InVivo Therapeutics (NVIVQ) 10-K 7 Mar 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 04, 2022	Jun. 30, 2021
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	NV
Entity Address, Address Line One	One Kendall Square
Entity Address, Address Line Two	Suite B14402
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Document Period End Date	Dec. 31, 2021
Entity Registrant Name	INVIVO THERAPEUTICS HOLDINGS CORP.
Title of 12(b) Security	Common Stock
Trading Symbol	NVIV
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
ICFR Auditor Attestation Flag	false
Entity Common Stock, Shares Outstanding		34,264,856
Entity File Number	001-37350
Entity Tax Identification Number	36-4528166
Entity Address, Postal Zip Code	02139
Local Phone Number	863-5500
City Area Code	617
Entity Public Float			$ 25,347,671
Auditor Name	RSM US LLP
Auditor Firm ID	49
Auditor Location	Massachusetts
Entity Central Index Key	0001292519
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 19,031	$ 19,493
Prepaid expenses and other current assets	111	163
Total current assets	19,142	19,656
Property, equipment and leasehold improvements, net	127	85
Restricted cash - non current	150	110
Operating lease right-of-use assets	1,229	928
Prepaid clinical trial expenses	1,122	1,122
Other assets		9
Total assets	21,770	21,910
Current liabilities:
Accounts payable	605	481
Operating lease liabilities	361	327
Accrued expenses	1,646	1,164
Total current liabilities	2,612	1,972
Other liabilities	94	59
Operating lease liabilities - non current	949	693
Total liabilities	3,655	2,724
Commitments and contingencies (Note 12)
Stockholders' equity:
Common stock, $0.00001 par value, authorized 50,000,000 shares; 34,264,856 shares issued and outstanding, including 6,302 shares of unvested restricted stock awards, at December 31, 2021; authorized 50,000,000 shares; 23,631,886 shares issued and outstanding, including 6,302 shares of unvested restricted stock awards, at December 31, 2020	3	3
Additional paid-in capital	256,241	247,417
Accumulated deficit	(238,129)	(228,234)
Total stockholders' equity	18,115	19,186
Total liabilities and stockholders' equity	$ 21,770	$ 21,910

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical)	12 Months Ended
	Dec. 31, 2020$ / sharesshares	Dec. 31, 2021$ / sharesshares	Aug. 04, 2020shares	Aug. 03, 2020shares	Feb. 11, 2020shares	Jan. 31, 2020shares	May 31, 2018shares
Common stock, par value (in dollars per share) | $ / shares	$ 0.00001	$ 0.00001
Common stock, authorized	50,000,000	50,000,000	50,000,000	16,666,667	16,666,667	500,000,000	25,000,000
Common stock, issued	23,631,886	34,264,856
Common stock, outstanding	23,631,886	34,264,856
Reverse stock split ratio	0.0333
Restricted Stock [Member]
Common stock, outstanding	6,302	6,302

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating expenses:
Research and development	$ 4,381	$ 3,939
General and administrative	5,519	5,158
Total operating expenses	9,900	9,097
Operating loss	(9,900)	(9,097)
Other income / (expense):
Interest income / (expense), net	3	19
Other income	2	4
Other income / (expense), net	5	23
Net loss	$ (9,895)	$ (9,074)
Net loss per share, basic and diluted	$ (0.30)	$ (1.31)
Weighted average number of common shares outstanding, basic and diluted (In Shares)	33,078,659	6,902,693

Consolidated Statements of Op_2

Consolidated Statements of Operations and Comprehensive Loss (Parenthetical)	12 Months Ended
	Dec. 31, 2020
Consolidated Statements of Operations and Comprehensive Loss
Reverse stock split ratio	0.0333

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($)	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Total
Beginning Balance at Dec. 31, 2019	$ 2,000	$ 224,741,000	$ (219,160,000)	$ 5,583,000
Beginning Balance, (in shares) at Dec. 31, 2019	550,736
Share-based compensation expense		215,000		$ 215,000
Issuance of common stock upon vesting of restricted stock units (in shares)	100			584
Issuance of restricted common stock	$ 7,692
Issuance of common stock under ESPP	$ (584)
Issuance of common stock upon exercise of warrants (in shares)	8,618,089
Increase in fair value attributable to warrant modifications	$ 1,000	22,118,000		$ 22,119,000
Issuance of common stock and warrants in public offerings		343,000		343,000
Issuance of common stock and warrants in public offerings (in shares)	14,455,853
Net loss			(9,074,000)	(9,074,000)
Ending Balance at Dec. 31, 2020	$ 3,000	247,417,000	$ (228,234,000)	$ 19,186,000
Ending Balance, (in shares) at Dec. 31, 2020	23,631,886			23,631,886
Share-based compensation expense		$ 315,000		$ 315,000
Issuance of common stock upon vesting of restricted stock units (in shares)	100
Fractional shares issued due to reverse stock split		8,509,000		8,509,000
Forfeiture of restricted stock			(9,895,000)	(9,895,000)
Issuance of common stock upon exercise of warrants (in shares)	10,632,870
Net loss				$ (9,895,000)
Ending Balance at Dec. 31, 2021	$ 3,000	$ 256,241,000	$ (238,129,000)	$ 18,115,000
Ending Balance, (in shares) at Dec. 31, 2021	34,264,856			34,264,856

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical)	12 Months Ended
	Dec. 31, 2020
Consolidated Statements of Changes in Stockholders' Equity (Deficit)
Reverse stock split ratio	0.0333

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (9,895)	$ (9,074)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	44	46
Amortization of operating lease right-of-use assets	328	283
Share-based compensation expense	315	215
Changes in operating assets and liabilities:
Prepaid expenses	52	14
Accounts payable	124	(461)
Operating lease liability	(339)	(294)
Accrued expenses and other liabilities	517	(263)
Net cash used in operating activities	(8,854)	(9,534)
Cash flows from investing activities:
Purchases of property and equipment	(77)	(41)
Net cash used in investing activities	(77)	(41)
Cash flows from financing activities:
Proceeds from exercise of warrants	8,509	343
Proceeds from issuance of common stock and warrants, net of commissions and issuance costs		22,119
Net cash provided by financing activities	8,509	22,462
Increase / (decrease) in cash and cash equivalents and restricted cash	(422)	12,887
Cash, cash equivalents and restricted cash at end of period	19,181	19,603
Cash, cash equivalents and restricted cash at beginning of period	19,603	6,716
Supplemental disclosure of cash flow information and non-cash investing and financing activities:
Fair value of warrants issued in connection with financing activities		15,194
Right-of-use assets and lease liability recorded upon adoption of ASC 842	629
Restricted cash included in other non-current assets	150	110
Cash and cash equivalents	19,031	19,493
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 19,181	$ 19,603

NATURE OF OPERATIONS AND GOING

NATURE OF OPERATIONS AND GOING CONCERN	12 Months Ended
	Dec. 31, 2021
NATURE OF OPERATIONS AND GOING CONCERN
NATURE OF OPERATIONS AND GOING CONCERN	1. NATURE OF OPERATIONS AND GOING CONCERN ​ Business ​ InVivo Therapeutics Holdings Corp., including its subsidiary, (the “Company”) is a biomaterials and biotechnology company with a focus on the treatment of spinal cord injuries (“SCIs”). The Company’s proprietary technologies incorporate intellectual property that is licensed under an exclusive, worldwide license from Boston Children’s Hospital (“BCH”) and the Massachusetts Institute of Technology (“MIT”), as well as intellectual property that has been developed internally in collaboration with its advisors and partners. ​ Since its inception, the Company has devoted substantially all of its efforts to business planning, research and development, recruiting management and technical staff, acquiring operating assets, and raising capital. The Company has historically financed its operations primarily through the sale of equity-related securities. At December 31, 2021, the Company had consolidated cash and cash equivalents of $19.0 million. Given the Company’s current plans, the Company estimates cash resources will be sufficient to fund its operations through the second quarter of 2023. The Company has not achieved profitability and may not be able to realize sufficient revenue to achieve or sustain profitability in the future. The Company does not expect to be profitable in the next several years, but rather expects to incur additional operating losses. The Company has limited liquidity and capital resources and must obtain significant additional capital resources in order to sustain its product development efforts, for acquisition of technologies and intellectual property rights, for preclinical and clinical testing of its anticipated products, pursuit of regulatory approvals, acquisition of capital equipment, laboratory and office facilities, establishment of production capabilities, for selling, general and administrative expenses, and other working capital requirements. The Company may raise capital through a combination of equity offerings, debt financings, other third-party funding, marketing and distribution arrangements, and other collaborations, strategic alliances, and licensing arrangements. The Company believes that it can be successful in obtaining additional capital if it is successful in increasing its authorized shares available; however, no assurance can be provided that it will be able to do so. There is no assurance, moreover, that any funds raised will be sufficient to enable the Company to attain profitable operations or continue as a going concern. ​ The COVID-19 pandemic, which began in December 2019, has had impacts worldwide, causing many governments to implement measures to slow the spread of the outbreak through quarantines, travel restrictions, heightened border scrutiny, and other measures. The Company is aware that a significant number of its clinical sites had temporarily suspended enrollment into the INSPIRE 2.0 Study in 2020 at their institution due to the COVID-19 pandemic, and as such, the COVID-19 pandemic has affected and may continue to affect the potential for enrollment in the Company’s INSPIRE 2.0 Study if clinical sites suspend studies in order to manage the pandemic. As of, March 4, 2022, the Company has 16 clinical sites open for enrollment, which is the total number of sites currently activated for enrollment in the study. The full impact of the COVID-19 pandemic continues to evolve as of the date of filing this Annual Report on Form 10-K, and we cannot be certain what future impact the COVID-19 pandemic may have on our clinical sites and their respective abilities to enroll patients. As the pandemic continues to evolve, there may be additional government actions or disruptions that could cause our clinical sites to suspend or alter operations in a manner that would impact enrollment of the INSPIRE 2.0 Study. The Company is actively monitoring the impact of the global situation on its financial condition, liquidity, operations, suppliers, industry, and workforce, although there remains significant uncertainty related to the public health situation globally. Given the daily evolution of the COVID-19 pandemic and the global responses to curb its spread, the Company is not able to estimate the ultimate effects of the COVID-19 pandemic on its future results of operations, financial condition, or liquidity in the future. However, as the COVID-19 pandemic continues, it may continue to have an adverse effect on enrollment in the Company’s INSPIRE 2.0 Study, and may also have an adverse effect on the Company’s results of future operations, financial position, and liquidity, and even after the COVID-19 pandemic has subsided, the Company may continue to experience adverse impacts to its business as a result of any economic recession or depression that has occurred or may occur in the future. ​ Going Concern ​ The Company’s consolidated financial statements as of December 31, 2021 were prepared under the assumption that the Company will continue as a going concern. At December 31, 2021, the Company had cash and cash equivalents of $19.0 million. Given the Company’s current plans, the Company estimates cash resources will be sufficient to fund its operations through the second quarter of 2023. ​ The Company’s ability to continue as a going concern depends on its ability to obtain additional equity or debt financing, attain further operating efficiencies, manage expenditures, and, ultimately, to generate revenue. If the Company is unable to continue as a going concern, it may have to liquidate its assets and may receive less than the value at which those assets are carried on its audited financial statements, and it is likely that investors will lose all or part of their investment. ​ Authorized Shares ​ In January 2020, the Company’s stockholders approved an amendment to the Company’s Articles of Incorporation to increase the number of shares of authorized Common Stock from 25,000,000 to 500,000,000 (without giving effect to the 2020 Reverse Stock Split). On February 11, 2020, the Company effected the 2020 Reverse Stock Split and the number of shares of authorized Common Stock was reduced to 16,666,667. ​ On August 4, 2020, the Company held its 2020 Annual Meeting of Stockholders (the “Annual Meeting”). At the Annual Meeting, the Company’s stockholders approved an amendment to the Company’s Articles of Incorporation to increase the number of shares of authorized common stock from 16,666,667 to 50,000,000 shares. ​

