Salarius Pharmaceuticals (SLRX) 10-Q 5 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 31, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	Flex Pharma, Inc.
Entity Central Index Key	1,615,219
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		18,069,476

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 12,961,126	$ 19,186,036
Marketable securities	0	14,129,723
Accounts receivable	20,993	10,385
Inventory	223,519	431,891
Prepaid expenses and other current assets	478,746	777,102
Total current assets	13,684,384	34,535,137
Property and equipment, net	127,090	331,040
Restricted cash	126,595	126,595
Total assets	13,938,069	34,992,772
Current liabilities:
Accounts payable	1,279,258	2,004,440
Accrued expenses and other current liabilities	1,554,679	3,712,221
Deferred revenue	0	72,188
Deferred rent, current portion	53,919	58,821
Total current liabilities	2,887,856	5,847,670
Deferred rent, net of current portion	0	39,214
Total liabilities	2,887,856	5,886,884
Stockholders' equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized at September 30, 2018 and December 31, 2017; none issued or outstanding at September 30, 2018 and December 31, 2017	0	0
Common stock, $0.0001 par value; 100,000,000 shares authorized at September 30, 2018 and December 31, 2017; 18,069,476 and 17,972,166 shares issued at September 30, 2018 and December 31, 2017, and 18,066,767 and 17,797,178 shares outstanding at September 30, 2018 and December 31, 2017, respectively	1,807	1,780
Additional paid-in capital	142,000,936	140,184,630
Accumulated other comprehensive loss	0	(1,247)
Accumulated deficit	(130,952,530)	(111,079,275)
Total stockholders' equity	11,050,213	29,105,888
Total liabilities and stockholders' equity	$ 13,938,069	$ 34,992,772

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (shares)	10,000,000	10,000,000
Preferred stock, shares issued (shares)	0	0
Preferred stock, shares outstanding (shares)	0	0
Common stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (shares)	100,000,000	100,000,000
Common stock, shares issued (shares)	18,069,476	17,972,166
Common stock, shares outstanding (shares)	18,066,767	17,797,178

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Total revenue	$ 250,991	$ 413,601	$ 675,075	$ 991,671
Costs and expenses:
Cost of product revenue	91,937	148,756	355,816	373,187
Research and development	865,765	4,739,360	11,720,535	12,730,554
Selling, general and administrative	1,959,872	4,934,937	8,651,808	14,520,596
Total costs and expenses	2,917,574	9,823,053	20,728,159	27,624,337
Loss from operations	(2,666,583)	(9,409,452)	(20,053,084)	(26,632,666)
Interest income, net	28,210	77,339	139,612	227,535
Net loss	(2,638,373)	(9,332,113)	(19,913,472)	(26,405,131)
Net loss attributable to common stockholders	$ (2,638,373)	$ (9,332,113)	$ (19,913,472)	$ (26,405,131)
Net loss per share attributable to common stockholders - basic and diluted (in usd per share)	$ (0.15)	$ (0.54)	$ (1.11)	$ (1.54)
Weighted-average number of common shares outstanding — basic and diluted (shares)	18,066,548	17,386,249	17,999,877	17,131,887
Net product revenue
Total revenue	$ 247,284	$ 407,241	$ 664,955	$ 978,221
Other revenue
Total revenue	$ 3,707	$ 6,360	$ 10,120	$ 13,450

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (2,638,373)	$ (9,332,113)	$ (19,913,472)	$ (26,405,131)
Other comprehensive gain (loss):
Unrealized gain (loss) on available-for-sale securities	0	4,305	1,247	303
Comprehensive loss	$ (2,638,373)	$ (9,327,808)	$ (19,912,225)	$ (26,404,828)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating activities
Net loss	$ (19,913,472)	$ (26,405,131)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	176,954	250,563
Stock-based compensation expense	1,698,323	3,266,879
Amortization and accretion on investments	11,537	(38,551)
Other non-cash items	22,274	0
Changes in operating assets and liabilities:
Accounts receivable	(3,848)	(22,953)
Inventory	191,380	(79,864)
Prepaid expenses and other current assets	283,463	(130,196)
Other assets	0	64,800
Accounts payable	(725,182)	(274,525)
Accrued expenses and other current liabilities	(2,161,081)	1,309,611
Deferred revenue	0	9,227
Deferred rent	(44,116)	83,247
Net cash used in operating activities	(20,463,768)	(21,966,893)
Investing activities
Purchases of marketable securities	(1,997,751)	(23,364,721)
Proceeds from maturities and sales of marketable securities	16,117,184	43,286,118
Purchases of property and equipment	0	(98,100)
Proceeds from sales of property and equipment	1,415	4,233
Net cash provided by investing activities	14,120,848	19,827,530
Financing activities
Proceeds from exercise of common stock	118,010	2,047
Net cash provided by financing activities	118,010	2,047
Net decrease in cash, cash equivalents and restricted cash	(6,224,910)	(2,137,316)
Cash, cash equivalents and restricted cash at beginning of period	19,312,631	22,542,635
Cash, cash equivalents and restricted cash at end of period	13,087,721	20,405,319
Supplemental cash flow information
Property and equipment purchases included in accounts payable at September 30, 2017	0	8,472
Property and equipment purchases included in accounts payable and accrued expenses at December 31, 2016	$ 0	$ 7,100

Organization and operations

Organization and operations	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and operations	Organization and operations The Company Flex Pharma, Inc. (the "Company") is a biotechnology company that was focused on developing innovative and proprietary treatments for muscle cramps, spasms and spasticity associated with severe neurological conditions. In June 2018, the Company announced that it was ending its ongoing Phase 2 clinical trials of FLX-787 in patients with motor neuron disease ("MND"), primarily with amyotrophic lateral sclerosis ("ALS"), and in patients with Charcot-Marie-Tooth disease ("CMT"), due to oral tolerability concerns observed in both studies. Additionally, in June 2018, the Company initiated a process to explore a range of strategic alternatives for enhancing stockholder value, including the potential sale or merger of the Company. Wedbush PacGrow has been engaged to act as the Company’s strategic financial advisor. The Company also announced the restructuring of the organization to reduce its cost structure in order to preserve liquidity. In connection with the restructuring plan, the Company reduced its workforce by approximately 60% , with the reduction completed as of September 30, 2018. While the strategic assessment is ongoing, the Company will continue to operate with a reduced internal team that will focus their efforts on limited research and development activities and operating its consumer business, which sells HOTSHOT®, the Company's consumer product launched in 2016 to prevent and treat exercise-associated muscle cramps. The Company's evaluation of strategic alternatives and its restructuring plans entails significant risks and uncertainties, including the risks and uncertainties set forth in Item 1A under the heading "Risk Factors" and Item 2 under the heading "Management's Discussion and Analysis of Financial Condition and Results of Operations" of this Quarterly Report on Form 10-Q and in the Company's Annual Report on Form 10-K. There can be no assurance that the Company's evaluation of potential strategic alternatives will result in any transaction. The Company operates as two reportable segments, Consumer Operations and Drug Development. See Note 12 for additional discussion and information on the reportable segments. Liquidity The Company incurred a loss of $2,638,373 for the three months ended September 30, 2018 , a loss of $19,913,472 for the nine months ended September 30, 2018 and had an accumulated deficit of $130,952,530 as of September 30, 2018 . The Company had unrestricted cash and cash equivalents of $12,961,126 at September 30, 2018 . The Company's operating plan assumes limited research and development activities and that the Consumer Operations segment will continue to sell HOTSHOT. In the event that the Company does not complete a sale or merger, the Company (i) may elect to pursue a dissolution and liquidation of the Company or (ii) may continue to market HOTSHOT and operate its consumer business. If the Company dissolves and liquidates, the Company's common stockholders may lose their entire investment. The amount of assets available for distribution to the Company's stockholders will depend heavily on the timing of such liquidation as well as the amount of cash that will be needed for commitments and contingent liabilities. Based on the Company's operating plan, the Company believes that its existing cash and cash equivalents will be sufficient to allow the Company to fund its current operating plan for at least 12 months from the date the financial statements are issued. The Company cannot predict the outcome of its strategic assessment or whether and to what extent it will resume drug development activities for FLX-787 or other drug product candidates and to what extent it will promote and sell HOTSHOT or other consumer products in the future. Accordingly, it is difficult to predict future cash needs. Management does expect the Company to incur losses for the foreseeable future. The Company's ability to achieve profitability in the future is dependent upon achieving a level of revenues adequate to support the Company's cost structure. The Company may never achieve profitability, and unless and until it does, the Company will continue to need to raise additional capital. If the Company raises funds through the issuance of additional equity, whether through private placements or additional public offerings, such an issuance would dilute the stockholders' ownership in the Company. There can be no assurances, however, that additional funding will be available on terms acceptable to the Company, or at all.

