InVivo Therapeutics (NVIVQ) 10-K 1 Apr 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Mar. 22, 2019	Jun. 30, 2018
Document and Entity Information
Entity Registrant Name	INVIVO THERAPEUTICS HOLDINGS CORP.
Entity Central Index Key	0001292519
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 6,914,896
Entity Common Stock, Shares Outstanding		9,311,070
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 16,660	$ 12,910
Restricted cash	4	361
Prepaid expenses and other current assets	461	535
Total current assets	17,125	13,806
Property, equipment and leasehold improvements, net	100	157
Restricted cash	110
Other assets	1,042	82
Total assets	18,377	14,045
Current liabilities:
Accounts payable	815	988
Loan payable, current portion	100	452
Derivative warrant liability		4
Deferred rent, current portion		30
Accrued expenses	1,290	1,638
Total current liabilities	2,205	3,112
Loan payable, net of current portion		400
Deferred rent, net of current portion		367
Other liabilities	61	56
Total liabilities	2,266	3,935
Commitments and contingencies (Note 15)
Stockholders’ equity:
Common stock, $0.00001 par value, authorized 25,000,000 shares; 9,309,255 shares issued and outstanding at December 31, 2018; 1,370,992 shares issued and outstanding at December 31, 2017	1	1
Additional paid-in capital	223,440	194,016
Accumulated deficit	(207,330)	(183,907)
Total stockholders’ equity	16,111	10,110
Total liabilities and stockholders’ equity	$ 18,377	$ 14,045

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical)	Apr. 16, 2018	Dec. 31, 2018$ / sharesshares	May 31, 2018shares	Apr. 30, 2018shares	Dec. 31, 2017$ / sharesshares
Consolidated Balance Sheets
Common stock, par value (in dollars per share) | $ / shares		$ 0.00001			$ 0.00001
Common stock, authorized		25,000,000	25,000,000	4,000,000	25,000,000
Common stock, issued		9,309,255			1,370,992
Common stock, outstanding		9,309,255			1,370,992
Reverse stock split ratio	0.04

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating expenses:
Research and development	$ 4,931	$ 11,083
General and administrative	7,836	13,510
Total operating expenses	12,767	24,593
Operating loss	(12,767)	(24,593)
Other income (expense):
Interest income / (expense), net	206	115
Other income	1,303
Derivatives (loss)	(12,165)	(2,267)
Other income / (expense), net	(10,656)	(2,152)
Net loss	$ (23,423)	$ (26,745)
Net loss per share, basic and diluted (in dollars per share)	$ (4.69)	$ (20.29)
Weighted average number of common shares outstanding, basic and diluted	4,990,089	1,318,003
Other comprehensive loss:
Net loss	$ (23,423)	$ (26,745)
Other comprehensive loss:
Comprehensive loss	$ (23,423)	$ (26,745)

Consolidated Statements of Op_2

Consolidated Statements of Operations and Comprehensive Loss (Parenthetical)	Apr. 16, 2018
Statement of Operations and Comprehensive Loss
Reverse stock split ratio	0.04

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Total
Stockholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2016	$ 1	$ 185,955	$ (157,007)	$ 28,949
Beginning Balance, (in shares) at Dec. 31, 2016	1,281,763
Share-based compensation expense		4,106		4,106
Issuance of common stock on warrant exchange		3,537		3,537
Issuance of common stock on warrant exchange (in shares)	80,857
Issuance of common stock for services (in shares)	14
Issuance of common stock upon exercise of warrants		3		3
Issuance of common stock upon exercise of warrants (in shares)	139
Issuance of common stock upon exercise of stock options		26		26
Issuance of common stock upon exercise of stock options (in shares)	3,576
Issuance of common stock under ESPP		51		51
Issuance of common stock under ESPP (in shares)	710
Issuance of common stock to 401(k) plan	$ 183	183		183
Issuance of common stock to 401(k) plan (in shares)	3,933
Net loss			(26,745)	(26,745)
Stockholders' Equity Attributable to Parent, Ending Balance at Dec. 31, 2017	$ 1	194,016	(183,907)	$ 10,110
Ending Balance, (in shares) at Dec. 31, 2017	1,370,992			1,370,992
Cumulative Adjustment on adoption of ASU 2016-09. | ASU 2016-09		155	(155)
Share-based compensation expense		618		$ 618
Fair value of derivative warrant liability reclassified to additional paid-in capital		25,327		25,327
Issuance of common stock upon vesting of restricted stock units (in shares)	4,250
Issuance of common stock upon exercise of warrants (in shares)	6,277,311
Issuance of common stock upon exercise of stock options		131		131
Issuance of common stock under ESPP		4		4
Issuance of common stock under ESPP (in shares)	1,133
Fractional shares issued due to reverse stock split	2,733
Issuance of common stock to 401(k) plan		6		6
Issuance of common stock to 401(k) plan (in shares)	440
Issuance of common stock in public offerings		3,338		3,338
Issuance of stock in public offering (in shares)	1,652,396
Net loss			(23,423)	(23,423)
Stockholders' Equity Attributable to Parent, Ending Balance at Dec. 31, 2018	$ 1	$ 223,440	$ (207,330)	$ 16,111
Ending Balance, (in shares) at Dec. 31, 2018	9,309,255			9,309,255

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical)	Apr. 16, 2018
Consolidated Statements of Changes in Stockholders' Equity (Deficit)
Reverse stock split ratio	0.04

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (23,423)	$ (26,745)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	91	395
Loss on impairment of fixed assets	48	41
Derivatives loss	12,165	2,267
Non-cash interest expense		5
Common stock issued to 401(k) plan	6	183
Gain on lease assignment	(603)
Share-based compensation expense	618	4,106
Non-cash investment (income) expense, net	3
Changes in operating assets and liabilities:
Prepaid expenses	77	(89)
Other assets	(985)	321
Accounts payable	(173)	(23)
Accrued expenses and other liabilities	(136)	(144)
Net cash used in operating activities	(12,312)	(19,683)
Cash flows from investing activities:
Purchases of marketable securities		(8,256)
Sales of marketable securities		19,833
Purchases of property and equipment	(65)	(65)
Net cash (used in) provided by investing activities	(65)	11,512
Cash flows from financing activities:
Proceeds from exercise of stock options		26
Proceeds from issuance of stock under ESPP	4	51
Proceeds from exercise of warrants	131	3
Repayment of loan payable	(752)	(423)
Repurchase of warrants	(14)	(40)
Proceeds from issuance of common stock and warrants, net of commissions and issuance costs	16,511
Net cash provided by (used in) financing activities	15,880	(383)
Increase (decrease) in cash and cash equivalents and restricted cash	3,503	(8,554)
Cash, cash equivalents and restricted cash at beginning of period	13,271	21,825
Cash, cash equivalents and restricted cash at end of period	16,774	13,271
Supplemental disclosure of cash flow information and non-cash investing and financing activities:
Cash paid for interest	44	71
Cash paid for taxes	18
Non-cash issuance of common stock for warrants	287	$ 3,537
Reclassification of derivative warrant liability to additional paid-in capital	$ 25,327

NATURE OF OPERATIONS AND GOING

NATURE OF OPERATIONS AND GOING CONCERN	12 Months Ended
	Dec. 31, 2018
NATURE OF OPERATIONS AND GOING CONCERN
NATURE OF OPERATIONS AND GOING CONCERN	1. NATURE OF OPERATIONS AND GOING CONCERN Business InVivo Therapeutics Holdings Corp. (the “Company”) is a pioneering 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 and the Massachusetts Institute of Technology, 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, 2018, the Company has consolidated cash and cash equivalents of $16.7 million. 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 expects that it will need additional capital to fund its operations, which it may raise through a combination of equity offerings, debt financings, other third party funding, marketing and distribution arrangements, and other collaborations, strategic alliances, and licensing arrangements. Going Concern The Company’s financial statements as of December 31, 2018 were prepared under the assumption that the Company will continue as a going concern. At December 31, 2018, the Company had cash and cash equivalents of $16.7 million. Given the Company’s development plans, the Company estimates cash resources will be sufficient to fund its operations into the first quarter of 2020. This estimate is based on assumptions that may prove to be wrong; expenses could prove to be significantly higher, leading to a more rapid consumption of the Company’s existing resources. 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, reduce 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. If the Company seeks additional financing to fund its business activities in the future and there remains substantial doubt about its ability to continue as a going concern, investors or other financing sources may be unwilling to provide additional funding to the Company on commercially reasonable terms or at all. Based on these factors, management determined that there is substantial doubt regarding the Company’s ability to continue as a going concern.

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2018
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. At December 31, 2018 and 2017, cash equivalents were comprised of money market funds and other short-term investments. Cash and cash equivalents consist of the following: December 31, December 31, (In thousands) 2018 2017 Cash $ (83) $ 23 Money market funds 16,743 12,887 Total cash and cash equivalents $ 16,660 $ 12,910 Restricted cash Restricted cash as of December 31, 2018 was $114 thousand and included a $50 thousand security deposit related to the Company’s credit card account, $4 thousand related to 401(k) reserve account and a $60 thousand standby letter of credit in favor of a landlord (see Note 15). Restricted cash as of December 31, 2017 was $361 thousand and included a $50 thousand security deposit related to the Company’s credit card account and a $311 thousand standby letter of credit in favor of a landlord (see Note 15). 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. The carrying value of the loan payable approximates fair value due to market terms. Property and equipment Property and equipment are carried at cost. Depreciation and amortization expense are recorded over the estimated useful lives of the assets using the straight‑line method. A summary of the estimated useful lives is as follows: Classification Estimated Useful Life Computer hardware 3 - 5 years Software 3 years Office furniture and equipment 5 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 CRO services. As of December 31, 2018, the Company had $1.3 million in prepayments for CRO services of which $290 thousand is included in prepaid and other current asset balance on the balance sheet and the remaining $996 thousand 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 1 operating segment, which is developing and commercializing biopolymer scaffolding devices for the treatment of spinal cord injuries. As of December 31, 2018, and 2017, all of the Company’s assets were located in 1 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 the current year. There were no material uncertain tax positions that required accrual or disclosure to the financial statements as of December 31, 2018 or 2017. Tax years subsequent to 2014 remain open to examination by U.S. federal and state tax authorities. The Tax Cuts and Jobs Act (“the Act”) was enacted on December 22, 2017. The Act reduced the US federal corporate tax rate from 35% to 21%, required companies to pay a 1-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and created new taxes on certain foreign sourced earnings. On December 22, 2017, the Securities and Exchange Commission issued guidance under Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (“SAB 118”) directing taxpayers to consider the impact of the U.S. legislation as “provisional” when it does not have the necessary information available, prepared or analyzed (including computations) in reasonable detail to complete its accounting for the change in tax law. At December 31, 2018, the Company had completed its accounting for the tax effects of enactment of the Act, including the effects on its existing deferred tax balances, and the corresponding valuation allowance and the 1-time transition tax. For the year ended December 31, 2018, the Company recognized no transition tax, remeasured deferred taxes, and its reassessment of uncertain tax positions and valuation allowances. 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. On May 3, 2018, the Company assigned the Cambridge Lease (as defined in Note 15) to a third party who assumed all of the Company’s remaining rights and obligations under the Cambridge Lease and as a result recorded an impairment charge of $48 thousand. On August 28, 2017, the Company implemented a strategic restructuring and as a result recorded an impairment charge of $41 thousand (see Note 3). Share‑based payments The Company accounts for all stock-based payment awards granted to employees and nonemployees using a 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 employee awards is the date of grant, and stock-based compensation costs are recognized as expense over the employees’ requisite service period, which is the vesting period, on a straight-line basis. The measurement date for nonemployee awards is the date the services are completed, resulting in periodic adjustments to stock-based compensation during the vesting period for changes in the fair value of the awards. 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; however, certain warrants to purchase common stock that do not meet the requirements for classification as equity are classified as 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 charged (credited) 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 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. Diluted net income per share of common stock has been computed by dividing net income by the weighted average number of shares outstanding plus the dilutive effect, if any, of outstanding stock options, warrants and convertible securities. Diluted net loss per share of common stock has been computed by dividing the net loss for the period by the weighted average number of shares of common stock outstanding during such period. 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, 2018 and 2017, 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, 2018 2017 Warrants 7,673,130 86,646 Stock options 54,849 134,770 Unvested restricted stock units 10,250 20,000 Total potentially dilutive securities 7,738,229 241,416 Recent accounting pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), to provide updated guidance on revenue recognition. ASU 2014-09 requires a company to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross Versus Net), which clarifies the implementation guidance on principal versus agent considerations. In April 2016, the FASB issued ASU No. 2016- 10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing, which clarifies certain aspects of identifying performance obligations and licensing implementation guidance. In May 2016, the FASB issued ASU No. 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients, which relates to disclosures of remaining performance obligations, as well as other amendments to guidance on collectability, non-cash consideration, and the presentation of sales and other similar taxes collected from customers. Collectively, these standards are effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within each annual reporting period. The Company adopted ASU 2014-09 on January 1, 2018, and it did not have any impact on the financial position, results of operations or disclosures as the Company currently does not generate any revenue. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”). ASU 2016-01 is intended to improve the recognition and measurement of financial instruments by; requiring equity investments to be measured at fair value with changes in fair value recognized in net income: requiring public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; requiring separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or the accompanying notes to the financial statements; eliminating the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured and amortized at cost on the balance sheet; and requiring a reporting organization to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the organization has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. ASU 2016-01 is effective for annual periods and interim periods within those annual periods, beginning after December 15, 2017. The amendments should be applied by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. The amendments related to equity securities without readily determinable fair values (including disclosure requirements) should be applied prospectively to equity investments that exist as of the date of adoption. In February 2018, the FASB issued ASU No. 2018-03 which includes technical corrections and improvements to clarify the guidance in ASU No. 2016-01. The Company adopted ASU 2016-01 on January 1, 2018 and it did not have any impact on its accounting for equity investments, fair value disclosures or other disclosure requirements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The guidance in this ASU supersedes the leasing guidance in Topic 840, Leases. Under the new guidance, lessees are required to recognize lease assets and lease liabilities on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance leases or operating leases, with classification affecting the pattern of expense recognition in the statement of operations. The FASB has subsequently issued amendments to the guidance, including the addition of an optional transition method and provided clarifications to address potential narrow-scope implementation issues. The adoption of ASU 2016-02 will result in an increase to the Company’s consolidated balance sheets for right-of-use assets and lease liabilities. The Company adopted ASU 2016- 02 effective January 1, 2019 and elected the optional transition method for adoption. The Company also took advantage of the transition package of practical expedients permitted within ASU 2016-02, which among other things, allowed it to carryforward historical lease classifications. The Company also elected to keep leases with an initial term of 12 months or less off of the balance sheet as a policy election and will recognize those lease payments in the consolidated statements of operations on a straight-line basis over the lease term. Based on our current lease portfolio, the Company estimates that the adoption of this standard will result in approximately $1.5 million of additional assets and liabilities being reflected on our consolidated balance sheets on January 1, 2019; however, there will not be a material impact to its consolidated statement of operations or cash flows. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU No. 2016-15”), which clarifies the classification of certain cash receipts and cash payments in the statement of cash flows, including debt prepayment or extinguishment costs, settlement of contingent consideration arising from a business combination and insurance settlement proceeds. The Company adopted ASU 2016-15 on January 1, 2018, and it did not result in any changes to the presentation of amounts shown on the Company’s consolidated statements of cash flows for all periods presented. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (A Consensus of the FASB Emerging Issues Task Force) (“ASU No 2016-18”). The amendments in this update require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The Company adopted ASU No. 2016-18 in the first quarter of 2018 and applied the guidance retrospectively to the prior period consolidated statement of cash flows. The following table provides a reconciliation of cash, cash equivalents, and restricted cash within the statement of financial position that sum to the total of the same such amounts shown in the statement of cash flows. December 31, December 31, (In thousands) 2018 2017 Cash and cash equivalents $ 16,660 $ 12,910 Restricted cash included in current assets 4 361 Restricted cash included in other non-current assets 110 — Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 16,774 $ 13,271 In May 2017, the FASB issued ASU No. 2017-09, Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting (“ASU 2017-09”), to clarify when to account for a change to the terms or conditions of a share-based payment award as a modification. Under this new guidance, modification accounting is required if the fair value, vesting conditions, or classification of the award changes as a result of the change in terms or conditions. ASU 2017-09 is effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within each annual reporting period. The Company adopted ASU 2017-09 on January 1, 2018 and it did not have a material effect on the Company’s financial position, results of operations or disclosures. In July 2017, the FASB issued ASU No. 2017-11, Part I. Accounting for Certain Financial Instruments with Down Round Features and Part II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception (“ASU 2017-11”). Part I of this guidance applies to entities that issue financial instruments such as warrants, convertible debt or convertible preferred stock that contain down round features. Part II of this guidance replaces the indefinite deferrals for certain mandatorily redeemable noncontrolling interests and mandatorily redeemable financial instruments of nonpublic entities. ASU 2017-11 is effective for annual reporting periods beginning after December 15, 2018, including interim reporting periods within each annual reporting period. The Company has concluded that the adoption of ASU 2017-11 will not have a material impact on the financial statements. In February 2018, the FASB issued Accounting Standards Update No. 2018-02 , Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . This update relates to the impacts of the tax legislation commonly referred to as the Tax Reform Act. The guidance permits the reclassification of certain income tax effects of the Tax Reform Act from other comprehensive income to retained earnings (stranded tax effects). The guidance also requires certain new disclosures. The guidance is effective for annual periods beginning after December 15, 2018, and interim periods within those reporting periods. Early adoption is permitted. Entities may adopt the guidance using 1 of 2 transition methods; retrospective to each period (or periods) in which the income tax effects of the Tax Reform Act related to the items remaining in other comprehensive income are recognized or at the beginning of the period of adoption. The Company is currently evaluating the impact that the guidance may have on its consolidated financial statements. In June 2018, the FASB issued Accounting Standards Update No. 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting which is intended to reduce cost and complexity and to improve financial reporting for nonemployee share-based payments. The amendment is effective for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. Early adoption is permitted, but no earlier than an entity’s adoption date of Topic 606. The Company does not expect the adoption of this Accounting Standard to have a material effect on its consolidated financial statements. In July 2018, the FASB issued Accounting Standards Update No. 2018-09, Codification Improvements which clarifies, corrects errors in, and makes improvements to several Codification Topics, including to: · Clarify when excess tax benefits should be recognized for share-based compensation awards · Remove inconsistent guidance in income tax accounting for business combinations · Clarify the circumstances when derivatives may be offset · Clarify the measurement of liability or equity-classified financial instruments when an identical asset is held as an asset · Allow portfolios of financial instruments and nonfinancial instruments accounted for as derivatives to use the portfolio exception to valuation The transition and effective date guidance is based on the facts and circumstances of each amendment. Some of the amendments in this Update do not require transition guidance and will be effective upon issuance of this Update. However, many of the amendments in this Update do have transition guidance with effective dates for annual periods beginning after December 15, 2018. The Company is currently evaluating the impact that the guidance may have on its consolidated financial statements. In August 2018, the FASB issued Accounting Standards Update No. 2018-13 - Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement which improves the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement. The amendments in this Update are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. Early adoption is permitted upon issuance of this Update. The Company does not expect the adoption of this Accounting Standard to have a material effect on its consolidated financial statements. In August 2018, the SEC adopted the final rule under SEC Release No. 33-10532, Disclosure Update and Simplification, amending certain disclosure requirements that were redundant, duplicative, overlapping, outdated or superseded. In addition, the amendments expanded the disclosure requirements on the analysis of stockholders' equity for interim financial statements. Under the amendments, an analysis of changes in each caption of stockholders' equity presented in the balance sheet must be provided in a note or separate statement. The analysis should present a reconciliation of the beginning balance to the ending balance of each period for which a statement of comprehensive income is required to be filed. This final rule is effective on November 5, 2018. The Company adopted this release in the third quarter of 2018.