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2021
SIGNIFICANT ACCOUNTING POLICIES
SIGNIFICANT ACCOUNTING POLICIES	2. SIGNIFICANT ACCOUNTING POLICIES ​ A summary of the significant accounting policies followed by the Company in the preparation of the financial statements is as follows: ​ Use of estimates ​ The process of preparing financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of assets and liabilities at the date of the financial statements and the reported amounts expensed during the reporting period. Actual results could differ from those estimates and changes in estimates may occur. ​ Basis of presentation and principles of consolidation ​ The consolidated financial statements include the accounts of InVivo Therapeutics Holdings Corp. and its wholly-owned subsidiary, InVivo Therapeutics Corporation. All significant intercompany balances and transactions have been eliminated in consolidation. The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. GAAP. ​ Cash and cash equivalents ​ The Company considers only those investments that are highly liquid, readily convertible to cash, and that mature within 3 months from date of purchase to be cash equivalents. As of December 31, 2021, the Company has cash balances in a financial institution in excess of insured limits. The Company has not experienced any losses related to these balances. Management believes it is not exposed to significant credit risk. At December 31, 2021 and 2020, cash equivalents were comprised primarily of money market funds. ​ Cash and cash equivalents consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ (In thousands) 2021 2020 Cash ​ $ 5 ​ $ (13) ​ Money market funds ​ 19,026 ​ 19,506 ​ Total cash and cash equivalents ​ $ 19,031 ​ $ 19,493 ​ ​ Restricted cash ​ Restricted cash as of December 31, 2021 and 2020 was $150 thousand and $110 thousand, respectively. Restricted cash as of December 31, 2021 included a $50 thousand security deposit related to the Company’s credit card account and a $100 thousand standby letter of credit in favor of a landlord (see Note 12). ​ Restricted cash as of December 31, 2020 included a $50 thousand security deposit related to the Company’s credit card account, and a $60 thousand standby letter of credit in favor of a landlord (see Note 12). ​ Fair Value of Financial instruments ​ The carrying amounts reported in the Company’s consolidated balance sheets for cash, cash equivalents and accounts payable approximate fair value based on the short-term nature of these instruments. ​ FASB Accounting Standards Codification (ASC) 820 Fair Value Measurements and Disclosures (ASC 820) defines fair value 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. ASC 820 also establishes a fair value hierarchy that distinguishes between (1) market participant assumptions developed based on market data obtained from independent sources (observable inputs) and (2) an entity’s own assumptions about market participant assumptions developed based on the best information available in the circumstances (unobservable inputs). The fair value hierarchy consists of three broad levels, which gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). The three levels of the fair value hierarchy are described below: ​ Level 1—Valuation is based on quoted prices in active markets for identical assets or liabilities. Level 1 assets and liabilities generally include debt and equity securities that are traded in an active exchange market. Valuations are obtained from readily available pricing sources for market transactions involving identical assets or liabilities. ​ Level 2—Valuation is based on observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. ​ Level 3—Valuation is based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. ​ Fair value estimates discussed herein are based upon certain market assumptions and pertinent information available to management as of December 31, 2021. The respective carrying value of certain on-balance-sheet financial instruments approximated their fair values due to the short-term nature of these instruments. These financial instruments include accounts payable and accrued expenses. ​ Property and equipment ​ Property and equipment of the Company is stated at cost. In accordance with ASC Topic 360 Property, Plant and Equipment, expenditure for fixed assets that substantially increase the useful lives of existing assets are capitalized at cost and depreciated. Routine expenditures for repairs and maintenance are expensed as incurred. Depreciation is provided principally on the straight-line method over the estimated useful lives of the asset. A summary of the estimated useful lives is as follows:: ​ ​ ​ ​ ​ Classification Estimated Useful Life Computer hardware 3 - 5 years ​ Software 3 years ​ Research and lab equipment 5 years ​ Leasehold improvements Remaining life of lease ​ ​ Research and development expenses ​ Costs incurred for research and development are expensed as incurred. Certain agreements require the Company to make pre-payments for clinical research organizations (“CROs”) services. As of December 31, 2021, the Company had $1.2 million in prepayments for CRO services of which $28 thousand is included in prepaid expense and other current assets balance on the balance sheet and the remaining $1.1 million is included within the other long term assets section of the balance sheet. As of December 31, 2020, the Company had $1.2 million in prepayments for CRO services of which $110 thousand is included in prepaid expense and other current assets balance on the balance sheet and the remaining $1.1 million is included within the other long term assets balance on the balance sheet. ​ Concentrations of credit risk ​ Financial instruments which potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents. The Company maintains cash in commercial banks, which may at times exceed Federally Insured limits. The Company has not experienced any loss in such accounts. The Company believes it is not exposed to any significant credit risk on cash and cash equivalents. ​ Segment information ​ Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, or decision making group, in making decisions regarding resource allocation and assessing performance. To date, the Company has viewed its operations and manages its business as principally one operating segment, which is developing and commercializing biopolymer scaffolding devices for the treatment of spinal cord injuries. As of December 31, 2021 and 2020, all of the Company’s assets were located in one location in the United States. ​ Income taxes ​ For federal and state income taxes, deferred tax assets and liabilities are recognized based upon temporary differences between the financial statement and the tax basis of assets and liabilities. Deferred income taxes are based upon prescribed rates and enacted laws applicable to periods in which differences are expected to reverse. A valuation allowance is recorded when it is more likely than not that some portion or all of the deferred tax assets will not be realized. Accordingly, the Company provides a valuation allowance, if necessary, to reduce deferred tax assets to amounts that are realizable. Tax positions taken or expected to be taken in the course of preparing the Company’s tax returns are required to be evaluated to determine whether the tax positions are “more-likely-than-not” of being sustained by the applicable tax authority. ​ Tax positions not deemed to meet a more-likely-than-not threshold would be recorded as a tax expense in 2021. There were no material uncertain tax positions that required accrual or disclosure to the financial statements as of December 31, 2021 or 2020. Tax years subsequent to 2018 remain open to examination by U.S. federal and state tax authorities. ​ Impairment of long-lived assets ​ The Company continually monitors events and changes in circumstances that could indicate that carrying amounts of long-lived assets may not be recoverable. An impairment loss is recognized when expected cash flows are less than an asset’s carrying value. Accordingly, when indicators of impairment are present, the Company evaluates the carrying value of such assets in relation to the operating performance and future undiscounted cash flows of the underlying assets. The Company’s policy is to record an impairment loss when it is determined that the carrying value of the asset may not be recoverable. ​ Share-based payments ​ The Company accounts for all stock-based payment awards granted to employees and nonemployees using the fair value method. The Company’s stock-based payments include stock options and grants of common stock, including common stock subject to vesting. The measurement date for both employee and nonemployee awards is the date of grant, and stock-based compensation costs are recognized as expense over the employees’ requisite service period, which is the vesting period, on a straight-line basis. Stock-based compensation costs for nonemployees are recognized as expense over the vesting period on a straight-line basis. Stock-based compensation is classified in the accompanying consolidated statements of operations and comprehensive loss based on the department to which the related services are provided. ​ Derivative instruments ​ The Company generally does not use derivative instruments to hedge exposures to cash-flow or market risks. In the past certain of the Company’s issued and outstanding warrants to purchase common stock previously contained anti-dilution provisions. These warrants did not meet the requirements for classification as equity and were thus recorded as derivative warrant liabilities. In such instances, net-cash settlement is assumed for financial reporting purposes, even when the terms of the underlying contracts do not provide for a net-cash settlement. Such financial instruments are initially recorded at fair value, with subsequent changes in fair value recorded to operations in each reporting period. If these instruments subsequently meet the requirements for classification as equity, the Company reclassifies the fair value to equity. ​ Net loss per common share ​ Basic and diluted net loss per share of common stock has been computed by dividing net loss by the weighted average number of shares outstanding during the period as follows: ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2021 ​ ​ 2020 Numerator: ​ ​ ​ ​ ​ Net Loss (in thousands) $ (9,895) ​ $ (9,074) ​ ​ ​ ​ ​ ​ Denominator: ​ ​ ​ ​ ​ Weighted average shares used in calculating net loss per share — basic diluted ​ 33,078,659 ​ ​ 6,902,693 Net loss per share — basic and diluted $ (0.30) ​ $ (1.31) ​ ​ In a net loss period, options, warrants, unvested restricted stock units and convertible securities are anti-dilutive and therefore excluded from diluted loss per share calculations. ​ For the year ended December 31, 2021 and 2020, the following potentially dilutive securities were not included in the computation of net loss per share because the effect would be anti-dilutive: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ ​ 2020 Warrants ​ 14,078,338 ​ ​ 24,714,084 Stock options ​ 364,005 ​ ​ 4,169 Unvested RSUs ​ — ​ ​ 100 Unvested RSAs ​ 6,302 ​ ​ 6,302 Total potentially dilutive securities ​ 14,448,645 ​ ​ 24,724,655 ​ New Accounting Pronouncements ​ In May 2021 Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2021-04, “Earnings Per Share (Topic 260), Debt-Modifications and Extinguishments (Subtopic 470-50), Compensation-Stock Compensation (Topic 718), and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40): Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options, a consensus of the Emerging Issues Task Force”. This ASU amends the FASB Accounting Standards Codification (“ASC”) to provide explicit guidance, and, thus, reduce diversity in practice, on accounting by issuers for modifications or exchanges of freestanding equity-classified written call options that remain equity classified after the modification or exchange. This amendment provides that for an entity that presents earnings per share (EPS) in accordance with Topic 260, the effects of a modification or an exchange of a freestanding equity-classified written call option that is recognized as a dividend should be an adjustment to net income (or net loss) in the basic EPS calculation. The amended guidance becomes mandatorily effective for all entities for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years, and should be applied prospectively to modifications or exchanges occurring on or after the effective date. ASU No. 2021- 04 is effective for the Company beginning in fiscal 2022. The Company will adopt ASU 2021-04 effective January 1, 2022, and it is expected that the adoption will not have a material impact to the Company's consolidated financial statements. ​ In January 2020, the FASB issued ASU No. 2020-01 “Investments—Equity Securities (Topic 321), Investments—Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815) —clarifying the interactions between Topic 321, Topic 323 and Topic 815 (a consensus of the emerging issues task force)”. The amendments in this ASU clarify the interaction between the accounting for investments in equity securities, investment in equity method and certain derivatives instruments. The ASU is expected to reduce diversity in practice and increase comparability of the accounting for these interactions. The pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2021. ASU No. 2020- 01 is effective for the Company beginning in fiscal 2022. The Company will adopt ASU 2021-01 effective January 1, 2022, and it is expected that the adoption will not have a material impact to the Company's consolidated financial statements. ​ No other accounting standards known by the Company to be applicable to it that have been issued by the FASB or other standard-setting bodies and that do not require adoption until a future date are expected to have a material impact on the Company’s consolidated financial statements upon adoption. ​

PROPERTY AND EQUIPMENT

PROPERTY AND EQUIPMENT	12 Months Ended
	Dec. 31, 2021
PROPERTY AND EQUIPMENT
PROPERTY AND EQUIPMENT	3. PROPERTY AND EQUIPMENT ​ Property and equipment, net consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ (In thousands) 2021 2020 Computer hardware ​ $ 52 ​ $ 35 ​ Computer Software ​ ​ 5 ​ ​ 5 ​ Research and lab equipment ​ 580 ​ 520 ​ Leasehold improvements ​ 66 ​ 66 ​ Property and equipment ​ ​ 703 ​ ​ 626 ​ Less accumulated depreciation ​ (576) ​ (541) ​ Property and equipment, net ​ $ 127 ​ $ 85 ​ ​ Depreciation expense for the years ended December 31, 2021 and 2020, was $35 thousand, and $29 thousand, respectively. Maintenance and repairs are charged to expense as incurred and any additions or improvements are capitalized. ​ The Company did not write off any assets during the year ended December 31, 2021. During the year ended December 31, 2020, the Company wrote off $132 thousand of fully depreciated computer software and hardware assets that were no longer in use.

INTANGIBLE ASSETS

INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2021
INTANGIBLE ASSETS
INTANGIBLE ASSETS	4. INTANGIBLE ASSETS ​ Intangible assets consisted of patent licensing fees paid to license intellectual property. In July 2007, the Company entered into a worldwide exclusive license (the “BCH License”) for patents co-owned by BCH and MIT initially covering the use of biopolymers to treat spinal cord injuries, and to promote the survival and proliferation of human stem cells in the spinal cord. During 2011, the BCH License was amended, and the Company obtained additional rights for use in the field of peripheral nerve injuries. The BCH License, as amended, has a 15 year term, or as long as the life of the last expiring patent right thereunder, whichever is longer, unless terminated earlier by the licensor, under certain conditions as defined in the related license agreement. The last expiring patent under the BCH License currently expires in 2027. In connection with the BCH License, the Company paid an initial $75 thousand licensing fee and is required to pay certain annual maintenance fees, milestone payments and royalties. License fees are capitalized and the gross total at December 31, 2021 and 2020 was $200 thousand. The Company accounts for milestone payments, maintenance fees and royalties when they become due and payable. The Company paid $10 thousand in maintenance fees during each of the years ended December 31, 2021 and 2020. The Company is amortizing the license fee as a research and development expense over the 15 – year term of the license. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ (In thousands) 2021 2020 Patent licensing fee ​ $ 200 ​ $ 200 ​ Accumulated amortization ​ (200) ​ (191) ​ Intangible assets ​ $ — ​ $ 9 ​ ​ For the years ended December 31, 2021 and 2020, amortization expense was $9 thousand and $13 thousand respectively. As of December 31, 2021 the license fee had been fully amortized.

