the remaining economic life of the underlying asset and whether the present value of lease payments represents substantially all of the fair value of the underlying asset. The Company applies the bright line thresholds referenced in ASC 842-10-55-2 to assist in evaluating leases for appropriate classification. The aforementioned bright lines are applied consistently to the Company’s leases. On January 1, 2022, the Company recorded right-of-use asset of $3.3 million and lease liability of $3.6 million. The standard did not have a material impact on the statement of operations or statement of cash flows. Additionally, there is no tax impact from the adoption as the net increase in deferred tax assets is fully offset with an increase to the valuation allowance. Accounting Pronouncements Issued and Not Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326) . The new standard adjusts the accounting for assets held at amortized cost basis, including marketable securities accounted for as available-for-sale. The standard eliminates the probable initial recognition threshold and requires an entity to reflect its current estimate of all expected credit losses. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial assets to present the net amount expected to be collected. The Company is required to adopt this standard effective January 1, 2023 and the Company is evaluating the impact the guidance will have on its condensed consolidated financial statements.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS The following tables present the Company’s assets that are measured at fair value on a recurring basis and indicate the level within the fair value hierarchy (in thousands): Fair Value Measurements at March 31, 2022 using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 42,690 $ — $ — $ 42,690 Marketable securities: Corporate obligations — 18,029 — 18,029 Total $ 42,690 $ 18,029 $ — $ 60,719 Fair Value Measurements at December 31, 2021 using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 23,021 $ — $ — $ 23,021 Marketable securities: Corporate obligations — 31,474 — 31,474 Total $ 23,021 $ 31,474 $ — $ 54,495 As of March 31, 2022 and December 31, 2021, the Company’s cash equivalents were invested in money market funds and were valued based on Level 1 inputs. The Company’s marketable securities consist of corporate obligations which are adjusted to fair value at each balance sheet date, based on quoted prices, which are considered Level 2 inputs. During the three months ended March 31, 2022 and 2021, there were no transfers between Level 1, Level 2 and Level 3.

MARKETABLE SECURITIES

MARKETABLE SECURITIES	3 Months Ended
	Mar. 31, 2022
Cash and Cash Equivalents [Abstract]
MARKETABLE SECURITIES	MARKETABLE SECURITIES As of March 31, 2022, and December 31, 2021, marketable securities by security type consisted of the following (in thousands): March 31, 2022 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Corporate obligations $ 18,099 $ 1 $ (71) $ 18,029 December 31, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Corporate obligations $ 31,526 $ — $ (52) $ 31,474 The amortized cost of marketable securities is adjusted for amortization of premiums and accretion of discounts to maturity. At March 31, 2022 and December 31, 2021, the balance in accumulated other comprehensive loss was comprised solely of activity related to marketable securities. For the three months ended March 31, 2022, the Company recognized realized losses on the sale or maturity of marketable securities of less than $0.1 million, as a result, the Company reclassified amounts out of accumulated other comprehensive loss during the period. There were no realized gains or losses on the sale or maturity of marketable securities for the three months ended March 31, 2021. The aggregate fair value of marketable securities by contractual maturity were as follows (in thousands): Contractual Maturities March 31, December 31, Mature in one year or less $ 18,029 $ 28,220 Mature in two years or less — 3,254 Total $ 18,029 $ 31,474 As of March 31, 2022, the Company did not intend to sell, and was more than likely not required to sell, the debt securities in a loss position before recovery of their amortized cost bases. As a result, the Company determined it did not hold any investments with any other-than-temporary impairment at March 31, 2022. There were sales of marketable securities during the three months ended March 31, 2022 worth $13.3 million. No such sales occurred during the three months ended March 31, 2021.

PROPERTY AND EQUIPMENT

PROPERTY AND EQUIPMENT	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT	PROPERTY AND EQUIPMENT Property and equipment consist of the following (in thousands): March 31, December 31, Laboratory equipment $ 3,561 $ 3,426 Leasehold improvements 564 564 Office and computer equipment 190 148 Furniture and fixtures 122 122 Property and equipment 4,437 4,260 Less: accumulated depreciation and amortization (3,467) (3,390) Property and equipment, net $ 970 $ 870

ACCRUED EXPENSES AND OTHER CURR

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	3 Months Ended
	Mar. 31, 2022
Payables and Accruals [Abstract]
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES Accrued expenses and other current liabilities consisted of the following (in thousands): March 31, December 31, Accrued employee compensation and benefits $ 1,168 $ 3,005 Accrued external research and development expenses 2,889 2,000 Accrued professional fees 685 601 Other 178 243 Total accrued expenses and other current liabilities $ 4,920 $ 5,849