PROPERTY AND EQUIPMENT

PROPERTY AND EQUIPMENT	12 Months Ended
	Dec. 31, 2018
PROPERTY AND EQUIPMENT
PROPERTY AND EQUIPMENT	3. PROPERTY AND EQUIPMENT Property and equipment, net consisted of the following: (In thousands) 2018 2017 Computer software and hardware $ 131 $ 241 Research and lab equipment 508 508 Leasehold improvements 66 431 Office equipment — 796 Property and equipment 705 1,976 Less accumulated depreciation and amortization (605) (1,819) Property and equipment, net $ 100 $ 157 Depreciation expense for the years ended December 31, 2018 and 2017, was $74 thousand, and $377 thousand, respectively. Maintenance and repairs are charged to expense as incurred and any additions or improvements are capitalized. On May 3, 2018, the Company assigned the Cambridge Lease to a third party who assumed all of the Company’s remaining rights and obligations under the Cambridge Lease and as a result wrote off $1.3 million of fully depreciated assets and also recorded an impairment loss of $48 thousand related to certain fixed assets in connection with the reassignment. On August 28, 2017, the Company implemented a strategic restructuring and as a result wrote off $1.8 million of fully depreciated assets and also recorded an impairment loss of $41 thousand related to certain fixed assets in connection with the restructuring.

INTANGIBLE ASSETS

INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2018
INTANGIBLE ASSETS
INTANGIBLE ASSETS	4. INTANGIBLE ASSETS Intangible assets, included in “other assets,” consisted of patent licensing fees paid to license intellectual property (see Note 14). The Company is amortizing the license fee as a research and development expense over the 15– year term of the license. (In thousands) 2018 2017 Patent licensing fee $ 200 $ 200 Accumulated amortization (156) (139) Intangible assets, net $ 44 $ 61 For each of the years ended December 31, 2018 and 2017, the amortization expense was $17 thousand. Amortization expense is expected to be $17 thousand per year for 2019 and 2020 and $10 thousand in 2021.

ACCRUED EXPENSES

ACCRUED EXPENSES	12 Months Ended
	Dec. 31, 2018
ACCRUED EXPENSES.
ACCRUED EXPENSES	5. ACCRUED EXPENSES Accrued expenses consisted of the following: December 31, December 31, (In thousands) 2018 2017 Severance and restructuring $ 517 $ 1,160 Compensation 489 196 Clinical 73 52 Legal 35 68 Other accrued expenses 176 162 Total accrued expenses $ 1,290 $ 1,638

FAIR VALUES OF ASSETS AND LIABI

FAIR VALUES OF ASSETS AND LIABILITIES	12 Months Ended
	Dec. 31, 2018
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. 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. The Company uses valuation methods and assumptions that consider, among other factors, the fair value of the underlying stock, risk‑free interest rate, volatility, expected life, and dividend rates in estimating the fair value for the warrants considered to be derivative instruments. Assets and liabilities measured at fair value on a recurring basis are summarized below: At December 31, 2018 (In thousands) Level 1 Level 2 Level 3 Fair Value Cash equivalents $ 16,743 $ — $ — $ 16,743 At December 31, 2017 (In thousands) Level 1 Level 2 Level 3 Fair Value Cash equivalents $ 12,887 $ — $ — $ 12,887 Derivative warrant liability $ — $ 4 $ — $ 4

LOAN PAYABLE

LOAN PAYABLE	12 Months Ended
	Dec. 31, 2018
LOAN PAYABLE
LOAN PAYABLE	7. LOAN PAYABLE In October 2012, the Company entered into a loan agreement with the Massachusetts Development Finance Agency (“MassDev”). The loan agreement provided the Company with a $2.0 million line of credit from the Commonwealth of Massachusetts’s Emerging Technology fund, with $200 thousand designated to be used for working capital purposes and the remainder to be used for the purchase of capital equipment. The annual interest rate on the loan is fixed at 6.5% with interest-only payments for the first 30 months, commencing on November 1, 2012, and then equal interest and principal payments over the next 54 months, until the final maturity of the loan on October 5, 2019. Commencing on May 1, 2015, equal monthly principal payments of $41 thousand are due until loan maturity. In May 2018, in order to obtain the consent of MassDev for facility changes, including the assignment of the Cambridge Lease, and the sale of certain assets, the Company paid down $300 thousand of principal on the MassDev loan. As of December 31, 2018, $100 thousand in principal payments will be due in the next 3 months. In October 2012, as part of the agreement, the Company issued MassDev a warrant for the purchase of 362 shares of the Company’s common stock of which 243 shares remaining outstanding at December 31, 2018. The warrant has a 7-year term and is exercisable at $166 per share. The fair value of the warrant was determined to be $32 thousand and is being amortized through interest expense over the life of the note. For the years ended December 31, 2018 and 2017, the expense was $7 thousand and $5 thousand respectively, and was included in interest expense in the Company’s consolidated statements of operations. The equipment line of credit is secured by substantially all the assets of the Company, excluding intellectual property. Interest expense related to this loan was $43 thousand and $71 thousand for the years ended December 31, 2018 and 2017, respectively. At December 31, loans payable consisted of the following: December 31, (In thousands) 2018 2017 MassDev Loan $ 100 $ 852 Less: current portion (100) (452) Notes Payable long-term portion $ — $ 400

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2018
INCOME TAXES
INCOME TAXES	8. 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, 2018, the Company had U.S. federal and Massachusetts net operating loss carryforwards of $128.9 million and $120.8 million, respectively, of which $117.3 million of federal carryforwards will expire in varying amounts beginning in 2026 and $11.6 million carry forward indefinitely . Massachusetts net operating losses begin to expire in 2029. Utili zation of net operating losses 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 an 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 $1.2 million and $258 thousand respectively, at December 31, 2018, which will begin to expire in 2022 unless previously utilized. On December 22, 2017, the Tax Cuts and Jobs Act (“the Act”) was enacted in the United States. The Act reduces the U.S. federal corporate tax rate from 35% to 21%, requires companies to pay a 1-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and creates new taxes on certain foreign sourced earnings. At December 31, 2018, the Company has completed its accounting for the tax effects of enactment of the Act, including the effects on our existing deferred tax balances, the corresponding valuation allowance and the 1- time transition tax. For the year ended December 31, 2018, the Company recognized no transition tax, have remeasured deferred taxes, and our reassessment of uncertain tax positions and valuation allowances. Significant components of the Company’s net deferred tax assets are as follows: December 31, (In thousands) 2018 2017 Net operating loss carryforward $ 34,846 $ 31,533 Research and development credit carryforward 1,390 1,173 Stock-based compensation 2,300 2,828 Depreciation and amortization 11 71 Accrued expenses 136 357 Charitable contributions — 27 Subtotal 38,683 35,989 Valuation allowance (38,683) (35,989) 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. During the year ending December 31, 2017, the Company adopted ASU 2016-09, Improvements to Employee Share-Based Payment Accounting. As part of the adoption, the Company recorded through retained earnings additional deferred tax assets of $642 thousand related to previously unrecognized tax losses with an equal and offsetting adjustment to the Company's valuation allowance. The net impact of the adoption on the Company's deferred tax assets was $0. In the years ended December 31, 2018 and 2017, the valuation allowance increased by $2.7 million and decreased by $7.9 million, respectively. The Company has no uncertain tax positions at December 31, 2018 and 2017 that would affect its effective tax rate. The Company does not anticipate a significant change in the amount of uncertain tax positions over the next 12 months. Since the Company is in a loss carryforward position, the Company is generally subject to U.S. federal and state income tax examinations by tax authorities for all years for which a loss carryforward is available. 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, 2018 2017 Statutory rate (21.0) % (34.0) % State taxes, net of benefit (2.9) % (4.7) % Permanent differences: Derivative losses 10.9 % 2.9 % Other 0.4 % 1.1 % Research and development tax credit (0.8) % (0.2) % Other 1.9 % 1.4 % Adoption of ASU 2016-09 — % 7.4 % Increase / (decrease) in valuation reserve 11.5 % (32.0) % Change in federal tax rate — % 58.1 % Effective tax rate % %