Summary of significant accounti

Summary of significant accounting policies and recent accounting pronouncements	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Summary of significant accounting policies and recent accounting pronouncements	Summary of significant accounting policies and recent accounting pronouncements The accompanying unaudited condensed consolidated financial statements reflect the application of certain significant accounting policies as described below and elsewhere in these notes to the condensed consolidated financial statements. As of September 30, 2018 , the Company’s significant accounting policies, which are detailed in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2017 (the “ 2017 10-K”), have not changed, other than as noted below. Accounts receivable and allowance for doubtful accounts Accounts receivable are stated at their carrying values, net of any allowances for doubtful accounts. Accounts receivable consist primarily of amounts due from specialty retailers and sports teams, for which collection is probable based on the customer's intent and ability to pay. Receivables are evaluated for collection probability on a regular basis and an allowance for doubtful accounts is recorded, if necessary. No allowance for doubtful accounts was deemed necessary at September 30, 2018 or December 31, 2017. Restricted cash The Company has restricted cash in the form of a letter of credit it maintains as a security deposit on the lease of its office space in Boston, Massachusetts. Advertising expense Advertising expense consists of media and production costs related to print and digital advertising. All advertising is expensed as incurred. Total advertising expenses are included in selling, general and administrative expenses in the condensed consolidated statement of operations, and were approximately $20,000 and $792,000 for the three and nine months ended September 30, 2018 and approximately $1,158,000 and $3,073,000 for the three and nine months ended September 30, 2017 . Shipping and handling costs Shipping and handling costs related to the movement of inventory to the Company's co-packer and from the co-packer to the Company's third-party warehousing and fulfillment partners are capitalized as inventory and expensed as cost of product revenue when revenue is recognized. Shipping and handling costs to move finished goods from the Company's third-party warehousing and fulfillment partners to customer locations are included in selling, general and administrative expenses in the condensed consolidated statement of operations, and were approximately $27,000 and $81,000 for the three and nine months ended September 30, 2018 , and approximately $64,000 and $145,000 for the three and nine months ended September 30, 2017 . Restructuring-related costs The Company records employee termination costs in accordance with Accounting Standards Codification ("ASC") Topic 712, " Compensation - Nonretirement and Postemployment Benefits" (ASC 712), if the termination benefits are paid as part of an ongoing benefit arrangement, which includes benefits provided as part of the Company's established severance policy or as part of an executive employment agreement. The Company accrues employee termination costs associated with an on-going benefit arrangement if the obligation is attributable to prior services rendered, the rights to the benefits have vested, the payment is probable and the Company can reasonably estimate the liability. The Company accounts for employee termination benefits that represent a one-time benefit in accordance with ASC Topic 420, " Exit or Disposal Cost Obligations" (ASC 420). Upon communication of the termination to the employee, the Company expenses these costs over the employee’s future service period, if any. Restructuring-related costs are recorded within research and development expenses and selling, general and administrative expenses on the Company's condensed consolidated statement of operations. Liabilities associated with the Company's restructuring activities are recorded as a component of accrued expenses and other current liabilities on its condensed consolidated balance sheet. See Note 7 for additional information on the Company's current restructuring plan. Unaudited interim financial information Certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the 2017 10-K. The condensed consolidated financial statements as of September 30, 2018 , for the three and nine months ended September 30, 2018 and 2017 , and the related information contained within the notes to the condensed consolidated financial statements, are unaudited. The unaudited condensed consolidated financial statements have been prepared on the same basis as annual audited consolidated financial statements, and in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of the Company’s condensed consolidated financial position as of September 30, 2018 , and the statements of operations, comprehensive loss and cash flows for the three and nine month periods ended September 30, 2018 and 2017 . The results for the three and nine months ended September 30, 2018 are not necessarily indicative of results to be expected for the year ending December 31, 2018 , or any other future annual or interim periods. Basis of presentation and use of estimates The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States ("GAAP"). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the ASC and Accounting Standards Update ("ASU") of the Financial Accounting Standards Board ("FASB"). The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, the Company's management evaluates its estimates, which include, but are not limited to, estimates related to clinical study accruals, estimates related to inventory realizability, stock-based compensation expense and amounts of expenses during the reported period. The Company bases its estimates on historical experience and other market-specific or other relevant assumptions that it believes to be reasonable under the circumstances. Actual results may differ from those estimates or assumptions. Principles of consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries: TK Pharma, Inc., a Massachusetts Securities Corporation, and Flex Innovation Group LLC, a Delaware limited liability company, which contains the Company's consumer-related operations. All significant intercompany balances and transactions have been eliminated in consolidation. Recent accounting pronouncements In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers ("ASC 606") . ASC 606 supersedes the revenue recognition requirements in ASC Topic 605, Revenue Recognition ("ASC 605") and requires entities to recognize revenue when control of the promised goods or services is transferred to customers at an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. The Company adopted ASC 606 as of January 1, 2018 using the modified retrospective transition method. See Note 3 for further details. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) . The ASU requires lessees to recognize the assets and liabilities on their balance sheet for the rights and obligations created by most leases and continue to recognize expenses on their income statements over the lease term. It will also require disclosures designed to give financial statement users information on the amount, timing and uncertainty of cash flows arising from leases. In July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, Leases. This ASU is intended to clarify or correct unintended application of the guidance outlined in ASU No. 2016-02. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements. This ASU is intended to address comparative reporting requirements for initial adoption. The guidance is effective for annual reporting periods beginning after December 15, 2018, and interim periods within those years. Early adoption is permitted. While the Company is currently evaluating the impact this standard will have on its consolidated financial statements, the Company expects that upon adoption, it will recognize right-of-use assets and lease liabilities and those amounts could be material. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments . The update amends the guidance in ASU Topic 230 and clarifies how entities should classify certain cash receipts and cash payments on the statement of cash flows with the objective of reducing the existing diversity in practice related to eight specific cash flow issues. The Company adopted ASU No. 2016-15 in the first quarter of 2018, retrospectively. The adoption of ASU No. 2016-15 did not have a significant impact on the consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows , which amends ASU Topic 230. This update requires entities to show the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. As a result, entities are no longer required to present transfers between cash and cash equivalents and restricted cash and restricted cash equivalents in the statement of cash flows. When cash, cash equivalents, restricted cash and restricted cash equivalents are presented in more than one line item on the balance sheet, the new guidance requires a reconciliation of the totals in the statement of cash flows to the related captions in the balance sheet. The Company adopted ASU No. 2016-18 in the first quarter of 2018, retrospectively, resulting in a change to the presentation of restricted cash on the condensed consolidated statement of cash flows. The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the condensed consolidated balance sheets that sum to the total of such amounts in the condensed consolidated statements of cash flows: September 30, 2018 December 31, 2017 Cash and cash equivalents $ 12,961,126 $ 19,186,036 Restricted cash 126,595 126,595 Cash, cash equivalents and restricted cash shown on the condensed consolidated statement of cash flows $ 13,087,721 $ 19,312,631 In May 2017, the FASB issued ASU No. 2017-09, Stock Compensation (Topic 718): Scope of Modification Accounting , to provide clarity and reduce diversity in practice, cost and complexity when applying the guidance of Topic 718. The guidance is effective for fiscal years beginning after December 15, 2017 and interim periods within those years. Early adoption is permitted and the guidance should be applied prospectively. The Company adopted ASU No. 2017-09 in the first quarter of 2018, which did not impact the Company's condensed consolidated financial statements or disclosures. In June 2018, the FASB issued ASU No. 2018-07, Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting ("ASU No. 2018-07"). This ASU is intended to simplify aspects of share-based compensation issued to non-employees by making the guidance consistent with the accounting for employee share-based compensation. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within that year. Early adoption is permitted, but not before an entity has adopted ASC 606, and the guidance should be applied using a modified retrospective transition approach. The Company early adopted ASU No. 2018-07 on July 1, 2018 and revalued its unvested nonemployee awards as of the July 1, 2018 adoption date. The adoption did not have a material impact on the condensed consolidated financial statements and therefore a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year was not required. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement. This ASU modifies the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement . The guidance is effective for annual reporting periods beginning after December 15, 2019, and interim periods within those years. Early adoption is permitted. The Company is currently evaluating the impact of ASU No. 2018-13 on its consolidated financial statements and disclosures. The Company believes that the impact of other recently issued standards that are not yet effective will not have a material effect on its consolidated financial position or results of operations upon adoption.

Revenue from contracts with cus

Revenue from contracts with customers	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue from contracts with customers	Revenue from contracts with customers Adoption of ASC Topic 606, "Revenue from Contracts with Customers" On January 1, 2018, the Company adopted ASC 606 using the modified retrospective method applied to contracts not yet completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under ASC 606, while prior period amounts are not adjusted and are reported in accordance with the Company's historical accounting under ASC 605. The primary impact of the adoption of ASC 606 related to the timing of revenue recognized for e-commerce sales, due to e-commerce refund rights. Under ASC 606, the Company recognizes revenue when control of the promised good is transferred to the customer, and reflects the consideration to which the Company expects to be entitled to receive in exchange for the good. This has resulted in accelerated revenue recognition for e-commerce sales, as under ASC 605, all revenue and related costs were deferred and recognized once the refund period lapsed. The cumulative effect of applying the new guidance to all contracts that were not completed as of January 1, 2018 was recorded as an adjustment to accumulated deficit of approximately $40,000 as of the adoption date, which was primarily the result of reducing deferred revenue by approximately $70,000 and deferred cost of product revenue and selling fees by approximately $30,000 , that were recorded on the consolidated balance sheet at December 31, 2017. The Company would have recognized approximately $1,000 and $29,000 of additional total revenue during the three and nine months ended September 30, 2018 , respectively, if the Company had continued to recognize revenue under ASC 605. The adoption of ASC 606 did not impact income taxes, as the Company fully reserves its net deferred tax assets. Therefore, the change to the Company's net deferred tax asset position due to adoption was offset by a corresponding change to the valuation allowance. Revenue recognition Revenue includes sales of HOTSHOT bottled finished goods to e-commerce customers, specialty retailers and sports teams, including professional and collegiate teams. Revenue also consists of payments made by customers for expedited shipping and handling. The Company expenses fulfillment costs as incurred because the amortization period would be less than one year in accordance with the ASC 606 practical expedient. In accordance with ASC 606, the Company applies the following steps to recognize revenue for the sale of bottled finished goods that reflects the consideration to which the Company expects to be entitled to receive in exchange for the promised goods: 1. Identify the contract with a customer A contract with a customer exists when the Company enters into an enforceable contract with a customer. The contract is based on either the acceptance of standard terms and conditions on the websites for e-commerce customers, or the execution of terms and conditions contracts with specialty retailers and sports teams. These contracts define each party's rights, payment terms and other contractual terms and conditions of the sale. The Company applies judgment in determining the customer’s ability and intention to pay, which is based on a variety of factors including the customer’s historical payment experience and, in some circumstances, published credit and financial information pertaining to the customer. 2. Identify the performance obligations in the contract Performance obligations promised in a contract are identified based on the goods that will be transferred to the customer that are both capable of being distinct and are distinct in the context of the contract, whereby the transfer of the goods is separately identifiable from other promises in the contract. The Company has concluded the sale of bottled finished goods and related shipping and handling are accounted for as a single performance obligation. 3. Determine the transaction price The transaction price is determined based on the consideration to which the Company will be entitled to receive in exchange for transferring goods to the customer. For sales through June 18, 2018, the Company offered refunds to e-commerce customers, upon request, within 30 days of delivery. For sales subsequent to June 18, 2018, the Company now offers refunds to e-commerce customers, upon request, within 14 days of delivery. The Company estimates the amount of potential refunds at each reporting period using a portfolio approach of historical data, adjusted for changes in expected customer experience, including seasonality and changes in economic factors, as necessary. For specialty retailers and sports teams, the Company does not offer a right of return or refund and revenue is recognized at the time products are delivered to customers. Discounts provided to customers are accounted for as an element of the transaction price and as a reduction to revenue, and were approximately $2,000 and $19,000 for the three and nine months ended September 30, 2018 , respectively, and approximately $82,000 and $202,000 for the three and nine months ended September 30, 2017 , respectively. Revenue is presented net of taxes collected from customers and remitted to governmental authorities. 4. Determine the satisfaction of performance obligation Revenue is recognized when control of the bottled finished goods is transferred to the customer. Control of the bottled finished goods is transferred at a point in time, upon delivery to the customer. The period of time between the satisfaction of the performance obligation and when payment is due from the customer is not significant. Concentrations of credit risk The Company had no customers that represented greater than 10% of total revenue during the three and nine months ended September 30, 2018 or the three and nine months ended September 30, 2017 . The vast majority of revenue was generated from sales within the United States.