ACCRUED EXPENSES

ACCRUED EXPENSES	12 Months Ended
	Dec. 31, 2021
ACCRUED EXPENSES.
ACCRUED EXPENSES	5. ACCRUED EXPENSES ​ Accrued expenses consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, (In thousands) 2021 2020 Compensation ​ $ 1,287 ​ $ 996 ​ Clinical ​ 218 ​ ​ 5 ​ Other accrued expenses ​ 141 ​ ​ 163 ​ Total accrued expenses ​ $ 1,646 ​ $ 1,164 ​ ​

FAIR VALUES OF ASSETS AND LIABI

FAIR VALUES OF ASSETS AND LIABILITIES	12 Months Ended
	Dec. 31, 2021
FAIR VALUES OF ASSETS AND LIABILITIES
FAIR VALUES OF ASSETS AND LIABILITIES	6. FAIR VALUES OF ASSETS AND LIABILITIES ​ The Company groups its assets and liabilities generally measured at fair value in 3 levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. Refer to Note 2, "Significant Accounting Policies," for additional information on the accounting policies related to fair value. ​ Assets and liabilities measured at fair value on a recurring basis are summarized below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2021 ​ (In thousands) Level 1 Level 2 Level 3 Fair Value ​ Cash equivalents ​ $ 19,026 ​ $ — ​ $ — ​ $ 19,026 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2020 ​ (In thousands) Level 1 Level 2 Level 3 Fair Value ​ Cash equivalents ​ $ 19,506 ​ $ — ​ $ — ​ $ 19,506 ​ ​ ​

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2021
INCOME TAXES
INCOME TAXES	7. INCOME TAXES ​ No provision or benefit for federal or state income taxes has been recorded as the Company has incurred a net loss for all of the periods presented and the Company has provided a full valuation allowance against its deferred tax assets. ​ At December 31, 2021, the Company had U.S. federal and Massachusetts net operating loss carryforwards of $158.5 million and $140.8 million, respectively, of which $117.3 million of federal carryforwards will expire in varying amounts beginning in 2026 and $41.3 million carry forward indefinitely. State net operating losses begin to expire in 2029. Utilization of net operating losses and tax credit carryforwards may be subject to substantial annual limitations due to the “change in ownership” provisions of the Internal Revenue Code, and similar state provisions. The annual limitations may result in the expiration of net operating losses before utilization. The Company has completed several financings since its inception, which may have resulted in a change in ownership, or could result in a change in ownership in the future but has not yet completed a Section 382 analysis of whether an ownership change limitation exists. The Company will complete an appropriate analysis before its tax attributes are utilized. The Company also had federal and state research and development tax credits of $1.5 million and $0.2 million respectively, at December 31, 2021, which will begin to expire in 2026 and 2030, respectively, unless previously utilized. ​ Significant components of the Company’s net deferred tax assets are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ (In thousands) 2021 2020 Net operating loss carryforward ​ $ 42,696 ​ $ 40,175 ​ Research and development credit carryforward ​ 1,663 ​ 1,608 ​ Stock-based compensation ​ 431 ​ 421 ​ Depreciation and amortization ​ 17 ​ 16 ​ Accrued expenses ​ — ​ 7 ​ Lease liability ​ ​ 344 ​ ​ 279 ​ Right of use asset ​ ​ (323) ​ ​ (253) ​ Subtotal ​ 44,828 ​ 42,253 ​ Valuation allowance ​ (44,828) ​ (42,253) ​ Net deferred taxes ​ $ — ​ $ — ​ ​ The Company has maintained a full valuation allowance against its deferred tax assets in all periods presented. A valuation allowance is required to be recorded when it is more likely than not that some portion or all of the net deferred tax assets will not be realized. Since the Company cannot be assured of generating taxable income and thereby realizing the net deferred tax assets, a full valuation allowance has been provided. In the years ended December 31, 2021 and 2020, the valuation allowance increased by $2.6 million and $0.6 million, respectively. ​ The Company has no uncertain tax positions at December 31, 2021 and 2020 that would affect its effective tax rate. The Company does not ​ Income tax benefits computed using the federal statutory income tax rate differ from the same benefits computed using the Company’s effective tax rate primarily due to the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2021 2020 Statutory rate ​ (21.0) % (21.0) % State taxes, net of benefit (4.7) % (5.8) % Permanent differences ​ 0.4 % 0.3 % Research and development tax credit (0.9) % (1.1) % Stock-based compensation ​ 0.2 % 21.2 % Increase in valuation reserve 26.0 % 6.4 % Effective tax rate 0.0 % 0.0 % ​ The Company is subject to U.S. Federal and Massachusetts state income taxes. The statute of limitations for assessment by the Internal Revenue Service or state tax authority is generally open for the tax years ending December 31, 2018 through December 31, 2021, however federal and state tax attributes that were generated prior to the tax year ending December 31, 2017 may still be adjusted upon examination by the Internal Revenue Service or stat tax authority if the attributes either have been, or will be, used in a future period . ​ On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security (CARES) Act was signed into law making several changes to the Internal Revenue Code. The changes include, but are not limited to: increasing the limitation on the amount of deductible interest expense, allowing companies to carryback certain net operating losses, and increasing the amount of net operating loss carryforwards that corporations can use to offset taxable income. The tax law changes in the Act did not have a material impact on the Company’s income tax provision .

COMMON STOCK

COMMON STOCK	12 Months Ended
	Dec. 31, 2021
COMMON STOCK.
COMMON STOCK	8. COMMON STOCK ​ On January 21, 2020, the Company held its 2019 Annual Meeting of Stockholders (the “2019 Annual Meeting”). At the 2019 Annual Meeting, the Company’s stockholders approved an amendment to the Company’s Articles of Incorporation to increase the number of shares of authorized common stock from 25,000,000 to 500,000,000 (without giving effect to the 2020 Reverse Stock Split). On February 11, 2020, the Company effected the 2020 Reverse Stock Split and the number of shares of authorized common stock was reduced to 16,666,667. On August 4, 2020, the Company held its 2020 Annual Meeting of Stockholders (the “2020 Annual Meeting”). At the 2020 Annual Meeting, the Company’s stockholders approved an amendment to the Company’s Articles of Incorporation to increase the number of shares of authorized common stock from 16,666,667 to 50,000,000 shares. As of December 31, 2021 and 2020, 34,264,856 and 23,631,886 shares were issued and outstanding respectively. ​ In October 2020, the Company completed a registered public offering (the “October 2020 Offering”) in which it sold an aggregate of (i) 11,785,000 shares of common stock, (the “October 2020 Shares”) and Series A Warrants exercisable for an aggregate of 11,785,000 shares of the Company’s common stock (the “October 2020 Series A Warrants”) at a combined public offering price of of the aggregate number of shares of common stock and October 2020 Series B Pre-funded Warrants sold in the October 2020 Offering. The October 2020 Placement Agent Warrants have an exercise price of ​ In April 2020, the Company entered into a securities purchase agreement (the "April 2020 Purchase Agreement") with certain institutional investors (the "April 2020 Purchasers"), pursuant to which the Company agreed to sell and issue, in a registered direct offering, an aggregate of 1,715,240 of common stock, at a purchase price per share of $1.75 (the "April 2020 Shares"; the offering, the “April 2020 Registered Offering”). The April 2020 Shares were offered by the Company pursuant to a shelf registration statement on Form S-3, which was declared effective by the SEC on November 14, 2019 (File No. 333-234353) and a prospectus supplement thereunder. Pursuant to the April 2020 Purchase Agreement, in a concurrent private placement, the Company also issued to the April 2020 Purchasers warrants (the "April 2020 Series C Warrants") to purchase up to 1,715,240 shares of common stock (the "Private Placement" and together with the April 2020 Registered Offering, the "April 2020 Offerings"). The April 2020 Series C Warrants are exercisable immediately at an exercise price of $1.62 per share of common stock, subject to adjustment in certain circumstances, and expire on October 17, 2025. In connection with the April 2020 Offerings, the Company also issued to Wainwright warrants to purchase an aggregate of 111,491 shares of the Company’s common stock (“April 2020 Placement Agent Warrants”) which represents a number of shares of common stock equal to 6.5% of the aggregate number of April 2020 Shares sold in the April 2020 Registered Offering, at an exercise price of $2.1875 per share with a term expiring on April 15, 2025. The net proceeds to the Company, after deducting Wainwright's placement agent fees and other offering expenses payable by the Company, were approximately $2.6 million. The Company assessed whether the April 2020 Series C Warrants, and the April 2020 Placement Agent Warrants required accounting as derivatives and determined that they were (1) indexed to the Company’s own stock and (2) classified in stockholders’ equity in accordance with ASC Topic 815, Derivatives and Hedging. As such, the Company concluded that the April 2020 Series C Warrants and the April 2020 Placement Agent Warrants meet the scope exception for determining whether the instruments require accounting as derivatives and accordingly are classified in stockholders’ equity. The fair value of the April 2020 Series C Warrants was estimated at $2.1 million, using a Black-Scholes model with the following assumptions: expected volatility of 115.84%, risk free interest rate of 0.40%, expected life of five and a half ​ In March 2020, the Company completed a registered public offering (the “March 2020 Offering”) in which it sold an aggregate of (i) 955,613 shares of common stock (the “March 2020 Shares”) and Series A Warrants exercisable for an aggregate of amount, as they were substantially pre-funded. During the year ended December 31, 2020, the Company did not issue any shares as a result of the March 2020 Placement Agent Warrants or March 2020 Series A Warrants exercise activity. ​ During the year ended December 31, 2021, there was no exercise activity related to any of the warrants that were issued in 2018 and 2019. During the year ended December 31, 2020, the Company issued an aggregate of 40,975 shares of common stock upon the exercise of certain warrants issued in 2018 for aggregate proceeds of $286 thousand. ​ During each of the years ended December 31, 2021 and 2020, the Company issued an aggregate of 100 shares of common stock upon vesting of restricted stock units. ​ During the year ended December 31, 2019, the Company issued an aggregate 6,886 restricted stock awards (“RSAs”) to its employees under the 2015 Equity Incentive Plan. These awards are considered issued and outstanding based on the dividend payment rights and the conveyance of voting rights that was granted to the grant holders. During year ended December 31, 2020, 584 restricted stock awards that were considered issued and outstanding as of December 31, 2019 were forfeited. ​ During the year ended December 31, 2020, as part of the adjustment to reflect the 2020 Reverse Stock Split, the Company issued an aggregate of 7,692 shares of common stock to account for the fractional roundup of shareholders. ​ Common Stock Reserves ​ As of December 31, 2021, the Company had the following reserves established for the future issuance of common stock as follows: ​ ​ ​ ​ ​ ​ ​ As of December 31, 2021 ​ Reserves for the exercise of warrants 14,078,338 ​ Reserves for the exercise of stock options 364,005 ​ Total Reserves 14,442,343 ​ ​