DEBT FINANCING

DEBT FINANCING	3 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
DEBT FINANCING	DEBT FINANCING Long-term debt consisted of the following (in thousands): March 31, December 31, Principal amount of long-term debt $ 26,000 $ 26,000 Debt discount (185) (196) Deferred financing fees (697) (734) Current portion of long-term debt (1,733) — Long-term debt, net of current portion and discount $ 23,385 $ 25,070 In 2021, the Company entered into a loan and security agreement (the "New Loan and Security Agreement") with SLR Investment Corp., formerly known as Solar Capital Ltd., for term loans in an aggregate principal amount of $26.0 million. The New Loan and Security Agreement replaced the prior loan and security agreement between the Company and SLR Investment Corp. (the "Prior Loan and Security Agreement"). The term loans under the New Loan and Security Agreement will accrue interest at an annual rate equal to 8.60% plus the greater of (a) the thirty (30) day U.S. Dollar LIBOR rate and (b) 0.10%, payable monthly in arrears. The interest rate was 8.83% as of March 31, 2022 . The monthly principal payments of $0.6 million will be paid over a period of 45 months beginning in January 2023 through the final maturity date of September 1, 2026. Per the New Loan and Security Agreement, the date on which repayment of principal commences can be further extended to July 2023 and January 2024, provided we satisfy certain equity related conditions. The term loans are also subject to a prepayment fee of 3.00% if prepayment occurs within the first year subsequent to September 2, 2021 , 2.00% in the second year and 1.00% in the third year through final maturity. The New Loan and Security Agreement also contains certain financial covenants, including an unrestricted minimum cash level until certain clinical trial study data conditions are met. Customary representations and warranties, as well as certain non-financial covenants, including engaging in any change of control transaction or incurring additional indebtedness or liens are included in the New Loan and Security Agreement as well. As security for its obligations under the New Loan and Security Agreement, the Company granted SLR Investment Corp. a first priority perfected security interest in all of the Company’s existing and after-acquired assets, including intellectual property. The scheduled principal maturity of the long-term debt as of March 31, 2022 is as follows (in thousands): Year Ending December 31, 2022 $ — 2023 6,933 2024 6,933 2025 6,934 2026 5,200 $ 26,000

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS' EQUITY Common Stock On June 5, 2020, the Company entered into a sales agreement with SVB Leerink LLC (“SVB Leerink”) pursuant to which the Company may offer and sell shares of its common stock having an aggregate offering price of up to $35.0 million from time to time through SVB Leerink, acting as its agent (the “ATM Offering”). During the three months ended March 31, 2022, the Company sold an aggregate of 232,600 shares of its common stock under the ATM Offering for net cash proceeds of $0.6 million, after deducting commissions and expenses of less than $0.1 million. On March 16, 2022, the Company completed a registered direct offering and in this transaction, and sold 13,089,002 shares of common stock were sold at the market for a purchase price of $1.91 per share, yielding net proceeds of approximately $24.8 million, after deducting expenses of $0.2 million. 2019 Stock Option and Incentive Plan The 2019 Stock Option and Incentive Plan (the "2019 Plan") was approved by the Company's board of directors on April 29, 2019. The 2019 Plan provides for the grant of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock units, restricted stock awards, unrestricted stock awards and cash-based awards to the Company's officers, employees, directors and consultants. Awards under the 2019 plan generally vest ratably over the vesting period (3-4 years) and have a maximum term of 10 years. The number of shares initially reserved for issuance under the 2019 Plan is 905,000, which was increased on January 1, 2020 and will be increased each January 1 thereafter by 4% of the number of shares of the Company's common stock outstanding on the immediately preceding December 31, or such lesser number of shares determined by the Company's board of directors or compensation committee of the board of directors. The number of options available for future grant under the 2019 Plan was 769,502 as of March 31, 2022. 2019 Employee Stock Purchase Plan The 2019 Employee Stock Purchase Plan (the "2019 ESPP") was approved by the Company's board of directors on April 29, 2019. A total of 237,181 shares of common stock were initially reserved for issuance under this plan, which was cumulatively increased on January 1, 2020 and will be increased each January 1 thereafter by 1% of the number of shares of the Company's common stock outstanding on the immediately preceding December 31, or such lesser number of shares determined by the Company's board of directors or compensation committee of the board of directors. The number of shares available for future issuance under the 2019 ESPP was 846,421 shares as of March 31, 2022. Stock-Based Compensation Expense In connection with all share-based payment awards, total stock-based compensation expense recognized was as follows (in thousands): Three Months Ended 2022 2021 Research and development $ 566 $ 410 General and administrative 943 1,018 Total stock-based compensation expense $ 1,509 $ 1,428 Fair Value of Stock Options The fair value of stock option awards was estimated using the Black-Scholes option-pricing model. The expected term of these awards was determined using the simplified method, which uses the midpoint between the vesting date and the contractual term. The risk-free interest rate was determined by reference to the U.S. Treasury yield curve for time periods approximately equal to the remaining contractual term of the stock awards. The expected dividend was zero as the Company had not paid any dividends on its common stock. Finally, as the Company does not have long-term trading history of its common stock, the expected volatility was derived from the average historical stock volatilities of several public companies within the industry that the Company considers to be comparable to the Company's business over a period equivalent to the expected term of the stock-based awards. The Black-Scholes option pricing model assumptions are included in the table below. Three Months Ended 2022 2021 Risk-free interest rate 1.87 % 0.76 % Expected option life (in years) 6.13 6.02 Expected dividend yield — % — % Expected volatility 91.4 % 97.2 % Stock Option Activity The following table summarizes the Company’s stock option activity for the three months ended March 31, 2022: Number of Shares Weighted Weighted Intrinsic Outstanding as of January 1, 2022 6,197,288 $ 5.72 Granted 1,864,259 1.84 Exercised (8,499) 0.72 Canceled (26,124) 8.05 Outstanding as of March 31, 2022 8,026,924 $ 4.81 7.76 $ 1,856 Exercisable as of March 31, 2022 3,861,142 $ 6.27 6.27 $ 254 Vested or expected to vest as of March 31, 2022 7,701,924 $ 4.75 7.36 $ 1,550 The intrinsic value of options exercised during the three months ended March 31, 2022 and 2021 was nominal. The weighted-average grant date fair value of the options granted during the three months ended March 31, 2022 and 2021 was $1.03 and $4.81 per share, respectively. As of March 31, 2022, there was $9.1 million of unrecognized compensation expense that is expected to be recognized over a weighted-average period of approximately 2.7 years. Restricted Stock Units The fair values of restricted stock units are based on the market value of the Company's common stock on the date of grant. The following table summarizes the Company's restricted stock unit activity for the three months ended March 31, 2022: Number of Shares Weighted Average Outstanding as of January 1, 2021 275,350 $ 4.15 Granted — — Vested (59,019) 4.73 Forfeited — — Outstanding as of March 31, 2022 216,331 $ 3.99

