Aclaris Therapeutics (ACRS) 10-Q 8 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 07, 2018
Document and Entity Information
Entity Registrant Name	Aclaris Therapeutics, Inc.
Entity Central Index Key	1,557,746
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		30,906,003
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 54,881	$ 20,202
Marketable securities	132,096	173,655
Accounts receivable, net	529	481
Prepaid expenses and other current assets	4,750	5,883
Total current assets	192,256	200,221
Marketable securities		14,997
Property and equipment, net	2,191	2,159
Intangible assets	7,330	7,349
Goodwill	18,504	18,504
Other assets	341	279
Total assets	220,622	243,509
Current liabilities:
Accounts payable	8,155	7,822
Accrued expenses	5,668	4,940
Total current liabilities	13,823	12,762
Contingent consideration	5,244	4,378
Other liabilities	534	558
Deferred tax liability	549	549
Total liabilities	20,150	18,247
Stockholders' Equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized and no shares issued or outstanding at March 31, 2018 and December 31, 2017
Common stock, $0.00001 par value; 100,000,000 shares authorized at March 31, 2018 and December 31, 2017; 30,905,629 and 30,856,505 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively
Additional paid-in capital	390,464	384,943
Accumulated other comprehensive loss	(328)	(246)
Accumulated deficit	(189,664)	(159,435)
Total stockholders’ equity	200,472	225,262
Total liabilities and stockholders’ equity	$ 220,622	$ 243,509

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Consolidated Balance Sheets
Preferred stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	30,905,629	30,856,505
Common stock, shares outstanding	30,905,629	30,856,505

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Consolidated Statements Of Operations And Comprehensive Loss
Revenue	$ 1,118
Cost of revenue	967
Gross profit	151
Operating expenses:
Research and development	13,606	$ 7,772
Sales and marketing	11,233	1,438
General and administrative	6,260	3,720
Total operating expenses	31,099	12,930
Loss from operations	(30,948)	(12,930)
Other income, net	719	371
Net loss	(30,229)	(12,559)
Net loss attributable to common stockholders	$ (30,229)	$ (12,559)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.98)	$ (0.48)
Weighted average common shares outstanding, basic and diluted (in shares)	30,885,928	26,080,806
Other comprehensive loss:
Unrealized loss on marketable securities, net of tax of $0	$ (65)	$ (52)
Foreign currency translation adjustments	(17)	72
Total other comprehensive (loss) income	(82)	20
Comprehensive loss	$ (30,311)	$ (12,539)

CONSOLIDATED STATEMENTS OF OPE5

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Consolidated Statements Of Operations And Comprehensive Loss
Unrealized (loss) gain on marketable securities, tax	$ 0	$ 0

CONSOLIDATED STATEMENT OF STOCK

CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Total
Balance at beginning of period at Dec. 31, 2017		$ 384,943	$ (246)	$ (159,435)	$ 225,262
Balance at beginning of period (in shares) at Dec. 31, 2017	30,856,505				30,856,505
Increase (Decrease) in Stockholders' Equity
Exercise of stock options and vesting of RSUs		378			$ 378
Exercise of stock options and vesting of RSUs, shares	49,124
Unrealized loss on marketable securities			(65)		(65)
Foreign currency translation adjustment			(17)		(17)
Stock-based compensation expense		5,143			5,143
Net loss				(30,229)	(30,229)
Balance at end of period at Mar. 31, 2018		$ 390,464	$ (328)	$ (189,664)	$ 200,472
Balance at end of period (in shares) at Mar. 31, 2018	30,905,629				30,905,629

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net loss	$ (30,229)	$ (12,559)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	222	50
Stock-based compensation expense	5,143	3,153
Change in fair value of contingent consideration	866
Changes in operating assets and liabilities:
Prepaid expenses and other assets	1,022	(2,597)
Accounts payable	316	831
Accrued expenses	788	(1,537)
Net cash used in operating activities	(21,872)	(12,659)
Cash flows from investing activities:
Purchases of property and equipment	(298)	(195)
Purchases of marketable securities	(35,614)	(17,158)
Proceeds from sales and maturities of marketable securities	92,105	23,309
Net cash provided by investing activities	56,193	5,956
Cash flows from financing activities
Capital lease payments	(36)
Proceeds from the exercise of employee stock options	394	209
Net cash provided by financing activities	358	209
Net increase (decrease) in cash and cash equivalents	34,679	(6,494)
Cash and cash equivalents at beginning of period	20,202	30,171
Cash and cash equivalents at end of period	54,881	23,677
Supplemental disclosures of non-cash investing and financing activities:
Additions to property and equipment included in accounts payable	210	$ 91
Offering costs included in accounts payable	$ 20