SHARE-BASED COMPENSATION, STOCK

SHARE-BASED COMPENSATION, STOCK OPTIONS, AND RESTRICTED SECURITIES	12 Months Ended
	Dec. 31, 2021
SHARE-BASED COMPENSATION, STOCK OPTIONS, AND RESTRICTED SECURITIES
SHARE-BASED COMPENSATION, STOCK OPTIONS, AND RESTRICTED SECURITIES	9. SHARE-BASED COMPENSATION, STOCK OPTIONS, AND RESTRICTED SECURITIES ​ On October 26, 2010, the Company’s Board of Directors adopted, and the Company’s shareholders subsequently approved, the 2010 Equity Incentive Plan (as subsequently amended, the “2010 Plan”). The 2010 Plan provided for grants of incentive stock options to employees, and nonqualified stock options and restricted common stock to employees, consultants, and non-employee directors of the Company. ​ In April 2015, the Company’s Board of Directors adopted, and the Company’ shareholders subsequently approved, the 2015 Equity Incentive Plan (the “2015 Plan”). The 2015 Plan provides for grants of incentive stock options to employees, and nonqualified stock, restricted common stock, restricted stock units and stock appreciation rights to employees, consultants, and directors of the Company. ​ As of December 31, 2021, the total number of shares available to be issued under the 2015 Plan was 2,767,436 shares, consisting of, (i) 5,333 shares initially authorized under the 2015 Plan shares plus (ii) the shares that remained available for grant under the 2010 Plan at the time of its termination adjusted for cumulative cancellations, forfeitures and issuances from the 2010 Plan and 2015 Plan, (iii) the 26,667 shares approved for increase during the January 2020 shareholders meeting (iv) the 400,000 shares approved for increase during the August 2020 shareholders meeting and, the 2,700,000 shares approved for increase during the Company’s 2021 Annual Meeting of Stockholders. While 2,767,436 shares are available to be issued under the 2015 Plan as of December 31, 2021, only 1,292,801 shares can be issued under the 2015 Plan due to restrictions on the usage of the 2015 Plan resulting from the total number of shares of common stock authorized under the Company’s certificate of incorporation. ​ Options issued under the 2010 Plan ​ Share-based compensation ​ For the years ended December 31, 2021 and 2020, Stock-based compensation recognized was classified in the consolidated statements of operations as follows: ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands) 2021 ​ 2020 Research and development $ 22 ​ $ 40 General and administrative ​ 293 ​ ​ 175 Total $ 315 ​ $ 215 ​ ​ ​ ​ ​ ​ ​ The fair value of each option award is estimated on the date of grant using the Black-Scholes option pricing model, which uses the assumptions noted in the following table. The Company uses historical data, as well as subsequent events occurring prior to the issuance of the financial statements, to estimate option exercises within the valuation model. The expected term of options granted under the Plans, all of which qualify as “plain vanilla,” is based on the average of the contractual term (10 years) and the vesting period (generally, 48 months ​ The Company did not grant any awards during year ended December 31, 2020. The assumptions used principally in determining the fair value of options granted during the year ended December 31, 2021, were as follows: ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ Risk-free interest rate 1.03% ​ ​ Expected dividend yield 0% ​ ​ Expected term (employee grants) 5.70 ​ ​ Expected volatility 117.34% ​ ​ ​ The Company grants restricted stock units, or RSUs, and RSAs, collectively referred to as restricted securities under the 2015 Equity Incentive Plan. These restricted securities generally vest over a three-year period, contingent on the recipient’s continued employment. Prior to vesting, all RSAs have the right to vote and receive dividends under the 2015 Equity Incentive Plan; however, the Company’s form of Restricted Stock Agreement provides that the payment of dividends on unvested RSAs shall be deferred until such time as the shares vest. The grant date fair value of these awards is based on the fair market value of our common stock on the date of grant. ​ Stock Options ​ A summary of option activity as of December 31, 2021 and changes for the year then ended are presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ Average ​ ​ ​ ​ ​ ​ ​ Average ​ ​ Remaining Aggregate ​ ​ ​ ​ Exercise ​ ​ Contractual Intrinsic Options Shares Price ​ Term in Years Value Outstanding as of December 31, 2020 4,169 ​ $ 1,054.01 ​ 7.18 ​ $ — Granted 360,000 ​ $ 1.10 ​ ​ ​ ​ ​ ​ Cancelled/Forfeited ​ (147) ​ $ 6,324.03 ​ ​ ​ ​ ​ ​ Expired ​ (17) ​ $ 5,940.00 ​ ​ ​ ​ ​ ​ Outstanding as of December 31, 2021 364,005 ​ $ 10.33 ​ ​ 9.18 ​ $ — Vested and Exercisable as of December 31, 2021 3,005 ​ $ 1,104.04 ​ ​ 6.17 ​ $ — Vested and expected to vest as of December 31, 2021 364,005 ​ $ 10.33 ​ 9.18 ​ $ — ​ The Company did not grant any awards during the year ended December 31, 2020. The Company granted 360,000 stock options during the year ended December 31, 2021. The weighted average grant-date fair value of options granted during the year ended December 31, 2021 was $0.93 per share. The total fair value of options that vested in years ended December 31, 2021 and 2020, was $67 thousand and $117 thousand, respectively. For the years ended December 31, 2021 and 2020, the Company recorded stock-based compensation expense of $219 thousand and $117 thousand, respectively, related to stock options. As of December 31, 2021, there was $176 thousand of total unrecognized compensation expense related to non-vested share-based option compensation arrangements. The unrecognized compensation expense is estimated to be recognized over a remaining weighted-average period of 1.12 years at December 31, 2021. ​ Restricted Securities ​ A summary of restricted securities activity as of December 31, 2021 and changes for the year then ended are presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average Restricted Securities Number of Grants Grant Date Fair Value Unvested balance as of December 31, 2020 ​ 6,402 ​ $ 25.67 Vested ​ (100) ​ $ 660.00 Unvested balance as of December 31, 2021 ​ 6,302 ​ $ 15.60 ​ For years ended December 31, 2021 and 2020, the Company recorded stock-based compensation expense of $96 thousand and $98 thousand respectively, related to the time-based restricted securities. As of December 31, 2021, total unrecognized compensation expense related to non-vested restricted securities amounted to $24 thousand which the Company expects to recognize over a remaining weighted-average period of 0.73 years. All the restricted securities that remain unvested and outstanding at December 31, 2021 are subject to time-based vesting.

WARRANTS

WARRANTS	12 Months Ended
	Dec. 31, 2021
WARRANTS
WARRANTS	10. WARRANTS ​ The following table presents information about warrants to purchase common stock issued and outstanding at December 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of Exercise Price as of ​ ​ Year Issued ​ Defined Name ​ Classification ​ Warrants ​ September 30, 2021 ​ Date of Expiration ​ 2018 ​ 2018 Series A Warrants ​ Equity ​ 211,921 ​ $ 6.98 ​ 6/25/2023 ​ 2019 ​ 2019 Placement Agent Warrants ​ Equity ​ 15,168 ​ $ 4.50 ​ 11/21/2024 ​ 2020 ​ March 2020 Series A Warrants ​ Equity ​ 2,545,455 ​ $ 2.75 ​ 3/10/2025 ​ 2020 ​ March 2020 Placement Agent Warrants ​ Equity ​ 165,455 ​ $ 3.4375 ​ 3/5/2025 ​ 2020 ​ March 2020 Series B Warrants ​ Equity ​ 12,728 ​ $ 0.00001 ​ Until Fully Exercised ​ 2020 ​ April 2020 Series C Warrants ​ Equity ​ 1,680,240 ​ $ 1.62 ​ 10/17/2025 ​ 2020 ​ April 2020 Placement Agent Warrants ​ Equity ​ 111,491 ​ $ 2.1875 ​ 4/15/2025 ​ 2020 ​ October 2020 Placement Agent Warrants ​ Equity ​ 1,206,562 ​ $ 1.00 ​ 10/22/2025 ​ 2020 ​ October 2020 Series A Warrants ​ Equity ​ 8,129,318 ​ $ 0.80 ​ 10/27/2025 ​ Total ​ ​ ​ ​ 14,078,338 ​ ​ ​ ​ ​ ​ Weighted average exercise price ​ ​ ​ $ 1.41 ​ ​ ​ Weighted average life in years ​ ​ ​ ​ ​ 3.66 ​ ​

EMPLOYEE BENEFIT PLAN

EMPLOYEE BENEFIT PLAN	12 Months Ended
	Dec. 31, 2021
EMPLOYEE BENEFIT PLAN
EMPLOYEE BENEFIT PLAN	11. EMPLOYEE BENEFIT PLAN ​ In November 2006, the Company adopted a 401(k) plan (the “Plan”) covering all employees. Employees must be 21 years of age in order to participate in the Plan. Under the Plan, the Company has the option to make matching contributions. During the years ended December 31, 2021 and 2020, the Company contributed $69 thousand and $60 thousand, respectively, in cash matching contributions to employee 401(k) accounts.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2021
COMMITMENTS AND CONTINGENCIES
COMMITMENTS AND CONTINGENCIES	12. COMMITMENTS AND CONTINGENCIES ​ Operating Leases ​ On May 3, 2018, the Company entered into a sublease for 5,104 square feet of space for its corporate offices and laboratory space in Cambridge Massachusetts (the “Cambridge Lease”). The Cambridge Lease commenced on May 3, 2018 and was scheduled to expire on October 31, 2023. In May 2021, the Company entered into an agreement to terminate the Cambridge Sublease (the “Sublease Termination”). In connection with the Sublease Termination, the $60 thousand standby letter of credit was cancelled and returned to the Company. ​ Concurrent with the Sublease Termination, the Company entered into a new lease for the same space with ARE-MA (the “Cambridge Lease”). The Cambridge Lease commenced on June 1, 2021 and was originally scheduled to expire on December 31, 2023. The Cambridge Lease contained rent escalation clauses. In connection with the Cambridge Lease, a new standby letter of credit was established for $100 thousand. Under the Cambridge Lease, the Company will be required to pay its proportionate share of certain operating costs and property taxes applicable to the leased premises in excess of new base year amounts. These costs are considered to be variable lease payments and are not included in the determination of the lease’s right-of-use asset or lease liability. The Sublease Termination and concurrent execution of the Cambridge Lease was determined to be a lease modification that qualified as a change of accounting on the existing lease and not a separate contract. As such, the right-of-use assets and operating lease liabilities were remeasured using an incremental borrowing rate at the date of modification of 5.74%, which resulted in an increase of $143 thousand in both the right-of-use asset and operating lease liabilities. On November 23, 2021, the Company amended the Cambridge Lease to extend the term through December 31, 2024. No other terms within the Cambridge Lease were amended. The amendment of the Cambridge Lease was determined to be a lease modification that qualified as a change of accounting on the existing lease and not a separate contract. As such, the right-of-use assets and operating lease liabilities were remeasured using an incremental borrowing rate at the date of modification of 5.97%, which resulted in an increase of $486 thousand in both the right-of-use asset and operating lease liabilities. The Company identified and assessed the following significant assumptions in recognizing its right-of-use assets and corresponding lease liabilities: ● As the Cambridge Lease does not provide an implicit rate, the Company estimated the incremental borrowing rate in calculating the present value of the lease payments. ● Since the Company elected to account for each lease component and its associated non-lease components as a single combined component, all contract consideration was allocated to the combined lease component. ● The expected lease terms include noncancelable lease periods. The elements of lease expense are as follows: ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, Lease cost (In thousands) 2021 2020 Operating lease cost $ 392 ​ $ 364 Short-term lease cost ​ 3 ​ ​ 21 Variable lease cost ​ 95 ​ ​ 139 Total lease cost $ 490 ​ $ 524 ​ ​ ​ ​ ​ ​ Other information (In thousands) ​ ​ ​ ​ ​ Increase in operating right-of-use assets and liabilities related to lease modifications $ 629 ​ $ — Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ Operating cash flows from short term leases $ 3 ​ $ 21 Operating cash flows from operating leases ​ 403 ​ ​ 375 Total cash paid for leases $ 406 ​ $ 396 Weighted-average remaining lease term - operating leases ​ 3 ​ ​ 2.83 Years Weighted-average discount rate - operating leases ​ 6.0% ​ ​ 7.0% ​ Maturities of lease liabilities due under the Company’s Cambridge Lease as of December 31, 2021 is as follows: ​ ​ ​ ​ ​ Leases (In thousands) As of December 31, 2021 2022 $ 427 ​ 2023 ​ 440 ​ 2024 ​ 568 ​ Total lease payments ​ 1,435 ​ Less: imputed interest ​ (125) ​ Present value of lease liabilities $ 1,310 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Leases (In thousands) ​ Classification December 31, 2021 ​ December 31, 2020 Assets ​ ​ ​ ​ ​ ​ ​ ​ Lease asset, net ​ Operating ​ $ 1,229 ​ $ 928 Total lease assets ​ ​ ​ $ 1,229 ​ $ 928 ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ Current ​ Operating ​ $ 361 ​ $ 327 Non-current ​ Operating ​ ​ 949 ​ ​ 693 Total lease liabilities ​ ​ ​ $ 1,310 ​ $ 1,020 ​ Clinical Trial Commitments The Company has engaged and executed contracts with clinical research organizations (“CROs”) to assist with the administration of its ongoing INSPIRE 1.0 and INSPIRE 2.0 clinical trials. As of December 31, 2021, approximately $4.3 million remains to be paid on these contracts. The timelines and related costs necessary to complete these trials may vary depending on a number of factors including the rate of patient enrollment into our INSPIRE 2.0 trial. In the event the Company were to close the INSPIRE 2.0 trial, certain financial penalties would become payable to the CROs for costs to wind down the closed trial.

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2021
RELATED PARTY TRANSACTIONS.
RELATED PARTY TRANSACTIONS	13. RELATED PARTY TRANSACTIONS ​ In our October 2020 Offering, the Company sold shares of our common stock and warrants to three investors that, based on Schedule 13-G filings with the SEC, owned more than 5% of our outstanding shares at the time of our October 2020 Offering: Sabby Volatility Warrant Master Fund, Ltd., which acquired 535,000 shares of the Company’s common stock and warrants to purchase 3,215,000 shares of the Company’s common stock; Intracoastal Capital, LLC, which acquired 500,000 shares of the Company’s common stock and warrants to purchase 2,000,000 shares of the Company’s common stock; and CVI Investments, Inc., which acquired 500,000 shares of the Company’s common stock and warrants to purchase 500,000 shares of the Company’s common stock. ​ In addition, in the March 2020 Offering, Dr. Toselli, Mr. Christopher Ms. Merrifield Mr. Christopher Ms. Merrifield ​ During the year ended December 31, 2021, the Company did not identify any related party transactions requiring disclosure. ​

NATURE OF OPERATIONS AND GOIN_2

NATURE OF OPERATIONS AND GOING CONCERN (Policy)	12 Months Ended
	Dec. 31, 2021
NATURE OF OPERATIONS AND GOING CONCERN
Going Concern	Going Concern ​ The Company’s consolidated financial statements as of December 31, 2021 were prepared under the assumption that the Company will continue as a going concern. At December 31, 2021, the Company had cash and cash equivalents of $19.0 million. Given the Company’s current plans, the Company estimates cash resources will be sufficient to fund its operations through the second quarter of 2023. ​ The Company’s ability to continue as a going concern depends on its ability to obtain additional equity or debt financing, attain further operating efficiencies, manage expenditures, and, ultimately, to generate revenue. If the Company is unable to continue as a going concern, it may have to liquidate its assets and may receive less than the value at which those assets are carried on its audited financial statements, and it is likely that investors will lose all or part of their investment.