COMMON STOCK

COMMON STOCK	12 Months Ended
	Dec. 31, 2018
COMMON STOCK.
COMMON STOCK	9. COMMON STOCK In May 2018, 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 4,000,000 to 25,000,000 shares of common stock. As of December 31, 2018, and 2017, 9,309,255, and 1,370,992 shares were issued and outstanding respectively. In June 2018, the Company closed an underwritten public offering of an aggregate of 1,378,400 Common Units, at an offering price of $2.00 each, each comprised of 1 share of its common stock, par value $0.00001 per share and 1 Series A warrant to purchase 1 share of common stock. The public offering also included 6,242,811 pre-funded units at an offering price of $1.99 each, each comprised of 1 pre-funded Series B Warrant and 1 Series A warrant to purchase 1 share of common stock. Each Series A warrant has an exercise price of $2.00 per share, exercisable immediately from the date of issuance and expires 5 years from the date of issuance. Each Series B warrant has an exercise price of $0.01 per share, exercisable immediately from the date of issuance and expires 20 years from the date of issuance. The net proceeds to the Company, after deducting the underwriting discounts and commissions and other offering expenses, were $13.5 million. In September 2018, the Company entered into an Amendment to Warrant Agency Agreement and Warrants (the “Ladenburg Warrant Amendment”) with Continental Stock Transfer & Trust Company (“Continental”) that amends the Warrant Agency Agreement, by and between the Company and Continental, as Warrant Agent, dated June 25, 2018, and the Series A Common Stock Purchase Warrant, and the Series B Pre-Funded Common Stock Purchase Warrant both dated June 25, 2018 (the Series A and Series B Warrant, collectively the “2018 Warrants”). The Ladenburg Warrant Amendment adds a provision to each of the warrants that allows the Company or a successor entity whose stock is not listed on a trading market to, in connection with a Fundamental Transaction (as such term is defined in the 2018 Warrants) that is not within the Company’s control, purchase the warrant from the holder, at the holder’s option, by paying the same form of consideration in the same proportion that is offered to the holders of the Company’s common stock in connection with the Fundamental Transaction, including cash, stock, any combination thereof and any choice of consideration thereof, in an amount equal to the Black-Sholes Value of the remaining unexercised portion of the Warrant on the consummation date of the Fundamental Transaction. As a result of the amendment, the Company reassessed the warrant classification and concluded that the warrants qualified for equity classification. The fair value of the amended 2018 Warrants was re-measured immediately prior to the date of the Ladenburg Warrant Amendment with changes in fair value recorded as a loss of $764 thousand in the Company’s consolidated statement of operations and $14.7 million was reclassified to equity. During the year ended December 31, 2018, the Company issued an aggregate of 6,242,811 and 34,500 shares of common stock upon the exercise of Series B and Series A warrants respectively for aggregate proceeds of $131 thousand. The Company reclassified $10.6 million from derivative warrant liability to additional paid-in capital and recorded a derivative loss of $1.2 million in connection with the warrant exercises. In January 2018, the Company entered into a purchase and a registration rights agreement with Lincoln Park Capital Fund, LLC (“Lincoln Park”), under which it has the right to sell up to $15 million, in shares of its common stock, $0.00001 par value per share, to Lincoln Park over a 24 month period, subject to certain limitations and conditions set forth in the purchase agreement and registration rights agreement. On May 30, 2018 the Company’s stockholders approved to increase the issuance and sale by the Company to Lincoln Park, including the Company’s prior issuances and sales of shares of common stock to Lincoln Park since January 2018, of up to 1,200,000 shares of common stock. In accordance with the terms of the purchase agreement, at the time the Company signed the purchase agreement and the registration rights agreement, it issued 17,192 shares to Lincoln Park as consideration for its commitment to purchase shares of the Company’s common stock under the purchase agreement and recorded $627 thousand in deferred offering costs of which the full amount was capitalized into additional paid-in capital as of December 31, 2018. During the year ended December 31, 2018 the Company sold an aggregate of 256,804 shares to Lincoln Park, for aggregate proceeds of $3.1 million net of issuance costs. In May 2018, the Company’s Board of Directors approved to increase the number of shares of Common Stock reserved under the 401(k) Plan by 4,000 shares, bringing the aggregate number of shares of Common Stock eligible for distribution pursuant to the 401(k) Plan as of that date to 4,100 shares. In the second quarter of 2018, the Company revised its 401(k) matching policy to move from share matching to cash-based matching. During the year ended December 31, 2018, the Company issued an aggregate of 440 shares of common stock with a fair value of $6 thousand to the Company’s 401(k) plan as a matching contribution. The Company contributed $44 thousand in matching cash contributions to employee 401(k) accounts during the year ended December 31, 2018. During the year ended December 31, 2018, the Company issued an aggregate of 1,133 shares of common stock under the Company’s Employee Stock Purchase Plan (the “ESPP”) and received cash proceeds of $4 thousand. As part of the adjustment to reflect the Company’s 1-for-25 reverse stock split on its common stock on April 16, 2018, the Company issued 2,733 shares of common stock to account for the fractional roundup of shareholders. During the year ended December 31, 2018, the Company issued an aggregate of 4,250 shares of common stock upon vesting of restricted stock units. During the year ended December 31, 2017, the Company issued an aggregate of 3,576 shares of common stock upon the exercise of stock options and received cash proceeds from such exercises of $26 thousand. During the year ended December 31, 2017, the Company issued an aggregate of 139 shares of common stock upon the exercise of warrants and received cash proceeds from such exercises of $3 thousand. During the year ended December 31, 2017, the Company issued an aggregate of 3,933 shares of common stock with a fair value of $183 thousand to the Company’s 401(k) plan as a matching contribution. During the year ended December 31, 2017, the Company issued an aggregate of 710 shares of common stock under the ESPP and received cash proceeds of $51 thousand. During the year ended December 31, 2017, the Company issued an aggregate of 80,857 shares of common stock to certain holders of warrants, dated May 9, 2014, in exchange for their warrants to purchase an aggregate of 23,102 shares of common stock. The Company did not receive any cash proceeds from the warrant exchanges. Common Stock Reserves As of December 31, 2018, the Company had the following reserves established for the future issuance of common stock as follows: Reserves for the exercise of warrants 7,673,130 Reserves for the exercise of stock options 54,849 Reserves for the vesting of restricted stock units 10,250 Total Reserves 7,738,229

DERIVATIVE INSTRUMENTS

DERIVATIVE INSTRUMENTS	12 Months Ended
	Dec. 31, 2018
DERIVATIVE INSTRUMENTS
DERIVATIVE INSTRUMENTS	10. DERIVATIVE INSTRUMENTS The warrants issued in connection with the Company’s 2018 underwritten public offering had provisions that precluded the Company from classifying them as equity instruments (See Note 12). Accordingly, these warrants had been accounted for as derivative warrant liabilities. The Company used the Black-Scholes model and assumptions that considered, among other factors, the fair value of the underlying stock, risk-free interest rate, volatility, expected life, and dividend rates in estimating fair value for these warrants. At inception, the fair value of the Series B pre-funded warrants was estimated at $11.5 million using a Black-Scholes model with the following assumptions: expected volatility of 202.51%, risk free interest rate of 2.95%, expected life of 20 years and no dividends. At inception, the fair value of the Series A warrants was estimated at $13.7 million using a Black-Scholes model with the following assumptions: expected volatility of 202.51%, risk free interest rate of 2.75%, expected life of 5 years and no dividends. The Company allocated $13.2 million of the net proceeds to record the relative fair value of the warrant liability, with the remaining amount of $287 thousand recorded to permanent equity. The Company subsequently recorded the fair value of the warrant liability at $25.2 million with the loss of $12 million being recorded as a derivative loss on the Company’s consolidated statement of operations and comprehensive loss during the second quarter of 2018. In September 2018, the Company entered into the Ladenburg Warrant Amendment. As a result of the amendment, the Company reassessed the warrant classification and concluded that the warrants qualified for equity classification. The fair value of the amended 2018 Warrants was re-measured immediately prior to the date of the Ladenburg Warrant Amendment with changes in fair value recorded as a loss of $764 thousand in the Company’s consolidated statement of operations and $14.7 million was reclassified to equity. During the year ended December 31, 2018, the Company issued an aggregate of 6,242,811 shares of common stock upon the exercise of Series B warrants for aggregate proceeds of $62 thousand. There are no outstanding Series B warrants as of December 31, 2018. During the year ended December 31, 2018, the Company issued an aggregate of 34,500 shares of common stock upon the exercise of Series A warrants for aggregate proceeds of $69 thousand. The Company reclassified $10.6 million from derivative warrant liability to additional paid-in capital and recorded a derivative loss of $1.2 million in connection with the warrant exercises. The 2014 Warrants issued in connection with the Company’s May 2014 public offering had anti-dilution protection provisions and, under certain conditions, required the Company to automatically reprice the 2014 Warrants (See Note 12). Accordingly, the 2014 Warrants had been accounted for as derivative warrant liabilities. Through the date of the warrant exchange (see Note 12), the Company used the Binomial Lattice option pricing model and assumptions that considered, among other factors, the fair value of the underlying stock, risk-free interest rate, volatility, expected life, and dividend rates in estimating fair value for the 2014 Warrants considered to be derivative instruments. In May 2018, the Company entered into the Warrant Amendment (as defined below), which removed provisions that had previously precluded equity classification treatment of the 2014 Warrants on the Company’s balance sheets. The fair value of the amended 2014 Warrants was re-measured immediately prior to the date of amendment with changes in fair value recorded as a loss of $1 thousand in the Company’s consolidated statement of operations and $1 thousand was reclassified to equity. As of December 31, 2018, the Company did not have any liability classified warrants. As of December 31, 2017, the derivative warrant liability was insignificant and was included as a derivative warrant liability in current liabilities on the balance sheet. Changes in the fair value of the derivative financial instruments were recognized in the Company’s consolidated statement of operations as a derivative gain or loss. The assumptions used principally in determining the fair value of the 2014 Warrants as of December 31, 2017 were as follows: 2014 Warrants 2017 Risk-free interest rate 1.91 % Expected dividend yield — % Contractual term 1.35 years Expected volatility 82.37 % The primary underlying risk exposure pertaining to the warrants is the change in fair value of the underlying common stock for each reporting period. The table below presents the changes in derivative warrant liability during years ended December 31, 2018 and 2017: Year Ended December 31, (In thousands) 2018 2017 Balance at beginning of year $ 4 $ 1,314 Issuance of new warrants 13,172 — Reduction in derivative liability due to exercise of warrants (10,620) — Reclassification of fair value of derivative liabilities to equity on amendment of warrant agreements (14,707) — Increase in derivative liability prior to warrant exchange — 3,029 Reduction in derivative liability due to warrant exchange — (3,537) Repurchase of warrants (14) (40) Increase (decrease) in the fair value of warrants 12,165 (762) Balance at end of year $ — $ 4

STOCK BASED COMPENSATION

STOCK BASED COMPENSATION	12 Months Ended
	Dec. 31, 2018
STOCK BASED COMPENSATION
STOCK BASED COMPENSATION	11. STOCK OPTIONS In 2007, the Company’s Board of Directors adopted, and the Company’s shareholders subsequently approved, the 2007 Employee, Director and Consultant Stock Plan (the “2007 Plan”). The 2007 Plan provided that the Company’s Board of Directors (or committees and/or executive officers delegated by the Board of Directors) could grant incentive and nonqualified stock options to the Company’s employees, officers, directors, consultants and advisors. 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 provides 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. Upon approval of the 2015 Plan by the Company’s shareholders on June 16, 2015, the 2010 Plan was terminated and no additional shares or share awards have been subsequently granted under the 2010 Plan. As of December 31, 2018, the total number of shares available to be issued under the 2015 Plan was 188,552 shares, consisting of 160,000 shares initially authorized under the 2015 Plan shares plus the 12,894 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. Options issued under the 2007 Plan, 2010 Plan, and 2015 Plan (collectively, the “Plans”) are exercisable for up to 10 years from the date of issuance. In March 2015, the Company’s Board of Directors adopted, and the Company’s shareholders subsequently approved the ESPP. The ESPP allows employees to buy company stock twice a year through after-tax payroll deductions at a discount from market. The Company’s Board of Directors initially authorized 7,500 shares for issuance under the ESPP. Commencing on the first day of the year ended December 31, 2016 and on the first day of each year thereafter during the term of the ESPP, the number of shares of common stock reserved for issuance shall be increased by the lesser of (i) 1% of the Company’s outstanding shares of common stock on such date, (ii) 2,000 shares or (iii) a lesser amount determined by the Board of Directors. Under the terms of the ESPP, in no event shall the aggregate number of shares reserved for issuance during the term of the ESPP exceed 50,000 shares. As of December 31, 2018, there were 7,923 shares reserved for issuance under the ESPP. The 2015 ESPP is considered a compensatory plan with the related compensation cost recognized over each respective 6 month offering period. As of December 31, 2018, approximately $1 thousand of employee payroll deductions had been withheld since July 1, 2018, the commencement of the offering period, and are included in accrued expenses in the accompanying balance sheet. The compensation expense related to the ESPP for the years ended December 31, 2018 and 2017 was $2 thousand and $14 thousand, respectively, and is included in stock-based compensation expense. In January 2019, 1,065 shares that were purchased as of December 31, 2018 were issued under the ESPP. Share‑based compensation For the years ended December 31, 2018 and 2017, the Company recorded stock‑based compensation expense of $618 thousand and $4.1 million, respectively, net of forfeitures, inclusive of the expense related to the ESPP. 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). For non‑employee options, the expected term is the contractual term. The risk‑free rate is based on the yield of a U.S. Treasury security with a term consistent with the option. The assumptions used principally in determining the fair value of options granted were as follows: December 31, December 31, 2018 2017 Risk-free interest rate 2.45 - 2.88% 1.69 - 2.36% Expected dividend yield 0% Expected term (employee grants) 5.62 Years 6.22 Years Expected volatility 104% A summary of option activity as of December 31, 2018 and 2017 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 at December 31, 2016 127,752 $ 188.00 $ 571 Granted 57,579 $ 98.50 Cancelled/Forfeited (46,985) $ 160.00 Exercised (3,576) $ 7.25 Outstanding at December 31, 2017 134,770 $ 164.29 $ 22 Granted 15,524 $ 4.97 Expired (5,334) $ 173.13 Cancelled/Forfeited (90,111) $ 175.00 Outstanding at December 31, 2018 54,849 $ 100.83 7.32 $ — Vested at December 31, 2018 32,522 $ 147.84 5.98 $ — The weighted average grant‑date fair value of options granted during the years ended December 31, 2018 and 2017 was $3.82 and $2.54 per share, respectively. The total fair value of options that vested in years ended December 31, 2018 and 2017, was $952 thousand and $3.8 million respectively. As of December 31, 2018, there was $253 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 1.99 years at December 31, 2018. Restricted Stock Units The following table summarizes the restricted stock unit (“RSU”) activity under the 2015 Equity Incentive Plan for the years ended December 31, 2018 and 2017: Weighted-Average Number of Grants Grant Date Fair Value Unvested balance at December 31, 2016 — $ — Granted 23,800 26.50 Vested/Released — $ — Forfeited (3,800) $ 31.25 Unvested balance at December 31, 2017 20,000 $ 25.70 Granted — — Vested/Released (4,250) $ 24.72 Forfeited (5,500) $ 31.25 Unvested balance at December 31, 2018 10,250 $ 23.13 For the year ended December 31, 2018, the Company recorded stock-based compensation expense of $88 thousand related to the time-based RSUs. As of December 31, 2018, total unrecognized compensation expense related to non-vested RSUs amounted to $223 thousand which the Company expects to recognize over a remaining weighted-average period of 2.68 years. All the RSU’s that remain unvested and outstanding at December 31, 2018 are subject to time-based vesting.