Organization and Nature of Busi

Organization and Nature of Business	3 Months Ended
	Mar. 31, 2018
Organization and Nature of Business
Organization and Nature of Business	1. Organization and Nature of Business Aclaris Therapeutics, Inc. was incorporated under the laws of the State of Delaware in 2012. In July 2015, Aclaris Therapeutics International Limited (“ATIL”) was established under the laws of the United Kingdom as a wholly-owned subsidiary of Aclaris Therapeutics, Inc. In March 2016, Vixen Pharmaceuticals, Inc. (“Vixen”) became a wholly-owned subsidiary of Aclaris Therapeutics, Inc. (see Note 12). In August 2017, Aclaris Life Sciences Inc. (formerly known as Confluence Life Sciences Inc.) (“Confluence”) was acquired by Aclaris Therapeutics, Inc. and became a wholly-owned subsidiary thereof (see Note 3). Aclaris Therapeutics, Inc., ATIL, Vixen and Confluence are referred to collectively as the “Company”. The Company is a dermatologist-led biopharmaceutical company focused on identifying, developing and commercializing innovative and differentiated therapies to address significant unmet needs in medical and aesthetic dermatology. The Company’s lead drug, ESKATA (hydrogen peroxide) Topical Solution, 40% (w/w) (“ESKATA”), is a proprietary high‑concentration formulation of hydrogen peroxide that the Company is commercializing as an office-based prescription treatment for raised seborrheic keratosis (“SK”), a common non‑malignant skin tumor. The Company submitted a New Drug Application (“NDA”) for ESKATA to the U.S. Food and Drug Administration (“FDA”) in February 2017, and it was approved in December 2017. The Company launched commercial product sales of ESKATA in May 2018. Liquidity The Company’s condensed consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities in the ordinary course of business. At March 31, 2018, the Company had cash, cash equivalents and marketable securities of $186,977 and an accumulated deficit of $189,664. Since inception, the Company has incurred net losses and negative cash flows from its operations. Prior to the acquisition of Confluence in August 2017, the Company had never generated any revenue. There can be no assurance that profitable operations will ever be achieved, and, if achieved, will be sustained on a continuing basis. In addition, development activities, clinical and preclinical testing, and commercialization of the Company’s products will require significant additional financing. The future viability of the Company is dependent on its ability to generate cash from operating activities or to raise additional capital to finance its operations. The Company’s failure to raise capital as and when needed could have a negative impact on its financial condition and ability to pursue its business strategies.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). The financial statements include the consolidated accounts of the Company and its wholly-owned subsidiaries, ATIL, Confluence and Vixen. All significant intercompany transactions have been eliminated. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, research and development expenses, contingent consideration and the valuation of stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates. Unaudited Interim Financial Information The accompanying condensed consolidated balance sheet as of March 31, 2018, the condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2018 and 2017, the condensed consolidated statement of stockholders’ equity for the three months ended March 31, 2018, and the condensed consolidated statements of cash flows for the three months ended March 31, 2018 and 2017 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements contained in the Company’s annual report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on March 12, 2018 and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of March 31, 2018, the results of its operations and comprehensive loss for the three months ended March 31, 2018 and 2017 and its cash flows for the three months ended March 31, 2018 and 2017. The condensed consolidated balance sheet data as of December 31, 2017 was derived from audited financial statements but does not include all disclosures required by GAAP. The financial data and other information disclosed in these notes related to the three months ended March 31, 2018 and 2017 are unaudited. The results for the three months ended March 31, 2018 are not necessarily indicative of results to be expected for the year ending December 31, 2018, any other interim periods, or any future year or period. The unaudited interim financial statements of the Company included herein have been prepared, pursuant to the rules and regulations of the SEC. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto for the year ended December 31, 2017 included in the Company’s annual report on Form 10-K filed with the SEC on March 12, 2018. Significant Accounting Policies The Company’s significant accounting policies are disclosed in the audited consolidated financial statements for the year ended December 31, 2017 included in the Company’s annual report on Form 10-K filed with the SEC on March 12, 2018. Since the date of such financial statements, there have been no changes to the Company’s significant accounting policies other than those noted below. In February 2017, the Company paid a $2.0 million PDUFA fee to the FDA in conjunction with the filing of its NDA for ESKATA. The Company requested a waiver and refund of this PDUFA fee, which was approved by the FDA in December 2017, and was received by the Company in January 2018. Revenue Recognition The Company accounts for revenue in accordance with Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers. Under Topic 606, revenue is recognized when a customer obtains control of promised goods or services in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. To determine revenue recognition in accordance with ASC Topic 606, the Company performs the following five steps: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract, and (v) recognize revenue when (or as) performance obligations are satisfied. At contract inception, the Company assesses the goods or services promised within a contract with a customer to identify the performance obligations, and to determine if they are distinct. The Company recognizes the revenue that is allocated to each distinct performance obligation when (or as) that performance obligation is satisfied. The Company only recognizes revenue when collection of the consideration it is entitled to under a contract with a customer is probable. The Company earns revenue from the provision of laboratory services to clients through Confluence, its wholly-owned subsidiary. Laboratory service revenue is generally evidenced by contracts with clients which are on an agreed upon fixed-price, fee-for-service basis and are generally billed on a monthly basis in arrears for services rendered. Revenue related to these contracts is generally recognized as the laboratory services are performed, based upon the rates specified in the contracts. Under ASC Topic 606, the Company elected to apply the “right to invoice” practical expedient when recognizing laboratory service revenue. The Company recognizes laboratory service revenue in the amount to which it has the right to invoice. The Company also receives revenue from grants under the Small Business Innovation Research program of the National Institutes of Health (“NIH”). The Company, through its Confluence subsidiary, currently has two active grants from NIH which are related to early-stage research. The Company recognizes revenue related to these grants as amounts become reimbursable under each grant, which is generally when research is performed and the related costs are incurred. Intangible Assets Intangible assets include both finite-lived and indefinite-lived assets. Finite-lived intangible assets are amortized over their estimated useful life based on the pattern over which the intangible assets are consumed or otherwise used up. If that pattern cannot be reliably determined, the straight-line method of amortization is used. Finite-lived intangible assets consist of a research technology platform the Company acquired through the acquisition of Confluence. Indefinite-lived intangible assets consist of an in-process research and development (“IPR&D”) drug candidate acquired through the acquisition of Confluence. IPR&D assets are considered indefinite-lived until the completion or abandonment of the associated research and development efforts. The cost of IPR&D assets is either amortized over their estimated useful life beginning when the underlying drug candidate is approved and launched commercially, or expensed immediately if development of the drug candidate is abandoned. Finite-lived intangible assets are tested for impairment when events or changes in circumstances indicate that the carrying value of the asset may not be recoverable. Indefinite-lived intangible assets are tested for impairment at least annually, which the Company performs during the fourth quarter, or when indicators of an impairment are present. The Company recognizes impairment losses when and to the extent that the estimated fair value of an indefinite-lived intangible asset is less than its carrying value. Goodwill Goodwill is not amortized, but rather is subject to testing for impairment at least annually, which the Company performs during the fourth quarter, or when indicators of an impairment are present. The Company considers each of its operating segments, dermatology therapeutics and contract research, to be a reporting unit since this is the lowest level for which discrete financial information is available. The Company has attributed the full amount of the goodwill acquired with Confluence, or $18,504, to the dermatology therapeutics segment. The annual impairment test performed by the Company is a qualitative assessment based upon current facts and circumstances related to operations of the dermatology therapeutics segment. If the qualitative assessment indicates an impairment may be present, the Company would perform the required quantitative analysis and an impairment charge would be recognized to the extent that the estimated fair value of the reporting unit is less than its carrying amount. However, any loss recognized would not exceed the total amount of goodwill allocated to that reporting unit. Contingent Consideration The Company initially recorded the contingent consideration related to future potential payments based upon the achievement of certain development, regulatory and commercial milestones, resulting from the acquisition of Confluence, at its estimated fair value on the date of acquisition. Changes in fair value reflect new information about the likelihood of the payment of the contingent consideration and the passage of time. Future changes in the fair value of the contingent consideration, if any, will be recorded as income or expense in the Company’s consolidated statement of operations. Segment Data The Company operates in two segments, dermatology therapeutics and contract research, for the purposes of assessing performance and making operating decisions. The Company’s dermatology therapeutics segment, which did not generate any revenue through March 31, 2018, is focused on identifying, developing and commercializing innovative and differentiated therapies to address significant unmet needs in medical and aesthetic dermatology and immunology. The Company’s contract research segment is focused on providing laboratory services under contract research arrangements to pharmaceutical and biotech companies looking to supplement their research and development efforts with difficult-to-execute specialty skills and programs. Recently Issued Accounting Pronouncements In January 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-01, Business Combinations-Clarifying the Definition of a Business (Topic 805). The amendments in this ASU provide a screen to determine when a set of acquired assets and/or activities is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired, or disposed of, is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. The amendments in this ASU will reduce the number of transactions that meet the definition of a business. ASU 2017-01 is effective for annual reporting periods beginning after December 15, 2017, including interim periods within those years, and early adoption will be permitted. The Company adopted the provisions of this standard on January 1, 2018, the impact of which on its consolidated financial statements was not significant. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606). Under this ASU, entities should recognize revenue in an amount that reflects the consideration to which they expect to be entitled to in exchange for goods and services provided. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2017. The Company adopted the provisions of this standard on January 1, 2018, using the modified retrospective transition method. The Company did not recognize any transition adjustments as a result of adopting ASU 2014-09 and, accordingly, comparative information has not been restated for the periods reported.

Acquisition of Confluence

Acquisition of Confluence	3 Months Ended
	Mar. 31, 2018
Acquisition of Confluence
Acquisition of Confluence	3. Acquisition of Confluence In August 2017, the Company acquired Confluence, at which time, Confluence became a wholly-owned subsidiary of the Company. The Company gave aggregate consideration with a fair value of $24,322 to the equity holders of Confluence. The Company also agreed to pay the Confluence equity holders contingent consideration of up to $80,000, based upon the achievement of certain development, regulatory and commercial milestones, including $2,500 of which may be paid in shares of the Company’s common stock upon the achievement of a specified development milestone. In addition, the Company has agreed to pay the Confluence equity holders specified future royalty payments calculated as a low single-digit percentage of annual net sales, subject to specified reductions, limitations and other adjustments, until the date that all of the patent rights for that product have expired, as determined on a country-by-country and product-by-product basis or, in specified circumstances, ten years from the first commercial sale of such product. The following table summarizes the fair value of total consideration given to the Confluence equity holders in connection with the acquisition: Cash consideration paid $ 10,269 Aclaris common stock issued 9,675 Contingent consideration 4,378 Total fair value of consideration to Confluence equity holders $ 24,322 The Company accounted for the acquisition of Confluence as a business combination using the acquisition method of accounting. Under the acquisition method of accounting, the assets acquired and liabilities assumed in this transaction were recorded at their respective fair values on the date of acquisition using assumptions that are subject to change. The Company expects to finalize its allocation of the purchase price upon the finalization of valuations for the identified intangible assets, final resolution of the post-closing working capital adjustment and certain tax accounts that are based on the best estimates of management. The completion and filing of federal and state tax returns for the acquired entity may result in adjustments to the carrying value of assets and liabilities. The following supplemental unaudited pro forma information presents the Company’s financial results, for the periods presented, as if the acquisition of Confluence had occurred on January 1, 2017. This supplemental unaudited pro forma financial information has been prepared for comparative purposes only, and is not necessarily indicative of what actual results would have been had the acquisition of Confluence occurred on January 1, 2017, nor is this information indicative of future results. Three Months Ended March 31, 2018 2017 Revenue $ 1,118 $ 1,236 Gross profit 151 563 Total operating expenses 31,099 13,607 Net loss (30,229) (12,673) The supplemental unaudited pro forma financial results for the three months ended March 31, 2017 include adjustments to exclude $301 of revenue billed to the Company by Confluence. The supplemental unaudited pro forma financial results for the three months ended March 31, 2017 also includes an adjustment for amortization expense related to the other intangible assets acquired.