SIGNIFICANT ACCOUNTING POLICI_2

SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2021
NATURE OF OPERATIONS AND GOING CONCERN
Use of estimates	Use of estimates ​ The process of preparing financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of assets and liabilities at the date of the financial statements and the reported amounts expensed during the reporting period. Actual results could differ from those estimates and changes in estimates may occur.
Basis of presentation and principles of consolidation	Basis of presentation and principles of consolidation ​ The consolidated financial statements include the accounts of InVivo Therapeutics Holdings Corp. and its wholly-owned subsidiary, InVivo Therapeutics Corporation. All significant intercompany balances and transactions have been eliminated in consolidation. The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. GAAP.
Cash and cash equivalents	Cash and cash equivalents ​ The Company considers only those investments that are highly liquid, readily convertible to cash, and that mature within 3 months from date of purchase to be cash equivalents. As of December 31, 2021, the Company has cash balances in a financial institution in excess of insured limits. The Company has not experienced any losses related to these balances. Management believes it is not exposed to significant credit risk. At December 31, 2021 and 2020, cash equivalents were comprised primarily of money market funds. ​ Cash and cash equivalents consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ (In thousands) 2021 2020 Cash ​ $ 5 ​ $ (13) ​ Money market funds ​ 19,026 ​ 19,506 ​ Total cash and cash equivalents ​ $ 19,031 ​ $ 19,493 ​
Restricted cash	Restricted cash ​ Restricted cash as of December 31, 2021 and 2020 was $150 thousand and $110 thousand, respectively. Restricted cash as of December 31, 2021 included a $50 thousand security deposit related to the Company’s credit card account and a $100 thousand standby letter of credit in favor of a landlord (see Note 12). ​ Restricted cash as of December 31, 2020 included a $50 thousand security deposit related to the Company’s credit card account, and a $60 thousand standby letter of credit in favor of a landlord (see Note 12).
Financial instruments	Fair Value of Financial instruments ​ The carrying amounts reported in the Company’s consolidated balance sheets for cash, cash equivalents and accounts payable approximate fair value based on the short-term nature of these instruments. ​ FASB Accounting Standards Codification (ASC) 820 Fair Value Measurements and Disclosures (ASC 820) defines fair value 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. ASC 820 also establishes a fair value hierarchy that distinguishes between (1) market participant assumptions developed based on market data obtained from independent sources (observable inputs) and (2) an entity’s own assumptions about market participant assumptions developed based on the best information available in the circumstances (unobservable inputs). The fair value hierarchy consists of three broad levels, which gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). The three levels of the fair value hierarchy are described below: ​ Level 1—Valuation is based on quoted prices in active markets for identical assets or liabilities. Level 1 assets and liabilities generally include debt and equity securities that are traded in an active exchange market. Valuations are obtained from readily available pricing sources for market transactions involving identical assets or liabilities. ​ Level 2—Valuation is based on observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. ​ Level 3—Valuation is based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. ​ Fair value estimates discussed herein are based upon certain market assumptions and pertinent information available to management as of December 31, 2021. The respective carrying value of certain on-balance-sheet financial instruments approximated their fair values due to the short-term nature of these instruments. These financial instruments include accounts payable and accrued expenses.
Property and equipment	Property and equipment ​ Property and equipment of the Company is stated at cost. In accordance with ASC Topic 360 Property, Plant and Equipment, expenditure for fixed assets that substantially increase the useful lives of existing assets are capitalized at cost and depreciated. Routine expenditures for repairs and maintenance are expensed as incurred. Depreciation is provided principally on the straight-line method over the estimated useful lives of the asset. A summary of the estimated useful lives is as follows:: ​ ​ ​ ​ ​ Classification Estimated Useful Life Computer hardware 3 - 5 years ​ Software 3 years ​ Research and lab equipment 5 years ​ Leasehold improvements Remaining life of lease ​
Concentrations of credit risk	Concentrations of credit risk ​ Financial instruments which potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents. The Company maintains cash in commercial banks, which may at times exceed Federally Insured limits. The Company has not experienced any loss in such accounts. The Company believes it is not exposed to any significant credit risk on cash and cash equivalents.
Segment information	Segment information ​ Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, or decision making group, in making decisions regarding resource allocation and assessing performance. To date, the Company has viewed its operations and manages its business as principally one operating segment, which is developing and commercializing biopolymer scaffolding devices for the treatment of spinal cord injuries. As of December 31, 2021 and 2020, all of the Company’s assets were located in one location in the United States.
Income taxes	Income taxes ​ For federal and state income taxes, deferred tax assets and liabilities are recognized based upon temporary differences between the financial statement and the tax basis of assets and liabilities. Deferred income taxes are based upon prescribed rates and enacted laws applicable to periods in which differences are expected to reverse. A valuation allowance is recorded when it is more likely than not that some portion or all of the deferred tax assets will not be realized. Accordingly, the Company provides a valuation allowance, if necessary, to reduce deferred tax assets to amounts that are realizable. Tax positions taken or expected to be taken in the course of preparing the Company’s tax returns are required to be evaluated to determine whether the tax positions are “more-likely-than-not” of being sustained by the applicable tax authority. ​ Tax positions not deemed to meet a more-likely-than-not threshold would be recorded as a tax expense in 2021. There were no material uncertain tax positions that required accrual or disclosure to the financial statements as of December 31, 2021 or 2020. Tax years subsequent to 2018 remain open to examination by U.S. federal and state tax authorities.
Impairment of long-lived assets	Impairment of long-lived assets ​ The Company continually monitors events and changes in circumstances that could indicate that carrying amounts of long-lived assets may not be recoverable. An impairment loss is recognized when expected cash flows are less than an asset’s carrying value. Accordingly, when indicators of impairment are present, the Company evaluates the carrying value of such assets in relation to the operating performance and future undiscounted cash flows of the underlying assets. The Company’s policy is to record an impairment loss when it is determined that the carrying value of the asset may not be recoverable.
Share-based payments	Share-based payments ​ The Company accounts for all stock-based payment awards granted to employees and nonemployees using the fair value method. The Company’s stock-based payments include stock options and grants of common stock, including common stock subject to vesting. The measurement date for both employee and nonemployee awards is the date of grant, and stock-based compensation costs are recognized as expense over the employees’ requisite service period, which is the vesting period, on a straight-line basis. Stock-based compensation costs for nonemployees are recognized as expense over the vesting period on a straight-line basis. Stock-based compensation is classified in the accompanying consolidated statements of operations and comprehensive loss based on the department to which the related services are provided.
Derivative instruments	Derivative instruments ​ The Company generally does not use derivative instruments to hedge exposures to cash-flow or market risks. In the past certain of the Company’s issued and outstanding warrants to purchase common stock previously contained anti-dilution provisions. These warrants did not meet the requirements for classification as equity and were thus recorded as derivative warrant liabilities. In such instances, net-cash settlement is assumed for financial reporting purposes, even when the terms of the underlying contracts do not provide for a net-cash settlement. Such financial instruments are initially recorded at fair value, with subsequent changes in fair value recorded to operations in each reporting period. If these instruments subsequently meet the requirements for classification as equity, the Company reclassifies the fair value to equity.
Net loss per common share	Net loss per common share ​ Basic and diluted net loss per share of common stock has been computed by dividing net loss by the weighted average number of shares outstanding during the period as follows: ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2021 ​ ​ 2020 Numerator: ​ ​ ​ ​ ​ Net Loss (in thousands) $ (9,895) ​ $ (9,074) ​ ​ ​ ​ ​ ​ Denominator: ​ ​ ​ ​ ​ Weighted average shares used in calculating net loss per share — basic diluted ​ 33,078,659 ​ ​ 6,902,693 Net loss per share — basic and diluted $ (0.30) ​ $ (1.31) ​ ​ In a net loss period, options, warrants, unvested restricted stock units and convertible securities are anti-dilutive and therefore excluded from diluted loss per share calculations. ​ For the year ended December 31, 2021 and 2020, the following potentially dilutive securities were not included in the computation of net loss per share because the effect would be anti-dilutive: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ ​ 2020 Warrants ​ 14,078,338 ​ ​ 24,714,084 Stock options ​ 364,005 ​ ​ 4,169 Unvested RSUs ​ — ​ ​ 100 Unvested RSAs ​ 6,302 ​ ​ 6,302 Total potentially dilutive securities ​ 14,448,645 ​ ​ 24,724,655
Recently Adopted Accounting Standards	New Accounting Pronouncements ​ In May 2021 Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2021-04, “Earnings Per Share (Topic 260), Debt-Modifications and Extinguishments (Subtopic 470-50), Compensation-Stock Compensation (Topic 718), and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40): Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options, a consensus of the Emerging Issues Task Force”. This ASU amends the FASB Accounting Standards Codification (“ASC”) to provide explicit guidance, and, thus, reduce diversity in practice, on accounting by issuers for modifications or exchanges of freestanding equity-classified written call options that remain equity classified after the modification or exchange. This amendment provides that for an entity that presents earnings per share (EPS) in accordance with Topic 260, the effects of a modification or an exchange of a freestanding equity-classified written call option that is recognized as a dividend should be an adjustment to net income (or net loss) in the basic EPS calculation. The amended guidance becomes mandatorily effective for all entities for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years, and should be applied prospectively to modifications or exchanges occurring on or after the effective date. ASU No. 2021- 04 is effective for the Company beginning in fiscal 2022. The Company will adopt ASU 2021-04 effective January 1, 2022, and it is expected that the adoption will not have a material impact to the Company's consolidated financial statements. ​ In January 2020, the FASB issued ASU No. 2020-01 “Investments—Equity Securities (Topic 321), Investments—Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815) —clarifying the interactions between Topic 321, Topic 323 and Topic 815 (a consensus of the emerging issues task force)”. The amendments in this ASU clarify the interaction between the accounting for investments in equity securities, investment in equity method and certain derivatives instruments. The ASU is expected to reduce diversity in practice and increase comparability of the accounting for these interactions. The pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2021. ASU No. 2020- 01 is effective for the Company beginning in fiscal 2022. The Company will adopt ASU 2021-01 effective January 1, 2022, and it is expected that the adoption will not have a material impact to the Company's consolidated financial statements. ​ No other accounting standards known by the Company to be applicable to it that have been issued by the FASB or other standard-setting bodies and that do not require adoption until a future date are expected to have a material impact on the Company’s consolidated financial statements upon adoption. ​

SIGNIFICANT ACCOUNTING POLICI_3

SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2021
SIGNIFICANT ACCOUNTING POLICIES
Schedule of cash and cash equivalents	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ (In thousands) 2021 2020 Cash ​ $ 5 ​ $ (13) ​ Money market funds ​ 19,026 ​ 19,506 ​ Total cash and cash equivalents ​ $ 19,031 ​ $ 19,493 ​
Summary of estimated useful lives	​ ​ ​ ​ ​ Classification Estimated Useful Life Computer hardware 3 - 5 years ​ Software 3 years ​ Research and lab equipment 5 years ​ Leasehold improvements Remaining life of lease ​
Schedule of potentially dilutive securities not included in the computation of net loss per share because effect would be anti-dilutive	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ ​ 2020 Warrants ​ 14,078,338 ​ ​ 24,714,084 Stock options ​ 364,005 ​ ​ 4,169 Unvested RSUs ​ — ​ ​ 100 Unvested RSAs ​ 6,302 ​ ​ 6,302 Total potentially dilutive securities ​ 14,448,645 ​ ​ 24,724,655
Schedule of earnings per share, basic and diluted	Basic and diluted net loss per share of common stock has been computed by dividing net loss by the weighted average number of shares outstanding during the period as follows: ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2021 ​ ​ 2020 Numerator: ​ ​ ​ ​ ​ Net Loss (in thousands) $ (9,895) ​ $ (9,074) ​ ​ ​ ​ ​ ​ Denominator: ​ ​ ​ ​ ​ Weighted average shares used in calculating net loss per share — basic diluted ​ 33,078,659 ​ ​ 6,902,693 Net loss per share — basic and diluted $ (0.30) ​ $ (1.31)

PROPERTY AND EQUIPMENT (Tables)

PROPERTY AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2021
PROPERTY AND EQUIPMENT
Schedule of property and equipment, net	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ (In thousands) 2021 2020 Computer hardware ​ $ 52 ​ $ 35 ​ Computer Software ​ ​ 5 ​ ​ 5 ​ Research and lab equipment ​ 580 ​ 520 ​ Leasehold improvements ​ 66 ​ 66 ​ Property and equipment ​ ​ 703 ​ ​ 626 ​ Less accumulated depreciation ​ (576) ​ (541) ​ Property and equipment, net ​ $ 127 ​ $ 85 ​