WARRANTS

WARRANTS	12 Months Ended
	Dec. 31, 2018
WARRANTS
WARRANTS	12. WARRANTS The following table presents information about warrants to purchase common stock issued and outstanding at December 31, 2018: Number of Exercise Year Issued Classification Warrants Price Date of Expiration 2012 Equity 243 $ 166.00 10/5/2019 2014 Equity 307 $ 11.75 5/9/2021 2016 Equity 85,869 $ 250.00 3/18/2021 2018 Equity 7,586,711 $ 2.00 6/25/2023 Total 7,673,130 Weighted average exercise price $ 4.78 Weighted average life in years 4.46 In June 2018, the Company closed an underwritten public offering of an aggregate of 1,378,400 Common Units, at an offering price of $2.00 each, each comprised of 1 share of the Company’s common stock, par value $0.00001 per share and 1 Series A warrant to purchase 1 share of common stock. The public offering also included 6,242,811 pre-funded units at an offering price of $1.99 each, each comprised of 1 pre-funded Series B Warrant, and 1 Series A warrant to purchase 1 share of common stock. Each Series A warrant has an exercise price of $2.00 per share, is exercisable immediately and expires 5 years from the date of issuance. Each Series B warrant has an exercise price of $0.01 per share, is exercisable immediately and will expire 20 years from the date of issuance (see Note 10). The net proceeds to the Company, after deducting the underwriting discounts and commissions and other offering expenses, were $13.5 million. At inception the 2014 Warrants and 2018 Warrants had provisions that precluded equity classification. Upon amendment, the Company assessed whether the warrants required accounting as derivatives and determined that the warrants were (1) indexed to the Company’s own stock and (2) classified in stockholders’ equity in accordance with FASB Accounting Standards Codification Topic 815, Derivatives and Hedging. As such, the Company concluded that the warrants meet the scope exception for determining whether the instruments require accounting as derivatives and accordingly are classified in stockholders’ equity. See below for a further description of the warrant amendments. Warrant Exchange On August 10, 2017, the Company entered into exchange agreements with certain holders of the warrants, dated May 9, 2014, to exchange such warrants for shares of common stock equivalent to 3.5 times the number of shares of common stock issuable to such holders at the $96.75 exercise price under the warrants as of the date of the exchanges. The Company issued an aggregate of 80,857 shares of common stock to the warrant holders in exchange for their warrants to purchase an aggregate of 23,102 shares of common stock. The warrants exchanged in this transaction were subsequently cancelled and terminated. The Company re-measured the fair value of the exchanged warrants immediately prior to the exchange and recorded a $3.0 million derivatives loss on the statement of operations and a corresponding increase to the warrant liability on the balance sheet. The fair value of the warrants immediately prior to the exchange was equivalent to 80,857 shares of common stock at the Company’s closing stock price of $43.75 on August 9, 2017, the day before execution of the exchange. As a result of the exchange, the Company recorded the settlement by removing the derivative liability related to the exchanged warrants and recorded the issuance of common stock for $3.5 million. Following the warrant exchange, there were additional warrants, dated May 9, 2014, to purchase shares of common stock that remain outstanding (“Outstanding 2014 Warrants”). As a result of the Company’s issuance of common stock in exchange for certain of the liability warrants, the exercise price of the Outstanding 2014 Warrants was adjusted downwards from $96.75 per share to $20.75 per share and additional warrants were issued such that the Outstanding 2014 Warrants were exercisable for an aggregate of 1,941 shares of common stock. Warrant Cancellation In the fourth quarter of 2017, the Company entered into warrant cancellation agreements with certain holders of the Outstanding 2014 Warrants to cancel and terminate such warrants for total cash consideration of $40 thousand. As of December 31, 2017, the remaining Outstanding 2014 Warrants were exercisable for an aggregate of 537 shares of common stock. During the year ended December 31, 2018 the Company entered into warrant cancellation agreements with certain holders of the Outstanding 2014 Warrants to cancel and terminate such warrants for total cash consideration of $14 thousand. As of December 31, 2018, the sole remaining Outstanding 2014 Warrants were exercisable for an aggregate of 307 shares of common stock. Warrant Amendments In May 2018, the Company entered into a warrant amendment agreement with the sole remaining holder of an Outstanding 2014 Warrant (the “Warrant Amendment”). The warrant holder received cash compensation of $19 thousand and a 2 year extension of warrant term in exchange for the removal of all anti-dilution provisions except those for stock splits, reverse splits or stock dividends. As a result of the amendment, the Company reclassified the remaining 2014 warrants valued at $1 thousand to stockholders’ equity (see Note 10). In September 2018, the Company entered into the Ladenburg Warrant Amendment. As a result of the Ladenburg Warrant Amendment, the Company reclassified the 2018 Warrants valued at $14.7 million to stockholders’ equity (see Note 10).

EMPLOYEE BENEFIT PLAN

EMPLOYEE BENEFIT PLAN	12 Months Ended
	Dec. 31, 2018
EMPLOYEE BENEFIT PLAN
EMPLOYEE BENEFIT PLAN	13. 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. In the second quarter of 2018 the Company revised its 401(k)-matching policy to move from share matching to cash-based matching. For the year ended December 31, 2018, the Company made matching contributions in the form of cash and shares of the Company’s common stock. For the year ended December 31, 2017, the Company made matching contributions in the form of shares of the Company’s common stock only. For the years ended December 31, 2018 and 2017, the Company issued 440, and 3,933 shares of its common stock, respectively, with related fair values of $6 thousand and $183 thousand respectively, which were recorded as expense in the statement of operations.

INTELLECTUAL PROPERTY LICENSE

INTELLECTUAL PROPERTY LICENSE	12 Months Ended
	Dec. 31, 2018
INTELLECTUAL PROPERTY LICENSE
INTELLECTUAL PROPERTY LICENSE	14. INTELLECTUAL PROPERTY LICENSE In July 2007, the Company entered into a worldwide exclusive license (the “BCH License”) for patents co-owned by Boston Children’s Hospital (“BCH”) and the Massachusetts Institute of Technology 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. 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, 2018 and 2017 was $200 thousand (see Note 4). The Company accounts for milestone payments, maintenance fees and royalties when they become due and payable. The Company did not pay any milestone payments for the year ended December 31, 2018. For the year ended December 31, 2017, the Company expensed milestone payments of $175 thousand.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2018
COMMITMENTS AND CONTINGENCIES
COMMITMENTS AND CONTINGENCIES	15. COMMITMENTS AND CONTINGENCIES Leases On November 30, 2011, the Company entered into a commercial lease for 26,342 square feet of office, laboratory and manufacturing space in Cambridge, Massachusetts (as amended on September 17, 2012 and October 31, 2017, the “Cambridge Lease”). The term of the Cambridge Lease is 6 years and 3 months, with one 5‑year extension option. On August 21, 2017, the Company exercised its option for the 5-year extension on the Cambridge Lease. The 5- year renewal lease term commences on November 1, 2018 and ends on October 31, 2023. The terms of the Cambridge Lease require a standby letter of credit in the amount of $311 thousand. On March 31, 2016, the Company entered into a short-term lease, to sub-lease 5,233 square feet of its facility (the “2016 Sublease”). The 2016 Sublease term was from April 1, 2016 through January 31, 2017. In connection with the 2016 Sublease, the Company received sublease income for the year ended December 31, 2017 of $26 thousand, which was recorded as an offset to rent expense. On June 13, 2017, the Company entered into a new short-term lease, to sub-lease 5,233 square feet of its facility (the “Moderna Sublease”). The lease term was from July 1, 2017 through October 26, 2018. On June 19, 2017, the Company received a $55 thousand security deposit under the terms of the Moderna Sublease. In conjunction with the assignment of the Cambridge Lease on May 3, 2018 further described below, this security deposit was transferred to the third party that assumed the lease. In connection with the Moderna Sublease, the Company received sublease income of $112 thousand for the year ended December 31, 2018, which was recorded as an offset to rent expense. On May 3, 2018, the Company assigned the Cambridge Lease to a third party who assumed all of the Company’s remaining rights and obligations under the Cambridge Lease including the Moderna Sublease. On the same date as the lease assignment, the Company entered into a sublease for 5,104 square feet of space, originally part of the Cambridge Lease, from the third party to which the Company assigned the Cambridge Lease (the “Current Cambridge Lease”). The Current Cambridge Lease commenced on May 3, 2018 and expires October 31, 2023 and contains rent holiday and rent escalation clauses. In connection with the Cambridge Lease Assignment and the Current Cambridge Lease, the $311 thousand standby letter of credit was terminated, and a new standby letter of credit was established for $40 thousand. On November 1, 2018, the standby letter of credit was increased to $60 thousand. The $55 thousand security deposit under the Moderna Sublease was transferred to the third party and $603 thousand of deferred rent was removed from the consolidated balance sheets as of June 30, 2018. The resulting gain was recorded within the consolidated statement of operations and comprehensive loss during the second quarter of 2018. The Company also wrote off certain furniture, fixtures and equipment (including laboratory equipment) and recorded an impairment charge of $48 thousand for the year ended December 31, 2018. The Company recognizes rent expense on a straight-line basis over the term of the lease and records the difference between the amount charged to expense and the rent paid as prepaid rent or deferred rent liability. As of December 31, 2018, and December 31, 2017, the amount of prepaid rent was $17 thousand and $0, respectively. As of December 31, 2018, and December 31, 2017, the amount of deferred rent liability was $0 and $397 thousand, respectively Pursuant to the terms of the non‑cancelable lease agreements in effect at December 31, 2018, the future minimum rent commitments are as follows: (In thousands) Year Ended December 31, 2019 $ 243 2020 375 2021 386 2022 398 2023 339 Total $ 1,741 Total rent expense for the years ended December 31, 2018 and 2017, including month‑to‑month leases, was $837 thousand, and $1.2 million, respectively. Compensation Commitment The Company entered into a compensation arrangement with an executive during September 2016 which provided for a future cash payment by the Company to the executive based on the February 13, 2017 stock price of the executive’s former employer. The award was earned over a period of 1 year. The expense related to the compensation arrangement was $174 thousand for the year ended December 31, 2017. As of December 31, 2018, there were no outstanding payments to the executive. Lawsuits with Former Employee In November 2013, the Company filed a lawsuit against Francis Reynolds, its former Chairman, Chief Executive Officer and Chief Financial Officer, in Middlesex Superior Court, Middlesex County, Massachusetts (InVivo Therapeutics Holdings Corp. v. Reynolds, Civil Action No. 13-5004). The complaint alleged breaches of fiduciary duties, breach of contract, conversion, misappropriation of corporate assets, unjust enrichment, and corporate waste, and seeks monetary damages and an accounting. The lawsuit involved approximately $500 thousand worth of personal and/or exorbitant expenses that the Company alleged Mr. Reynolds inappropriately caused it to pay while he was serving as the Company’s Chief Executive Officer, Chief Financial Officer, President, and Chairman of the Company’s Board of Directors. On December 6, 2013, Mr. Reynolds answered the complaint, and filed counterclaims against the Company and the Company’s Board of Directors. The counterclaims alleged two counts of breach of contract, two counts of breach of the covenant of good faith and fair-dealing, and tortious interference with a contract, and sought monetary damages and a declaratory judgment. The counterclaims related to Mr. Reynolds’s allegations that the Company and the Company’s Board of Directors interfered with the performance of his duties under the terms of his employment agreement, and that Mr. Reynolds was entitled to additional shares upon the exercise of certain stock options that he did not receive. On January 9, 2014, the Company, along with the directors named in the counterclaims, filed the Company’s answer denying that Mr. Reynolds was entitled to any relief. On March 3, 2017, the counterclaim defendants filed a motion for summary judgement on all counterclaims asserted by Mr. Reynolds. On October 18, 2017, the Court allowed the motion for summary judgment in substantial part, and denied it in part. The Court, citing disputed issues of fact, declined to dismiss the counterclaims for breach of contract, breach of implied covenant of good faith and fair dealing, and declaratory judgment concerning Mr. Reynolds’ attempted exercise of certain stock options, which Mr. Reynolds claims is the equivalent of 47,864 shares of common stock, but dismissed all other claims asserted by Mr. Reynolds. In July 2018, the parties reported the case as settled to the Court. Vendor Dispute In July 2018, the Company entered into a settlement agreement with a former vendor under which the vendor agreed to pay the Company $1.2 million, of which the full amount has been paid and is included in other income on the statement of operations and other comprehensive loss.

RESTRUCTURING

RESTRUCTURING	12 Months Ended
	Dec. 31, 2018
RESTRUCTURING
RESTRUCTURING	16. RESTRUCTURING In August 2017, the Company implemented a strategic restructuring. In conjunction with the strategic restructuring, the Company completed a reduction in force eliminating approximately 39% of its workforce. The Company did not record any restructuring expenses for the year ended December 31, 2018. For the year ended December 31, 2017, the Company recorded $898 thousand in restructuring expenses, including employee severance benefits and related costs, as well as a write-off of certain fixed assets. The following table summarizes the restructuring costs by category for the periods indicated: Year Ended December 31, 2017 (In thousands) Cash Non-Cash (1) Total Research and development $ 669 $ 41 $ 710 General and administrative 188 — 188 Restructuring Costs $ 857 $ 41 $ 898 (1) The non-cash restructuring expenses represent write-offs of certain fixed assets in connection with the restructuring. The write-offs were recorded as a charge to research and development expense on the statement of operations. The following table summarizes the restructuring reserve for the periods indicated: (In thousands) December 31, 2018 December 31, 2017 Restructuring reserve beginning balance $ 348 $ — Cash restructuring expenses incurred during the period — 857 Amounts paid during the period (348) (509) Restructuring reserve ending balance $ — $ 348

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2018
RELATED PARTY TRANSACTIONS.
RELATED PARTY TRANSACTIONS	17. RELATED PARTY TRANSACTIONS In January 2017, the Company entered into a consulting agreement with Dr. Robert Langer, a member of the Company’s Scientific Advisory Board, who at the time of entering into the consulting agreement was a holder of over 5% of the Company’s common stock, for certain consulting services. Dr. Langer was one of the original co-founders of the Company. Pursuant to the terms of the agreement, the Company initially agreed to pay Dr. Langer $250 thousand per year in consulting fees, but that amount was reduced effective October 2017 to $100 thousand per year in consulting fees. For the years ended December 31, 2018 and 2017 the Company paid Dr. Langer $83 thousand and $204 thousand in consulting fees respectively. Dr Langer holds less than 5% of the Company’s common stock as of December 31, 2018.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2018
SUBSEQUENT EVENTS
SUBSEQUENT EVENTS	18. SUBSEQUENT EVENTS In connection with the employment agreement for the Company's new Chief Finance Officer and Treasurer, the Company granted a non-statutory stock option to purchase up to 90,000 shares of the Company’s common stock, as an inducement grant outside of the Company’s 2015 Stock Incentive Plan pursuant to Nasdaq Listing Rule 5635(c)(4). On March 1, 2019, the Company paid off the remaining outstanding MassDev loan payable amounts.