Fair value measurements

Fair value measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements The Company records cash equivalents and marketable securities at fair value. ASC Topic 820, Fair Value Measurements and Disclosures, established a fair value hierarchy for those instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). The hierarchy consists of three levels: Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 – Quoted prices for similar assets and liabilities in active markets, quoted prices in markets that are not active, or inputs which are observable, directly or indirectly, for substantially the full term of the asset or liability. Level 3 – Unobservable inputs that reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability in which there is little, if any, market activity for the asset or liability at the measurement date. The following tables summarize the cash equivalents and marketable securities measured at fair value on a recurring basis as of September 30, 2018 and December 31, 2017 : Level 1 Level 2 Level 3 Balance as of September 30, 2018 Cash equivalents $ 2,321,614 $ — $ — $ 2,321,614 $ 2,321,614 $ — $ — $ 2,321,614 Level 1 Level 2 Level 3 Balance as of December 31, 2017 Cash equivalents $ 5,046,205 $ — $ — $ 5,046,205 Marketable securities: U.S. government agency securities — 8,986,259 — 8,986,259 Commercial paper — 4,440,689 — 4,440,689 Corporate debt securities — 702,775 — 702,775 $ 5,046,205 $ 14,129,723 $ — $ 19,175,928 Cash equivalents and marketable securities have been initially valued at the transaction price and subsequently valued, at the end of each reporting period, utilizing third-party pricing services or other market observable data. The third-party pricing services utilize industry standard valuation models, including both income and market based approaches and observable market inputs to determine value. The Company's cash equivalents consist of money market funds that are valued based on publicly available quoted market prices for identical securities as of September 30, 2018 . After completing its validation procedures, the Company did not adjust or override any fair value carrying amounts as of September 30, 2018 . The carrying amounts reflected in the condensed consolidated balance sheets for cash, accounts receivable, prepaid expenses and other current assets, accounts payable, accrued expenses and other current liabilities approximate their fair values at September 30, 2018 and December 31, 2017 , due to their short-term nature. The Company evaluates transfers between levels at the end of each reporting period. There were no transfers of assets or liabilities between Level 1 and Level 2 during the nine months ended September 30, 2018 or the year ended December 31, 2017 . The Company had no financial assets or liabilities that were classified as Level 3 at any time during the nine months ended September 30, 2018 or the year ended December 31, 2017 .

Cash equivalents and marketable

Cash equivalents and marketable securities	9 Months Ended
	Sep. 30, 2018
Cash and Cash Equivalents [Abstract]
Cash equivalents and marketable securities	Cash equivalents and marketable securities The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents. Cash equivalents as of September 30, 2018 and December 31, 2017 consisted of money market funds. The Company held no marketable securities as of September 30, 2018 . Marketable securities as of December 31, 2017 consisted of U.S. government agency securities, commercial paper and corporate debt securities. Management determines the appropriate classification of the securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. The Company classifies its marketable securities as available-for-sale pursuant to ASC 320, Investments – Debt and Equity Securities . Marketable securities are recorded at fair value, with unrealized gains and losses included as a component of accumulated other comprehensive income (loss) in stockholders’ equity and a component of total comprehensive income (loss) in the condensed consolidated statement of comprehensive loss, until realized. Realized gains and losses are included in investment income on a specific-identification basis. There were no realized gains on marketable securities during the three and nine months ended September 30, 2018 , or during the three and nine months ended September 30, 2017 . The Company reviews marketable securities for other-than-temporary impairment whenever the fair value of a marketable security is less than the amortized cost and evidence indicates that a marketable security’s carrying amount is not recoverable within a reasonable period of time. Other-than-temporary impairments of investments are recognized in the consolidated statement of operations if the Company has experienced a credit loss, has the intent to sell the marketable security, or if it is more likely than not that the Company will be required to sell the marketable security before recovery of the amortized cost basis. Evidence considered in this assessment includes reasons for the impairment, compliance with the Company’s investment policy, the severity and the duration of the impairment and changes in value subsequent to the end of the period. The Company held no marketable securities at September 30, 2018 . Marketable securities at December 31, 2017 consisted of the following: Amortized Cost Unrealized Gains Unrealized Losses Fair Value As of December 31, 2017 Current (due within 1 year): U.S. government agency securities $ 8,987,254 $ 38 $ (1,033 ) $ 8,986,259 Commercial paper 4,440,689 — — 4,440,689 Corporate debt securities 703,027 — (252 ) 702,775 Total $ 14,130,970 $ 38 $ (1,285 ) $ 14,129,723 At December 31, 2017 , the Company held six debt securities that were in an unrealized loss position, all of which had been in a continuous loss position for less than 12 months. The aggregate fair value of debt securities in an unrealized loss position was $8,191,315 at December 31, 2017 . There were no individual securities that were in a significant unrealized loss position as of December 31, 2017 . At December 31, 2017 , all investments held by the Company were classified as current. Investments classified as current have maturities of less than one year. Investments classified as noncurrent are those that (i) have a maturity greater than one year and (ii) management does not intend to liquidate within the next year, although these funds are available for use and therefore classified as available-for-sale.

Inventory

Inventory	9 Months Ended
	Sep. 30, 2018
Inventory Disclosure [Abstract]
Inventory	Inventory Inventory has been recorded at cost as of September 30, 2018 and December 31, 2017 . Costs capitalized at September 30, 2018 and December 31, 2017 relate to HOTSHOT finished goods, as well as raw materials available to be used for future production runs. The following table presents inventory: September 30, 2018 December 31, 2017 Raw materials $ 7,240 $ 17,411 Finished goods 216,279 414,480 Total inventory $ 223,519 $ 431,891 In the second quarter of 2018, the Company wrote off raw materials that are not expected to be used in future production runs, as well as finished goods inventory no longer expected to be used for product sampling. In the prior year, the Company wrote off raw materials not expected to be used in future production runs and expiring finished goods not anticipated to be sold. There were no inventory write-offs during the three months ended September 30, 2018 . Write-offs totaled approximately $85,000 for the nine months ended September 30, 2018 , and approximately $15,000 and $34,000 for the three and nine months ended September 30, 2017 , respectively, and were included in cost of product revenue in the accompanying condensed consolidated statement of operations.