INTANGIBLE ASSETS (Tables)

INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2021
INTANGIBLE ASSETS
Summary of intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ (In thousands) 2021 2020 Patent licensing fee ​ $ 200 ​ $ 200 ​ Accumulated amortization ​ (200) ​ (191) ​ Intangible assets ​ $ — ​ $ 9 ​

ACCRUED EXPENSES (Tables)

ACCRUED EXPENSES (Tables)	12 Months Ended
	Dec. 31, 2021
ACCRUED EXPENSES.
Summary of accrued expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, (In thousands) 2021 2020 Compensation ​ $ 1,287 ​ $ 996 ​ Clinical ​ 218 ​ ​ 5 ​ Other accrued expenses ​ 141 ​ ​ 163 ​ Total accrued expenses ​ $ 1,646 ​ $ 1,164 ​

FAIR VALUES OF ASSETS AND LIA_2

FAIR VALUES OF ASSETS AND LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2021
FAIR VALUES OF ASSETS AND LIABILITIES
Summary of assets and liabilities measured at fair value on a recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2021 ​ (In thousands) Level 1 Level 2 Level 3 Fair Value ​ Cash equivalents ​ $ 19,026 ​ $ — ​ $ — ​ $ 19,026 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2020 ​ (In thousands) Level 1 Level 2 Level 3 Fair Value ​ Cash equivalents ​ $ 19,506 ​ $ — ​ $ — ​ $ 19,506 ​

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2021
INCOME TAXES
Schedule of significant components of net deferred tax assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ (In thousands) 2021 2020 Net operating loss carryforward ​ $ 42,696 ​ $ 40,175 ​ Research and development credit carryforward ​ 1,663 ​ 1,608 ​ Stock-based compensation ​ 431 ​ 421 ​ Depreciation and amortization ​ 17 ​ 16 ​ Accrued expenses ​ — ​ 7 ​ Lease liability ​ ​ 344 ​ ​ 279 ​ Right of use asset ​ ​ (323) ​ ​ (253) ​ Subtotal ​ 44,828 ​ 42,253 ​ Valuation allowance ​ (44,828) ​ (42,253) ​ Net deferred taxes ​ $ — ​ $ — ​
Schedule of income tax benefits computed using the federal statutory income tax rate	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2021 2020 Statutory rate ​ (21.0) % (21.0) % State taxes, net of benefit (4.7) % (5.8) % Permanent differences ​ 0.4 % 0.3 % Research and development tax credit (0.9) % (1.1) % Stock-based compensation ​ 0.2 % 21.2 % Increase in valuation reserve 26.0 % 6.4 % Effective tax rate 0.0 % 0.0 %

COMMON STOCK (Tables)

COMMON STOCK (Tables)	12 Months Ended
	Dec. 31, 2021
COMMON STOCK.
Schedule of reserves established for future issuance of common stock	​ ​ ​ ​ ​ ​ ​ As of December 31, 2021 ​ Reserves for the exercise of warrants 14,078,338 ​ Reserves for the exercise of stock options 364,005 ​ Total Reserves 14,442,343 ​

SHARE-BASED COMPENSATION, STO_2

SHARE-BASED COMPENSATION, STOCK OPTIONS, AND RESTRICTED SECURITIES (Tables)	12 Months Ended
	Dec. 31, 2021
SHARE-BASED COMPENSATION, STOCK OPTIONS, AND RESTRICTED SECURITIES
Summary of stock based compensation classified in the consolidated statements of operations	For the years ended December 31, 2021 and 2020, Stock-based compensation recognized was classified in the consolidated statements of operations as follows: ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands) 2021 ​ 2020 Research and development $ 22 ​ $ 40 General and administrative ​ 293 ​ ​ 175 Total $ 315 ​ $ 215 ​ ​ ​ ​ ​ ​
Schedule of assumptions used principally in determining the fair value of options granted	​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ Risk-free interest rate 1.03% ​ ​ Expected dividend yield 0% ​ ​ Expected term (employee grants) 5.70 ​ ​ Expected volatility 117.34% ​ ​
Summary of option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ Average ​ ​ ​ ​ ​ ​ ​ Average ​ ​ Remaining Aggregate ​ ​ ​ ​ Exercise ​ ​ Contractual Intrinsic Options Shares Price ​ Term in Years Value Outstanding as of December 31, 2020 4,169 ​ $ 1,054.01 ​ 7.18 ​ $ — Granted 360,000 ​ $ 1.10 ​ ​ ​ ​ ​ ​ Cancelled/Forfeited ​ (147) ​ $ 6,324.03 ​ ​ ​ ​ ​ ​ Expired ​ (17) ​ $ 5,940.00 ​ ​ ​ ​ ​ ​ Outstanding as of December 31, 2021 364,005 ​ $ 10.33 ​ ​ 9.18 ​ $ — Vested and Exercisable as of December 31, 2021 3,005 ​ $ 1,104.04 ​ ​ 6.17 ​ $ — Vested and expected to vest as of December 31, 2021 364,005 ​ $ 10.33 ​ 9.18 ​ $ —
Summary of restricted stock unit activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average Restricted Securities Number of Grants Grant Date Fair Value Unvested balance as of December 31, 2020 ​ 6,402 ​ $ 25.67 Vested ​ (100) ​ $ 660.00 Unvested balance as of December 31, 2021 ​ 6,302 ​ $ 15.60

WARRANTS (Tables)

WARRANTS (Tables)	12 Months Ended
	Dec. 31, 2021
WARRANTS
Schedule of information about warrants to purchase common stock issued and outstanding	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of Exercise Price as of ​ ​ Year Issued ​ Defined Name ​ Classification ​ Warrants ​ September 30, 2021 ​ Date of Expiration ​ 2018 ​ 2018 Series A Warrants ​ Equity ​ 211,921 ​ $ 6.98 ​ 6/25/2023 ​ 2019 ​ 2019 Placement Agent Warrants ​ Equity ​ 15,168 ​ $ 4.50 ​ 11/21/2024 ​ 2020 ​ March 2020 Series A Warrants ​ Equity ​ 2,545,455 ​ $ 2.75 ​ 3/10/2025 ​ 2020 ​ March 2020 Placement Agent Warrants ​ Equity ​ 165,455 ​ $ 3.4375 ​ 3/5/2025 ​ 2020 ​ March 2020 Series B Warrants ​ Equity ​ 12,728 ​ $ 0.00001 ​ Until Fully Exercised ​ 2020 ​ April 2020 Series C Warrants ​ Equity ​ 1,680,240 ​ $ 1.62 ​ 10/17/2025 ​ 2020 ​ April 2020 Placement Agent Warrants ​ Equity ​ 111,491 ​ $ 2.1875 ​ 4/15/2025 ​ 2020 ​ October 2020 Placement Agent Warrants ​ Equity ​ 1,206,562 ​ $ 1.00 ​ 10/22/2025 ​ 2020 ​ October 2020 Series A Warrants ​ Equity ​ 8,129,318 ​ $ 0.80 ​ 10/27/2025 ​ Total ​ ​ ​ ​ 14,078,338 ​ ​ ​ ​ ​ ​ Weighted average exercise price ​ ​ ​ $ 1.41 ​ ​ ​ Weighted average life in years ​ ​ ​ ​ ​ 3.66 ​

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2021
COMMITMENTS AND CONTINGENCIES
Schedule of other information	​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, Lease cost (In thousands) 2021 2020 Operating lease cost $ 392 ​ $ 364 Short-term lease cost ​ 3 ​ ​ 21 Variable lease cost ​ 95 ​ ​ 139 Total lease cost $ 490 ​ $ 524 ​ ​ ​ ​ ​ ​ Other information (In thousands) ​ ​ ​ ​ ​ Increase in operating right-of-use assets and liabilities related to lease modifications $ 629 ​ $ — Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ Operating cash flows from short term leases $ 3 ​ $ 21 Operating cash flows from operating leases ​ 403 ​ ​ 375 Total cash paid for leases $ 406 ​ $ 396 Weighted-average remaining lease term - operating leases ​ 3 ​ ​ 2.83 Years Weighted-average discount rate - operating leases ​ 6.0% ​ ​ 7.0%
Schedule of maturities of lease liabilities	​ ​ ​ ​ ​ Leases (In thousands) As of December 31, 2021 2022 $ 427 ​ 2023 ​ 440 ​ 2024 ​ 568 ​ Total lease payments ​ 1,435 ​ Less: imputed interest ​ (125) ​ Present value of lease liabilities $ 1,310 ​
Schedule of balance sheet information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Leases (In thousands) ​ Classification December 31, 2021 ​ December 31, 2020 Assets ​ ​ ​ ​ ​ ​ ​ ​ Lease asset, net ​ Operating ​ $ 1,229 ​ $ 928 Total lease assets ​ ​ ​ $ 1,229 ​ $ 928 ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ Current ​ Operating ​ $ 361 ​ $ 327 Non-current ​ Operating ​ ​ 949 ​ ​ 693 Total lease liabilities ​ ​ ​ $ 1,310 ​ $ 1,020

NATURE OF OPERATIONS AND GOIN_3

NATURE OF OPERATIONS AND GOING CONCERN - Reverse Stock Split (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares	Aug. 04, 2020shares	Aug. 03, 2020shares	Feb. 11, 2020shares	Jan. 31, 2020shares	May 31, 2018shares
NATURE OF OPERATIONS AND GOING CONCERN
Cash and cash equivalents | $	$ 19,031	$ 19,493
Common stock, par value (in dollars per share) | $ / shares	$ 0.00001	$ 0.00001
Reverse stock split ratio		0.0333
Proceeds from Warrant Exercises | $	$ 8,509	$ 343
Common Stock, Shares Authorized | shares	50,000,000	50,000,000	50,000,000	16,666,667	16,666,667	500,000,000	25,000,000
Stock issued during period, shares, reverse stock splits | shares		7,692
Going concern	false

SIGNIFICANT ACCOUNTING POLICI_4

SIGNIFICANT ACCOUNTING POLICIES - CASH AND CASH EQUIVALENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
CASH AND CASH EQUIVALENTS
Cash	$ 5	$ (13)
Money market funds	19,026	19,506
Total cash and cash equivalents	$ 19,031	$ 19,493

SIGNIFICANT ACCOUNTING POLICI_5

SIGNIFICANT ACCOUNTING POLICIES - RESTRICTED CASH (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Restricted cash	$ 150	$ 110
Security deposit related to credit card account
Restricted cash		50
Standby letter of credit in favor of a landlord
Restricted cash	$ 100	$ 60

SIGNIFICANT ACCOUNTING POLICI_6

SIGNIFICANT ACCOUNTING POLICIES, PROPERTY AND EQUIPMENT (Details)	12 Months Ended
	Dec. 31, 2021
Computer hardware | Minimum
Property and equipment
Estimated Useful Life	3 years
Computer hardware | Maximum
Property and equipment
Estimated Useful Life	5 years
Software
Property and equipment
Estimated Useful Life	3 years
Research and lab equipment
Property and equipment
Estimated Useful Life	5 years

SIGNIFICANT ACCOUNTING POLICI_7

SIGNIFICANT ACCOUNTING POLICIES, RESEARCH AND DEVELOPMENT AND SEGMENT (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)locationsegment	Dec. 31, 2020USD ($)location
Prepayments for CRO services	$ 1,200	$ 1,200
Number of operating segments | segment	1
Number of locations in the United States | location	1	1
Prepaid and other current assets
Prepayments for CRO services	$ 28	$ 110
Other long term assets
Prepayments for CRO services	$ 1,100	$ 1,100

SIGNIFICANT ACCOUNTING POLICI_8

SIGNIFICANT ACCOUNTING POLICIES, NET LOSS PER COMMON SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
SIGNIFICANT ACCOUNTING POLICIES
Net Loss (Basic)	$ (9,895)	$ (9,074)
Net Loss (Diluted)	$ (9,895)	$ (9,074)
Weighted average shares used in calculating net loss per share, Basic	33,078,659	6,902,693
Weighted average shares used in calculating net loss per share, Diluted	33,078,659	6,902,693
Net loss per share - Basic	$ (0.30)	$ (1.31)
Net loss per share, Diluted	$ (0.30)	$ (1.31)

SIGNIFICANT ACCOUNTING POLICI_9

SIGNIFICANT ACCOUNTING POLICIES, POTENTIALLY DILUTIVE SECURITIES (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Anti-dilutive
Total potentially dilutive securities (in shares)	14,448,645	24,724,655
Warrant One
Anti-dilutive
Total potentially dilutive securities (in shares)	14,078,338	24,714,084
Stock Options
Anti-dilutive
Total potentially dilutive securities (in shares)	364,005	4,169
Unvested RSUs
Anti-dilutive
Total potentially dilutive securities (in shares)		100
Unvested RSAs
Anti-dilutive
Total potentially dilutive securities (in shares)	6,302	6,302