SIGNIFICANT ACCOUNTING POLICI_2

SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2018
SIGNIFICANT ACCOUNTING POLICIES
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. At December 31, 2018 and 2017, cash equivalents were comprised of money market funds and other short-term investments. Cash and cash equivalents consist of the following: December 31, December 31, (In thousands) 2018 2017 Cash $ (83) $ 23 Money market funds 16,743 12,887 Total cash and cash equivalents $ 16,660 $ 12,910
Restricted cash	Restricted cash Restricted cash as of December 31, 2018 was $114 thousand and included a $50 thousand security deposit related to the Company’s credit card account, $4 thousand related to 401(k) reserve account and a $60 thousand standby letter of credit in favor of a landlord (see Note 15). Restricted cash as of December 31, 2017 was $361 thousand and included a $50 thousand security deposit related to the Company’s credit card account and a $311 thousand standby letter of credit in favor of a landlord (see Note 15).
Financial instruments	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. The carrying value of the loan payable approximates fair value due to market terms.
Property and equipment	Property and equipment Property and equipment are carried at cost. Depreciation and amortization expense are recorded over the estimated useful lives of the assets using the straight‑line method. A summary of the estimated useful lives is as follows: Classification Estimated Useful Life Computer hardware 3 - 5 years Software 3 years Office furniture and equipment 5 years Research and lab equipment 5 years Leasehold improvements Remaining life of lease
Research and development expenses	Research and development expenses Costs incurred for research and development are expensed as incurred. Certain agreements require the Company to make pre-payments for CRO services. As of December 31, 2018, the Company had $1.3 million in prepayments for CRO services of which $290 thousand is included in prepaid and other current asset balance on the balance sheet and the remaining $996 thousand is included within the other long term assets balance on the balance sheet.
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 1 operating segment, which is developing and commercializing biopolymer scaffolding devices for the treatment of spinal cord injuries. As of December 31, 2018, and 2017, all of the Company’s assets were located in 1 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 the current year. There were no material uncertain tax positions that required accrual or disclosure to the financial statements as of December 31, 2018 or 2017. Tax years subsequent to 2014 remain open to examination by U.S. federal and state tax authorities. The Tax Cuts and Jobs Act (“the Act”) was enacted on December 22, 2017. The Act reduced the US federal corporate tax rate from 35% to 21%, required companies to pay a 1-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and created new taxes on certain foreign sourced earnings. On December 22, 2017, the Securities and Exchange Commission issued guidance under Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (“SAB 118”) directing taxpayers to consider the impact of the U.S. legislation as “provisional” when it does not have the necessary information available, prepared or analyzed (including computations) in reasonable detail to complete its accounting for the change in tax law. At December 31, 2018, the Company had completed its accounting for the tax effects of enactment of the Act, including the effects on its existing deferred tax balances, and the corresponding valuation allowance and the 1-time transition tax. For the year ended December 31, 2018, the Company recognized no transition tax, remeasured deferred taxes, and its reassessment of uncertain tax positions and valuation allowances.
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. On May 3, 2018, the Company assigned the Cambridge Lease (as defined in Note 15) to a third party who assumed all of the Company’s remaining rights and obligations under the Cambridge Lease and as a result recorded an impairment charge of $48 thousand. On August 28, 2017, the Company implemented a strategic restructuring and as a result recorded an impairment charge of $41 thousand (see Note 3).
Share-based payments	Share‑based payments The Company accounts for all stock-based payment awards granted to employees and nonemployees using a 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 employee awards is the date of grant, and stock-based compensation costs are recognized as expense over the employees’ requisite service period, which is the vesting period, on a straight-line basis. The measurement date for nonemployee awards is the date the services are completed, resulting in periodic adjustments to stock-based compensation during the vesting period for changes in the fair value of the awards. 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; however, certain warrants to purchase common stock that do not meet the requirements for classification as equity are classified as 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 charged (credited) 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 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. Diluted net income per share of common stock has been computed by dividing net income by the weighted average number of shares outstanding plus the dilutive effect, if any, of outstanding stock options, warrants and convertible securities. Diluted net loss per share of common stock has been computed by dividing the net loss for the period by the weighted average number of shares of common stock outstanding during such period. 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, 2018 and 2017, 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, 2018 2017 Warrants 7,673,130 86,646 Stock options 54,849 134,770 Unvested restricted stock units 10,250 20,000 Total potentially dilutive securities 7,738,229 241,416
Recent accounting pronouncements	Recent accounting pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), to provide updated guidance on revenue recognition. ASU 2014-09 requires a company to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross Versus Net), which clarifies the implementation guidance on principal versus agent considerations. In April 2016, the FASB issued ASU No. 2016- 10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing, which clarifies certain aspects of identifying performance obligations and licensing implementation guidance. In May 2016, the FASB issued ASU No. 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients, which relates to disclosures of remaining performance obligations, as well as other amendments to guidance on collectability, non-cash consideration, and the presentation of sales and other similar taxes collected from customers. Collectively, these standards are effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within each annual reporting period. The Company adopted ASU 2014-09 on January 1, 2018, and it did not have any impact on the financial position, results of operations or disclosures as the Company currently does not generate any revenue. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”). ASU 2016-01 is intended to improve the recognition and measurement of financial instruments by; requiring equity investments to be measured at fair value with changes in fair value recognized in net income: requiring public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; requiring separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or the accompanying notes to the financial statements; eliminating the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured and amortized at cost on the balance sheet; and requiring a reporting organization to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the organization has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. ASU 2016-01 is effective for annual periods and interim periods within those annual periods, beginning after December 15, 2017. The amendments should be applied by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. The amendments related to equity securities without readily determinable fair values (including disclosure requirements) should be applied prospectively to equity investments that exist as of the date of adoption. In February 2018, the FASB issued ASU No. 2018-03 which includes technical corrections and improvements to clarify the guidance in ASU No. 2016-01. The Company adopted ASU 2016-01 on January 1, 2018 and it did not have any impact on its accounting for equity investments, fair value disclosures or other disclosure requirements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The guidance in this ASU supersedes the leasing guidance in Topic 840, Leases. Under the new guidance, lessees are required to recognize lease assets and lease liabilities on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance leases or operating leases, with classification affecting the pattern of expense recognition in the statement of operations. The FASB has subsequently issued amendments to the guidance, including the addition of an optional transition method and provided clarifications to address potential narrow-scope implementation issues. The adoption of ASU 2016-02 will result in an increase to the Company’s consolidated balance sheets for right-of-use assets and lease liabilities. The Company adopted ASU 2016- 02 effective January 1, 2019 and elected the optional transition method for adoption. The Company also took advantage of the transition package of practical expedients permitted within ASU 2016-02, which among other things, allowed it to carryforward historical lease classifications. The Company also elected to keep leases with an initial term of 12 months or less off of the balance sheet as a policy election and will recognize those lease payments in the consolidated statements of operations on a straight-line basis over the lease term. Based on our current lease portfolio, the Company estimates that the adoption of this standard will result in approximately $1.5 million of additional assets and liabilities being reflected on our consolidated balance sheets on January 1, 2019; however, there will not be a material impact to its consolidated statement of operations or cash flows. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU No. 2016-15”), which clarifies the classification of certain cash receipts and cash payments in the statement of cash flows, including debt prepayment or extinguishment costs, settlement of contingent consideration arising from a business combination and insurance settlement proceeds. The Company adopted ASU 2016-15 on January 1, 2018, and it did not result in any changes to the presentation of amounts shown on the Company’s consolidated statements of cash flows for all periods presented. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (A Consensus of the FASB Emerging Issues Task Force) (“ASU No 2016-18”). The amendments in this update require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The Company adopted ASU No. 2016-18 in the first quarter of 2018 and applied the guidance retrospectively to the prior period consolidated statement of cash flows. The following table provides a reconciliation of cash, cash equivalents, and restricted cash within the statement of financial position that sum to the total of the same such amounts shown in the statement of cash flows. December 31, December 31, (In thousands) 2018 2017 Cash and cash equivalents $ 16,660 $ 12,910 Restricted cash included in current assets 4 361 Restricted cash included in other non-current assets 110 — Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 16,774 $ 13,271 In May 2017, the FASB issued ASU No. 2017-09, Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting (“ASU 2017-09”), to clarify when to account for a change to the terms or conditions of a share-based payment award as a modification. Under this new guidance, modification accounting is required if the fair value, vesting conditions, or classification of the award changes as a result of the change in terms or conditions. ASU 2017-09 is effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within each annual reporting period. The Company adopted ASU 2017-09 on January 1, 2018 and it did not have a material effect on the Company’s financial position, results of operations or disclosures. In July 2017, the FASB issued ASU No. 2017-11, Part I. Accounting for Certain Financial Instruments with Down Round Features and Part II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception (“ASU 2017-11”). Part I of this guidance applies to entities that issue financial instruments such as warrants, convertible debt or convertible preferred stock that contain down round features. Part II of this guidance replaces the indefinite deferrals for certain mandatorily redeemable noncontrolling interests and mandatorily redeemable financial instruments of nonpublic entities. ASU 2017-11 is effective for annual reporting periods beginning after December 15, 2018, including interim reporting periods within each annual reporting period. The Company has concluded that the adoption of ASU 2017-11 will not have a material impact on the financial statements. In February 2018, the FASB issued Accounting Standards Update No. 2018-02 , Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . This update relates to the impacts of the tax legislation commonly referred to as the Tax Reform Act. The guidance permits the reclassification of certain income tax effects of the Tax Reform Act from other comprehensive income to retained earnings (stranded tax effects). The guidance also requires certain new disclosures. The guidance is effective for annual periods beginning after December 15, 2018, and interim periods within those reporting periods. Early adoption is permitted. Entities may adopt the guidance using 1 of 2 transition methods; retrospective to each period (or periods) in which the income tax effects of the Tax Reform Act related to the items remaining in other comprehensive income are recognized or at the beginning of the period of adoption. The Company is currently evaluating the impact that the guidance may have on its consolidated financial statements. In June 2018, the FASB issued Accounting Standards Update No. 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting which is intended to reduce cost and complexity and to improve financial reporting for nonemployee share-based payments. The amendment is effective for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. Early adoption is permitted, but no earlier than an entity’s adoption date of Topic 606. The Company does not expect the adoption of this Accounting Standard to have a material effect on its consolidated financial statements. In July 2018, the FASB issued Accounting Standards Update No. 2018-09, Codification Improvements which clarifies, corrects errors in, and makes improvements to several Codification Topics, including to: · Clarify when excess tax benefits should be recognized for share-based compensation awards · Remove inconsistent guidance in income tax accounting for business combinations · Clarify the circumstances when derivatives may be offset · Clarify the measurement of liability or equity-classified financial instruments when an identical asset is held as an asset · Allow portfolios of financial instruments and nonfinancial instruments accounted for as derivatives to use the portfolio exception to valuation The transition and effective date guidance is based on the facts and circumstances of each amendment. Some of the amendments in this Update do not require transition guidance and will be effective upon issuance of this Update. However, many of the amendments in this Update do have transition guidance with effective dates for annual periods beginning after December 15, 2018. The Company is currently evaluating the impact that the guidance may have on its consolidated financial statements. In August 2018, the FASB issued Accounting Standards Update No. 2018-13 - Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement which improves the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement. The amendments in this Update are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. Early adoption is permitted upon issuance of this Update. The Company does not expect the adoption of this Accounting Standard to have a material effect on its consolidated financial statements. In August 2018, the SEC adopted the final rule under SEC Release No. 33-10532, Disclosure Update and Simplification, amending certain disclosure requirements that were redundant, duplicative, overlapping, outdated or superseded. In addition, the amendments expanded the disclosure requirements on the analysis of stockholders' equity for interim financial statements. Under the amendments, an analysis of changes in each caption of stockholders' equity presented in the balance sheet must be provided in a note or separate statement. The analysis should present a reconciliation of the beginning balance to the ending balance of each period for which a statement of comprehensive income is required to be filed. This final rule is effective on November 5, 2018. The Company adopted this release in the third quarter of 2018.

SIGNIFICANT ACCOUNTING POLICI_3

SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2018
SIGNIFICANT ACCOUNTING POLICIES
Schedule of cash and cash equivalents	December 31, December 31, (In thousands) 2018 2017 Cash $ (83) $ 23 Money market funds 16,743 12,887 Total cash and cash equivalents $ 16,660 $ 12,910
Summary of estimated useful lives	Classification Estimated Useful Life Computer hardware 3 - 5 years Software 3 years Office furniture and equipment 5 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, 2018 2017 Warrants 7,673,130 86,646 Stock options 54,849 134,770 Unvested restricted stock units 10,250 20,000 Total potentially dilutive securities 7,738,229 241,416
Schedule of reconciliation of cash, cash equivalents and restricted cash in statement of cash flows	December 31, December 31, (In thousands) 2018 2017 Cash and cash equivalents $ 16,660 $ 12,910 Restricted cash included in current assets 4 361 Restricted cash included in other non-current assets 110 — Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 16,774 $ 13,271

PROPERTY AND EQUIPMENT (Tables)

PROPERTY AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2018
PROPERTY AND EQUIPMENT
Schedule of property and equipment, net	(In thousands) 2018 2017 Computer software and hardware $ 131 $ 241 Research and lab equipment 508 508 Leasehold improvements 66 431 Office equipment — 796 Property and equipment 705 1,976 Less accumulated depreciation and amortization (605) (1,819) Property and equipment, net $ 100 $ 157

INTANGIBLE ASSETS (Tables)

INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2018
INTANGIBLE ASSETS
Summary of intangible assets	(In thousands) 2018 2017 Patent licensing fee $ 200 $ 200 Accumulated amortization (156) (139) Intangible assets, net $ 44 $ 61

ACCRUED EXPENSES (Tables)

ACCRUED EXPENSES (Tables)	12 Months Ended
	Dec. 31, 2018
ACCRUED EXPENSES.
Summary of accrued expenses	December 31, December 31, (In thousands) 2018 2017 Severance and restructuring $ 517 $ 1,160 Compensation 489 196 Clinical 73 52 Legal 35 68 Other accrued expenses 176 162 Total accrued expenses $ 1,290 $ 1,638

FAIR VALUES OF ASSETS AND LIA_2

FAIR VALUES OF ASSETS AND LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2018
FAIR VALUES OF ASSETS AND LIABILITIES
Summary of assets and liabilities measured at fair value on a recurring basis	At December 31, 2018 (In thousands) Level 1 Level 2 Level 3 Fair Value Cash equivalents $ 16,743 $ — $ — $ 16,743 At December 31, 2017 (In thousands) Level 1 Level 2 Level 3 Fair Value Cash equivalents $ 12,887 $ — $ — $ 12,887 Derivative warrant liability $ — $ 4 $ — $ 4

LOAN PAYABLE (Tables)

LOAN PAYABLE (Tables)	12 Months Ended
	Dec. 31, 2018
LOAN PAYABLE
Summary of loans payable	December 31, (In thousands) 2018 2017 MassDev Loan $ 100 $ 852 Less: current portion (100) (452) Notes Payable long-term portion $ — $ 400