NET LOSS PER SHARE

NET LOSS PER SHARE	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
NET LOSS PER SHARE	NET LOSS PER SHARE Basic and diluted net loss per share attributable to common stockholders was calculated as follows (in thousands, except share and per share amounts): Three Months Ended 2022 2021 Numerator: Net loss $ (19,039) $ (15,189) Denominator: Weighted average common shares outstanding, basic and diluted 41,426,107 37,652,158 Net loss per share, basic and diluted $ (0.46) $ (0.40) The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: Three Months Ended 2022 2021 Options to purchase common stock 8,026,924 6,038,833 Unvested restricted stock units 216,331 408,503 Shares issuable under employee stock purchase plan 37,820 22,870 8,281,075 6,470,206

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Leases The Company leases a facility containing 19,200 square feet of laboratory and office space, which is located at 840 Memorial Drive, Cambridge, Massachusetts. The lease expires in April 2024, subject to an option to extend the lease for an additional three years. The lease agreement and most recent amendment contained escalating rent payments. The following table contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company’s operating leases for the three months ended March 31, 2022 (in thousands, except weighted average figures): Operating leases Three Months Ended March 31, 2022 Lease cost Operating lease cost $ 401 Variable lease cost 193 Total lease cost $ 594 Other information Operating cash flows used for operating leases $ 603 Weighted average remaining lease term (years) 2.1 Weighted average discount rate (percentage) 9.0 % Future minimum lease payments and lease liabilities as of March 31, 2022 and December 31, 2021 were as follows (in thousands): As of Maturity of lease liabilities March 31, December 31, 2022 $ 1,262 $ 1,672 2023 1,722 1,722 2024 580 580 Total future minimum lease payments $ 3,564 $ 3,974 Less: imputed interest (328) Total lease liability $ 3,236 Reported as: Operating lease liability $ 1,452 Operating lease liability, net of current portion 1,784 Total lease liability $ 3,236 Other Commitments We enter into contracts in the normal course of business with contract research organizations ("CROs"), contract manufacturing organizations ("CMOs") and other third parties for preclinical research studies, Clinical Studies, Clinical Trials and testing and manufacturing services. These contracts do not contain minimum purchase commitments and are cancelable upon prior written notice. Payments due upon cancellation consist only of payments for services provided or expenses incurred, including non-cancelable obligations of service providers, up to the date of cancellation. Legal Proceedings