PROPERTY AND EQUIPMENT, SCHEDUL

PROPERTY AND EQUIPMENT, SCHEDULE (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property and equipment
Property and equipment	$ 703	$ 626
Less accumulated depreciation and amortization	(576)	(541)
Property and equipment, net	127	85
Computer hardware
Property and equipment
Property and equipment	52	35
Computer Software [Member]
Property and equipment
Property and equipment	5	5
Research and lab equipment
Property and equipment
Property and equipment	580	520
Leasehold improvements
Property and equipment
Property and equipment	$ 66	$ 66

PROPERTY AND EQUIPMENT (Details

PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Depreciation
Depreciation	$ 35	$ 29
Write off of fully depreciated assets		$ 132

INTANGIBLE ASSETS (Details)

INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Jul. 31, 2007
Bch License
Intangible assets
Useful life	15 years
Intangible assets - gross	$ 200	$ 200	$ 75
Maintenance fees	$ 10	10
Patent licensing fee
Intangible assets
Useful life	15 years
Intangible assets - gross	$ 200	200
Accumulated amortization	$ (200)	(191)
Intangible assets, net		$ 9

INTANGIBLE ASSETS, AMORTIZATION

INTANGIBLE ASSETS, AMORTIZATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Amortization
Amortization expense	$ 9	$ 13

ACCRUED EXPENSES (Details)

ACCRUED EXPENSES (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
ACCRUED EXPENSES.
Compensation	$ 1,287	$ 996
Clinical	218	5
Other accrued expenses	141	163
Total accrued expenses	$ 1,646	$ 1,164

FAIR VALUES OF ASSETS AND LIA_3

FAIR VALUES OF ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets and liabilities measured at fair value on a recurring basis
Transfers from Level 1 to Level 2	$ 0	$ 0
Transfers from Level 2 to Level 1	0	0
Recurring basis
Assets and liabilities measured at fair value on a recurring basis
Cash equivalents	19,026	19,506
Recurring basis | Level 1
Assets and liabilities measured at fair value on a recurring basis
Cash equivalents	$ 19,026	$ 19,506

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
INCOME TAXES
Provision or benefit for federal or state income taxes	$ 0	$ 0

INCOME TAXES, CARRYFORWARDS (De

INCOME TAXES, CARRYFORWARDS (Details) $ in Millions	Dec. 31, 2021USD ($)
U.S. federal
Net operating loss carryforwards
Net operating loss carryforwards	$ 158.5
U.S. federal | Expiring beginning in 2026
Net operating loss carryforwards
Net operating loss carryforwards	117.3
U.S. federal | Never expiring
Net operating loss carryforwards
Net operating loss carryforwards	41.3
Massachusetts
Net operating loss carryforwards
Net operating loss carryforwards	$ 140.8

INCOME TAXES, CREDITS (Details)

INCOME TAXES, CREDITS (Details) $ in Millions	Dec. 31, 2021USD ($)
U.S. federal
Tax credit carryforwards
Research and development tax credit carryforwards	$ 1.5
Massachusetts
Tax credit carryforwards
Research and development tax credit carryforwards	$ 0.2

INCOME TAXES, Tax Act (Details)

INCOME TAXES, Tax Act (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
INCOME TAXES
Statutory tax rate (as a percent)	21.00%	21.00%

INCOME TAXES, NET DEFERRED TAX

INCOME TAXES, NET DEFERRED TAX ASSET (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Significant components of net deferred tax asset
Net operating loss carryforward	$ 42,696	$ 40,175
Research and development credit carryforward	1,663	1,608
Stock-based compensation	431	421
Depreciation and amortization	17	16
Accrued expenses		7
Lease liability	344	279
Right of use asset	(323)	(253)
Subtotal	44,828	42,253
Valuation allowance	(44,828)	(42,253)
Net deferred taxes	0	0
Retained earnings	(238,129)	(228,234)
Increase (decrease) in valuation allowance	2,600	600
Uncertain tax positions that would affect its effective tax rate	0	$ 0
Amount of significant change in uncertain tax positions over the next 12 months	$ 0

INCOME TAXES, STATUTORY INCOME

INCOME TAXES, STATUTORY INCOME TAX RATES (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income tax benefits computed using the federal statutory income tax rate
Statutory rate	(21.00%)	(21.00%)
State taxes, net of benefit	(4.70%)	(5.80%)
Permanent differences:
Permanent differences	0.40%	0.30%
Research and development tax credit	(0.90%)	(1.10%)
Stock-based compensation	0.20%	21.20%
Increase in valuation reserve	26.00%	6.40%
Effective tax rate	0.00%	0.00%

COMMON STOCK, AUTHORIZED (Detai

COMMON STOCK, AUTHORIZED (Details) - shares	Dec. 31, 2021	Dec. 31, 2020	Aug. 04, 2020	Aug. 03, 2020	Feb. 11, 2020	Jan. 31, 2020	May 31, 2018
Common stock, number of shares, par value and other disclosures
Common stock, authorized	50,000,000	50,000,000	50,000,000	16,666,667	16,666,667	500,000,000	25,000,000
Common stock, issued	34,264,856	23,631,886
Common stock, outstanding	34,264,856	23,631,886

COMMON STOCK, TRANSACTIONS (Det

COMMON STOCK, TRANSACTIONS (Details)	1 Months Ended			12 Months Ended
	Oct. 31, 2020USD ($)$ / sharesshares	Apr. 30, 2020USD ($)$ / sharesshares	Mar. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)shares	Dec. 31, 2019shares
Common stock disclosures
Proceeds from issuance of common stock and warrants, net of issuance costs | $					$ 22,119,000
Proceeds from exercise of warrants | $				$ 8,509,000	343,000
Number of Warrants				14,078,338
Aggregate number of shares reserved for issuance				14,442,343
Restricted stock awards issued						6,886
Series B Prefunded Warrants October 2020
Common stock disclosures
Fair value of warrants | $				$ 0
Series A Warrants
Common stock disclosures
Exercise price (in dollars per unit) | $ / shares			$ 2.75
Number of Warrants			1,589,842
Series B Warrants 2020
Common stock disclosures
Exercise price (in dollars per unit) | $ / shares			$ 0.00001
Intrinsic value | $				$ 4,400,000
Shares issued on exercise of warrants				1,577,114
Number of Warrants			1,589,842
April 2020 Warrants
Common stock disclosures
Fair value of warrants | $		$ 2,100,000
Number of shares into which a warrant may be converted		1,715,240
Exercise price (in dollars per unit) | $ / shares		$ 1.62
Proceeds from exercise of warrants | $					$ 57,000
Shares issued on exercise of warrants				0	35,000
April 2020 Warrants | Expected volatility
Common stock disclosures
Fair value assumptions		1.1584
April 2020 Warrants | Risk-free interest rate
Common stock disclosures
Fair value assumptions		0.0040
April 2020 Warrants | Contractual term
Common stock disclosures
Warrant expiration term (in years)		5 years 6 months
April 2020 Warrants | Expected dividend yield
Common stock disclosures
Fair value assumptions | $		0
Wainwright 2020 Placement Agent Warrants
Common stock disclosures
Fair value of warrants | $		$ 128,000
Number of shares into which a warrant may be converted		111,491
Exercise price (in dollars per unit) | $ / shares		$ 2.1875
Proceeds from issuance of common stock and warrants, net of issuance costs | $	$ 13,500,000		$ 6,000,000
Percentage of warrants issued as a percentage of the warrants issued to the investors		6.50%
Proceeds from issuance of common stock, net of issuance costs | $		$ 2,600,000
Wainwright 2020 Placement Agent Warrants | Expected volatility
Common stock disclosures
Fair value assumptions		1.1614
Wainwright 2020 Placement Agent Warrants | Risk-free interest rate
Common stock disclosures
Fair value assumptions		0.0036
Wainwright 2020 Placement Agent Warrants | Contractual term
Common stock disclosures
Warrant expiration term (in years)		5 years
Wainwright 2020 Placement Agent Warrants | Expected dividend yield
Common stock disclosures
Fair value assumptions | $		0
March 2020 Series A Warrants
Common stock disclosures
Issuance of common stock and warrants in public offerings (in shares)			955,613
Shares issued on exercise of warrants					0
2018 Warrants
Common stock disclosures
Proceeds from exercise of warrants | $				$ 286,000
Shares issued on exercise of warrants				0
2018 Warrant Exercise price $6.98
Common stock disclosures
Exercise price (in dollars per unit) | $ / shares				$ 6.98
Number of Warrants				211,921
Placement Agent Warrants
Common stock disclosures
Exercise price (in dollars per unit) | $ / shares			$ 3.4375	$ 1
Percentage of aggregate number of shares available | $			$ 6.5
Number of Warrants			165,455	1,206,562
Common Stock
Common stock disclosures
Issuance of common stock and warrants in public offerings (in shares)					14,455,853
Warrant One
Common stock disclosures
Aggregate number of shares reserved for issuance				14,078,338
October 2020 Offering
Common stock disclosures
Issuance of common stock and warrants in public offerings (in shares)	11,785,000
Equity issuance (in price per unit) | $ / shares	$ 0.80
October 2020 Offering | Expected volatility
Common stock disclosures
Fair value assumptions	1.1913
October 2020 Offering | Risk-free interest rate
Common stock disclosures
Fair value assumptions	0.0035
October 2020 Offering | Contractual term
Common stock disclosures
Warrant expiration term (in years)	5 years
October 2020 Offering | Expected dividend yield
Common stock disclosures
Fair value assumptions | $ / shares	0
October 2020 Offering | Series A Prefunded Warrants October 2020
Common stock disclosures
Issuance of common stock and warrants in public offerings (in shares)	6,965,000
Equity issuance (in price per unit) | $ / shares	$ 0.80
Fair value of warrants | $	$ 8,700,000
October 2020 Offering | Series B Prefunded Warrants October 2020
Common stock disclosures
Fair value of warrants | $	$ 5,600,000
Number of shares into which a warrant may be converted	6,965,000
Exercise price (in dollars per unit) | $ / shares	$ 0.00001
October 2020 Offering | Series A Warrants
Common stock disclosures
Number of shares into which a warrant may be converted	11,785,000
Exercise price (in dollars per unit) | $ / shares	$ 0.80
October 2020 Offering | Wainwright 2020 Placement Agent Warrants
Common stock disclosures
Number of shares into which a warrant may be converted	1,218,750
Exercise price (in dollars per unit) | $ / shares	$ 1
Percentage of aggregate number of shares available | $	$ 6.5
October 2020 Offering | Placement Agent Warrants
Common stock disclosures
Fair value of warrants | $	$ 551,300
October 2020 Offering | Common Stock
Common stock disclosures
Proceeds from exercise of warrants | $				$ 8,500,000
October 2020 Offering | Common Stock | Series A Prefunded Warrants October 2020
Common stock disclosures
Issuance of common stock and warrants in public offerings (in shares)				10,620,682
October 2020 Offering | Common Stock | Series B Prefunded Warrants October 2020
Common stock disclosures
Issuance of common stock and warrants in public offerings (in shares)					6,965,000
October 2020 Offering | Common Stock | Placement Agent Warrants
Common stock disclosures
Issuance of common stock and warrants in public offerings (in shares)				12,188
April 2020 Shares
Common stock disclosures
Issuance of common stock and warrants in public offerings (in shares)		1,715,240
Equity issuance (in price per unit) | $ / shares		$ 1.75
Underwritten Public Offering March 2020 [Member]
Common stock disclosures
Issuance of common stock and warrants in public offerings (in shares)			955,613
Equity issuance (in price per unit) | $ / shares			$ 2.75
Underwritten Public Offering March 2020 [Member] | Expected volatility
Common stock disclosures
Fair value assumptions			1.1522
Underwritten Public Offering March 2020 [Member] | Risk-free interest rate
Common stock disclosures
Fair value assumptions			0.0063
Underwritten Public Offering March 2020 [Member] | Contractual term
Common stock disclosures
Warrant expiration term (in years)			5 years
Underwritten Public Offering March 2020 [Member] | Expected dividend yield
Common stock disclosures
Fair value assumptions | $ / shares			0
Underwritten Public Offering March 2020 [Member] | Series A Warrants
Common stock disclosures
Fair value of warrants | $			$ 3,500,000
Underwritten Public Offering March 2020 [Member] | Placement Agent Warrants
Common stock disclosures
Fair value of warrants | $			$ 218,000