Accrued expenses and other curr

Accrued expenses and other current liabilities	9 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
Accrued expenses and other current liabilities	Accrued expenses and other current liabilities Accrued expenses and other current liabilities consisted of the following: September 30, 2018 December 31, 2017 Phase 2 MND and CMT clinical trial-related costs $ 609,222 $ 1,850,115 Payroll and other employee-related costs 430,560 874,246 Professional fees 284,725 227,980 Restructuring-related costs 189,927 — Other research and development-related costs 23,808 652,285 Consumer product-related costs 16,437 107,595 Total $ 1,554,679 $ 3,712,221 Phase 2 MND and CMT clinical trial-related costs In June 2018, the Company announced that it was ending its ongoing Phase 2 clinical trials of FLX-787 in MND and CMT due to oral tolerability concerns observed in both studies. The close out of the studies resulted in increased expense during the second quarter of 2018, with the remainder of close out costs occurring in the third quarter of 2018. Accrued costs as of September 30, 2018 totaled approximately $610,000 . All work for the studies was complete as of September 30, 2018. Previously, the Company expected work for the studies to take place through mid-2019. Restructuring-related costs In June 2018, the Company's Board of Directors ("Board") approved a corporate restructuring plan to reduce the Company's cost structure. In connection with the corporate restructuring plan, the Company reduced its workforce by approximately 60% , with the reduction completed as of September 30, 2018. Also, in June 2018, the Board approved employee retention arrangements and certain increased severance payments related to the corporate restructuring plan, to incentivize certain employees to remain with the Company through a potential sale or merger. Cash retention benefits totaling approximately $1,210,000 will be payable to these employees upon the occurrence of a change in control event, including a sale or merger of the Company. Of this total, $500,000 relates to amounts payable only upon a change in control event, and $710,000 relates to amounts payable upon a change in control event or at certain timepoints through early 2019 if the individuals are employed by the Company and in good standing at the date of payment, even if a change in control event has not occurred. Upon a change in control event and termination without cause, these employees will be eligible for up to approximately $1,125,000 , in the aggregate, of severance benefits. The Company records employee termination costs in accordance with ASC 712, if the termination benefits are paid as part of an ongoing benefit arrangement, which includes benefits provided as part of the Company's established severance policy or as part of an executive employment agreement. The Company accrues employee termination costs associated with an on-going benefit arrangement if the obligation is attributable to prior services rendered, the rights to the benefits have vested, the payment is probable and the Company can reasonably estimate the liability. The Company accounts for employee termination benefits that represent a one-time benefit in accordance with ASC 420. Upon communication of the termination to the employee, the Company expenses these costs over the employee’s future service period, if any. During the three months ended September 30, 2018 , the Company recognized expense for restructuring-related activities of approximately $212,000 , which is comprised of approximately $77,000 of one-time termination benefit costs for terminated employees and approximately $147,000 in retention benefits for seven retained employees who have retention bonuses not contingent on a change in control event, partially offset by approximately $12,000 recorded as a credit to termination benefits under ongoing benefit arrangements for terminated employees as certain benefit payments are no longer expected to occur. During the nine months ended September 30, 2018 , the Company recognized expense for restructuring-related activities of approximately $1,130,000 which is comprised of approximately $851,000 recorded as termination benefits under ongoing benefit arrangements for terminated employees, approximately $99,000 as one-time termination benefit costs for terminated employees, approximately $165,000 in retention benefits for seven retained employees who have retention bonuses not triggered by a change in control event and approximately $15,000 of other restructuring related costs including consulting and legal fees. There are currently no assurances a change in control event will take place. The Company does not consider the payment of severance benefits for retained employees or the payment of retention benefits only payable upon a change in control to be probable for accounting purposes as of September 30, 2018 . Unless and until the Company's Board has approved a specific transaction, the Company's probability assessment regarding a change in control event is not expected to change. The Company expects to incur between approximately $1,173,000 and $3,353,000 in total costs for its restructuring-related activities, including approximately $1,130,000 that was recorded during the second and third quarters of 2018. Approximately $50,000 is expected to be recorded during the fourth quarter of 2018, based on the Company's current probability assessment regarding a change in control event and termination of retained employees. The range noted above includes approximately $500,000 related to retention benefits only payable upon a change in control event and $1,125,000 of severance benefits only payable upon a change in control event and termination under certain circumstances. The following table outlines the Company's restructuring activities for the nine months ended September 30, 2018 : Opening balance $ — Charges: Employee termination benefits 950,637 Employee retention benefits 164,813 Other 14,995 Payments (940,518 ) Accrued restructuring balance as of September 30, 2018 $ 189,927 The Company's accrued restructuring balance as of September 30, 2018 is included as a component of accrued expenses and other current liabilities on the Company's condensed consolidated balance sheet as of September 30, 2018 . For the three months ended September 30, 2018 , approximately $133,000 of the restructuring-related charges are included in research and development expenses and approximately $79,000 are included in selling, general and administrative expenses in the Company's condensed consolidated statement of operations. For the nine months ended September 30, 2018 , approximately $837,000 of the restructuring-related charges are included in research and development expenses and approximately $293,000 are included in selling, general and administrative expenses in the Company's condensed consolidated statement of operations. For the three months ended September 30, 2018 , approximately $19,000 of the restructuring-related charges were incurred by our Consumer Operations segment, approximately $133,000 were incurred by our Drug Development segment and the remaining charges of approximately $60,000 related to corporate costs. For the nine months ended September 30, 2018 , approximately $75,000 of the restructuring-related charges were incurred by our Consumer Operations segment, approximately $837,000 were incurred by our Drug Development segment and the remaining charges of approximately $218,000 related to corporate costs. The Company may incur total restructuring-related charges of up to approximately $113,000 and $1,048,000 within our Consumer Operations and Drug Development segments, respectively. The Company may incur up to $2,192,000 of corporate costs that do not relate to a reportable segment. Litigation On June 19, 2018, a putative class action lawsuit was filed against the Company and certain of its current executive officers in the United States District Court for the Southern District of New York, captioned Teofilina Rumaldo v. Flex Pharma, Inc., et al., Case No. 1:18-cv-05493. The complaint purports to be brought on behalf of stockholders who purchased the Company’s common stock between November 6, 2017 and June 12, 2018. The complaint generally alleges that the Company and certain of its current officers violated Sections 10(b) and/or 20(a) of the Securities Exchange Act of 1934, as amended, and Rule 10b-5 promulgated thereunder by making allegedly false and misleading statements or omissions regarding the Company’s business, operational and compliance policies. Specifically, the complaint alleges that the Company overstated the viability and approval prospects for its product candidate FLX-787 for the treatment of MND and CMT and, as a result, the Company’s public statements were materially false and misleading at all relevant times. The complaint seeks unspecified damages, attorneys’ fees and other costs. The court-appointed lead plaintiff has until December 10, 2018, to file an amended complaint. The Company denies any allegations of wrongdoing and intends to vigorously defend against this lawsuit. The Company is unable, however, to predict the outcome of this matter at this time and has not accrued any expense related to this lawsuit as of September 30, 2018.

Common stock

Common stock	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Common stock	Common stock As of September 30, 2018 , the Company had authorized 100,000,000 shares of common stock, $0.0001 par value per share. Each share of common stock is entitled to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and when declared by the board of directors. The Company does not intend to declare dividends for the foreseeable future. Restricted common stock to founders In March 2014, the Company sold 4,553,415 shares of restricted common stock to the founders of the Company ("recipients"), for $0.0004 per share, for total proceeds of $1,950 . In April 2014, based upon anti-dilution provisions granted to the recipients, an additional 867,314 shares of restricted common stock were sold to the same recipients, after which the anti-dilution provisions were terminated. The restricted common stock vested 25% upon issuance, and the remaining 75% vested ratably over four years , during which time the Company had the right to repurchase the unvested shares held by a recipient if the relationship between such recipient and the Company ceased. Such shares were not accounted for as outstanding until they vested. Unvested restricted common stock awards to non-employees were re-measured at each vest date and each financial reporting date. All restricted common stock sold to recipients had vested as of September 30, 2018, and is no longer subject to re-valuation or eligible for repurchase. The following is a summary of restricted common stock activity: Number of Shares Weighted-Average Grant Date Fair Value Unvested at December 31, 2017 169,654 $ 0.10 Issued — — Vested (169,654 ) 0.10 Forfeited — — Unvested at September 30, 2018 — $ — Restricted common stock to consultants During 2016, the Company issued 18,194 shares of restricted common stock to non-employee consultants and advisors. Such shares are not accounted for as outstanding until they vest. There were 15,485 shares of restricted common stock issued to consultants outstanding as of September 30, 2018 . Prior to July 1, 2018, unvested restricted common stock awards to non-employees were re-measured at each vest date and each financial reporting date. On July 1, 2018, the Company adopted ASU No. 2018-07 using a modified retrospective transition approach. As a result, the Company permanently revalued all unvested stock awards granted to non-employees as of July 1, 2018. The adoption-date fair value did not materially change from the fair value as of June 30, 2018 and therefore, a cumulative-effect adjustment was not required. The following is a summary of restricted common stock activity: Number of Shares Weighted-Average Grant Date Fair Value Unvested at December 31, 2017 5,334 $ 10.51 Issued — — Vested (2,625 ) 9.95 Forfeited — — Unvested at September 30, 2018 2,709 $ 11.05

Stock-based compensation

Stock-based compensation	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based compensation	Stock-based compensation In March 2014, the Company adopted the Flex Pharma, Inc. 2014 Equity Incentive Plan (the "2014 Plan"), under which it had the ability to grant incentive stock options ("ISOs"), non-qualified stock options, restricted stock awards, restricted stock units and stock appreciation rights to purchase up to 116,754 shares of common stock. In April 2014, the Company amended the 2014 Plan to reserve for the issuance of up to 1,451,087 shares of common stock pursuant to equity awards. In September 2014, the Company further amended the 2014 Plan to reserve for the issuance of up to 2,070,200 shares of common stock pursuant to equity awards. Terms of stock award agreements, including vesting requirements, were determined by the Board, subject to the provisions of the 2014 Plan. For options granted under the 2014 Plan, the exercise price equaled the fair market value of the common stock as determined by the Board on the date of grant. No further awards will be granted under the 2014 Plan. In January 2015, the Company's Board adopted, and the Company's stockholders approved, the 2015 Equity Incentive Plan (the "2015 Plan"), which became effective immediately prior to the closing of the Company's initial public offering ("IPO"). The 2015 Plan provides for the grant of ISOs, nonstatutory stock options, restricted stock awards, restricted stock units, stock appreciation rights, performance-based stock awards and other stock-based awards. Additionally, the 2015 Plan provides for the grant of performance-based cash awards. ISOs may be granted only to the Company's employees. All other awards may be granted to the Company's employees, including officers, and to non-employee directors and consultants. As of September 30, 2018 , there were 1,480,758 shares remaining available for the grant of stock awards under the 2015 Plan. The Company has awarded stock options to its employees, directors, advisors and consultants, pursuant to the plans described above. Stock options subsequent to the completion of the Company's IPO are granted with an exercise price equal to the closing market price of the Company's common stock on the date of grant. Stock options generally vest over one to four years and have a contractual term of ten years . Stock options are valued using the Black-Scholes option pricing model and compensation cost is recognized based on the resulting value over the service period. Prior to July 1, 2018, unvested awards to non-employees were re-measured at each vest date and at each financial reporting date. On July 1, 2018, the Company adopted ASU No. 2018-07 using a modified retrospective transition approach. As a result, the Company permanently revalued all unvested stock options granted to non-employees as of July 1, 2018. The adoption-date fair value did not materially change from the fair value as of June 30, 2018 and therefore, a cumulative-effect adjustment was not required. The following table summarizes stock option activity for employees and non-employees for the nine months ended September 30, 2018 : Shares Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (in years) Aggregate Outstanding at December 31, 2017 2,580,491 $ 6.65 7.55 $ 803,600 Granted 1,517,544 2.74 Exercised (97,310 ) 1.21 Forfeited (714,699 ) 5.96 Expired (705,387 ) 8.35 Outstanding at September 30, 2018 2,580,639 $ 4.28 8.07 $ — Exercisable at September 30, 2018 1,126,248 $ 5.92 6.55 $ — Vested or expected to vest at September 30, 2018 2,580,639 $ 4.28 8.07 $ — Total stock-based compensation expense recognized for employee and non-employee restricted common stock, and stock options granted to employees and non-employees is included in the Company's condensed consolidated statements of operations as follows: Three Months Ended September 30, 2018 Three Months Ended September 30, 2017 Nine Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Research and development $ 43,369 $ 386,636 $ 674,775 $ 1,172,655 Selling, general and administrative 235,021 618,145 1,023,548 2,094,224 Total $ 278,390 $ 1,004,781 $ 1,698,323 $ 3,266,879 As of September 30, 2018 , there was approximately $2,481,000 of total unrecognized compensation cost related to unvested equity awards. Total unrecognized compensation cost will be adjusted for future changes in employee and non-employee forfeitures, if any. The Company expects to recognize that cost over a remaining weighted-average period of 2.90 years . In June 2018, the Company extended the three -month post termination exercisability of 877,137 option awards held by six employees and one adviser to one -year post termination. The Company also extended the three -month post termination exercisability of 500,000 option awards held by one employee to three -years post termination. The valuation of these awards did not change as a result of the modification of these awards and as such, the Company did not recognize any additional compensation expense related to the modification. On June 14, 2018, the Company granted 654,544 stock options, in the aggregate, to seven employees as part of the Company's retention arrangements with these employees. These awards vest monthly over 48 months as the employees provide continuous service, and expense is being recognized over this period. The awards are exercisable for one to three -years post termination depending on the employee to which the stock options were granted. The awards vest in full upon a change in control event and termination of the employees under certain circumstances. A change in control event is not currently considered probable for accounting purposes. Unless and until the Company's Board has approved a specific transaction, the Company's probability assessment regarding a change in control event is not expected to change. Employee stock purchase plan In 2015, the Company's Board adopted, and the Company's stockholders approved, the 2015 Employee Stock Purchase Plan (the "ESPP"). As of September 30, 2018 , no shares of common stock have been purchased under the ESPP.