RELATED-PARTY TRANSACTIONS

RELATED-PARTY TRANSACTIONS	3 Months Ended
	Mar. 31, 2022
Related Party Transactions [Abstract]
RELATED-PARTY TRANSACTIONS	RELATED-PARTY TRANSACTIONS In August 2019, the Company entered into a consulting agreement with the chairman of the Company's Board of Directors to provide various consulting services to the Company in exchange for cash and equity compensation. In March 2021, the consulting agreement was modified so that the chairman would no longer receive cash compensation for his consulting services and would instead be compensated solely via equity compensation. The aggregate grant date fair value of the equity awarded to the chairman in 2022 and 2021 for his consulting services was $0.1 million and $0.6 million, respectively. The grant date fair value is calculated in accordance with FASB ASC Topic 718. The total cash paid under the agreement was $0.1 million for the three months ended March 31, 2021. No cash was paid under the agreement for the three months ended March 31, 2022. On March 17, 2022, the chairman and the Company mutually agreed to terminate the consulting agreement, such termination to be effective immediately. The consulting agreement was terminated in connection with a new compensation arrangement for the chairman’s service as the non-executive chairman of the Board.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	3 Months Ended
	Mar. 31, 2022
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTSThe Company has evaluated subsequent events for financial statement purposes occurring through the date these condensed consolidated financial statements were issued and determined that there are no material recognized or unrecognized subsequent events requiring disclosure.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). Furthermore, the accompanying condensed consolidated financial statements are unaudited and certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. During the three months ended March 31, 2022, we adopted ASU No. 2016-02, Leases (Topic 842) and the related accounting policies. Other than the adoption of Topic 842 , there were no material changes to the Company's significant accounting policies and estimates as reported in it's Annual Report on Form 10-K for the year ended December 31, 2021, which was filed with the SEC on March 30, 2022. The unaudited interim financial statements have been prepared on the same basis as the audited annual financial statements as of and for the year ended December 31, 2021. The accompanying interim condensed consolidated financial statements reflect all adjustments, consisting of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of March 31, 2022, the results of its operations for the three months ended March 31, 2022 and 2021, its cash flows for the three months ended March 31, 2022 and 2021, and its statements of stockholders’ equity for the three months ended March 31, 2022 and 2021. The results for the three months ended March 31, 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022, any other interim periods, or any future year or period. These interim financial statements should be read in conjunction with the audited financial statements as of and for the year ended December 31, 2021, and the notes thereto, together with Management’s Discussion and Analysis of Financial Condition and Results of Operations, contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021.
Principles of Consolidation	Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of Axcella Health Inc. and its wholly owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation.
Segment Information	Segment InformationOperating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the CEO, who is the chief operating decision maker, in making decisions on how to allocate resources and assess performance. The Company operates in one reportable business segment.
Use of Estimates	Use of Estimates The preparation of the condensed consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, expenses and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the Company’s ability to continue as a going concern. The Company bases its estimates on historical experience, known trends and other market-specific or relevant factors that it believes to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates as there are changes in circumstances, facts and experience. Actual results may differ from those estimates or assumptions.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include cash held in banks and amounts held in interest-bearing money market accounts. Cash equivalents are carried at cost, which approximates their fair market value. The Company considers all highly liquid investments with a remaining maturity when purchased of three months or less to also be cash equivalents.
Marketable Securities	Marketable Securities The Company’s marketable securities, which consisted of corporate debt obligations as of March 31, 2022, are classified as available-for-sale and are reported at fair value. Unrealized gains and losses on available-for-sale securities are reported as a component of accumulated other comprehensive income (loss) in stockholders’ equity. Realized gains and losses and declines in value determined to be other than temporary are based on the specific identification method and are included as a component of other income (expense), net in the condensed consolidated statements of operations and comprehensive loss. The Company evaluates its marketable securities with unrealized losses for other-than-temporary impairment. When assessing marketable securities for other-than-temporary declines in value, the Company considers such factors as, among other things, how significant the decline in value is as a percentage of the original cost, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions in general. If any adjustment to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the condensed consolidated statements of operations and comprehensive loss. No such adjustments were necessary during the periods presented.
Concentrations of Credit Risk	Concentrations of Credit Risk The Company has no off-balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company’s cash equivalents and marketable securities as of March 31, 2022 consisted of bank deposits, money market funds that invest in U.S. treasury securities, and corporate obligations. The Company invests in high-quality financial instruments and it's portfolio does not consist of any instrument with a maturity duration in excess of twenty-four months, which the Company believes limits it's credit risk. In addition, the Company's investment policy includes guidelines on the quality of the institutions and financial instruments and defines the allowable investments that the Company believes minimizes the exposure to concentrations of credit risk. The Company has not experienced any credit losses and does not believe that it is subject to significant credit risk.
Fair Value Measurements	Fair Value Measurements Certain assets and liabilities of the Company are carried at fair value. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1 — Quoted prices in active markets for identical assets or liabilities. • Level 2 — Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3 — Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The Company’s cash equivalents and marketable securities are carried at fair value, determined according to the fair value hierarchy described above. The carrying values of the Company’s accounts payable and accrued expenses approximate their fair values due to the short-term nature of these liabilities. The carrying value of the long-term debt approximates fair value as evidenced by the recent amendment to the Company's debt facility.
Comprehensive Loss	Comprehensive loss Comprehensive loss includes net loss as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders. For the three months ended March 31, 2022, the Company’s only element of other comprehensive loss was unrealized gains (losses) on marketable securities.
Net Loss Per Share	Net Loss Per ShareBasic net loss per share attributable to common stockholders is calculated by dividing net loss by the weighted average shares outstanding during the period. Diluted net income (loss) per share is calculated by adjusting weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period. All common stock equivalents have been excluded from the calculation of diluted net loss per share, as their effect would be anti-dilutive for all periods presented.
Newly Adopted Accounting Pronouncements and Accounting Pronouncements Issued and Not Adopted	Newly Adopted Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) , as amended by various subsequently issued ASUs. The standard requires lessees to recognize an operating lease with a term greater than one year on their balance sheets as a right-of-use asset and corresponding lease liability, measured at the present value of the lease payments. Under the standard, disclosures are required to enable financial statement users to assess the amount, timing, and uncertainty of cash flows arising from the leases. Companies are also required to recognize and measure leases existing at, or entered into after, the adoption date using a modified retrospective approach, with certain practical expedients available. Comparative periods prior to adoption have not been retrospectively adjusted. Effective January 1, 2022, the Company adopted ASU 2016-02, using the required modified retrospective approach and utilizing January 1, 2022 as its date of initial application. As a result, prior periods are presented in accordance with the previous guidance in ASC 840, Leases (Topic 840) . At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present in the arrangement. Leases with a term greater than one year are recognized on the balance sheet as right-of-use assets and short-term and long-term lease liabilities, as applicable. The Company does not have material financing leases. Operating lease liabilities and their corresponding right-of-use assets are initially recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the right-of-use asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate to discount lease payments, which reflects an internally developed rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. Prospectively, the Company will adjust the right-of-use assets for straight-line rent expense or any incentives received and remeasure the lease liability at the net present value using the same incremental borrowing rate that was in effect as of the lease commencement or transition date. The Company has elected not to recognize leases with an original term of one year or less on the balance sheet. The Company typically only includes an initial lease term in its assessment of a lease arrangement. Options to renew a lease are not included in the Company’s assessment unless there is reasonable certainty that the Company will renew. ASC 842 transition practical expedients and application of transition provisions to leases at the transition date The Company elected the following practical expedients, which must be elected as a package and applied consistently to all of its leases at the transition date (including those for which the entity is a lessee or a lessor): i) the Company did not reassess whether any expired or existing contracts are or contain leases; ii) the Company did not reassess the lease classification for any expired or existing leases (that is, all existing leases that were classified as operating leases in accordance with ASC 840 are classified as operating leases, and all existing leases that were classified as capital leases in accordance with ASC 840 are classified as finance leases); and iii) the Company did not reassess initial direct costs for any existing leases. For leases that existed prior to the date of initial application of ASC 842 (which were previously classified as operating leases), a lessee may elect to use either the total lease term measured at lease inception under ASC 840 or the remaining lease term as of the date of initial application of ASC 842 in determining the period for which to measure its incremental borrowing rate. In transition to ASC 842, the Company utilized the remaining lease term of its leases in determining the appropriate incremental borrowing rates. Application of ASC 842 policy elections to leases post adoption The Company has made certain policy elections to apply to its leases executed post adoption, or subsequent to January 1, 2022, as further described below. In accordance with ASC 842, components of a lease should be split into three categories: lease components, non-lease components, and non-components. The fixed and in-substance fixed contract consideration (including any consideration related to non-components) must be allocated based on the respective relative fair values to the lease components and non-lease components. Entities may elect not to separate lease and non-lease components. Rather, entities would account for each lease component and related non-lease component together as a single lease component. The Company has elected to account for lease and non-lease components together as a single lease component for all underlying assets and allocate all of the contract consideration to the lease component only. ASC 842 allows for the use of judgment in determining whether the assumed lease term is for a major part of the remaining economic life of the underlying asset and whether the present value of lease payments represents substantially all of the fair value of the underlying asset. The Company applies the bright line thresholds referenced in ASC 842-10-55-2 to assist in evaluating leases for appropriate classification. The aforementioned bright lines are applied consistently to the Company’s leases. On January 1, 2022, the Company recorded right-of-use asset of $3.3 million and lease liability of $3.6 million. The standard did not have a material impact on the statement of operations or statement of cash flows. Additionally, there is no tax impact from the adoption as the net increase in deferred tax assets is fully offset with an increase to the valuation allowance. Accounting Pronouncements Issued and Not Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326) . The new standard adjusts the accounting for assets held at amortized cost basis, including marketable securities accounted for as available-for-sale. The standard eliminates the probable initial recognition threshold and requires an entity to reflect its current estimate of all expected credit losses. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial assets to present the net amount expected to be collected. The Company is required to adopt this standard effective January 1, 2023 and the Company is evaluating the impact the guidance will have on its condensed consolidated financial statements.