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities	3 Months Ended
	Mar. 31, 2018
Fair Value of Financial Assets and Liabilities
Fair Value of Financial Assets and Liabilities	4. Fair Value of Financial Assets and Liabilities The following tables present information about the Company’s assets and liabilities, which are measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values: March 31, 2018 Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 36,035 $ 17,471 $ — $ 53,506 Marketable securities — 132,096 — 132,096 Total Assets $ 36,035 $ 149,567 $ — $ 185,602 Liabilities: Acquisition-related contingent consideration $ — $ — $ 5,244 $ 5,244 Total liabilities $ — $ — $ 5,244 $ 5,244 December 31, 2017 Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 19,339 $ — $ — $ 19,339 Marketable securities — 188,652 — 188,652 Total Assets $ 19,339 $ 188,652 $ — $ 207,991 Liabilities: Acquisition-related contingent consideration $ — $ — $ 4,378 $ 4,378 Total liabilities $ — $ — $ 4,378 $ 4,378 As of March 31, 2018 and December 31, 2017, the Company’s cash equivalents consisted of investments with maturities of less than three months and included a money market fund, which was valued based upon Level 1 inputs, and commercial paper and asset-backed securities, which were valued based upon Level 2 inputs. In determining the fair value of its Level 2 investments the Company relied on quoted prices for identical securities in markets that are not active. These quoted prices were obtained by the Company with the assistance of a third-party pricing service based on available trade, bid and other observable market data for identical securities. On a quarterly basis, the Company compares the quoted prices obtained from the third-party pricing service to other available independent pricing information to validate the reasonableness of those quoted prices. The Company evaluates whether adjustments to third-party pricing is necessary and, historically, the Company has not made adjustments to the quoted prices obtained from the third-party pricing service. During the three months ended March 31, 2018 and the year ended December 31, 2017, there were no transfers between Level 1, Level 2 and Level 3. As of March 31, 2018 and December 31, 2017, the fair value of the Company’s available for sale marketable securities by type of security was as follows: March 31, 2018 Gross Gross Amortized Unrealized Unrealized Fair Cost Gain Loss Value Marketable securities: Corporate debt securities $ 36,733 $ — $ (115) $ 36,618 Commercial paper 48,610 — (3) 48,607 Asset-backed securities 21,003 — (35) 20,968 U.S. government agency debt securities 25,985 — (82) 25,903 Total marketable securities $ 132,331 $ — $ (235) $ 132,096 December 31, 2017 Gross Gross Amortized Unrealized Unrealized Fair Cost Gain Loss Value Marketable securities: Corporate debt securities $ 37,401 $ — $ (68) $ 37,333 Commercial paper 85,202 — — 85,202 Asset-backed securities 16,708 — (13) 16,695 U.S. government agency debt securities 49,511 — (89) 49,422 Total marketable securities $ 188,822 $ — $ (170) $ 188,652

Property and Equipment, Net

Property and Equipment, Net	3 Months Ended
	Mar. 31, 2018
Property and Equipment, Net
Property and Equipment, Net	5. Property and Equipment, Net Property and equipment, net consisted of the following: March 31, December 31, 2018 2017 Computer equipment $ 817 $ 650 Manufacturing equipment 562 511 Lab equipment 721 721 Furniture and fixtures 524 327 Leasehold improvements 250 430 Property and equipment, gross 2,874 2,639 Accumulated depreciation (683) (480) Property and equipment, net $ 2,191 $ 2,159 Depreciation expense was $203 and $50 for the three months ended March 31, 2018 and 2017, respectively.

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2018
Accrued Expenses
Accrued Expenses	6. Accrued Expenses Accrued expenses consisted of the following: March 31, December 31, 2018 2017 Employee compensation expenses $ 2,999 $ 3,010 Research and development expenses 1,362 627 Sales and marketing expenses 521 39 Payable to NST — 590 Vixen contract payable 100 100 Capital leases, current portion 142 142 Other 544 432 Total accrued expenses $ 5,668 $ 4,940

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2018
Stockholders' Equity
Stockholders' Equity	7. Stockholders’ Equity Preferred Stock As of March 31, 2018 and December 31, 2017, the Company’s amended and restated certificate of incorporation authorized the Company to issue 10,000,000 shares of undesignated preferred stock. No shares of preferred stock were outstanding as of March 31, 2018 or December 31, 2017. Common Stock As of March 31, 2018 and December 31, 2017, the Company’s amended and restated certificate of incorporation authorized the Company to issue 100,000,000 shares of $0.00001 par value common stock. Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are entitled to receive dividends, as may be declared by the board of directors, if any, subject to any preferential dividend rights of any series of preferred stock that may be outstanding. No dividends have been declared through March 31, 2018. At-The-Market Equity Offering In November 2016, the Company entered into an at-the-market sales agreement with Cowen and Company, LLC to sell the Company’s securities under a shelf registration statement filed in November 2016. During the three months ended March 31, 2018, the Company did not issue any shares of common stock under the at-the-market sales agreement. As of March 31, 2018, the Company had issued and sold an aggregate of 635,000 shares of common stock under the at-the-market sales agreement at a weighted average price per share of $31.50, for aggregate gross proceeds of $20,003. The Company has incurred expenses of $691 in connection with the shares issued under the at-the-market sales agreement. Public Offering of Common Stock In August 2017, the Company entered into an underwriting agreement pursuant to which the Company issued and sold 3,747,602 shares of common stock under a registration statement on Form S-3 (the “Public Offering”), including the underwriters’ partial exercise of their option to purchase additional shares. The shares of common stock were sold to the public at a price of $23.02 per share, for gross proceeds of $86,270. The Company paid underwriting discounts and commissions of $5,176 to the underwriters in connection with the Public Offering. In addition, the Company incurred expenses of $176 in connection with the Public Offering. The net offering proceeds received by the Company, after deducting underwriting discounts and commissions and offering expenses, were $80,918.