Income taxes

Income taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income taxes	Income taxes Deferred tax assets and deferred tax liabilities are recognized based on temporary differences between the financial reporting and tax basis of assets and liabilities using statutory rates. A valuation allowance is recorded against deferred tax assets if it is more likely than not that some or all of the deferred tax assets will not be realized. Based upon the Company's history of operating losses and the uncertainty surrounding the realization of the favorable tax attributes in future tax returns, the Company has recorded a full valuation allowance against the Company’s otherwise recognizable net deferred tax assets. There was no significant income tax provision or benefit for the nine months ended September 30, 2018 or 2017 . In March 2018, the FASB issued ASU No. 2018-05, Income Taxes (Topic 740), Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 . The ASU adds various Securities and Exchange Commission (“SEC”) paragraphs pursuant to the issuance of the December 2017 SEC Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118), which was effective immediately. The SEC issued SAB 118 to address concerns about a reporting entity's ability to timely comply with the accounting requirements to recognize all of the effects of the Tax Cuts and Jobs Act in the period of enactment. SAB 118 allows disclosure that timely determination of some or all of the income tax effects from the Tax Cuts and Jobs Act are incomplete by the due date of the financial statements and, if possible, to provide a reasonable estimate. The Company's accounting for certain income tax effects is incomplete, but it has determined reasonable estimates for those effects and has included provisional amounts in its condensed consolidated financial statements as of September 30, 2018 and December 31, 2017.

Net loss per share

Net loss per share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Net loss per share	Net loss per share Basic net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding for the period. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares and dilutive common stock equivalents outstanding for the period, determined using the treasury stock method and the if-converted method, for convertible securities, if inclusion of these is dilutive. As the Company has reported a net loss for the periods presented, diluted net loss per common share is the same as basic net loss per common share. The following potentially dilutive securities outstanding, prior to the use of the treasury stock method or if-converted method, have been excluded from the computation of diluted weighted-average shares outstanding for the periods indicated, because including them would have had an anti-dilutive impact: September 30, 2018 September 30, 2017 Options to purchase common stock 2,580,639 2,701,922 Unvested restricted common stock 2,709 430,439 Total 2,583,348 3,132,361

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Segment Information	Segment Information The Company operates as two reportable segments: • The Consumer Operations segment, which reflects the total revenue and costs and expenses related to HOTSHOT and the Company's consumer operations. • The Drug Development segment, which reflects the costs and expenses related to the Company's efforts to develop innovative and proprietary drug products; previously to treat muscle cramps, spasms and spasticity associated with severe neurological conditions. The Company discloses information about its reportable segments based on the way that the Company's Chief Operating Decision Maker, who the Company has identified as the Chief Executive Officer, and management, organize segments within the Company for making operating decisions and assessing financial performance. The Company evaluates the performance of its reportable segments based on revenue and operating income or loss. The accounting policies of the segments are the same as those described herein as well as those described in Note 2 to the audited consolidated financial statements in the 2017 Form 10-K. Corporate and unallocated amounts that do not relate to a reportable segment have been allocated to "Corporate". No asset information has been provided for the Company's reportable segments as management does not measure or allocate such assets on a reportable segment basis. Information for the Company's reportable segments for the three months ended September 30, 2018 and 2017 are as follows: Three Months Ended September 30, 2018 Consumer Operations Drug Development Corporate Consolidated Total revenue $ 250,991 — — $ 250,991 Interest income, net $ — — 28,210 $ 28,210 Loss from operations $ 18,293 864,934 1,783,356 $ 2,666,583 Three Months Ended September 30, 2017 Consumer Operations Drug Development Corporate Consolidated Total revenue $ 413,601 — — $ 413,601 Interest income, net $ — — 77,339 $ 77,339 Loss from operations $ 2,323,919 4,683,533 2,402,000 $ 9,409,452 Information for the Company's reportable segments for the nine months ended September 30, 2018 and 2017 are as follows: Nine Months Ended September 30, 2018 Consumer Operations Drug Development Corporate Consolidated Total revenue $ 675,075 — — $ 675,075 Interest income, net $ — — 139,612 $ 139,612 Loss from operations $ 1,921,286 11,699,499 6,432,299 $ 20,053,084 Nine Months Ended September 30, 2017 Consumer Operations Drug Development Corporate Consolidated Total revenue $ 991,671 — — $ 991,671 Interest income, net $ — — 227,535 $ 227,535 Loss from operations $ 7,072,225 12,472,149 7,088,292 $ 26,632,666