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Assets Measured at Fair Value	The following tables present the Company’s assets that are measured at fair value on a recurring basis and indicate the level within the fair value hierarchy (in thousands): Fair Value Measurements at March 31, 2022 using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 42,690 $ — $ — $ 42,690 Marketable securities: Corporate obligations — 18,029 — 18,029 Total $ 42,690 $ 18,029 $ — $ 60,719 Fair Value Measurements at December 31, 2021 using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 23,021 $ — $ — $ 23,021 Marketable securities: Corporate obligations — 31,474 — 31,474 Total $ 23,021 $ 31,474 $ — $ 54,495

MARKETABLE SECURITIES (Tables)

MARKETABLE SECURITIES (Tables)	3 Months Ended
	Mar. 31, 2022
Cash and Cash Equivalents [Abstract]
Schedule of Cash, Cash Equivalents, and Marketable Securities by Security Type	As of March 31, 2022, and December 31, 2021, marketable securities by security type consisted of the following (in thousands): March 31, 2022 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Corporate obligations $ 18,099 $ 1 $ (71) $ 18,029 December 31, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Corporate obligations $ 31,526 $ — $ (52) $ 31,474
Schedule of Fair Values of Cash Equivalents and Marketable Securities by Contractual Maturities	The aggregate fair value of marketable securities by contractual maturity were as follows (in thousands): Contractual Maturities March 31, December 31, Mature in one year or less $ 18,029 $ 28,220 Mature in two years or less — 3,254 Total $ 18,029 $ 31,474

PROPERTY AND EQUIPMENT (Tables)

PROPERTY AND EQUIPMENT (Tables)	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment	Property and equipment consist of the following (in thousands): March 31, December 31, Laboratory equipment $ 3,561 $ 3,426 Leasehold improvements 564 564 Office and computer equipment 190 148 Furniture and fixtures 122 122 Property and equipment 4,437 4,260 Less: accumulated depreciation and amortization (3,467) (3,390) Property and equipment, net $ 970 $ 870

ACCRUED EXPENSES AND OTHER CU_2

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)	3 Months Ended
	Mar. 31, 2022
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): March 31, December 31, Accrued employee compensation and benefits $ 1,168 $ 3,005 Accrued external research and development expenses 2,889 2,000 Accrued professional fees 685 601 Other 178 243 Total accrued expenses and other current liabilities $ 4,920 $ 5,849

DEBT FINANCING (Tables)