Stock-Based Awards

Stock-Based Awards	3 Months Ended
	Mar. 31, 2018
Stock-Based Awards
Stock-Based Awards	8. Stock‑Based Awards 2017 Inducement Plan In July 2017, the Company’s board of directors adopted the 2017 Inducement Plan (the “2017 Inducement Plan”). The 2017 Inducement Plan is a non-shareholder approved stock plan adopted pursuant to the “inducement exception” provided under NASDAQ listing rules. The only employees eligible to receive grants of awards under the 2017 Inducement Plan are individuals who satisfy the standards for inducement grants under NASDAQ rules, generally including individuals who were not previously an employee or director of the Company. Under the terms of the 2017 Inducement Plan upon adoption, the Company may grant up to 1,000,000 shares of common stock pursuant to nonqualified stock options, stock appreciation rights, restricted stock awards, restricted stock unit (“RSU”) awards, and other stock awards. The shares of common stock underlying any awards that expire, or are otherwise terminated, settled in cash or repurchased by the Company under the 2017 Inducement Plan will be added back to the shares of common stock available for issuance under the 2017 Inducement Plan. As of March 31, 2018, 150,624 shares of common stock were available for grant under the 2017 Inducement Plan. 2015 Equity Incentive Plan In September 2015, the Company’s board of directors adopted the 2015 Equity Incentive Plan (the “2015 Plan”), and on September 16, 2015, the Company’s stockholders approved the 2015 Plan. The 2015 Plan became effective in connection with the Company’s initial public offering in October 2015. Beginning at the time the 2015 Plan became effective, no further grants may be made under the Company’s 2012 Equity Compensation Plan, as amended and restated (the “2012 Plan”). The 2015 Plan provides for the grant of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock awards, RSU awards, performance stock awards, cash-based awards and other stock-based awards. The number of shares initially reserved for issuance under the 2015 Plan was 1,643,872 shares of common stock. The number of shares of common stock that may be issued under the 2015 Plan will automatically increase on January 1 of each year, beginning on January 1, 2016 and ending on January 1, 2025, in an amount equal to the lesser of (i) 4.0% of the shares of the Company’s common stock outstanding on December 31 of the preceding calendar year or (ii) an amount determined by the Company’s board of directors. The shares of common stock underlying any awards that expire, are otherwise terminated, settled in cash or repurchased by the Company under the 2015 Plan and the 2012 Plan will be added back to the shares of common stock available for issuance under the 2015 Plan. As of January 1, 2018, the number of shares of common stock that may be issued under the 2015 Plan was automatically increased by 1,234,260 shares. As of March 31, 2018, 1,599,031 shares remained available for grant under the 2015 Plan. 2012 Equity Compensation Plan Upon the 2015 Plan becoming effective, no further grants can be made under the 2012 Plan. The Company granted stock options to purchase a total of 1,140,524 shares under the 2012 Plan, of which 957,013 and 984,720 were outstanding as of March 31, 2018 and December 31, 2017, respectively. Stock options granted under the 2012 Plan vest over four years and expire after ten years. As required, the exercise price for the stock options granted under the 2012 Plan was not less than the fair value of the shares of common stock underlying the awards as determined by the Company as of the date of grant. Stock Option Valuation The weighted average assumptions the Company used to estimate the fair value of stock options granted were as follows: Three Months Ended March 31, 2018 2017 Risk-free interest rate 2.61 % 2.10 % Expected term (in years) 6.3 6.0 Expected volatility 95.60 % 95.20 % Expected dividend yield 0 % 0 % The Company recognizes compensation expense for awards over their vesting period. Compensation expense for awards includes the impact of forfeitures in the period when they occur. Stock Options The following table summarizes stock option activity from January 1, 2018 through March 31, 2018: Weighted Weighted Average Average Remaining Aggregate Number Exercise Contractual Intrinsic of Shares Price Term Value (in years) Outstanding as of December 31, 2017 3,328,757 $ 20.69 8.28 $ 19,812 Granted 1,090,000 22.17 Exercised (46,700) 8.43 Forfeited and cancelled (25,147) 28.40 Outstanding as of March 31, 2018 4,346,910 $ 21.15 8.60 $ 10,779 Options vested and expected to vest as of March 31, 2018 4,346,910 $ 21.15 8.60 $ 10,779 Options exercisable as of March 31, 2018 1,265,616 (1) $ 15.33 7.55 $ 8,066 (1) All options granted under the 2012 Plan are exercisable immediately, subject to a repurchase right in the Company’s favor that lapses as the option vests. This amount reflects the number of shares under options that were vested, as opposed to exercisable, as of March 31, 2018. The weighted average grant date fair value of stock options granted during the three months ended March 31, 2018 was $17.43 per share. The intrinsic value of a stock option is calculated as the difference between the exercise price of the stock option and the fair value of the underlying common stock, and cannot be less than zero. Restricted Stock Units The following table summarizes RSU activity from January 1, 2018 through March 31, 2018: Weighted Average Grant Date Number Fair Value of Shares Per Share Outstanding as of December 31, 2017 283,553 $ 27.02 Granted 317,360 22.14 Vested (3,150) 20.39 Forfeited and cancelled (2,500) 23.62 Outstanding as of March 31, 2018 595,263 $ 24.46 Stock‑Based Compensation The following table summarizes stock‑based compensation expense recorded by the Company: Three Months Ended March 31, 2018 2017 Cost of revenue $ 176 $ — Research and development 1,727 1,217 Sales and marketing 907 380 General and administrative 2,333 1,556 Total stock-based compensation expense $ 5,143 $ 3,153 As of March 31, 2018, the Company had unrecognized stock‑based compensation expense for stock options and RSUs of $50,862 and $11,752, respectively, which is expected to be recognized over weighted average periods of 3.12 years and 3.41 years, respectively.

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2018
Net Loss per Share
Net Loss per Share	9. Net Loss per Share Basic and diluted net loss per share is summarized in the following table: Three Months Ended March 31, 2018 2017 Numerator: Net loss $ (30,229) $ (12,559) Denominator: Weighted average shares of common stock outstanding 30,885,928 26,080,806 Net loss per share, basic and diluted $ (0.98) $ (0.48) The Company’s potentially dilutive securities, which included stock options and RSUs, have been excluded from the computation of diluted net loss per share since the effect would be to reduce the net loss per share. Therefore, the weighted average number of shares of common stock outstanding used to calculate both basic and diluted net loss per share is the same. The following table presents potential shares of common stock excluded from the calculation of diluted net loss per share for the three months ended March 31, 2018 and 2017. All share amounts presented in the table below represent the total number outstanding as of March 31, 2018 and 2017. Three Months Ended March 31, 2018 2017 Options to purchase common stock 4,346,910 2,656,941 Restricted stock unit awards 595,263 214,343 Total potential shares of common stock 4,942,173 2,871,284

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies
Commitments and Contingencies	10. Commitments and Contingencies Agreements for Office Space In November 2017, the Company entered into a sublease agreement with Auxilium Pharmaceuticals, LLC (the “Sublandlord”) pursuant to which it subleases 33,019 square feet of office space for its headquarters in Wayne, Pennsylvania. Subject to the consent of Chesterbrook Partners, LP (“Landlord”) as set forth in the lease by and between them and Sublandlord, the sublease has a term that runs through October 2023. If for any reason the lease between the Landlord and Sublandlord is terminated or expires prior to October 2023, the Company’s sublease will automatically terminate. In November 2016, the Company entered into a lease agreement with a third party for additional office space in Malvern, Pennsylvania with a term ending in November 2019. The Company also occupies office and laboratory space in St. Louis, Missouri under the terms of an agreement which it entered into in January 2018 and which expires in December 2018. Rent expense was $276 and $84 for the three months ended March 31, 2018 and 2017, respectively. The Company recognizes rent expense on a straight-line basis over the term of the lease and has accrued for rent expense incurred but not yet paid. As of March 31, 2018, future minimum lease payments under these agreements were as follows: Year Ending December 31, 2018 $ 568 2019 627 2020 589 2021 605 2022 622 Thereafter 532 Total $ 3,543 Capital Leases for Laboratory Equipment The Company leases laboratory equipment which is used in its laboratory space in St. Louis, Missouri under two capital lease financing arrangements which the Company entered into in August 2017 and October 2017, respectively. The capital leases have terms which end in October 2020 and December 2020, respectively.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2018
Related Party Transactions
Related Party Transactions	11. Related Party Transactions In August 2013, the Company entered into a sublease agreement with NeXeption, Inc. ("NeXeption"), which was subsequently assigned to NST Consulting, LLC, a wholly-owned subsidiary of NST, LLC. In November 2017, the Company terminated the sublease with NST Consulting, LLC effective March 31, 2018. The Company agreed to pay $590 to NST Consulting, LLC, which amount represents accelerated rent payments. Total payments made under the sublease during the three months ended March 31, 2018 and 2017 were $570 and $75, respectively. In February 2014, the Company entered into a services agreement with NST, LLC (the “NST Services Agreement”), pursuant to which NST, LLC provided certain pharmaceutical development, management and other administrative services to the Company. Under the same agreement, the Company also provided services to another company under common control with the Company and NST, LLC and was reimbursed by NST, LLC for those services. In November 2017, the Company terminated the NST Services Agreement effective December 31, 2017. Mr. Stephen Tullman, the chairman of the Company’s board of directors, was an executive officer of NeXeption and is also the manager of NST Consulting, LLC and NST, LLC, and three of the Company’s executive officers are and have been members of entities affiliated with NST, LLC. During the three months ended March 31, 2018 and 2017, amounts included in the condensed consolidated statement of operations and comprehensive loss for the NST Services Agreement are summarized in the following table: Three Months Ended March 31, 2018 2017 Services provided by NST Consulting, LLC $ — $ 56 Services provided to NST Consulting, LLC — (11) General and administrative expense, net $ — $ 45 Net payments made to NST Consulting, LLC $ — $ 135 The Company had a net amount payable of $0 and $570 to NST Consulting, LLC under the NST Services Agreement as of March 31, 2018 and December 31, 2017, respectively.