Summary of significant accoun_2

Summary of significant accounting policies and recent accounting pronouncements (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Accounts receivable	Accounts receivable are stated at their carrying values, net of any allowances for doubtful accounts. Accounts receivable consist primarily of amounts due from specialty retailers and sports teams, for which collection is probable based on the customer's intent and ability to pay.
Allowance for doubtful accounts	Receivables are evaluated for collection probability on a regular basis and an allowance for doubtful accounts is recorded, if necessary.
Restricted Cash	The Company has restricted cash in the form of a letter of credit it maintains as a security deposit on the lease of its office space in Boston, Massachusetts.
Advertising expense	Advertising expense consists of media and production costs related to print and digital advertising. All advertising is expensed as incurred.
Shipping and handling costs	Shipping and handling costs related to the movement of inventory to the Company's co-packer and from the co-packer to the Company's third-party warehousing and fulfillment partners are capitalized as inventory and expensed as cost of product revenue when revenue is recognized. Shipping and handling costs to move finished goods from the Company's third-party warehousing and fulfillment partners to customer locations are included in selling, general and administrative expenses in the condensed consolidated statement of operations, and were approximately $27,000 and $81,000 for the three and nine months ended September 30, 2018 , and approximately $64,000 and $145,000 for the three and nine months ended September 30, 2017 .
Restructuring-related costs	The Company records employee termination costs in accordance with Accounting Standards Codification ("ASC") Topic 712, " Compensation - Nonretirement and Postemployment Benefits" (ASC 712), if the termination benefits are paid as part of an ongoing benefit arrangement, which includes benefits provided as part of the Company's established severance policy or as part of an executive employment agreement. The Company accrues employee termination costs associated with an on-going benefit arrangement if the obligation is attributable to prior services rendered, the rights to the benefits have vested, the payment is probable and the Company can reasonably estimate the liability. The Company accounts for employee termination benefits that represent a one-time benefit in accordance with ASC Topic 420, " Exit or Disposal Cost Obligations" (ASC 420). Upon communication of the termination to the employee, the Company expenses these costs over the employee’s future service period, if any. Restructuring-related costs are recorded within research and development expenses and selling, general and administrative expenses on the Company's condensed consolidated statement of operations. Liabilities associated with the Company's restructuring activities are recorded as a component of accrued expenses and other current liabilities on its condensed consolidated balance sheet.
Basis of presentation	The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States ("GAAP"). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the ASC and Accounting Standards Update ("ASU") of the Financial Accounting Standards Board ("FASB").
Use of estimates	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, the Company's management evaluates its estimates, which include, but are not limited to, estimates related to clinical study accruals, estimates related to inventory realizability, stock-based compensation expense and amounts of expenses during the reported period. The Company bases its estimates on historical experience and other market-specific or other relevant assumptions that it believes to be reasonable under the circumstances. Actual results may differ from those estimates or assumptions.
Principles of consolidation	The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries: TK Pharma, Inc., a Massachusetts Securities Corporation, and Flex Innovation Group LLC, a Delaware limited liability company, which contains the Company's consumer-related operations. All significant intercompany balances and transactions have been eliminated in consolidation.
Recent accounting pronouncements	In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers ("ASC 606") . ASC 606 supersedes the revenue recognition requirements in ASC Topic 605, Revenue Recognition ("ASC 605") and requires entities to recognize revenue when control of the promised goods or services is transferred to customers at an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. The Company adopted ASC 606 as of January 1, 2018 using the modified retrospective transition method. See Note 3 for further details. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) . The ASU requires lessees to recognize the assets and liabilities on their balance sheet for the rights and obligations created by most leases and continue to recognize expenses on their income statements over the lease term. It will also require disclosures designed to give financial statement users information on the amount, timing and uncertainty of cash flows arising from leases. In July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, Leases. This ASU is intended to clarify or correct unintended application of the guidance outlined in ASU No. 2016-02. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements. This ASU is intended to address comparative reporting requirements for initial adoption. The guidance is effective for annual reporting periods beginning after December 15, 2018, and interim periods within those years. Early adoption is permitted. While the Company is currently evaluating the impact this standard will have on its consolidated financial statements, the Company expects that upon adoption, it will recognize right-of-use assets and lease liabilities and those amounts could be material. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments . The update amends the guidance in ASU Topic 230 and clarifies how entities should classify certain cash receipts and cash payments on the statement of cash flows with the objective of reducing the existing diversity in practice related to eight specific cash flow issues. The Company adopted ASU No. 2016-15 in the first quarter of 2018, retrospectively. The adoption of ASU No. 2016-15 did not have a significant impact on the consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows , which amends ASU Topic 230. This update requires entities to show the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. As a result, entities are no longer required to present transfers between cash and cash equivalents and restricted cash and restricted cash equivalents in the statement of cash flows. When cash, cash equivalents, restricted cash and restricted cash equivalents are presented in more than one line item on the balance sheet, the new guidance requires a reconciliation of the totals in the statement of cash flows to the related captions in the balance sheet. The Company adopted ASU No. 2016-18 in the first quarter of 2018, retrospectively, resulting in a change to the presentation of restricted cash on the condensed consolidated statement of cash flows. The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the condensed consolidated balance sheets that sum to the total of such amounts in the condensed consolidated statements of cash flows: September 30, 2018 December 31, 2017 Cash and cash equivalents $ 12,961,126 $ 19,186,036 Restricted cash 126,595 126,595 Cash, cash equivalents and restricted cash shown on the condensed consolidated statement of cash flows $ 13,087,721 $ 19,312,631 In May 2017, the FASB issued ASU No. 2017-09, Stock Compensation (Topic 718): Scope of Modification Accounting , to provide clarity and reduce diversity in practice, cost and complexity when applying the guidance of Topic 718. The guidance is effective for fiscal years beginning after December 15, 2017 and interim periods within those years. Early adoption is permitted and the guidance should be applied prospectively. The Company adopted ASU No. 2017-09 in the first quarter of 2018, which did not impact the Company's condensed consolidated financial statements or disclosures. In June 2018, the FASB issued ASU No. 2018-07, Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting ("ASU No. 2018-07"). This ASU is intended to simplify aspects of share-based compensation issued to non-employees by making the guidance consistent with the accounting for employee share-based compensation. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within that year. Early adoption is permitted, but not before an entity has adopted ASC 606, and the guidance should be applied using a modified retrospective transition approach. The Company early adopted ASU No. 2018-07 on July 1, 2018 and revalued its unvested nonemployee awards as of the July 1, 2018 adoption date. The adoption did not have a material impact on the condensed consolidated financial statements and therefore a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year was not required. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement. This ASU modifies the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement . The guidance is effective for annual reporting periods beginning after December 15, 2019, and interim periods within those years. Early adoption is permitted. The Company is currently evaluating the impact of ASU No. 2018-13 on its consolidated financial statements and disclosures. The Company believes that the impact of other recently issued standards that are not yet effective will not have a material effect on its consolidated financial position or results of operations upon adoption.
Fair value measurements	The Company records cash equivalents and marketable securities at fair value. ASC Topic 820, Fair Value Measurements and Disclosures, established a fair value hierarchy for those instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). The hierarchy consists of three levels: Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 – Quoted prices for similar assets and liabilities in active markets, quoted prices in markets that are not active, or inputs which are observable, directly or indirectly, for substantially the full term of the asset or liability. Level 3 – Unobservable inputs that reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability in which there is little, if any, market activity for the asset or liability at the measurement date.
Cash equivalents	The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents. Cash equivalents as of September 30, 2018 and December 31, 2017 consisted of money market funds.
Marketable securities	Management determines the appropriate classification of the securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. The Company classifies its marketable securities as available-for-sale pursuant to ASC 320, Investments – Debt and Equity Securities . Marketable securities are recorded at fair value, with unrealized gains and losses included as a component of accumulated other comprehensive income (loss) in stockholders’ equity and a component of total comprehensive income (loss) in the condensed consolidated statement of comprehensive loss, until realized. Realized gains and losses are included in investment income on a specific-identification basis. There were no realized gains on marketable securities during the three and nine months ended September 30, 2018 , or during the three and nine months ended September 30, 2017 . The Company reviews marketable securities for other-than-temporary impairment whenever the fair value of a marketable security is less than the amortized cost and evidence indicates that a marketable security’s carrying amount is not recoverable within a reasonable period of time. Other-than-temporary impairments of investments are recognized in the consolidated statement of operations if the Company has experienced a credit loss, has the intent to sell the marketable security, or if it is more likely than not that the Company will be required to sell the marketable security before recovery of the amortized cost basis. Evidence considered in this assessment includes reasons for the impairment, compliance with the Company’s investment policy, the severity and the duration of the impairment and changes in value subsequent to the end of the period.

Summary of significant accoun_3

Summary of significant accounting policies and recent accounting pronouncements (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Schedule Of Cash And Cash Equivalents	The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the condensed consolidated balance sheets that sum to the total of such amounts in the condensed consolidated statements of cash flows: September 30, 2018 December 31, 2017 Cash and cash equivalents $ 12,961,126 $ 19,186,036 Restricted cash 126,595 126,595 Cash, cash equivalents and restricted cash shown on the condensed consolidated statement of cash flows $ 13,087,721 $ 19,312,631
Restrictions On Cash And Cash Equivalents	The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the condensed consolidated balance sheets that sum to the total of such amounts in the condensed consolidated statements of cash flows: September 30, 2018 December 31, 2017 Cash and cash equivalents $ 12,961,126 $ 19,186,036 Restricted cash 126,595 126,595 Cash, cash equivalents and restricted cash shown on the condensed consolidated statement of cash flows $ 13,087,721 $ 19,312,631

Fair value measurements (Tables

Fair value measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Summary Of Cash Equivalents And Marketable Securities Measured At Fair Value On A Recurring Basis	The following tables summarize the cash equivalents and marketable securities measured at fair value on a recurring basis as of September 30, 2018 and December 31, 2017 : Level 1 Level 2 Level 3 Balance as of September 30, 2018 Cash equivalents $ 2,321,614 $ — $ — $ 2,321,614 $ 2,321,614 $ — $ — $ 2,321,614 Level 1 Level 2 Level 3 Balance as of December 31, 2017 Cash equivalents $ 5,046,205 $ — $ — $ 5,046,205 Marketable securities: U.S. government agency securities — 8,986,259 — 8,986,259 Commercial paper — 4,440,689 — 4,440,689 Corporate debt securities — 702,775 — 702,775 $ 5,046,205 $ 14,129,723 $ — $ 19,175,928

Cash equivalents and marketab_2

Cash equivalents and marketable securities (Tables)	9 Months Ended
	Sep. 30, 2018
Cash and Cash Equivalents [Abstract]
Schedule Of Marketable Securities	Marketable securities at December 31, 2017 consisted of the following: Amortized Cost Unrealized Gains Unrealized Losses Fair Value As of December 31, 2017 Current (due within 1 year): U.S. government agency securities $ 8,987,254 $ 38 $ (1,033 ) $ 8,986,259 Commercial paper 4,440,689 — — 4,440,689 Corporate debt securities 703,027 — (252 ) 702,775 Total $ 14,130,970 $ 38 $ (1,285 ) $ 14,129,723

Inventory (Tables)

Inventory (Tables)	9 Months Ended
	Sep. 30, 2018
Inventory Disclosure [Abstract]
Schedule Of Inventory, Net	The following table presents inventory: September 30, 2018 December 31, 2017 Raw materials $ 7,240 $ 17,411 Finished goods 216,279 414,480 Total inventory $ 223,519 $ 431,891

Accrued expenses and other cu_2

Accrued expenses and other current liabilities (Tables)	9 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
Schedule Of Accrued Expenses	Accrued expenses and other current liabilities consisted of the following: September 30, 2018 December 31, 2017 Phase 2 MND and CMT clinical trial-related costs $ 609,222 $ 1,850,115 Payroll and other employee-related costs 430,560 874,246 Professional fees 284,725 227,980 Restructuring-related costs 189,927 — Other research and development-related costs 23,808 652,285 Consumer product-related costs 16,437 107,595 Total $ 1,554,679 $ 3,712,221
Schedule Of Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following: September 30, 2018 December 31, 2017 Phase 2 MND and CMT clinical trial-related costs $ 609,222 $ 1,850,115 Payroll and other employee-related costs 430,560 874,246 Professional fees 284,725 227,980 Restructuring-related costs 189,927 — Other research and development-related costs 23,808 652,285 Consumer product-related costs 16,437 107,595 Total $ 1,554,679 $ 3,712,221
Restructuring And Related Costs	The following table outlines the Company's restructuring activities for the nine months ended September 30, 2018 : Opening balance $ — Charges: Employee termination benefits 950,637 Employee retention benefits 164,813 Other 14,995 Payments (940,518 ) Accrued restructuring balance as of September 30, 2018 $ 189,927

Common stock (Tables)