COMMON STOCK, TRANSACTIONS, OTH

COMMON STOCK, TRANSACTIONS, OTHER (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)shares	Dec. 31, 2020USD ($)shares
Common stock disclosures
Reverse stock split ratio		0.0333
Stock issued during period, shares, reverse stock splits		7,692
Issuance of common stock upon vesting of restricted stock units (in shares)		584
Proceeds from exercise of warrants | $	$ 8,509	$ 343
2018 Warrants
Common stock disclosures
Shares issued on exercise of warrants	0
Proceeds from exercise of warrants | $	$ 286
Issuance of stock in exchange for warrants (in shares)		40,975
Common Stock
Common stock disclosures
Issuance of common stock upon vesting of restricted stock units (in shares)	100	100

COMMON STOCK, RESERVES (Details

COMMON STOCK, RESERVES (Details)	Dec. 31, 2021shares
Summary of common stock reserves
Total Reserves	14,442,343
Warrant One
Summary of common stock reserves
Total Reserves	14,078,338
Stock Options
Summary of common stock reserves
Total Reserves	364,005

SHARE-BASED COMPENSATION, STO_3

SHARE-BASED COMPENSATION, STOCK OPTIONS, AND RESTRICTED SECURITIES (Details) - USD ($) $ in Thousands	Jul. 16, 2021	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2021	Aug. 04, 2020	Jan. 31, 2020	Apr. 30, 2015
Stock options
Granted (in shares)			360,000
Expected term		10 years
Aggregate number of shares reserved for issuance		14,442,343
Vesting period		48 months
Stock-based compensation (in dollars)		$ 315	$ 215
Stock Options
Stock options
Granted (in shares)		360,000	0
Aggregate number of shares reserved for issuance		364,005
Stock-based compensation (in dollars)		$ 219	$ 117
RSU
Stock options
Vesting period		3 years
Stock-based compensation (in dollars)		$ 96	$ 98
2010 Plan
Stock options
Expected term		10 years
2015 Plan
Stock options
Shares available for future grants		2,767,436		2,767,436
Shares authorized for issuance		1,292,801			400,000	26,667	5,333
Expected term		10 years
Increase in shares of common stock reserved for issuance (in shares)	2,700,000

SHARE-BASED COMPENSATION, STO_4

SHARE-BASED COMPENSATION, STOCK OPTIONS, AND RESTRICTED SECURITIES, SHARE-BASED COMPENSATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stock options
Stock-based compensation (in dollars)	$ 315	$ 215
Expected term	10 years
Vesting period	48 months
Cumulative Adjustment on adoption of ASU 2016-09.	$ 18,115	19,186	$ 5,583
Research and development
Stock options
Stock-based compensation (in dollars)	22	40
General and administrative
Stock options
Stock-based compensation (in dollars)	293	175
Stock Options
Stock options
Stock-based compensation (in dollars)	$ 219	$ 117

SHARE-BASED COMPENSATION, STO_5

SHARE-BASED COMPENSATION, STOCK OPTIONS, AND RESTRICTED SECURITIES, ASSUMPTIONS USED IN DETERMINING THE FAIR VALUE (Details) - Stock Options	12 Months Ended
	Dec. 31, 2021
Assumptions used principally in determining the fair value of options granted
Risk-free interest rate (as a percent)	1.03%
Expected dividend yield (as a percent)	0.00%
Expected term (employee grants)	5 years 8 months 12 days
Expected volatility (as a percent)	117.34%

SHARE-BASED COMPENSATION, STO_6

SHARE-BASED COMPENSATION, STOCK OPTIONS, AND RESTRICTED SECURITIES, SUMMARY OF OPTION ACTIVITY - (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Summary of option activity - Shares
Granted (in shares)		360,000
Stock Option
Stock-based compensation (in dollars)	$ 315	$ 215
Stock Options
Summary of option activity - Shares
Outstanding at the beginning of year (in shares)	4,169
Granted (in shares)	360,000	0
Expired (in shares)	(17)
Cancelled/Forfeited (in shares)	(147)
Outstanding at the end of period (in shares)	364,005	4,169
Vested at the end of period (in shares)	3,005
Vested and expected to vest at the end of period (in shares)	364,005
Summary of option activity - Weighted Average Exercise Price
Outstanding at the beginning of year (in dollars per shares)	$ 1,054.01
Granted (in dollars per shares)	1.10
Expired (in dollars per shares)	5,940
Cancelled/Forfeited (in dollars per shares)	6,324.03
Outstanding at the end of period (in dollars per shares)	10.33	$ 1,054.01
Vested at the end of period (in dollars per share)	1,104.04
Vested and expected to vest at the end of period (in dollars per share)	$ 10.33
Option activity disclosures
Weighted Average Remaining Contractual Term - Outstanding	9 years 2 months 4 days	7 years 2 months 4 days
Weighted Average Remaining Contractual Term - Vested	6 years 2 months 1 day
Weighted Average Remaining Contractual Term - Vested and expected to vest	9 years 2 months 4 days
Stock Option
Weighted average grant-date fair value of options granted	$ 0.93
Total fair value of options vested	$ 67	$ 117
Stock-based compensation (in dollars)	219	$ 117
Total unrecognized compensation expense	$ 176
Period for unrecognized compensation expense is estimated to be recognized	1 year 1 month 13 days

SHARE-BASED COMPENSATION, STO_7

SHARE-BASED COMPENSATION, STOCK OPTIONS, AND RESTRICTED SECURITIES, RESTRICTED STOCK (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Number of Grants
Forfeiture of restricted stock	(9,895,000)
Restricted stock units issued
Number of shares issued to employees (in shares)			6,886
Share-based compensation
Stock-based compensation (in dollars)	$ 315	$ 215
RSU
Number of Grants
Unvested balance at	6,402
Vested/Released (in shares)	(100)
Unvested balance at	6,302	6,402
Weighted-Average Grant Date Fair Value
Unvested balance at (in dollars per share)	$ 25.67
Vested/Released (in dollars per share)	660
Unvested balance at (in dollars per share)	$ 15.60	$ 25.67
Share-based compensation
Stock-based compensation (in dollars)	$ 96	$ 98
Unrecognized compensation
Total unrecognized compensation expense	$ 24
Period for unrecognized compensation expense is estimated to be recognized	8 months 23 days

WARRANTS (Details)

WARRANTS (Details) - $ / shares	12 Months Ended
	Dec. 31, 2021	Mar. 31, 2020
Warrants to purchase common stock issued and outstanding
Number of Warrants	14,078,338
Weighted average exercise price	$ 1.41
Weighted average life in years	3 years 7 months 28 days
2018 Warrant Exercise price $6.98
Warrants to purchase common stock issued and outstanding
Warrants Issued Year	2018
Number of Warrants	211,921
Warrant Exercise Price	$ 6.98
2019 Warrant Exercise price $4.50
Warrants to purchase common stock issued and outstanding
Warrants Issued Year	2019
Number of Warrants	15,168
Warrant Exercise Price	$ 4.50
Expiration date	Nov. 21, 2024
2020 Series A Warrants Exercise price $2.75
Warrants to purchase common stock issued and outstanding
Warrants Issued Year	2020
Number of Warrants	2,545,455
Warrant Exercise Price	$ 2.75
Expiration date	Mar. 10, 2025
2020 Placement Agent Warrants Exercise price $3.475
Warrants to purchase common stock issued and outstanding
Warrants Issued Year	2020
Number of Warrants	165,455
Warrant Exercise Price	$ 3.4375
Expiration date	Mar. 5, 2025
2020 Series B Warrants Exercise price $ 0.00001
Warrants to purchase common stock issued and outstanding
Warrants Issued Year	2020
Number of Warrants	12,728
Warrant Exercise Price	$ 0.00001
2020 Series C Warrants Exercise price $1.62
Warrants to purchase common stock issued and outstanding
Warrants Issued Year	2020
Number of Warrants	1,680,240
Warrant Exercise Price	$ 1.62
Expiration date	Oct. 17, 2025
2020 Placement Agent Warrants Exercise price $2.1875
Warrants to purchase common stock issued and outstanding
Warrants Issued Year	2020
Number of Warrants	111,491
Warrant Exercise Price	$ 2.1875
Expiration date	Apr. 15, 2025
2018 Warrants
Warrants to purchase common stock issued and outstanding
Expiration date	Jun. 25, 2023
Placement Agent Warrants
Warrants to purchase common stock issued and outstanding
Warrants Issued Year	2020
Number of Warrants	1,206,562	165,455
Warrant Exercise Price	$ 1	$ 3.4375
Expiration date	Oct. 22, 2025
October 2020 Offering
Warrants to purchase common stock issued and outstanding
Warrants Issued Year	2020
Number of Warrants	8,129,318
Warrant Exercise Price	$ 0.80
Expiration date	Oct. 27, 2025

EMPLOYEE BENEFIT PLAN (Details)

EMPLOYEE BENEFIT PLAN (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
EMPLOYEE BENEFIT PLAN
Eligibility criteria for participation in the Plan	21 years
Employer Matching Contribution	$ 69	$ 60

COMMITMENTS AND CONTINGENCIES,

COMMITMENTS AND CONTINGENCIES, LEASES (Details) $ in Thousands	Nov. 23, 2021USD ($)	Jun. 01, 2021USD ($)	May 31, 2021USD ($)	Dec. 31, 2021USD ($)	May 03, 2018ft²
Lessee, Lease, Description [Line Items]
Letter of credit terminated amount			$ 60
Borrowing rate used in modification	5.97%			5.74%
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 486	$ 143		$ 629
Cambridge Lease
Lessee, Lease, Description [Line Items]
Standby letter of credit		$ 100
Cambridge Lease | Sublease
Lessee, Lease, Description [Line Items]
Lease space (in square feet) | ft²					5,104

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES, LEASE EXPENSE (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Lease expense
Operating lease cost	$ 392	$ 364
Short-term lease cost	3	21
Variable lease cost	95	139
Total lease cost	$ 490	$ 524

COMMITMENTS AND CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES, LEASE OTHER INFORMATION (Details) - USD ($) $ in Thousands	Nov. 23, 2021	Jun. 01, 2021	Dec. 31, 2021	Dec. 31, 2020
COMMITMENTS AND CONTINGENCIES
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 486	$ 143	$ 629
Operating cash flows from short term leases			3	$ 21
Operating cash flows from operating leases			403	375
Total cash paid for leases			$ 406	$ 396
Weighted-average remaining lease term - operating leases (years)			3 years	2 years 9 months 29 days
Weighted-average discount rate - operating leases			6.00%	7.00%

COMMITMENTS AND CONTINGENCIES_4

COMMITMENTS AND CONTINGENCIES, MATURITIES OF LEASE LIABILITIES (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Maturities of lease liabilities
2022	$ 427
2023	440
2024	568
Total lease payments	1,435
Less: imputed interest	(125)
Present value of lease liabilities	$ 1,310	$ 1,020

COMMITMENTS AND CONTINGENCIES_5

COMMITMENTS AND CONTINGENCIES, LEASE CLASSIFICATION (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
COMMITMENTS AND CONTINGENCIES
Operating Lease, Right-of-Use Asset	$ 1,229	$ 928
Financial position	Total lease assets
Total lease assets	$ 1,229	928
Operating Liabilities - Current	$ 361	327
Financial position	Operating Liabilities - Current
Operating Liabilities - Non Current	$ 949	693
Financial position	Operating Liabilities - Non Current
Total Operating Liabilities	$ 1,310	$ 1,020
Financial position	Operating Liabilities - Current, Operating Liabilities - Non Current

COMMITMENTS AND CONTINGENCIES_6

COMMITMENTS AND CONTINGENCIES, COMPENSATION (Details) $ in Millions	Dec. 31, 2021USD ($)
Research and Development Arrangement [Member]
Compensation Arrangement
Commitments	$ 4.3

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details)	1 Months Ended
	Oct. 31, 2020entityshares	Mar. 31, 2020shares
Related Party Transactions
Number of investors who owned more then five percent of outstanding shares at time of offering | entity	3
Maximum percent ownership threshold	5.00%
October 2020 Offering
Related Party Transactions
Issuance of common stock and warrants in public offerings (in shares)	11,785,000
Dr. Toselli [Member]
Related Party Transactions
Issuance of common stock and warrants in public offerings (in shares)		3,636
Warrants for purchase of common stock (in shares)		3,636
Mr. Christopher [Member]
Related Party Transactions
Issuance of common stock and warrants in public offerings (in shares)		3,636
Warrants for purchase of common stock (in shares)		3,636
Ms. Merrifield [Member]
Related Party Transactions
Issuance of common stock and warrants in public offerings (in shares)		3,636
Warrants for purchase of common stock (in shares)		3,636
Sabby Volatility Warrant Master Fund, Limited [Member]
Related Party Transactions
Issuance of common stock and warrants in public offerings (in shares)	535,000
Warrants for purchase of common stock (in shares)	3,215,000
Intracoastal Capital, LLC [Member]
Related Party Transactions
Issuance of common stock and warrants in public offerings (in shares)	500,000
Warrants for purchase of common stock (in shares)	2,000,000
CVI Investments [Member]
Related Party Transactions
Issuance of common stock and warrants in public offerings (in shares)	500,000
Warrants for purchase of common stock (in shares)	500,000