Agreements Related to Intellect

Agreements Related to Intellectual Property	3 Months Ended
	Mar. 31, 2018
Agreements Related to Intellectual Property
Agreements Related to Intellectual Property	12. Agreements Related to Intellectual Property Assignment Agreement and Finder’s Services Agreement In August 2012, the Company entered into an assignment agreement with the Estate of Mickey Miller, or the Miller Estate, under which the Company acquired some of the intellectual property rights covering A-101. In connection with obtaining the assignment of the intellectual property from the Miller Estate, the Company also entered into a separate finder’s services agreement with KPT Consulting, LLC. In February 2016, under the terms of the assignment agreement and the finder’s services agreement, the Company made a milestone payment of $300 upon the dosing of the first human subject with ESKATA in the Company’s Phase 3 clinical trial. In April 2017, the Company made an additional milestone payment of $1,000 upon the achievement of specified regulatory milestones. The payments were recorded as general and administrative expenses in the Company’s condensed consolidated statement of operations. Under the finder’s services agreement, the Company is obligated to make additional milestone payments of up to $4,500 upon the achievement of specified commercial milestones. Under each of the assignment agreement and the finder’s services agreement, the Company is also obligated to pay royalties on sales of A-101 or related products, at low single-digit percentages of net sales, subject to reduction in specified circumstances. The Company has not made any royalty payments to date under either agreement. Both agreements will terminate upon the expiration of the last pending, viable patent claim of the patents acquired under the assignment agreement, but no sooner than 15 years from the effective date of the agreements.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Taxes
Income Taxes	13. Income Taxes The Company did not record a federal or state income tax benefit for losses incurred during the three months ended March 31, 2018 and 2017 due to the Company’s conclusion that a valuation allowance was required for those periods.

Segments

Segments	3 Months Ended
	Mar. 31, 2018
Segments [Abstract]
Segments	14. Segment Information The Company has two reportable segments, dermatology therapeutics and contract research. The dermatology therapeutics segment is focused on identifying, developing and commercializing innovative and differentiated therapies to address significant unmet needs in medical and aesthetic dermatology. The Company’s lead drug, ESKATA, is a proprietary formulation of high-concentration hydrogen peroxide topical solution that the Company is commercializing as an office-based prescription treatment for raised SKs, a common non-malignant skin tumor, and which will be distributed by a wholesaler. The contract research segment earns revenue from the provision of laboratory services to clients through Confluence, the Company’s wholly-owned subsidiary. Laboratory service revenue is generally evidenced by contracts with clients which are on an agreed upon fixed-price, fee-for-service basis. The Company does not report balance sheet information by segment since it is not reviewed by the chief operating decision maker, and all of the Company’s tangible assets are held in the United States. The Company’s results of operations by segment for the three months ended March 31, 2018 and 2017 are summarized in the tables below: Dermatology Contract Corporate Total Three Months Ended March 31, 2018 Therapeutics Research and Other Company Revenue $ — $ 2,502 $ (1,384) $ 1,118 Cost of revenue — 2,120 (1,153) 967 Research and development 13,606 — — 13,606 Sales and marketing 11,221 12 — 11,233 General and administrative — 472 5,788 6,260 Loss from operations $ (24,827) $ (102) $ (6,019) $ (30,948) Dermatology Contract Corporate Total Three Months Ended March 31, 2017 Therapeutics Research and Other Company Revenue $ — $ — $ — $ — Cost of revenue — — — — Research and development 7,772 — — 7,772 Sales and marketing 1,438 — — 1,438 General and administrative 93 — 3,627 3,720 Loss from operations $ (9,303) $ — $ (3,627) $ (12,930) Foreign Subsidiary The Company’s wholly-owned subsidiary, ATIL, was formed and operates in the United Kingdom. ATIL is utilized for research and development, regulatory and administrative functions and had $142 and $175 of net assets, composed principally of cash, as of March 31, 2018 and December 31, 2017, respectively. Intersegment Revenue Revenue for the contract research segment includes $1,384 for services performed on behalf of the dermatology therapeutics segment for the three months ended March 31, 2018. The Company did not generate any revenue in the three months ended March 31, 2017. All intersegment revenue has been eliminated in the Company’s condensed consolidated statement of operations.