DEBT FINANCING (Tables)	3 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Summary of Long-term Debt	Long-term debt consisted of the following (in thousands): March 31, December 31, Principal amount of long-term debt $ 26,000 $ 26,000 Debt discount (185) (196) Deferred financing fees (697) (734) Current portion of long-term debt (1,733) — Long-term debt, net of current portion and discount $ 23,385 $ 25,070
Schedule of Principal Maturities of Long-term Debt	The scheduled principal maturity of the long-term debt as of March 31, 2022 is as follows (in thousands): Year Ending December 31, 2022 $ — 2023 6,933 2024 6,933 2025 6,934 2026 5,200 $ 26,000

STOCKHOLDERS' EQUITY (Tables)

STOCKHOLDERS' EQUITY (Tables)	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Schedule of Stock-based Compensation Expense Recognized	In connection with all share-based payment awards, total stock-based compensation expense recognized was as follows (in thousands): Three Months Ended 2022 2021 Research and development $ 566 $ 410 General and administrative 943 1,018 Total stock-based compensation expense $ 1,509 $ 1,428
Schedule of Fair Value Assumptions for Stock Options	The Black-Scholes option pricing model assumptions are included in the table below. Three Months Ended 2022 2021 Risk-free interest rate 1.87 % 0.76 % Expected option life (in years) 6.13 6.02 Expected dividend yield — % — % Expected volatility 91.4 % 97.2 %
Schedule of Stock Option Activity	The following table summarizes the Company’s stock option activity for the three months ended March 31, 2022: Number of Shares Weighted Weighted Intrinsic Outstanding as of January 1, 2022 6,197,288 $ 5.72 Granted 1,864,259 1.84 Exercised (8,499) 0.72 Canceled (26,124) 8.05 Outstanding as of March 31, 2022 8,026,924 $ 4.81 7.76 $ 1,856 Exercisable as of March 31, 2022 3,861,142 $ 6.27 6.27 $ 254 Vested or expected to vest as of March 31, 2022 7,701,924 $ 4.75 7.36 $ 1,550
Schedule of Restricted Stock Unit Activity	The following table summarizes the Company's restricted stock unit activity for the three months ended March 31, 2022: Number of Shares Weighted Average Outstanding as of January 1, 2021 275,350 $ 4.15 Granted — — Vested (59,019) 4.73 Forfeited — — Outstanding as of March 31, 2022 216,331 $ 3.99

NET LOSS PER SHARE (Tables)

NET LOSS PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Basic and diluted net loss per share attributable to common stockholders was calculated as follows (in thousands, except share and per share amounts): Three Months Ended 2022 2021 Numerator: Net loss $ (19,039) $ (15,189) Denominator: Weighted average common shares outstanding, basic and diluted 41,426,107 37,652,158 Net loss per share, basic and diluted $ (0.46) $ (0.40)
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: Three Months Ended 2022 2021 Options to purchase common stock 8,026,924 6,038,833 Unvested restricted stock units 216,331 408,503 Shares issuable under employee stock purchase plan 37,820 22,870 8,281,075 6,470,206

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	3 Months Ended
	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Schedule of Lease Costs	The following table contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company’s operating leases for the three months ended March 31, 2022 (in thousands, except weighted average figures): Operating leases Three Months Ended March 31, 2022 Lease cost Operating lease cost $ 401 Variable lease cost 193 Total lease cost $ 594 Other information Operating cash flows used for operating leases $ 603 Weighted average remaining lease term (years) 2.1 Weighted average discount rate (percentage) 9.0 %
Schedule of Future Minimum Lease Payments	Future minimum lease payments and lease liabilities as of March 31, 2022 and December 31, 2021 were as follows (in thousands): As of Maturity of lease liabilities March 31, December 31, 2022 $ 1,262 $ 1,672 2023 1,722 1,722 2024 580 580 Total future minimum lease payments $ 3,564 $ 3,974 Less: imputed interest (328) Total lease liability $ 3,236 Reported as: Operating lease liability $ 1,452 Operating lease liability, net of current portion 1,784 Total lease liability $ 3,236

NATURE OF BUSINESS (Details)

NATURE OF BUSINESS (Details) - USD ($) $ in Thousands	Mar. 16, 2022	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Nature Of Business [Line Items]
Net loss		$ (19,039)	$ (15,189)
Accumulated deficit		(356,280)		$ (337,241)
Net cash used in operations		(16,862)	$ (14,145)
Cash, cash equivalents, and marketable securities		$ 63,200
Registered Direct Offering
Nature Of Business [Line Items]
Net proceeds on offering	$ 24,800

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)segment	Jan. 01, 2022USD ($)	Dec. 31, 2021USD ($)
Accounting Policies [Line Items]
Number of operating segments | segment	1
Right-of-use asset	$ 3,017		$ 0
Lease liability	$ 3,236
Accounting Standards Update 2016-02
Accounting Policies [Line Items]
Right-of-use asset		$ 3,300
Lease liability		$ 3,600

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Assets, Fair Value Disclosure [Abstract]
Money market funds	$ 42,690	$ 23,021
Corporate obligations	18,029	31,474
Total	60,719	54,495
Level 1
Assets, Fair Value Disclosure [Abstract]
Money market funds	42,690	23,021
Corporate obligations	0	0
Total	42,690	23,021
Level 2
Assets, Fair Value Disclosure [Abstract]
Money market funds	0	0
Corporate obligations	18,029	31,474
Total	18,029	31,474
Level 3
Assets, Fair Value Disclosure [Abstract]
Money market funds	0	0
Corporate obligations	0	0
Total	$ 0	$ 0