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2018
INCOME TAXES
Schedule of significant components of net deferred tax assets	December 31, (In thousands) 2018 2017 Net operating loss carryforward $ 34,846 $ 31,533 Research and development credit carryforward 1,390 1,173 Stock-based compensation 2,300 2,828 Depreciation and amortization 11 71 Accrued expenses 136 357 Charitable contributions — 27 Subtotal 38,683 35,989 Valuation allowance (38,683) (35,989) Net deferred taxes $ — $ —
Schedule of income tax benefits computed using the federal statutory income tax rate	December 31, 2018 2017 Statutory rate (21.0) % (34.0) % State taxes, net of benefit (2.9) % (4.7) % Permanent differences: Derivative losses 10.9 % 2.9 % Other 0.4 % 1.1 % Research and development tax credit (0.8) % (0.2) % Other 1.9 % 1.4 % Adoption of ASU 2016-09 — % 7.4 % Increase / (decrease) in valuation reserve 11.5 % (32.0) % Change in federal tax rate — % 58.1 % Effective tax rate % %

COMMON STOCK (Tables)

COMMON STOCK (Tables)	12 Months Ended
	Dec. 31, 2018
COMMON STOCK.
Schedule of reserves established for future issuance of common stock	Reserves for the exercise of warrants 7,673,130 Reserves for the exercise of stock options 54,849 Reserves for the vesting of restricted stock units 10,250 Total Reserves 7,738,229

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2018
DERIVATIVE INSTRUMENTS
Assumptions used in determining fair value of warrants	2014 Warrants 2017 Risk-free interest rate 1.91 % Expected dividend yield — % Contractual term 1.35 years Expected volatility 82.37 %
Changes in derivative warrant liability	Year Ended December 31, (In thousands) 2018 2017 Balance at beginning of year $ 4 $ 1,314 Issuance of new warrants 13,172 — Reduction in derivative liability due to exercise of warrants (10,620) — Reclassification of fair value of derivative liabilities to equity on amendment of warrant agreements (14,707) — Increase in derivative liability prior to warrant exchange — 3,029 Reduction in derivative liability due to warrant exchange — (3,537) Repurchase of warrants (14) (40) Increase (decrease) in the fair value of warrants 12,165 (762) Balance at end of year $ — $ 4

STOCK BASED COMPENSATION (Table

STOCK BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2018
STOCK BASED COMPENSATION
Schedule of assumptions used principally in determining the fair value of options granted	December 31, December 31, 2018 2017 Risk-free interest rate 2.45 - 2.88% 1.69 - 2.36% Expected dividend yield 0% Expected term (employee grants) 5.62 Years 6.22 Years Expected volatility 104%
Summary of option activity	Weighted Weighted Average Average Remaining Aggregate Exercise Contractual Intrinsic Options Shares Price Term in Years Value Outstanding at December 31, 2016 127,752 $ 188.00 $ 571 Granted 57,579 $ 98.50 Cancelled/Forfeited (46,985) $ 160.00 Exercised (3,576) $ 7.25 Outstanding at December 31, 2017 134,770 $ 164.29 $ 22 Granted 15,524 $ 4.97 Expired (5,334) $ 173.13 Cancelled/Forfeited (90,111) $ 175.00 Outstanding at December 31, 2018 54,849 $ 100.83 7.32 $ — Vested at December 31, 2018 32,522 $ 147.84 5.98 $ —
Summary of restricted stock unit activity	Weighted-Average Number of Grants Grant Date Fair Value Unvested balance at December 31, 2016 — $ — Granted 23,800 26.50 Vested/Released — $ — Forfeited (3,800) $ 31.25 Unvested balance at December 31, 2017 20,000 $ 25.70 Granted — — Vested/Released (4,250) $ 24.72 Forfeited (5,500) $ 31.25 Unvested balance at December 31, 2018 10,250 $ 23.13

WARRANTS (Tables)

WARRANTS (Tables)	12 Months Ended
	Dec. 31, 2018
WARRANTS
Schedule of information about warrants to purchase common stock issued and outstanding	Number of Exercise Year Issued Classification Warrants Price Date of Expiration 2012 Equity 243 $ 166.00 10/5/2019 2014 Equity 307 $ 11.75 5/9/2021 2016 Equity 85,869 $ 250.00 3/18/2021 2018 Equity 7,586,711 $ 2.00 6/25/2023 Total 7,673,130 Weighted average exercise price $ 4.78 Weighted average life in years 4.46

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2018
COMMITMENTS AND CONTINGENCIES
Future minimum rent commitments	(In thousands) Year Ended December 31, 2019 $ 243 2020 375 2021 386 2022 398 2023 339 Total $ 1,741

RESTRUCTURING (Tables)

RESTRUCTURING (Tables)	12 Months Ended
	Dec. 31, 2018
RESTRUCTURING
Schedule of restructuring costs payments by category	Year Ended December 31, 2017 (In thousands) Cash Non-Cash (1) Total Research and development $ 669 $ 41 $ 710 General and administrative 188 — 188 Restructuring Costs $ 857 $ 41 $ 898
Schedule of restructuring reserve	(In thousands) December 31, 2018 December 31, 2017 Restructuring reserve beginning balance $ 348 $ — Cash restructuring expenses incurred during the period — 857 Amounts paid during the period (348) (509) Restructuring reserve ending balance $ — $ 348

NATURE OF OPERATIONS AND GOIN_2

NATURE OF OPERATIONS AND GOING CONCERN- (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
NATURE OF OPERATIONS AND GOING CONCERN
Cash and cash equivalents	$ 16,660	$ 12,910
Going concern	false

SIGNIFICANT ACCOUNTING POLICI_4

SIGNIFICANT ACCOUNTING POLICIES - CASH AND CASH EQUIVALENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
SIGNIFICANT ACCOUNTING POLICIES
Cash		$ 23
Cash	$ (83)
Money market funds	16,743	12,887
Total cash and cash equivalents	$ 16,660	$ 12,910

SIGNIFICANT ACCOUNTING POLICI_5

SIGNIFICANT ACCOUNTING POLICIES - RESTRICTED CASH (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Restricted cash	$ 114	$ 361
Security deposit related to credit card account
Restricted cash	50	50
401K reserve account
Restricted cash	4
Standby letter of credit
Restricted cash	$ 60	$ 311

SIGNIFICANT ACCOUNTING POLICI_6

SIGNIFICANT ACCOUNTING POLICIES, PROPERTY AND EQUIPMENT (Details)	12 Months Ended
	Dec. 31, 2018
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
Office furniture and equipment
Property and equipment
Estimated Useful Life	5 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, 2018USD ($)segmentitem	Dec. 31, 2017item
Prepayments for CRO services	$ 1,300
Number of operating segments | segment	1
Number of locations in the United States | item	1	1
Prepaid and other current assets
Prepayments for CRO services	$ 290
Other long term assets
Prepayments for CRO services	$ 996

SIGNIFICANT ACCOUNTING POLICI_8

SIGNIFICANT ACCOUNTING POLICIES, INCOME TAXES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Taxes
Statutory tax rate (as a percent)	21.00%	34.00%
Transition tax	$ 0
Maximum
Income Taxes
Statutory tax rate (as a percent)		35.00%

SIGNIFICANT ACCOUNTING POLICI_9

SIGNIFICANT ACCOUNTING POLICIES, IMPAIRMENTS (Details) - USD ($) $ in Thousands	May 03, 2018	Aug. 28, 2017	Dec. 31, 2018	Dec. 31, 2017
SIGNIFICANT ACCOUNTING POLICIES
Impairment loss	$ 48	$ 41	$ 48	$ 41

SIGNIFICANT ACCOUNTING POLIC_10

SIGNIFICANT ACCOUNTING POLICIES, NET LOSS PER COMMON SHARE (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Anti-dilutive
Total potentially dilutive securities (in shares)	7,738,229	241,416
Warrants.
Anti-dilutive
Total potentially dilutive securities (in shares)	7,673,130	86,646
Stock Options
Anti-dilutive
Total potentially dilutive securities (in shares)	54,849	134,770
Unvested restricted stock units
Anti-dilutive
Total potentially dilutive securities (in shares)	10,250	20,000

SIGNIFICANT ACCOUNTING POLIC_11

SIGNIFICANT ACCOUNTING POLICIES, RECENT ACCOUNTING PRONOUNCEMENTS, ASU 2016-09 (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New accounting pronouncements
Cash and cash equivalents		$ 16,660	$ 12,910
Restricted cash included in current assets		4	361
Restricted cash included in other non-current assets		110
Total cash, cash equivalents and restricted cash shown in the statement of cash flows		$ 16,774	$ 13,271	$ 21,825
ASU No. 2016-02 | Restatement Adjustment
New accounting pronouncements
Operating lease assets	$ 1,500
Operating lease liabilities	$ 1,500

PROPERTY AND EQUIPMENT, SCHEDUL

PROPERTY AND EQUIPMENT, SCHEDULE (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property and equipment
Property and equipment	$ 705	$ 1,976
Less accumulated depreciation and amortization	(605)	(1,819)
Property and equipment, net	100	157
Computer software and hardware
Property and equipment
Property and equipment	131	241
Research and lab equipment
Property and equipment
Property and equipment	508	508
Leasehold improvements
Property and equipment
Property and equipment	$ 66	431
Office equipment
Property and equipment
Property and equipment		$ 796

PROPERTY AND EQUIPMENT (Details

PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	May 03, 2018	Aug. 28, 2017	Dec. 31, 2018	Dec. 31, 2017
Depreciation
Depreciation			$ 74	$ 377
Write off of fully depreciated assets	$ 1,300	$ 1,800
Impairment loss	$ 48	$ 41	$ 48	$ 41

INTANGIBLE ASSETS (Details)

INTANGIBLE ASSETS (Details) - Patent licensing fee - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Intangible assets
Useful life	15 years
Intangible assets - gross	$ 200	$ 200
Accumulated amortization	(156)	(139)
Intangible assets, net	$ 44	$ 61

INTANGIBLE ASSETS, AMORTIZATION

INTANGIBLE ASSETS, AMORTIZATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Amortization
Amortization expense	$ 17	$ 17
Future amortization
2019	17
2020	17
2021	$ 10

ACCRUED EXPENSES (Details)

ACCRUED EXPENSES (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
ACCRUED EXPENSES.
Severance and restructuring	$ 517	$ 1,160
Compensation	489	196
Clinical	73	52
Legal	35	68
Other accrued expenses	176	162
Total accrued expenses	$ 1,290	$ 1,638

FAIR VALUES OF ASSETS AND LIA_3

FAIR VALUES OF ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets and liabilities measured at fair value on a recurring basis
Derivative warrant liability		$ 4	$ 1,314
Recurring basis
Assets and liabilities measured at fair value on a recurring basis
Cash equivalents	$ 16,743	12,887
Derivative warrant liability		4
Recurring basis | Level 1
Assets and liabilities measured at fair value on a recurring basis
Cash equivalents	$ 16,743	12,887
Recurring basis | Level 2
Assets and liabilities measured at fair value on a recurring basis
Derivative warrant liability		$ 4

LOAN PAYABLE, ACTIVITY (Details

LOAN PAYABLE, ACTIVITY (Details) $ / shares in Units, $ in Thousands	May 01, 2015USD ($)	May 31, 2018USD ($)	Oct. 31, 2012USD ($)$ / sharesshares	Dec. 31, 2018USD ($)M$ / sharesshares	Dec. 31, 2017USD ($)
Loans Payable
Number of warrants outstanding | shares				7,673,130
2012 Warrant Exercise price $166.00
Loans Payable
Number of warrants outstanding | shares				243
Exercise price of warrant (in dollars per share) | $ / shares				$ 166
MassDev
Loans Payable
Line of credit, maximum			$ 2,000
Line of credit for working capital purpose			$ 200
Fixed interest rate (as a percent)			6.50%
Period for interest-only payments			30 months
Period for charging equal installments of interest and principal			54 months
Maturity date			Oct. 5, 2019
Commencement date of monthly installments	May 1, 2015
Amount of monthly payment	$ 41
Repayment of principal		$ 300
Payments due in next twelve months				$ 100
Number of months the principal due | M				3
MassDev | 2012 Warrant Exercise price $166.00
Loans Payable
Warrant expiration term (in years)			7 years
Exercise price of warrant (in dollars per share) | $ / shares			$ 166
Fair value of warrants			$ 32
MassDev | 2012 Warrant Exercise price $166.00 | Interest Expense
Loans Payable
Amortization				$ 7	$ 5
MassDev | 2012 Warrant Exercise price $166.00 | Common Stock
Loans Payable
Number of shares into which a warrant may be converted | shares			362
Number of warrants outstanding | shares				243
MassDev | Equipment Line of Credit
Loans Payable
Interest expense				$ 43	$ 71

LOAN PAYABLE (Details)

LOAN PAYABLE (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Summary of loans payable
MassDev Loan	$ 100	$ 852
Less: current portion	$ (100)	(452)
Notes Payable long-term portion		$ 400

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
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, 2018USD ($)
U.S. federal
Net operating loss carryforwards
Net operating loss carryforwards	$ 128.9
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	11.6
Massachusetts
Net operating loss carryforwards
Net operating loss carryforwards	$ 120.8

INCOME TAXES, CREDITS (Details)

INCOME TAXES, CREDITS (Details) $ in Thousands	Dec. 31, 2017USD ($)
U.S. federal
Tax credit carryforwards
Research and development tax credit carryforwards	$ 1,200
Massachusetts
Tax credit carryforwards
Research and development tax credit carryforwards	$ 258

INCOME TAXES, Tax Act (Details)

INCOME TAXES, Tax Act (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Taxes
Statutory tax rate (as a percent)	21.00%	34.00%
Transition tax	$ 0
Maximum
Income Taxes
Statutory tax rate (as a percent)		35.00%

INCOME TAXES, NET DEFERRED TAX

INCOME TAXES, NET DEFERRED TAX ASSET (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Significant components of net deferred tax asset
Net operating loss carryforward	$ 34,846	$ 31,533
Research and development credit carryforward	1,390	1,173
Stock-based compensation	2,300	2,828
Depreciation and amortization	11	71
Accrued expenses	136	357
Charitable contributions		27
Subtotal	38,683	35,989
Valuation allowance	(38,683)	(35,989)
Retained earnings	(207,330)	(183,907)
Increase (decrease) in valuation allowance	2,700	(7,900)
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
Restatement Adjustment | ASU 2016-09
Significant components of net deferred tax asset
Valuation allowance		642
Retained earnings		642
Net deferred tax assets		$ 0

INCOME TAXES, STATUTORY INCOME

INCOME TAXES, STATUTORY INCOME TAX RATES (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income tax benefits computed using the federal statutory income tax rate
Statutory rate	(21.00%)	(34.00%)
State taxes, net of benefit	(2.90%)	(4.70%)
Permanent differences:
Derivative losses	10.90%	2.90%
Other	0.40%	1.10%
Research and development tax credit	(0.80%)	(0.20%)
Other	1.90%	1.40%
Adoption of ASU 2016-09		7.40%
Increase / (decrease) in valuation reserve	11.50%	(32.00%)
Change in federal tax rate		58.10%
Effective tax rate	0.00%	0.00%