Common stock (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Restricted Common Stock Activity	The following is a summary of restricted common stock activity: Number of Shares Weighted-Average Grant Date Fair Value Unvested at December 31, 2017 5,334 $ 10.51 Issued — — Vested (2,625 ) 9.95 Forfeited — — Unvested at September 30, 2018 2,709 $ 11.05 The following is a summary of restricted common stock activity: Number of Shares Weighted-Average Grant Date Fair Value Unvested at December 31, 2017 169,654 $ 0.10 Issued — — Vested (169,654 ) 0.10 Forfeited — — Unvested at September 30, 2018 — $ —

Stock-based compensation (Table

Stock-based compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary Of Stock Option Activity	The following table summarizes stock option activity for employees and non-employees for the nine months ended September 30, 2018 : Shares Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (in years) Aggregate Outstanding at December 31, 2017 2,580,491 $ 6.65 7.55 $ 803,600 Granted 1,517,544 2.74 Exercised (97,310 ) 1.21 Forfeited (714,699 ) 5.96 Expired (705,387 ) 8.35 Outstanding at September 30, 2018 2,580,639 $ 4.28 8.07 $ — Exercisable at September 30, 2018 1,126,248 $ 5.92 6.55 $ — Vested or expected to vest at September 30, 2018 2,580,639 $ 4.28 8.07 $ —
Summary Of Stock-based Compensation Expense	Total stock-based compensation expense recognized for employee and non-employee restricted common stock, and stock options granted to employees and non-employees is included in the Company's condensed consolidated statements of operations as follows: Three Months Ended September 30, 2018 Three Months Ended September 30, 2017 Nine Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Research and development $ 43,369 $ 386,636 $ 674,775 $ 1,172,655 Selling, general and administrative 235,021 618,145 1,023,548 2,094,224 Total $ 278,390 $ 1,004,781 $ 1,698,323 $ 3,266,879

Net loss per share (Tables)

Net loss per share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Schedule Of Antidilutive Securities Excluded from Computation Of Earnings Per Share	The following potentially dilutive securities outstanding, prior to the use of the treasury stock method or if-converted method, have been excluded from the computation of diluted weighted-average shares outstanding for the periods indicated, because including them would have had an anti-dilutive impact: September 30, 2018 September 30, 2017 Options to purchase common stock 2,580,639 2,701,922 Unvested restricted common stock 2,709 430,439 Total 2,583,348 3,132,361

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Schedule Of Information For The Company's Operating Segments	Information for the Company's reportable segments for the three months ended September 30, 2018 and 2017 are as follows: Three Months Ended September 30, 2018 Consumer Operations Drug Development Corporate Consolidated Total revenue $ 250,991 — — $ 250,991 Interest income, net $ — — 28,210 $ 28,210 Loss from operations $ 18,293 864,934 1,783,356 $ 2,666,583 Three Months Ended September 30, 2017 Consumer Operations Drug Development Corporate Consolidated Total revenue $ 413,601 — — $ 413,601 Interest income, net $ — — 77,339 $ 77,339 Loss from operations $ 2,323,919 4,683,533 2,402,000 $ 9,409,452 Information for the Company's reportable segments for the nine months ended September 30, 2018 and 2017 are as follows: Nine Months Ended September 30, 2018 Consumer Operations Drug Development Corporate Consolidated Total revenue $ 675,075 — — $ 675,075 Interest income, net $ — — 139,612 $ 139,612 Loss from operations $ 1,921,286 11,699,499 6,432,299 $ 20,053,084 Nine Months Ended September 30, 2017 Consumer Operations Drug Development Corporate Consolidated Total revenue $ 991,671 — — $ 991,671 Interest income, net $ — — 227,535 $ 227,535 Loss from operations $ 7,072,225 12,472,149 7,088,292 $ 26,632,666

Organization and operations (De

Organization and operations (Details)	1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)segment	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Percentage decrease in company workforce	60.00%			60.00%
Number of reportable segments | segment				2
Net loss		$ 2,638,373	$ 9,332,113	$ 19,913,472	$ 26,405,131
Retained earnings (accumulated deficit)		(130,952,530)		(130,952,530)		$ (111,079,275)
Cash and cash equivalents		$ 12,961,126		$ 12,961,126

Summary of significant accoun_4

Summary of significant accounting policies and recent accounting pronouncements - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Accounting Policies [Abstract]
Advertising expense	$ 20,000	$ 1,158,000	$ 792,000	$ 3,073,000
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of product revenue	91,937	148,756	355,816	373,187
Shipping and Handling
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of product revenue	$ 27,000	$ 64,000	$ 81,000	$ 145,000

Summary of significant accoun_5

Summary of significant accounting policies and recent accounting pronouncements - Summary of cash and cash equivalents and restricted cash (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Cash and cash equivalents	$ 12,961,126	$ 19,186,036
Restricted cash	126,595	126,595
Cash, cash equivalents and restricted cash shown on the condensed consolidated statement of cash flows	$ 13,087,721	$ 19,312,631	$ 20,405,319	$ 22,542,635

Revenue from contracts with c_2

Revenue from contracts with customers (Details) - USD ($)	3 Months Ended			6 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Jun. 18, 2018	Sep. 30, 2018	Sep. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Increase to retained earnings due to adoption of Topic 606	$ (130,952,530)	$ (130,952,530)			$ (130,952,530)			$ (111,079,275)
Total revenue		250,991	$ 413,601		675,075	$ 991,671
Refund period	14 days			30 days
Discounts to customers		2,000	$ 82,000		19,000	$ 202,000
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Increase to retained earnings due to adoption of Topic 606							$ 40,000
Decrease in deferred revenue							70,000
Decrease in deferred costs from product revenue							$ 30,000
Total revenue		$ (1,000)			$ (29,000)

Fair value measurements (Detail

Fair value measurements (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Marketable securities:
Marketable securities	$ 0	$ 14,129,723
U.S. government agency securities
Marketable securities:
Marketable securities		8,986,259
Commercial paper
Marketable securities:
Marketable securities		4,440,689
Corporate debt securities
Marketable securities:
Marketable securities		702,775
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	2,321,614	5,046,205
Marketable securities:
Total assets	2,321,614	19,175,928
Fair Value, Measurements, Recurring | U.S. government agency securities
Marketable securities:
Marketable securities		8,986,259
Fair Value, Measurements, Recurring | Commercial paper
Marketable securities:
Marketable securities		4,440,689
Fair Value, Measurements, Recurring | Corporate debt securities
Marketable securities:
Marketable securities		702,775
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	2,321,614	5,046,205
Marketable securities:
Total assets	2,321,614	5,046,205
Fair Value, Measurements, Recurring | Level 1 | U.S. government agency securities
Marketable securities:
Marketable securities		0
Fair Value, Measurements, Recurring | Level 1 | Commercial paper
Marketable securities:
Marketable securities		0
Fair Value, Measurements, Recurring | Level 1 | Corporate debt securities
Marketable securities:
Marketable securities		0
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Marketable securities:
Total assets	0	14,129,723
Fair Value, Measurements, Recurring | Level 2 | U.S. government agency securities
Marketable securities:
Marketable securities		8,986,259
Fair Value, Measurements, Recurring | Level 2 | Commercial paper
Marketable securities:
Marketable securities		4,440,689
Fair Value, Measurements, Recurring | Level 2 | Corporate debt securities
Marketable securities:
Marketable securities		702,775
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Marketable securities:
Total assets	$ 0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. government agency securities
Marketable securities:
Marketable securities		0
Fair Value, Measurements, Recurring | Level 3 | Commercial paper
Marketable securities:
Marketable securities		0
Fair Value, Measurements, Recurring | Level 3 | Corporate debt securities
Marketable securities:
Marketable securities		$ 0

Cash equivalents and marketab_3

Cash equivalents and marketable securities (Details)	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)security
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		$ 14,130,970
Unrealized Gains		38
Unrealized Losses		(1,285)
Fair Value	$ 0	$ 14,129,723
Number of debt securities in an unrealized loss position | security		6
Aggregate fair value of debt securities in an unrealized loss position		$ 8,191,315
Number of debt securities in a significant unrealized loss position | security		0
U.S. government agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		$ 8,987,254
Unrealized Gains		38
Unrealized Losses		(1,033)
Fair Value		8,986,259
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		4,440,689
Unrealized Gains		0
Unrealized Losses		0
Fair Value		4,440,689
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		703,027
Unrealized Gains		0
Unrealized Losses		(252)
Fair Value		$ 702,775

Inventory (Details)

Inventory (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 7,240		$ 7,240		$ 17,411
Finished goods	216,279		216,279		414,480
Total inventory	223,519		223,519		$ 431,891
Write-off of inventory	$ 0	$ 15,000	$ 85,000	$ 34,000

Accrued expenses and other cu_3

Accrued expenses and other current liabilities - Summary of accrued expenses and other current liabilities (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Phase 2 MND and CMT clinical trial-related costs	$ 609,222	$ 1,850,115
Payroll and other employee-related costs	430,560	874,246
Professional fees	284,725	227,980
Restructuring-related costs	189,927	0
Other research and development-related costs	23,808	652,285
Consumer product-related costs	16,437	107,595
Total	$ 1,554,679	$ 3,712,221