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). The financial statements include the consolidated accounts of the Company and its wholly-owned subsidiaries, ATIL, Confluence and Vixen. All significant intercompany transactions have been eliminated.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, research and development expenses, contingent consideration and the valuation of stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying condensed consolidated balance sheet as of March 31, 2018, the condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2018 and 2017, the condensed consolidated statement of stockholders’ equity for the three months ended March 31, 2018, and the condensed consolidated statements of cash flows for the three months ended March 31, 2018 and 2017 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements contained in the Company’s annual report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on March 12, 2018 and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of March 31, 2018, the results of its operations and comprehensive loss for the three months ended March 31, 2018 and 2017 and its cash flows for the three months ended March 31, 2018 and 2017. The condensed consolidated balance sheet data as of December 31, 2017 was derived from audited financial statements but does not include all disclosures required by GAAP. The financial data and other information disclosed in these notes related to the three months ended March 31, 2018 and 2017 are unaudited. The results for the three months ended March 31, 2018 are not necessarily indicative of results to be expected for the year ending December 31, 2018, any other interim periods, or any future year or period. The unaudited interim financial statements of the Company included herein have been prepared, pursuant to the rules and regulations of the SEC. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto for the year ended December 31, 2017 included in the Company’s annual report on Form 10-K filed with the SEC on March 12, 2018.
Significant Accounting Policies	Significant Accounting Policies The Company’s significant accounting policies are disclosed in the audited consolidated financial statements for the year ended December 31, 2017 included in the Company’s annual report on Form 10-K filed with the SEC on March 12, 2018. Since the date of such financial statements, there have been no changes to the Company’s significant accounting policies other than those noted below. In February 2017, the Company paid a $2.0 million PDUFA fee to the FDA in conjunction with the filing of its NDA for ESKATA. The Company requested a waiver and refund of this PDUFA fee, which was approved by the FDA in December 2017, and was received by the Company in January 2018.
Revenue Recognition	Revenue Recognition The Company accounts for revenue in accordance with Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers. Under Topic 606, revenue is recognized when a customer obtains control of promised goods or services in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. To determine revenue recognition in accordance with ASC Topic 606, the Company performs the following five steps: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract, and (v) recognize revenue when (or as) performance obligations are satisfied. At contract inception, the Company assesses the goods or services promised within a contract with a customer to identify the performance obligations, and to determine if they are distinct. The Company recognizes the revenue that is allocated to each distinct performance obligation when (or as) that performance obligation is satisfied. The Company only recognizes revenue when collection of the consideration it is entitled to under a contract with a customer is probable. The Company earns revenue from the provision of laboratory services to clients through Confluence, its wholly-owned subsidiary. Laboratory service revenue is generally evidenced by contracts with clients which are on an agreed upon fixed-price, fee-for-service basis and are generally billed on a monthly basis in arrears for services rendered. Revenue related to these contracts is generally recognized as the laboratory services are performed, based upon the rates specified in the contracts. Under ASC Topic 606, the Company elected to apply the “right to invoice” practical expedient when recognizing laboratory service revenue. The Company recognizes laboratory service revenue in the amount to which it has the right to invoice. The Company also receives revenue from grants under the Small Business Innovation Research program of the National Institutes of Health (“NIH”). The Company, through its Confluence subsidiary, currently has two active grants from NIH which are related to early-stage research. The Company recognizes revenue related to these grants as amounts become reimbursable under each grant, which is generally when research is performed and the related costs are incurred.
Intangible Assets	Intangible Assets Intangible assets include both finite-lived and indefinite-lived assets. Finite-lived intangible assets are amortized over their estimated useful life based on the pattern over which the intangible assets are consumed or otherwise used up. If that pattern cannot be reliably determined, the straight-line method of amortization is used. Finite-lived intangible assets consist of a research technology platform the Company acquired through the acquisition of Confluence. Indefinite-lived intangible assets consist of an in-process research and development (“IPR&D”) drug candidate acquired through the acquisition of Confluence. IPR&D assets are considered indefinite-lived until the completion or abandonment of the associated research and development efforts. The cost of IPR&D assets is either amortized over their estimated useful life beginning when the underlying drug candidate is approved and launched commercially, or expensed immediately if development of the drug candidate is abandoned. Finite-lived intangible assets are tested for impairment when events or changes in circumstances indicate that the carrying value of the asset may not be recoverable. Indefinite-lived intangible assets are tested for impairment at least annually, which the Company performs during the fourth quarter, or when indicators of an impairment are present. The Company recognizes impairment losses when and to the extent that the estimated fair value of an indefinite-lived intangible asset is less than its carrying value.
Goodwill	Goodwill Goodwill is not amortized, but rather is subject to testing for impairment at least annually, which the Company performs during the fourth quarter, or when indicators of an impairment are present. The Company considers each of its operating segments, dermatology therapeutics and contract research, to be a reporting unit since this is the lowest level for which discrete financial information is available. The Company has attributed the full amount of the goodwill acquired with Confluence, or $18,504, to the dermatology therapeutics segment. The annual impairment test performed by the Company is a qualitative assessment based upon current facts and circumstances related to operations of the dermatology therapeutics segment. If the qualitative assessment indicates an impairment may be present, the Company would perform the required quantitative analysis and an impairment charge would be recognized to the extent that the estimated fair value of the reporting unit is less than its carrying amount. However, any loss recognized would not exceed the total amount of goodwill allocated to that reporting unit.
Contingent consideration	Contingent Consideration The Company initially recorded the contingent consideration related to future potential payments based upon the achievement of certain development, regulatory and commercial milestones, resulting from the acquisition of Confluence, at its estimated fair value on the date of acquisition. Changes in fair value reflect new information about the likelihood of the payment of the contingent consideration and the passage of time. Future changes in the fair value of the contingent consideration, if any, will be recorded as income or expense in the Company’s consolidated statement of operations.
Segment Data	Segment Data The Company operates in two segments, dermatology therapeutics and contract research, for the purposes of assessing performance and making operating decisions. The Company’s dermatology therapeutics segment, which did not generate any revenue through March 31, 2018, is focused on identifying, developing and commercializing innovative and differentiated therapies to address significant unmet needs in medical and aesthetic dermatology and immunology. The Company’s contract research segment is focused on providing laboratory services under contract research arrangements to pharmaceutical and biotech companies looking to supplement their research and development efforts with difficult-to-execute specialty skills and programs.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In January 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-01, Business Combinations-Clarifying the Definition of a Business (Topic 805). The amendments in this ASU provide a screen to determine when a set of acquired assets and/or activities is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired, or disposed of, is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. The amendments in this ASU will reduce the number of transactions that meet the definition of a business. ASU 2017-01 is effective for annual reporting periods beginning after December 15, 2017, including interim periods within those years, and early adoption will be permitted. The Company adopted the provisions of this standard on January 1, 2018, the impact of which on its consolidated financial statements was not significant. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606). Under this ASU, entities should recognize revenue in an amount that reflects the consideration to which they expect to be entitled to in exchange for goods and services provided. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2017. The Company adopted the provisions of this standard on January 1, 2018, using the modified retrospective transition method. The Company did not recognize any transition adjustments as a result of adopting ASU 2014-09 and, accordingly, comparative information has not been restated for the periods reported.

Acquisition of Confluence (Tabl

Acquisition of Confluence (Tables) - Confluence	3 Months Ended
	Mar. 31, 2018
Business Acquisition [Line Items]
Schedule of Consideration Transferred	Cash consideration paid $ 10,269 Aclaris common stock issued 9,675 Contingent consideration 4,378 Total fair value of consideration to Confluence equity holders $ 24,322
Schedule of Pro Forma Information	Three Months Ended March 31, 2018 2017 Revenue $ 1,118 $ 1,236 Gross profit 151 563 Total operating expenses 31,099 13,607 Net loss (30,229) (12,673)

Fair Value of Financial Asset24

Fair Value of Financial Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value of Financial Assets and Liabilities
Schedule of assets and liabilities measured at fair value on a recurring basis	March 31, 2018 Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 36,035 $ 17,471 $ — $ 53,506 Marketable securities — 132,096 — 132,096 Total Assets $ 36,035 $ 149,567 $ — $ 185,602 Liabilities: Acquisition-related contingent consideration $ — $ — $ 5,244 $ 5,244 Total liabilities $ — $ — $ 5,244 $ 5,244 December 31, 2017 Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 19,339 $ — $ — $ 19,339 Marketable securities — 188,652 — 188,652 Total Assets $ 19,339 $ 188,652 $ — $ 207,991 Liabilities: Acquisition-related contingent consideration $ — $ — $ 4,378 $ 4,378 Total liabilities $ — $ — $ 4,378 $ 4,378
Schedule of the fair value of available for sale marketable securities	March 31, 2018 Gross Gross Amortized Unrealized Unrealized Fair Cost Gain Loss Value Marketable securities: Corporate debt securities $ 36,733 $ — $ (115) $ 36,618 Commercial paper 48,610 — (3) 48,607 Asset-backed securities 21,003 — (35) 20,968 U.S. government agency debt securities 25,985 — (82) 25,903 Total marketable securities $ 132,331 $ — $ (235) $ 132,096 December 31, 2017 Gross Gross Amortized Unrealized Unrealized Fair Cost Gain Loss Value Marketable securities: Corporate debt securities $ 37,401 $ — $ (68) $ 37,333 Commercial paper 85,202 — — 85,202 Asset-backed securities 16,708 — (13) 16,695 U.S. government agency debt securities 49,511 — (89) 49,422 Total marketable securities $ 188,822 $ — $ (170) $ 188,652

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2018
Property and Equipment, Net
Schedule of property and equipment, net	March 31, December 31, 2018 2017 Computer equipment $ 817 $ 650 Manufacturing equipment 562 511 Lab equipment 721 721 Furniture and fixtures 524 327 Leasehold improvements 250 430 Property and equipment, gross 2,874 2,639 Accumulated depreciation (683) (480) Property and equipment, net $ 2,191 $ 2,159

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2018
Accrued Expenses
Schedule of accrued expenses	March 31, December 31, 2018 2017 Employee compensation expenses $ 2,999 $ 3,010 Research and development expenses 1,362 627 Sales and marketing expenses 521 39 Payable to NST — 590 Vixen contract payable 100 100 Capital leases, current portion 142 142 Other 544 432 Total accrued expenses $ 5,668 $ 4,940

Stock-Based Awards (Tables)