COMMON STOCK, AUTHORIZED (Detai

COMMON STOCK, AUTHORIZED (Details) - shares	Dec. 31, 2018	May 31, 2018	Apr. 30, 2018	Dec. 31, 2017
Common stock, number of shares, par value and other disclosures
Common stock, authorized	25,000,000	25,000,000	4,000,000	25,000,000
Common stock, issued	9,309,255			1,370,992
Common stock, outstanding	9,309,255			1,370,992

COMMON STOCK, TRANSACTIONS (Det

COMMON STOCK, TRANSACTIONS (Details) - USD ($) $ / shares in Units, $ in Thousands	May 30, 2018	Sep. 30, 2018	Jun. 30, 2018	May 31, 2018	Jan. 31, 2018	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Common stock disclosures
Common stock, par value (in dollars per share)							$ 0.00001	$ 0.00001
Proceeds from issuance of common stock and warrants, net of issuance costs							$ 16,511
Fair value adjustment of warrants							(12,165)	$ 762
Warrant reclassified to equity							14,707
Proceeds from exercise of warrants							$ 131	3
Aggregate number of shares reserved for issuance							7,738,229
Issuance of common stock to 401(k) plan							$ 6	$ 183
401(k)
Common stock disclosures
Company contributions to employee 401(k) accounts							$ 44
2018 Series A Warrant Exercise price $2.00
Common stock disclosures
Exercise price (in dollars per unit)							$ 2
2018 Warrants
Common stock disclosures
Fair value adjustment of warrants		$ 764
Warrant reclassified to equity		$ 14,700
Common Stock
Common stock disclosures
Issuance of stock in public offering (in shares)							1,652,396
Issuance of common stock upon exercise of warrants (in shares)							6,277,311	139
Proceeds from exercise of warrants								$ 3
Issuance of common stock to 401(k) plan (in shares)							440	3,933
Issuance of common stock to 401(k) plan								$ 183
Common Stock | 401(k)
Common stock disclosures
Aggregate number of shares reserved for issuance				4,100
Number of additional shares reserved				4,000
Issuance of common stock to 401(k) plan (in shares)							440
Issuance of common stock to 401(k) plan							$ 6
Warrants.
Common stock disclosures
Aggregate number of shares reserved for issuance							7,673,130
Underwritten Public Offering, June 2018
Common stock disclosures
Proceeds from issuance of common stock and warrants, net of issuance costs			$ 13,500
Reclassification of derivative warrant liability to additional paid-in capital			$ 287
Derivative loss						$ 12,000
Underwritten Public Offering, June 2018 | 2018 Series A Warrant Exercise price $2.00
Common stock disclosures
Number of shares/warrants comprised in a unit (in shares)			1
Exercise price (in dollars per unit)			$ 2			$ 2	$ 2
Warrant expiration term (in years)			5 years			5 years
Proceeds from exercise of warrants							$ 69
Reclassification of derivative warrant liability to additional paid-in capital							10,600
Derivative loss							$ 1,200
Underwritten Public Offering, June 2018 | 2018 Series B Warrant Exercise price $.01
Common stock disclosures
Exercise price (in dollars per unit)			$ 0.01			$ 0.01	$ 0.01
Warrant expiration term (in years)			20 years			20 years
Proceeds from exercise of warrants							$ 62
Underwritten Public Offering, June 2018 | 2018 Warrants
Common stock disclosures
Proceeds from exercise of warrants							131
Reclassification of derivative warrant liability to additional paid-in capital							10,600
Derivative loss							$ 1,200
Underwritten Public Offering, June 2018 | Common Stock
Common stock disclosures
Number of shares/warrants comprised in a unit (in shares)			1
Common stock, par value (in dollars per share)			$ 0.00001			$ 0.00001
Number of shares of common stock to be purchased by each warrant			1			1
Underwritten Public Offering, June 2018 | Common Stock | 2018 Series A Warrant Exercise price $2.00
Common stock disclosures
Issuance of common stock upon exercise of warrants (in shares)							34,500
Underwritten Public Offering, June 2018 | Common Stock | 2018 Series B Warrant Exercise price $.01
Common stock disclosures
Issuance of common stock upon exercise of warrants (in shares)							6,242,811
Underwritten Public Offering, June 2018 | Common Stock And Warrants
Common stock disclosures
Issuance of stock in public offering (in shares)			1,378,400
Equity issuance (in price per unit)			$ 2			$ 2
Pre Funded Units
Common stock disclosures
Issuance of stock in public offering (in shares)			6,242,811
Equity issuance (in price per unit)			$ 1.99			$ 1.99
Pre Funded Units | 2018 Series A Warrant Exercise price $2.00
Common stock disclosures
Number of shares/warrants comprised in a unit (in shares)			1
Pre Funded Units | 2018 Series B Warrant Exercise price $.01
Common stock disclosures
Number of shares/warrants comprised in a unit (in shares)			1
Pre Funded Units | Common Stock
Common stock disclosures
Number of shares of common stock to be purchased by each warrant			1			1
Purchase and registration rights agreement | Common Stock
Common stock disclosures
Issuance of stock in public offering (in shares)	17,192						256,804
Common stock, par value (in dollars per share)					$ 0.00001
Aggregate proceeds could be received					$ 15,000
Term					24 months
Deferred offering costs	$ 627
Proceeds from issuance of common stock, net of issuance costs							$ 3,100
Purchase and registration rights agreement | Common Stock | Maximum
Common stock disclosures
Aggregate number of shares reserved for issuance	1,200,000

COMMON STOCK, TRANSACTIONS, OTH

COMMON STOCK, TRANSACTIONS, OTHER (Details) $ in Thousands	Apr. 16, 2018shares	Aug. 10, 2017shares	Dec. 31, 2018USD ($)shares	Dec. 31, 2017USD ($)shares	Aug. 11, 2017shares
Common stock disclosures
Proceeds from issuance of stock under ESPP | $			$ 4	$ 51
Reverse stock split ratio	0.04
Proceeds from exercise of stock options | $				26
Proceeds from exercise of warrants | $			131	3
Issuance of common stock to 401(k) plan | $			$ 6	$ 183
Common Stock
Common stock disclosures
Stock issued under ESPP (in shares)			1,133	710
Proceeds from issuance of stock under ESPP | $			$ 4	$ 51
Reverse stock split ratio	0.04
Stock issued during period, shares, reverse stock splits	2,733
Issuance of common stock upon vesting of restricted stock units (in shares)			4,250
Issuance of common stock upon exercise of stock options (in shares)				3,576
Proceeds from exercise of stock options | $				$ 26
Issuance of common stock upon exercise of warrants (in shares)			6,277,311	139
Proceeds from exercise of warrants | $				$ 3
Issuance of common stock to 401(k) plan (in shares)			440	3,933
Issuance of common stock to 401(k) plan | $				$ 183
Issuance of stock in exchange for warrants (in shares)				80,857
Common Stock | Warrant Exchange Agreement
Common stock disclosures
Issuance of stock in exchange for warrants (in shares)		80,857		80,857
Common Stock | 2014 Warrant Exercise price $11.75
Common stock disclosures
Number of shares into which a warrant may be converted			307	537
Common Stock | 2014 Warrant Exercise price $11.75 | Warrant Exchange Agreement
Common stock disclosures
Number of shares into which a warrant may be converted		23,102		23,102	1,941

COMMON STOCK, RESERVES (Details

COMMON STOCK, RESERVES (Details)	Dec. 31, 2018shares
Summary of common stock reserves
Total Reserves	7,738,229
Warrants.
Summary of common stock reserves
Total Reserves	7,673,130
Stock Options
Summary of common stock reserves
Total Reserves	54,849
Restricted Stock Units (RSUs)
Summary of common stock reserves
Total Reserves	10,250

DERIVATIVE INSTRUMENTS, INCEPTI

DERIVATIVE INSTRUMENTS, INCEPTION FAIR VALUE OF WARRANTS (Details) $ in Millions	Jun. 30, 2018USD ($)Y	Dec. 31, 2017Yitem
2018 Series B Warrant Exercise price $.01
Fair value of warrants
Fair value of warrants | $	$ 11.5
2018 Series A Warrant Exercise price $2.00
Fair value of warrants
Fair value of warrants | $	$ 13.7
Risk-free interest rate | 2018 Series B Warrant Exercise price $.01
Fair value of warrants
Derivative warrant liability measurement input	2.95
Risk-free interest rate | 2018 Series A Warrant Exercise price $2.00
Fair value of warrants
Derivative warrant liability measurement input	2.75
Risk-free interest rate | 2014 Warrant Exercise price $11.75
Fair value of warrants
Derivative warrant liability measurement input | item		0.0191
Expected dividend yield | 2018 Series B Warrant Exercise price $.01
Fair value of warrants
Derivative warrant liability measurement input	0
Expected dividend yield | 2018 Series A Warrant Exercise price $2.00
Fair value of warrants
Derivative warrant liability measurement input	0
Contractual term | 2018 Series B Warrant Exercise price $.01
Fair value of warrants
Derivative warrant liability measurement input	20
Contractual term | 2018 Series A Warrant Exercise price $2.00
Fair value of warrants
Derivative warrant liability measurement input	5
Contractual term | 2014 Warrant Exercise price $11.75
Fair value of warrants
Derivative warrant liability measurement input		1.35
Expected volatility | 2018 Series B Warrant Exercise price $.01
Fair value of warrants
Derivative warrant liability measurement input	202.51
Expected volatility | 2018 Series A Warrant Exercise price $2.00
Fair value of warrants
Derivative warrant liability measurement input	202.51
Expected volatility | 2014 Warrant Exercise price $11.75
Fair value of warrants
Derivative warrant liability measurement input | item		82.37

DERIVATIVE INSTRUMENTS (Details

DERIVATIVE INSTRUMENTS (Details) - USD ($) $ in Thousands	1 Months Ended			3 Months Ended	12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	May 31, 2018	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative instruments
Derivative warrant liability						$ 4	$ 1,314
Proceeds from exercise of warrants					$ 131	3
Number of warrants outstanding					7,673,130
Fair value adjustment of warrants					$ (12,165)	$ 762
Warrant reclassified to equity					$ 14,707
Underwritten Public Offering, June 2018
Derivative instruments
Proceeds allocated to warrant liability		$ 13,200
Amount recorded to permanent equity		287
Derivative warrant liability		25,200		$ 25,200
Derivative loss				$ 12,000
Reclassification of derivative warrant liability to additional paid-in capital		$ 287
2018 Series A Warrant Exercise price $2.00
Derivative instruments
Number of warrants outstanding					7,586,711
2018 Series A Warrant Exercise price $2.00 | Underwritten Public Offering, June 2018
Derivative instruments
Amount recorded to permanent equity					$ 10,600
Derivative loss					1,200
Proceeds from exercise of warrants					69
Reclassification of derivative warrant liability to additional paid-in capital					10,600
2018 Series B Warrant Exercise price $.01 | Underwritten Public Offering, June 2018
Derivative instruments
Proceeds from exercise of warrants					$ 62
Number of warrants outstanding					0
2014 Warrant Exercise price $11.75
Derivative instruments
Number of warrants outstanding					307
Fair value adjustment of warrants			$ 1
Warrant reclassified to equity			$ 1
2018 Warrants
Derivative instruments
Fair value adjustment of warrants	$ 764
Warrant reclassified to equity	$ 14,700
2018 Warrants | Underwritten Public Offering, June 2018
Derivative instruments
Amount recorded to permanent equity					$ 10,600
Derivative loss					1,200
Proceeds from exercise of warrants					131
Reclassification of derivative warrant liability to additional paid-in capital					$ 10,600
Common Stock
Derivative instruments
Issuance of common stock upon exercise of warrants (in shares)					6,277,311	139
Proceeds from exercise of warrants						$ 3
Common Stock | 2018 Series A Warrant Exercise price $2.00 | Underwritten Public Offering, June 2018
Derivative instruments
Issuance of common stock upon exercise of warrants (in shares)					34,500
Common Stock | 2018 Series B Warrant Exercise price $.01 | Underwritten Public Offering, June 2018
Derivative instruments
Issuance of common stock upon exercise of warrants (in shares)					6,242,811

DERIVATIVE INSTRUMENTS, FAIR VA

DERIVATIVE INSTRUMENTS, FAIR VALUE OF WARRANTS (Details) - 2014 Warrant Exercise price $11.75	Dec. 31, 2017Yitem
Risk-free interest rate
Fair value of warrants
Derivative warrant liability measurement input	0.0191
Contractual term
Fair value of warrants
Derivative warrant liability measurement input | Y	1.35
Expected volatility
Fair value of warrants
Derivative warrant liability measurement input	82.37

DERIVATIVE INSTRUMENTS, CHANGES

DERIVATIVE INSTRUMENTS, CHANGES IN DERIVATIVE WARRANT LIABILITY (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Changes in Derivative Warrant Liability
Balance at beginning of year	$ 4	$ 1,314
Issuance of new warrants	13,172
Reduction in derivative liability due to exercise of warrants	(10,620)
Reclassification of fair value of derivative liabilities to equity on amendment of warrant agreements	(14,707)
Increase in derivative liability prior to warrant exchange		3,029
Reduction in derivative liability due to warrant exchange		(3,537)
Repurchase of warrants	(14)	(40)
Increase (decrease) in the fair value of warrants	$ 12,165	(762)
Balance at end of period		$ 4

STOCK BASED COMPENSATION (Detai

STOCK BASED COMPENSATION (Details) - USD ($) $ in Thousands	1 Months Ended		6 Months Ended	12 Months Ended		43 Months Ended
	Jan. 31, 2019	Mar. 31, 2015	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Apr. 30, 2015
Stock options
Aggregate number of shares reserved for issuance			7,738,229	7,738,229		7,738,229
Stock-based compensation (in dollars)				$ 618	$ 4,100
Stock Options
Stock options
Granted (in shares)				15,524	57,579
Expected term				10 years
Aggregate number of shares reserved for issuance			54,849	54,849		54,849
2010 Plan
Stock options
Granted (in shares)						0
Shares available for future grants			12,894	12,894		12,894
Expected term				10 years
2015 Plan
Stock options
Shares available for future grants			188,552	188,552		188,552
Shares authorized for issuance							160,000
Expected term				10 years
2007 Plan
Stock options
Expected term				10 years
Employee Stock Purchase Plan
Stock options
Shares authorized for issuance		7,500
Percentage of outstanding shares reserved for future issuance		1.00%
Increase in shares of common stock reserved for issuance (in shares)		2,000
Aggregate number of shares reserved for issuance			7,923	7,923		7,923
Stock issued under ESPP (in shares)	1,065
Offering Period				6 months
Stock-based compensation (in dollars)				$ 2	$ 14
Employee Stock Purchase Plan | Maximum
Stock options
Aggregate number of shares reserved for issuance		50,000
Common Stock
Stock options
Stock issued under ESPP (in shares)				1,133	710
Accrued expenses | Employee Stock Purchase Plan
Stock options
Employee payroll deductions (in dollars)			$ 1