Accrued expenses and other cu_4

Accrued expenses and other current liabilities - Narrative (Details)	1 Months Ended	3 Months Ended		6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2018USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)employee	Sep. 30, 2018USD ($)	Sep. 30, 2018USD ($)employee	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Restructuring Cost and Reserve [Line Items]
Accrued research and development expense			$ 609,222	$ 609,222	$ 609,222		$ 1,850,115
Percentage decrease in company workforce	60.00%				60.00%
Cash retention bonuses payable	$ 1,210,000
Cash retention bonuses payable upon change in control	500,000
Cash retention bonuses payable upon employees in good standing	710,000
Severance benefits payable upon change in control and termination without cause	$ 1,125,000
Restructuring charges			$ 212,000	$ 1,130,000	$ 1,130,000
Number of retained employees | employee			7		7
Ongoing Termination Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 12,000		$ 851,000
One-time termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges			77,000		99,000
Employee retention benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges			147,000		164,813
Other
Restructuring Cost and Reserve [Line Items]
Restructuring charges					14,995
Research and development
Restructuring Cost and Reserve [Line Items]
Restructuring charges			133,000		837,000
Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Restructuring charges			79,000		293,000
Consumer Operations
Restructuring Cost and Reserve [Line Items]
Restructuring charges			19,000		75,000
Drug Development
Restructuring Cost and Reserve [Line Items]
Restructuring charges			133,000		837,000
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 60,000		$ 218,000
Scenario, Forecast
Restructuring Cost and Reserve [Line Items]
Severance benefits payable upon change in control and termination without cause						$ 1,125,000
Restructuring charges		$ 50,000
Restructuring charges to be incurred if change of control occurs						500,000
Scenario, Forecast | Consumer Operations
Restructuring Cost and Reserve [Line Items]
Restructuring charges						113,000
Scenario, Forecast | Drug Development
Restructuring Cost and Reserve [Line Items]
Restructuring charges						1,048,000
Scenario, Forecast | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring charges						2,192,000
Scenario, Forecast | Minimum
Restructuring Cost and Reserve [Line Items]
Restructuring charges						1,173,000
Scenario, Forecast | Maximum
Restructuring Cost and Reserve [Line Items]
Restructuring charges						$ 3,353,000

Accrued expenses and other cu_5

Accrued expenses and other current liabilities - Summary of restructuring reserve activity (Details) - USD ($)	3 Months Ended	6 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2018
Restructuring Reserve [Roll Forward]
Opening balance			$ 0
Charges:	$ 212,000	$ 1,130,000	1,130,000
Payments			(940,518)
Accrued restructuring balance as of September 30, 2018	189,927	$ 189,927	189,927
Employee termination benefits
Restructuring Reserve [Roll Forward]
Charges:			950,637
Employee retention benefits
Restructuring Reserve [Roll Forward]
Charges:	$ 147,000		164,813
Other
Restructuring Reserve [Roll Forward]
Charges:			$ 14,995

Common stock - Narrative (Detai

Common stock - Narrative (Details)	Jun. 14, 2018	Apr. 30, 2014shares	Mar. 31, 2014USD ($)$ / sharesshares	Sep. 30, 2018vote$ / sharesshares	Dec. 31, 2016shares	Dec. 31, 2017$ / sharesshares
Equity [Abstract]
Common stock, shares authorized (shares)				100,000,000		100,000,000
Common stock, par value (in usd per share) | $ / shares				$ 0.0001		$ 0.0001
Common stock, number of votes per share | vote				1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock, vesting period (in years)	48 months
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock, shares sold (shares)		867,314	4,553,415
Restricted common stock, price per share (in usd per share) | $ / shares			$ 0.0004
Proceeds from sale of restricted common stock to founders | $			$ 1,950
Restricted stock | Non-employee Consultants and Advisers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock, shares sold (shares)					18,194
Restricted common stock, shares outstanding (shares)				15,485
Restricted stock | Vests upon issuance
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock, percent vested				25.00%
Restricted stock | Vests ratably over four years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock, percent vested				75.00%
Restricted common stock, vesting period (in years)				4 years

Common stock - Restricted commo

Common stock - Restricted common stock activity (Details) - Restricted stock	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Number of Shares
Beginning balance, unvested (shares) | shares	169,654
Issued (shares) | shares	0
Vested (shares) | shares	(169,654)
Forfeited (shares) | shares	0
Ending balance, unvested (shares) | shares	0
Weighted-Average Grant Date Fair Value
Beginning balance, weighted average grant date fair value (in usd per share) | $ / shares	$ 0.10
Issued, weighted average grant date fair value (in usd per share) | $ / shares	0
Vested, weighted average grant date fair value (in usd per share) | $ / shares	0.10
Forfeited, weighted average grant date fair value (in usd per share) | $ / shares	0
Ending balance, weighted average grant date fair value (in usd per share) | $ / shares	$ 0
Non-employee Consultants and Advisers
Number of Shares
Beginning balance, unvested (shares) | shares	5,334
Issued (shares) | shares	0
Vested (shares) | shares	(2,625)
Forfeited (shares) | shares	0
Ending balance, unvested (shares) | shares	2,709
Weighted-Average Grant Date Fair Value
Beginning balance, weighted average grant date fair value (in usd per share) | $ / shares	$ 10.51
Issued, weighted average grant date fair value (in usd per share) | $ / shares	0
Vested, weighted average grant date fair value (in usd per share) | $ / shares	9.95
Forfeited, weighted average grant date fair value (in usd per share) | $ / shares	0
Ending balance, weighted average grant date fair value (in usd per share) | $ / shares	$ 11.05

Stock-based compensation - Narr

Stock-based compensation - Narrative (Details) $ in Thousands	Jun. 14, 2018employeeshares	Jun. 30, 2018adviseremployeeshares	Sep. 30, 2018USD ($)shares	Dec. 31, 2017shares	Sep. 30, 2014shares	Apr. 30, 2014shares	Mar. 31, 2014shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, vesting period (in years)	48 months
Unrecognized compensation cost | $			$ 2,481
Unrecognized compensation cost, recognition period (in years)			2 years 10 months 24 days
Number of options outstanding (shares)			2,580,639	2,580,491
Number of stock options granted (shares)	654,544		1,517,544
Number of employees granted options | employee	7
Employee stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, contractual term			10 years
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, post termination exercisability extended period	1 year
Minimum | Employee stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, vesting period (in years)			1 year
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, post termination exercisability extended period	3 years
Maximum | Employee stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, vesting period (in years)			4 years
2014 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized					2,070,200	1,451,087	116,754
2015 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares remaining available for grant of stock awards			1,480,758
Employee Stock Option, One-Year Post Termination Exercisability
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, post termination exercisability period		3 months
Number of options outstanding (shares)		877,137
Number of employees holding options | employee		6
Number of advisers holding options | adviser		1
Stock options, post termination exercisability extended period		1 year
Employee Stock Option, Three-Year Post Termination Exercisability
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, post termination exercisability period		3 months
Number of options outstanding (shares)		500,000
Number of employees holding options | employee		1
Stock options, post termination exercisability extended period		3 years

Stock-based compensation - Summ

Stock-based compensation - Summary of stock option activity (Details) - USD ($)	Jun. 14, 2018	Sep. 30, 2018	Dec. 31, 2017
Shares
Shares outstanding, Beginning Balance (shares)		2,580,491
Shares granted (shares)	654,544	1,517,544
Shares exercised (shares)		(97,310)
Shares forfeited (shares)		(714,699)
Shares expired (shares)		(705,387)
Shares outstanding, Ending Balance (shares)		2,580,639	2,580,491
Shares exercisable (shares)		1,126,248
Shares vested or expected to vest (shares)		2,580,639
Weighted-Average Exercise Price
Shares outstanding, weighted-average exercise price, Beginning Balance (in usd per share)		$ 6.65
Shares granted, weighted-average exercise price (in usd per share)		2.74
Shares exercised, weighted-average exercise price (in usd per share)		1.21
Shares forfeited, weighted-average exercise price (in usd per share)		5.96
Shares expired, weighted-average exercise price (in usd per share)		8.35
Shares outstanding, weighted-average exercise price, Ending Balance (in usd per share)		4.28	$ 6.65
Shares exercisable, weighted-average exercise price (in usd per share)		5.92
Shares vested or expected to vest, weighted-average exercise price (in usd per share)		$ 4.28
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding, weighted-average remaining contractual term (in years)		8 years 26 days	7 years 6 months 18 days
Exercisable, weighted-average remaining contractual term (in years)		6 years 6 months 18 days
Vested or expected to vest, weighted-average remaining contractual term (in years)		8 years 26 days
Outstanding, aggregate intrinsic value		$ 0	$ 803,600
Exercisable, aggregate intrinsic value		0
Vested or expected to vest, aggregate intrinsic value		$ 0

Stock-based compensation - Su_2

Stock-based compensation - Summary of stock-based compensation expense (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Employee Service Share-Based Compensation Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 278,390	$ 1,004,781	$ 1,698,323	$ 3,266,879
Research and development
Employee Service Share-Based Compensation Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	43,369	386,636	674,775	1,172,655
Selling, general and administrative
Employee Service Share-Based Compensation Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 235,021	$ 618,145	$ 1,023,548	$ 2,094,224

Income taxes (Details)

Income taxes (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income tax provision (benefit)	$ 0	$ 0

Net loss per share (Details)

Net loss per share (Details) - shares	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (shares)	2,583,348	3,132,361
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (shares)	2,580,639	2,701,922
Unvested restricted common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (shares)	2,709	430,439

Segment Information (Details)

Segment Information (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)segment	Sep. 30, 2017USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment			2
Segment Reporting Information [Line Items]
Total revenue	$ 250,991	$ 413,601	$ 675,075	$ 991,671
Interest income, net	28,210	77,339	139,612	227,535
Loss from operations	2,666,583	9,409,452	20,053,084	26,632,666
Operating Segments | Consumer Operations
Segment Reporting Information [Line Items]
Total revenue	250,991	413,601	675,075	991,671
Interest income, net	0	0	0	0
Loss from operations	18,293	2,323,919	1,921,286	7,072,225
Operating Segments | Drug Development
Segment Reporting Information [Line Items]
Total revenue	0	0	0	0
Interest income, net	0	0	0	0
Loss from operations	864,934	4,683,533	11,699,499	12,472,149
Corporate
Segment Reporting Information [Line Items]
Total revenue	0	0	0	0
Interest income, net	28,210	77,339	139,612	227,535
Loss from operations	$ 1,783,356	$ 2,402,000	$ 6,432,299	$ 7,088,292