Stock-Based Awards (Tables)	3 Months Ended
	Mar. 31, 2018
Stock-Based Awards
Assumptions used to determine fair value of stock options granted	Three Months Ended March 31, 2018 2017 Risk-free interest rate 2.61 % 2.10 % Expected term (in years) 6.3 6.0 Expected volatility 95.60 % 95.20 % Expected dividend yield 0 % 0 %
Summary of stock option activity	Weighted Weighted Average Average Remaining Aggregate Number Exercise Contractual Intrinsic of Shares Price Term Value (in years) Outstanding as of December 31, 2017 3,328,757 $ 20.69 8.28 $ 19,812 Granted 1,090,000 22.17 Exercised (46,700) 8.43 Forfeited and cancelled (25,147) 28.40 Outstanding as of March 31, 2018 4,346,910 $ 21.15 8.60 $ 10,779 Options vested and expected to vest as of March 31, 2018 4,346,910 $ 21.15 8.60 $ 10,779 Options exercisable as of March 31, 2018 1,265,616 (1) $ 15.33 7.55 $ 8,066 (1) All options granted under the 2012 Plan are exercisable immediately, subject to a repurchase right in the Company’s favor that lapses as the option vests. This amount reflects the number of shares under options that were vested, as opposed to exercisable, as of March 31, 2018.
Summary of restricted stock units activity	Weighted Average Grant Date Number Fair Value of Shares Per Share Outstanding as of December 31, 2017 283,553 $ 27.02 Granted 317,360 22.14 Vested (3,150) 20.39 Forfeited and cancelled (2,500) 23.62 Outstanding as of March 31, 2018 595,263 $ 24.46
Stock-based compensation expense	Three Months Ended March 31, 2018 2017 Cost of revenue $ 176 $ — Research and development 1,727 1,217 Sales and marketing 907 380 General and administrative 2,333 1,556 Total stock-based compensation expense $ 5,143 $ 3,153

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Net Loss per Share
Basic and diluted net loss per share	Three Months Ended March 31, 2018 2017 Numerator: Net loss $ (30,229) $ (12,559) Denominator: Weighted average shares of common stock outstanding 30,885,928 26,080,806 Net loss per share, basic and diluted $ (0.98) $ (0.48)
Potential common shares excluded from the calculation of diluted net loss per share attributable to common stockholders	Three Months Ended March 31, 2018 2017 Options to purchase common stock 4,346,910 2,656,941 Restricted stock unit awards 595,263 214,343 Total potential shares of common stock 4,942,173 2,871,284

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies
Schedule of future minimum lease payments	Year Ending December 31, 2018 $ 568 2019 627 2020 589 2021 605 2022 622 Thereafter 532 Total $ 3,543

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2018
Related Party Transactions
Schedule of Related Party Amounts Included in the Statements of Operations	Three Months Ended March 31, 2018 2017 Services provided by NST Consulting, LLC $ — $ 56 Services provided to NST Consulting, LLC — (11) General and administrative expense, net $ — $ 45 Net payments made to NST Consulting, LLC $ — $ 135

Segments (Tables)

Segments (Tables)	3 Months Ended
	Mar. 31, 2018
Segments [Abstract]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Dermatology Contract Corporate Total Three Months Ended March 31, 2018 Therapeutics Research and Other Company Revenue $ — $ 2,502 $ (1,384) $ 1,118 Cost of revenue — 2,120 (1,153) 967 Research and development 13,606 — — 13,606 Sales and marketing 11,221 12 — 11,233 General and administrative — 472 5,788 6,260 Loss from operations $ (24,827) $ (102) $ (6,019) $ (30,948) Dermatology Contract Corporate Total Three Months Ended March 31, 2017 Therapeutics Research and Other Company Revenue $ — $ — $ — $ — Cost of revenue — — — — Research and development 7,772 — — 7,772 Sales and marketing 1,438 — — 1,438 General and administrative 93 — 3,627 3,720 Loss from operations $ (9,303) $ — $ (3,627) $ (12,930)

Organization and Nature of Bu32

Organization and Nature of Business (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Organization and Nature of Business
Cash, cash equivalents and marketable securities	$ 186,977
Accumulated deficit	$ 189,664	$ 159,435

Summary of Significant Accoun33

Summary of Significant Accounting Policies (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018item	Feb. 28, 2017USD ($)
Summary of Significant Accounting Policies
PDUFA fee paid for which waiver has been applied | $		$ 2
Revenue Recognition
Revenue, Practical Expedient, Remaining Performance Obligation [true/false]	true
Number of active research grants | item	2

Summary of Significant Accoun34

Summary of Significant Accounting Policies - Goodwill, Segments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)item	Dec. 31, 2017USD ($)
Summary Of Accounting Policies [Line Items]
Goodwill	$ 18,504	$ 18,504
Number of operating segments | item	2
Confluence
Summary Of Accounting Policies [Line Items]
Goodwill	$ 18,504

Summary of Significant Accoun35

Summary of Significant Accounting Policies - Recent Pronouncements (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative effect recognized on initial adoption of the new guidance	$ (189,664,000)	$ (159,435,000)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative effect recognized on initial adoption of the new guidance	$ 0

Acquisition of Confluence - Sum

Acquisition of Confluence - Summary of fair value consideration (Details) - Confluence $ in Thousands	1 Months Ended
	Aug. 31, 2017USD ($)
Business Acquisition [Line Items]
Additional contingent consideration based on milestones, maximum, per Agreement	$ 80,000
Additional contingent consideration based on milestones, portion payable in shares	$ 2,500
Royalty term	10 years
Fair value of consideration
Cash consideration paid	$ 10,269
Aclaris common stock issued	9,675
Contingent consideration	4,378
Total fair value of consideration to Confluence equity holders	$ 24,322

Acquisition of Confluence - Sup

Acquisition of Confluence - Supplemental pro forma financial information (Details) - Confluence - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Business Acquisition [Line Items]
Revenue	$ 1,118	$ 1,236
Gross profit	151	563
Total operating expenses	31,099	13,607
Net loss	(30,229)	$ (12,673)
Billed revenues
Business Acquisition [Line Items]
Net loss	$ (301)

Fair Value of Financial Asset38

Fair Value of Financial Assets and Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Assets:
Marketable securities	$ 132,096	$ 188,652
Liabilities:
Transfers from Level 1 to Level 2	0	0
Transfers from Level 2 to Level 1	0	0
Transfers into or out of Level 3	0	0
Recurring
Assets:
Cash equivalents	53,506	19,339
Marketable securities	132,096	188,652
Total assets measured at fair value	185,602	207,991
Liabilities:
Acquisition-related contingent consideration	5,244	4,378
Total liabilities measured at fair value	5,244	4,378
Recurring | Level 1
Assets:
Cash equivalents	36,035	19,339
Total assets measured at fair value	36,035	19,339
Recurring | Level 2
Assets:
Cash equivalents	17,471
Marketable securities	132,096	188,652
Total assets measured at fair value	149,567	188,652
Recurring | Level 3
Liabilities:
Acquisition-related contingent consideration	5,244	4,378
Total liabilities measured at fair value	$ 5,244	$ 4,378

Fair Value of Financial Asset39

Fair Value of Financial Assets and Liabilities - by type (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Marketable securities:
Amortized Cost	$ 132,331	$ 188,822
Gross Unrealized Loss	(235)	(170)
Fair Value	132,096	188,652
Corporate debt securities
Marketable securities:
Amortized Cost	36,733	37,401
Gross Unrealized Loss	(115)	(68)
Fair Value	36,618	37,333
Commercial paper
Marketable securities:
Amortized Cost	48,610	85,202
Gross Unrealized Loss	(3)
Fair Value	48,607	85,202
Asset-backed securities
Marketable securities:
Amortized Cost	21,003	16,708
Gross Unrealized Loss	(35)	(13)
Fair Value	20,968	16,695
U.S. government agency debt securities
Marketable securities:
Amortized Cost	25,985	49,511
Gross Unrealized Loss	(82)	(89)
Fair Value	$ 25,903	$ 49,422

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Property and Equipment, net
Property and equipment	$ 2,874		$ 2,639
Accumulated depreciation	(683)		(480)
Property and equipment, net	2,191		2,159
Depreciation	203	$ 50
Computer equipment
Property and Equipment, net
Property and equipment	817		650
Manufacturing equipment
Property and Equipment, net
Property and equipment	562		511
Laboratory Equipment [Member]
Property and Equipment, net
Property and equipment	721		721
Furniture and Fixtures
Property and Equipment, net
Property and equipment	524		327
Leasehold Improvements
Property and Equipment, net
Property and equipment	$ 250		$ 430