STOCK BASED COMPENSATION, SHARE

STOCK BASED COMPENSATION, SHARE-BASED COMPENSATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Stock options
Stock-based compensation (in dollars)	$ 618	$ 4,100
Stock Options
Stock options
Expected term	10 years
Vesting period	48 months

STOCK BASED COMPENSATION, ASSUM

STOCK BASED COMPENSATION, ASSUMPTIONS USED IN DETERMINING THE FAIR VALUE (Details) - Stock Options	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Assumptions used principally in determining the fair value of options granted
Expected dividend yield (as a percent)	0.00%	0.00%
Expected term	5 years 7 months 13 days	6 years 2 months 19 days
Expected volatility (as a percent)	104.00%	104.00%
Minimum
Assumptions used principally in determining the fair value of options granted
Risk-free interest rate (as a percent)	2.45%	1.69%
Maximum
Assumptions used principally in determining the fair value of options granted
Risk-free interest rate (as a percent)	2.88%	2.36%

STOCK BASED COMPENSATION, SUMMA

STOCK BASED COMPENSATION, SUMMARY OF OPTION ACTIVITY - (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock Option
Stock-based compensation (in dollars)	$ 618	$ 4,100
Stock Options
Summary of option activity - Shares
Outstanding at the beginning of year (in shares)	134,770	127,752
Granted (in shares)	15,524	57,579
Expired (in shares)	(5,334)
Cancelled/Forfeited (in shares)	(90,111)	(46,985)
Exercised (in shares)		(3,576)
Outstanding at the end of period (in shares)	54,849	134,770	127,752
Vested at the end of period (in shares)	32,522
Summary of option activity - Weighted Average Exercise Price
Outstanding at the beginning of year (in dollars per shares)	$ 164.29	$ 188
Granted (in dollars per shares)	4.97	98.50
Expired (in dollars per shares)	173.13
Cancelled/Forfeited (in dollars per shares)	175	160
Exercised (in dollars per shares)		7.25
Outstanding at the end of period (in dollars per shares)	100.83	$ 164.29	$ 188
Vested at the end of period (in dollars per share)	$ 147.84
Option activity disclosures
Weighted Average Remaining Contractual Term - Outstanding	7 years 3 months 26 days	7 years 1 month 21 days	6 years 11 months 5 days
Weighted Average Remaining Contractual Term - Vested	5 years 11 months 23 days
Aggregate Intrinsic Value - Outstanding (in dollars)		$ 22	$ 571
Stock Option
Weighted average grant-date fair value of options granted	$ 3.82	$ 2.54
Total fair value of options vested	$ 952	$ 3,800
Total unrecognized compensation expense	$ 253
Period for unrecognized compensation expense is estimated to be recognized	1 year 11 months 27 days

STOCK BASED COMPENSATION, RESTR

STOCK BASED COMPENSATION, RESTRICTED STOCK (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based compensation
Stock-based compensation (in dollars)	$ 618	$ 4,100
Restricted Stock Units (RSUs)
Number of Grants
Unvested balance at	20,000
Granted (in shares)		23,800
Vested/Released (in shares)	(4,250)
Forfeited (in shares)	(5,500)	(3,800)
Unvested balance at	10,250	20,000
Weighted-Average Grant Date Fair Value
Unvested balance at (in dollars per share)	$ 25.70
Granted (in dollars per share)		$ 26.50
Vested (in dollars per share)	24.72
Forfeited (in dollars per share)	31.25	31.25
Unvested balance at (in dollars per share)	$ 23.13	$ 25.70
Share-based compensation
Stock-based compensation (in dollars)	$ 88
Unrecognized compensation
Total unrecognized compensation expense	$ 223
Period for unrecognized compensation expense is estimated to be recognized	2 years 8 months 5 days

WARRANTS (Details)

WARRANTS (Details)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Warrants to purchase common stock issued and outstanding
Number of Warrants | shares	7,673,130
Weighted average exercise price | $ / shares	$ 4.78
Weighted average life in years	4 years 5 months 16 days
2012 Warrant Exercise price $166.00
Warrants to purchase common stock issued and outstanding
Warrants Issued Year	2012
Number of Warrants | shares	243
Warrant Exercise Price | $ / shares	$ 166
Expiration date	Oct. 5, 2019
2014 Warrant Exercise price $11.75
Warrants to purchase common stock issued and outstanding
Warrants Issued Year	2014
Number of Warrants | shares	307
Warrant Exercise Price | $ / shares	$ 11.75
Expiration date	May 9, 2021
2016 Warrant Exercise price $250.00
Warrants to purchase common stock issued and outstanding
Warrants Issued Year	2016
Number of Warrants | shares	85,869
Warrant Exercise Price | $ / shares	$ 250
Expiration date	Mar. 18, 2021
2018 Series A Warrant Exercise price $2.00
Warrants to purchase common stock issued and outstanding
Warrants Issued Year	2018
Number of Warrants | shares	7,586,711
Warrant Exercise Price | $ / shares	$ 2
Expiration date	Jun. 25, 2023

WARRANTS, UNDERWRITTEN PUBLIC O

WARRANTS, UNDERWRITTEN PUBLIC OFFERING JUNE 2018 (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Warrants to purchase common stock issued and outstanding
Common stock, par value (in dollars per share)		$ 0.00001	$ 0.00001
Proceeds from issuance of common stock and warrants, net of issuance costs		$ 16,511
2018 Series A Warrant Exercise price $2.00
Warrants to purchase common stock issued and outstanding
Exercise price (in dollars per unit)		$ 2
Common Stock
Warrants to purchase common stock issued and outstanding
Number of shares issued (in shares)		1,652,396
Underwritten Public Offering, June 2018
Warrants to purchase common stock issued and outstanding
Proceeds from issuance of common stock and warrants, net of issuance costs	$ 13,500
Underwritten Public Offering, June 2018 | 2018 Series A Warrant Exercise price $2.00
Warrants to purchase common stock issued and outstanding
Number of shares/warrants comprised in a unit (in shares)	1
Exercise price (in dollars per unit)	$ 2	$ 2
Warrant expiration term (in years)	5 years
Underwritten Public Offering, June 2018 | 2018 Series B Warrant Exercise price $.01
Warrants to purchase common stock issued and outstanding
Exercise price (in dollars per unit)	$ 0.01	$ 0.01
Warrant expiration term (in years)	20 years
Underwritten Public Offering, June 2018 | Common Stock
Warrants to purchase common stock issued and outstanding
Number of shares/warrants comprised in a unit (in shares)	1
Common stock, par value (in dollars per share)	$ 0.00001
Number of shares of common stock to be purchased by each warrant	1
Underwritten Public Offering, June 2018 | Common Stock And Warrants
Warrants to purchase common stock issued and outstanding
Number of shares issued (in shares)	1,378,400
Equity issuance (in price per unit)	$ 2
Pre Funded Units
Warrants to purchase common stock issued and outstanding
Number of shares issued (in shares)	6,242,811
Equity issuance (in price per unit)	$ 1.99
Pre Funded Units | 2018 Series A Warrant Exercise price $2.00
Warrants to purchase common stock issued and outstanding
Number of shares/warrants comprised in a unit (in shares)	1
Pre Funded Units | 2018 Series B Warrant Exercise price $.01
Warrants to purchase common stock issued and outstanding
Number of shares/warrants comprised in a unit (in shares)	1
Pre Funded Units | Common Stock
Warrants to purchase common stock issued and outstanding
Number of shares of common stock to be purchased by each warrant	1

WARRANTS, EXCHANGE (Details)

WARRANTS, EXCHANGE (Details) $ / shares in Units, $ in Thousands	Aug. 10, 2017USD ($)item$ / sharesshares	Aug. 09, 2017USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)shares	Aug. 11, 2017$ / sharesshares
Warrants
Derivatives (loss) | $			$ (12,165)	$ (2,267)
Value of stock issued | $			$ 3,338
2014 Warrant Exercise price $11.75
Warrants
Exercise price (in dollars per unit) | $ / shares			$ 11.75
Common Stock
Warrants
Issuance of stock in exchange for warrants (in shares)				80,857
Common Stock | 2014 Warrant Exercise price $11.75
Warrants
Number of shares into which a warrant may be converted			307	537
Warrant Exchange Agreement | 2014 Warrant Exercise price $11.75
Warrants
Number of times for exchange of warrants | item	3.5
Exercise price (in dollars per unit) | $ / shares	$ 96.75				$ 20.75
Derivatives (loss) | $		$ (3,000)
Warrant Exchange Agreement | Common Stock
Warrants
Issuance of stock in exchange for warrants (in shares)	80,857			80,857
Value of stock issued | $	$ 3,500
Share price (in dollars per share) | $ / shares		$ 43.75
Warrant Exchange Agreement | Common Stock | 2014 Warrant Exercise price $11.75
Warrants
Number of shares into which a warrant may be converted	23,102			23,102	1,941
Warrant Exchange Agreement | Fair Value | Common Stock
Warrants
Issuance of stock in exchange for warrants (in shares)		80,857

WARRANTS, CANCELLATION AND AMEN

WARRANTS, CANCELLATION AND AMENDMENT (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended	12 Months Ended
	Sep. 30, 2018	May 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Warrants
Repurchase of warrants				$ 14	$ 40
Warrant reclassified to equity				14,707
2014 Warrant Exercise price $11.75
Warrants
Repurchase of warrants			$ 40	$ 14
Cash compensation to warrant holder		$ 19
Warranty extension period		2 years
Warrant reclassified to equity		$ 1
2014 Warrant Exercise price $11.75 | Common Stock
Warrants
Number of shares into which a warrant may be converted			537	307	537
2018 Warrants
Warrants
Warrant reclassified to equity	$ 14,700

EMPLOYEE BENEFIT PLAN (Details)

EMPLOYEE BENEFIT PLAN (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Employee benefit plan disclosures
Eligibility criteria for participation in the Plan	21 years
Expense portion of fair value of stock	$ 6	$ 183
Common Stock
Employee benefit plan disclosures
Issuance of common stock to 401(k) plan (in shares)	440	3,933
Expense portion of fair value of stock	$ 6	$ 183

INTELLECTUAL PROPERTY LICENSE (

INTELLECTUAL PROPERTY LICENSE (Details) - Boston Childrens Hospital Bch License - USD ($) $ in Thousands	Dec. 31, 2011	Dec. 31, 2018	Dec. 31, 2017
Intellectual Property License
Useful life	15 years
Initial license fee paid	$ 75
Capitalized license fees, gross		$ 200	$ 200
Milestone payments expensed		$ 175

COMMITMENTS AND CONTINGENCIES,

COMMITMENTS AND CONTINGENCIES, LEASES (Details) $ in Thousands	May 03, 2018USD ($)ft²	Oct. 31, 2017USD ($)ft²item	Aug. 28, 2017USD ($)	Jun. 30, 2018USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Nov. 01, 2018USD ($)	Jun. 19, 2017USD ($)	Jun. 13, 2017ft²	Mar. 31, 2016ft²
Commitments
Deferred rent removed and gain on lease assignment					$ 603
Loss on impairment of fixed assets	$ 48		$ 41		48	$ 41
Prepaid rent					17	0
Deferred rent liability					0	397
Cambridge Lease
Commitments
Lease space (in square feet) | ft²		26,342
Term of commercial lease		6 years 3 months					5 years
Number of options to extend lease | item		1
Term of lease extension option		5 years
Standby letter of credit		$ 311
Letter of credit terminated amount	$ 311
Deferred rent removed and gain on lease assignment				$ 603
Loss on impairment of fixed assets					48
Sublease
Commitments
Lease space (in square feet) | ft²										5,233
Sublease income recorded as offset to rent expense						$ 26
Moderna Sublease
Commitments
Lease space (in square feet) | ft²									5,233
Sublease income recorded as offset to rent expense					$ 112
Tenant security deposit								$ 55
Third Party Lease
Commitments
Lease space (in square feet) | ft²	5,104
Standby letter of credit	$ 40						$ 60
Tenant security deposit				$ 55

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES, FUTURE MINIMUM RENT COMMITMENTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Future minimum rent commitments
2019	$ 243
2020	375
2021	386
2022	398
2023	339
Total	1,741
Commitments
Total rent expense	$ 837	$ 1,200

COMMITMENTS AND CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES, COMPENSATION (Details) - Executive - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2018
Compensation Arrangement
Term of award	1 year
Compensation expense		$ 174
Outstanding payments			$ 0

COMMITMENTS AND CONTINGENCIES_4

COMMITMENTS AND CONTINGENCIES, LITIGATION LAWSUITS WITH FORMER EMPLOYEE (Details) $ in Thousands	Mar. 03, 2017shares	Dec. 06, 2013claim	Nov. 30, 2013USD ($)
InVivo Therapeutics Holdings Corp. v. Reynolds
Litigation
Value of damages sought worth of personal and/or exorbitant expenses | $			$ 500
Reynolds counterclaim against InVivo Therapeutics Holdings Corp.
Litigation
Number of breach of contract claims		2
Number of breach of covenant of good faith and fair-dealing claims		2
Equivalent number of common shares related to attempted exercise of certain stock options | shares	47,864

COMMITMENTS AND CONTINGENCIES_5

COMMITMENTS AND CONTINGENCIES, LITIGATION VENDOR DISPUTE (Details) - Former vendor $ in Millions	1 Months Ended
	Jul. 31, 2018USD ($)
Litigation
Damages awarded	$ 1.2
Other income
Litigation
Proceeds received from settlement agreement	$ 1.2

RESTRUCTURING (Details)

RESTRUCTURING (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2017	Dec. 31, 2017
RESTRUCTURING
Percentage of reduction in headcount	39.00%
Restructuring costs		$ 898

RESTRUCTURING, COSTS BY CATEGOR

RESTRUCTURING, COSTS BY CATEGORY (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Restructuring costs by category
Restructuring costs, cash	$ 857
Restructuring costs, non cash	41
Restructuring costs	898
Research and development
Restructuring costs by category
Restructuring costs, cash	669
Restructuring costs, non cash	41
Restructuring costs	710
General and administrative
Restructuring costs by category
Restructuring costs, cash	188
Restructuring costs	$ 188

RESTRUCTURING, RESERVE (Details

RESTRUCTURING, RESERVE (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Restructuring reserve
Restructuring reserve, beginning balance	$ 348
Cash restructuring expenses incurred during the period		$ 857
Amounts paid during the period	$ (348)	(509)
Restructuring reserve, ending balance		$ 348

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details) - Dr. Robert Langer - Consulting agreement - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Oct. 31, 2017	Jan. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Related Party Transactions
Consulting fees per year	$ 100	$ 250
Consulting fees paid			$ 83	$ 204
Minimum
Related Party Transactions
Holding percentage of common stock		5.00%
Maximum
Related Party Transactions
Holding percentage of common stock			5.00%

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details)	Jan. 14, 2019shares
Subsequent event | Maximum | Inducement Award
Subsequent events
Number of securities to be purchased for each non-statutory stock option	90,000