MARKETABLE SECURITIES - Schedul

MARKETABLE SECURITIES - Schedule of Securities by Type (Details) - Corporate obligations - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Line Items]
Amortized Cost	$ 18,099	$ 31,526
Gross Unrealized Gains	1	0
Gross Unrealized Losses	(71)	(52)
Estimated Fair Value	$ 18,029	$ 31,474

MARKETABLE SECURITIES - Sched_2

MARKETABLE SECURITIES - Schedule of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Abstract]
Mature in one year or less	$ 18,029	$ 28,220
Mature in two years or less	0	3,254
Total	$ 18,029	$ 31,474

MARKETABLE SECURITIES - Narrati

MARKETABLE SECURITIES - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash and Cash Equivalents [Abstract]
Realized gain (losses) on sale or maturity of marketable securities	$ (100,000)
Sales of marketable securities	$ 13,300,000	$ 0

PROPERTY AND EQUIPMENT - Summar

PROPERTY AND EQUIPMENT - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property and equipment	$ 4,437	$ 4,260
Less: accumulated depreciation and amortization	(3,467)	(3,390)
Property and equipment, net	970	870
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property and equipment	3,561	3,426
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	564	564
Office and computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment	190	148
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment	$ 122	$ 122

PROPERTY AND EQUIPMENT - Narrat

PROPERTY AND EQUIPMENT - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 77,000	$ 64,000
Property and equipment disposed of	$ 0	$ 0

ACCRUED EXPENSES AND OTHER CU_3

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Accrued employee compensation and benefits	$ 1,168	$ 3,005
Accrued external research and development expenses	2,889	2,000
Accrued professional fees	685	601
Other	178	243
Total accrued expenses and other current liabilities	$ 4,920	$ 5,849

DEBT FINANCING - Summary of Lon

DEBT FINANCING - Summary of Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
Principal amount of long-term debt	$ 26,000	$ 26,000
Debt discount	(185)	(196)
Deferred financing fees	(697)	(734)
Current portion of long-term debt	(1,733)	0
Long-term debt, net of current portion and discount	$ 23,385	$ 25,070

DEBT FINANCING - Narrative (Det

DEBT FINANCING - Narrative (Details) - USD ($) $ in Thousands	Jan. 01, 2023	Sep. 02, 2021	Mar. 31, 2022	Dec. 31, 2021
Line of Credit Facility [Line Items]
Principal amount of long-term debt			$ 26,000	$ 26,000
New Loan and Security Agreement | Line of Credit
Line of Credit Facility [Line Items]
Principal amount of long-term debt		$ 26,000
Basis spread on interest rate		8.60%
Interest rate floor, on which basis spread is added		0.10%
New Loan and Security Agreement | Line of Credit | Debt Instrument, Redemption, Period One
Line of Credit Facility [Line Items]
Prepayment fee, percent of principal			0.0300
New Loan and Security Agreement | Line of Credit | Debt Instrument, Redemption, Period Two
Line of Credit Facility [Line Items]
Prepayment fee, percent of principal			0.0200
New Loan and Security Agreement | Line of Credit | Debt Instrument, Redemption, Period Three
Line of Credit Facility [Line Items]
Prepayment fee, percent of principal			0.0100
New Loan and Security Agreement | LIBOR | Line of Credit
Line of Credit Facility [Line Items]
Interest rate at end of period			8.83%
Forecast | New Loan and Security Agreement | Line of Credit
Line of Credit Facility [Line Items]
Principal periodic payments	$ 600
Period of payment	45 months

DEBT FINANCING - Maturities of

DEBT FINANCING - Maturities of Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
2022	$ 0
2023	6,933
2024	6,933
2025	6,934
2026	5,200
Principal amount of long-term debt	$ 26,000	$ 26,000

STOCKHOLDERS' EQUITY - Narrativ

STOCKHOLDERS' EQUITY - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 16, 2022	Jun. 05, 2020	Apr. 29, 2019	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance costs				$ 71	$ 31
Number of shares initially reserved for future issuance (in shares)			237,181
Annual percent increase in authorized shares available for issuance under share based payment arrangements			1.00%
Weighted-average grand date fair value of options granted in the period (USD per share)				$ 1.03	$ 4.81
Unrecognized compensation expense related to unvested stock options				$ 9,100
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)				846,421
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield				0.00%	0.00%	0.00%
Unrecognized compensation expense, recognition period				2 years 8 months 12 days
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense, recognition period				1 year 8 months 12 days
Unrecognized compensation expense related to unvested stock RSUs				$ 300
Stock Option And Incentive Plan 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum award term				10 years
Number of shares initially reserved for future issuance (in shares)			905,000
Annual percent increase in authorized shares available for issuance under share based payment arrangements			4.00%
Common stock reserved for future issuance (in shares)				769,502
Maximum | Stock Option And Incentive Plan 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				4 years
Minimum | Stock Option And Incentive Plan 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				3 years
At-the-Market Offering
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net proceeds on offering				$ 600
Shares sold (in shares)				232,600
Issuance costs				$ 100
At-the-Market Offering | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net proceeds on offering		$ 35,000
Registered Direct Offering
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net proceeds on offering	$ 24,800
Shares sold (in shares)	13,089,002
Issuance costs	$ 200
Shares sold, par value (USD per share)	$ 1.91

STOCKHOLDERS' EQUITY - Summary

STOCKHOLDERS' EQUITY - Summary of Stock Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 1,509	$ 1,428
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	566	410
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 943	$ 1,018

STOCKHOLDERS' EQUITY - Stock Op

STOCKHOLDERS' EQUITY - Stock Option Valuation Fair Value Measurement Inputs (Details) - Stock options	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.87%	0.76%
Expected option life (in years)	6 years 1 month 17 days	6 years 7 days
Expected dividend yield	0.00%	0.00%	0.00%
Expected volatility	91.40%	97.20%

STOCKHOLDERS' EQUITY - Summar_2

STOCKHOLDERS' EQUITY - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)$ / sharesshares
Number of Shares
Outstanding at beginning of period (in shares) | shares	6,197,288
Granted (in shares) | shares	1,864,259
Exercised (in shares) | shares	(8,499)
Canceled (in shares) | shares	(26,124)
Outstanding at end of period (in shares) | shares	8,026,924
Shares exercisable (in shares) | shares	3,861,142
Shares vested or expected to vest (in shares) | shares	7,701,924
Weighted Average Exercise Price
Weighted average exercise price of shares outstanding at beginning of period (USD per share) | $ / shares	$ 5.72
Weighted-average exercise price of shares granted (USD per share) | $ / shares	1.84
Weighted-average exercise price of shares exercised (USD per share) | $ / shares	0.72
Weighted-average exercise price of shares canceled (USD per share) | $ / shares	8.05
Weighted average exercise price of shares outstanding at end of period (USD per share) | $ / shares	4.81
Weighted-average exercise price of shares exercisable (USD per share) | $ / shares	6.27
Weighted-average exercise price of shares vested or expected to vest (USD per share) | $ / shares	$ 4.75
Weighted Average Remaining Life (in Years)
Weighted average remaining life of shares outstanding (in years)	7 years 9 months 3 days
Weighted average remaining life of shares exercisable (in years)	6 years 3 months 7 days
Weighted average remaining life of shares vested or expected to vest (in years)	7 years 4 months 9 days
Intrinsic value of shares outstanding | $	$ 1,856
Intrinsic value of shares exercisable | $	254
Intrinsic value of shares vested or expected to vest | $	$ 1,550

STOCKHOLDERS' EQUITY - Summar_3

STOCKHOLDERS' EQUITY - Summary of Restricted Stock Units (Details) - RSUs	3 Months Ended
	Mar. 31, 2022$ / sharesshares
Number of Shares
Outstanding at beginning of period (in shares) | shares	275,350
Granted (in shares) | shares	0
Vested (in shares) | shares	(59,019)
Forfeited (in shares) | shares	0
Outstanding at end of period (in shares) | shares	216,331
Weighted Average Grant Date Fair Value per Share
Weighted average exercise price of RSUs outstanding at beginning of period (USD per share) | $ / shares	$ 4.15
Weighted-average exercise price of RSUs granted (USD per share) | $ / shares	0
Weighted-average exercise price of RSUs vested (USD per share) | $ / shares	4.73
Weighted-average exercise price of RSUs forfeited (USD per share) | $ / shares	0
Weighted average exercise price of RSUs outstanding at end of period (USD per share) | $ / shares	$ 3.99

NET LOSS PER SHARE - Schedule o

NET LOSS PER SHARE - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net loss	$ (19,039)	$ (15,189)
Denominator:
Weighted average common shares outstanding, basic (in shares)	41,426,107	37,652,158
Weighted average common shares outstanding, diluted (in shares)	41,426,107	37,652,158
Net loss per share, basic (USD per share)	$ (0.46)	$ (0.40)
Net loss per share, diluted (USD per share)	$ (0.46)	$ (0.40)

NET LOSS PER SHARE - Schedule_2

NET LOSS PER SHARE - Schedule of Anti-dilutive Securities (Details) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share (in shares)	8,281,075	6,470,206
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share (in shares)	8,026,924	6,038,833
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share (in shares)	216,331	408,503
Shares issuable under employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share (in shares)	37,820	22,870

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Narrative (Details)	Mar. 31, 2022ft²
Commitments and Contingencies Disclosure [Abstract]
Leased facility area (in square feet)	19,200
Lease extension term	3 years

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES - Schedule of Lease Costs (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 401
Variable lease cost	193
Total lease cost	594
Operating cash flows used for operating leases	$ 603
Weighted average remaining lease term (years)	2 years 1 month 6 days
Weighted average discount rate (percentage)	9.00%

COMMITMENTS AND CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES - Schedule of Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2022	$ 1,262
2023	1,722
2024	580
Total future minimum lease payments	3,564
Less: imputed interest	(328)
Total lease liability	3,236
Operating lease liability	1,452	$ 0
Operating lease liability, net of current portion	$ 1,784	0
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2022		1,672
2023		1,722
2024		580
Total future minimum lease payments		$ 3,974

RELATED-PARTY TRANSACTIONS (Det

RELATED-PARTY TRANSACTIONS (Details) - Related Party Consulting Agreement - Board of Directors Chairman - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Related Party Transaction [Line Items]
Grant date fair value of equity awarded	$ 100,000		$ 600,000
Related party costs	$ 100,000	$ 0