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accrued Expenses
Employee compensation expenses	$ 2,999	$ 3,010
Research and development expenses	1,362	627
Payable to NST		590
Sales and marketing expenses	521	39
Vixen contract payable.	100	100
Capital leases, current portion	142	142
Other	544	432
Total accrued expenses	$ 5,668	$ 4,940

Stockholders' Equity (Details)

Stockholders' Equity (Details)	3 Months Ended
	Mar. 31, 2018USD ($)Vote$ / sharesshares	Dec. 31, 2017$ / sharesshares
Stockholders' Equity
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares outstanding	0	0
Common stock shares authorized	100,000,000	100,000,000
Common stock par value (in dollars per share) | $ / shares	$ 0.00001	$ 0.00001
Number of votes per share | Vote	1
Dividends declared | $	$ 0

Stockholders' Equity - IPO, etc

Stockholders' Equity - IPO, etc. (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended
	Aug. 31, 2017	Mar. 31, 2018	Dec. 31, 2017
Subsidiary, Sale of Stock [Line Items]
Common stock, shares outstanding		30,905,629	30,856,505
Gross proceeds	$ 86,270
Offering proceeds, net of discounts, commissions and expenses	$ 80,918
IPO
Subsidiary, Sale of Stock [Line Items]
Number of shares issued	3,747,602
Issuance price (in dollars per share)	$ 23.02
Underwriters' discounts and commissions	$ 176
Exercise of over-allotment option
Subsidiary, Sale of Stock [Line Items]
Underwriters' discounts and commissions	$ 5,176
At The Market Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares issued		0
Common stock, shares outstanding		635,000
Issuance price (in dollars per share)		$ 31.50
Gross proceeds		$ 20,003
Expenses related to stock issuance		$ 691

Stock-Based Awards (Details)

Stock-Based Awards (Details) - shares	Jan. 01, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2014	Dec. 31, 2017	Jul. 31, 2017	Sep. 30, 2015
Stock-based awards
Options granted (in shares)		1,090,000
Options outstanding		4,346,910			3,328,757
Stock Option Valuation
Risk-free interest rate (as a percent)		2.61%	2.10%
Expected term (in years)		6 years 3 months 18 days	6 years
Expected volatility (as a percent)		95.60%	95.20%
Expected dividend yield (as a percent)		0.00%	0.00%
2017 Inducement Plan
Stock-based awards
Number of shares authorized						1,000,000
Number of shares available for grant		150,624
2015 Equity Incentive Plan
Stock-based awards
Number of shares authorized							1,643,872
Number of shares available for grant		1,599,031
Percentage increase to shares available for grant from common outstanding as of preceding December 31 (as a percent)		4.00%
Additional shares available	1,234,260
2012 Equity Compensation Plan
Stock-based awards
Number of shares available for grant		0
Options granted (in shares)				1,140,524
Options outstanding		957,013			984,720
Vesting period (in years)		4 years
Term of award (in years)		10 years

Stock-Based Awards - Option Act

Stock-Based Awards - Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Options, Number of Shares
Number of Shares, beginning balance	3,328,757
Number of Shares, Granted	1,090,000
Number of Shares, Exercised	(46,700)
Number of Shares, Forfeited and cancelled	(25,147)
Number of Shares, ending balance	4,346,910	3,328,757
Number of Shares, Options vested and expected to vest	4,346,910
Number of Shares, Options exercisable	1,265,616
Options, Weighted Average Exercise Price
Weighted Average Exercise Price, beginning balance (in dollars per share)	$ 20.69
Weighted Average Exercise Price, Granted (in dollars per share)	22.17
Weighted Average Exercise Price, Exercised (in dollars per share)	8.43
Weighted Average Exercise Price, Forfeited and cancelled (in dollars per share)	28.40
Weighted Average Exercise Price, ending balance (in dollars per share)	21.15	$ 20.69
Weighted Average Exercise Price, Options vested and expected to vest (in dollars per share)	21.15
Weighted Average Exercise Price, Options exercisable (in dollars per share)	$ 15.33
Options, Weighted Average Remaining Contractual Term
Weighted Average Remaining Contractual Term (in years)	8 years 7 months 6 days	8 years 3 months 11 days
Weighted Average Remaining Contractual Term, Options vested and expected to vest (in years)	8 years 7 months 6 days
Weighted Average Remaining Contractual Term, Options exercisable (in years)	7 years 6 months 18 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value	$ 10,779	$ 19,812
Aggregate Intrinsic Value, Options vested and expected to vest	10,779
Aggregate Intrinsic Value, Options exercisable	$ 8,066
Weighted average grant-date fair value of stock options granted (in dollars per share)	$ 17.43

Stock-Based Awards - RSUs (Deta

Stock-Based Awards - RSUs (Details)	3 Months Ended
	Mar. 31, 2018$ / sharesshares
RSU, Number of Units
Units outstanding, beginning of period | shares	283,553
Granted | shares	317,360
Vested | shares	(3,150)
Forfeited and cancelled | shares	(2,500)
Units outstanding, end of period | shares	595,263
RSU, Weighted Average Grant Date Fair Value Per Unit
Weighted average grant date fair value, beginning balance (in dollars per share) | $ / shares	$ 27.02
Granted, estimated grant-date fair value (in dollars per share) | $ / shares	22.14
Weighted average grant date fair value, vested (in dollars per share) | $ / shares	20.39
Forfeited and cancelled, estimated grant date fair value (in dollars per share) | $ / shares	23.62
Weighted average grant date fair value, ending balance (in dollars per share) | $ / shares	$ 24.46

Stock-Based Awards - Compensati

Stock-Based Awards - Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stock-based compensation expense
Stock-based compensation expense	$ 5,143	$ 3,153
Unrecognized stock-based compensation cost, options	50,862
Unrecognized compensation, RSUs	$ 11,752
Weighted average recognition period unrecognized stock-based compensation cost (in years)	3 years 1 month 13 days
Cost of revenue.
Stock-based compensation expense
Stock-based compensation expense	$ 176
Research and development expense.
Stock-based compensation expense
Stock-based compensation expense	1,727	1,217
General and administrative expense.
Stock-based compensation expense
Stock-based compensation expense	$ 2,333	$ 1,556
Options to Purchase Common Stock
Stock-based compensation expense
Weighted average recognition period unrecognized stock-based compensation cost (in years)	3 years 1 month 13 days
Restricted Stock Unit Awards
Stock-based compensation expense
Weighted average recognition period unrecognized stock-based compensation cost (in years)	3 years 4 months 28 days

Net Loss per Share (Details)

Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator:
Net loss	$ (30,229)	$ (12,559)
Net loss attributable to common stockholders	$ (30,229)	$ (12,559)
Denominator:
Weighted average common shares outstanding used in calculating net loss per share attributable to common stockholders, basic and diluted	30,885,928	26,080,806
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.98)	$ (0.48)

Net Loss per Share - Anti-dilut

Net Loss per Share - Anti-dilution (Details) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from the calculation of diluted net loss per share attributable to common stockholders	4,942,173	2,871,284
Options to Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from the calculation of diluted net loss per share attributable to common stockholders	4,346,910	2,656,941
Restricted Stock Unit Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from the calculation of diluted net loss per share attributable to common stockholders	595,263	214,343

Commitments and Contingencies50

Commitments and Contingencies (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)ft²item	Mar. 31, 2017USD ($)
Agreements for Office Space
Area leased from third party | ft²	33,019
Rent expense under operating leases	$ 276	$ 84
Future minimum lease payments under the sublease
2,018	568
2,019	627
2,020	589
2,021	605
2,022	622
Thereafter	532
Total	$ 3,543
Number of capital lease arrangements | item	2

Related Party Transactions (Det

Related Party Transactions (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)item	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)
NST, LLC [Member]
Related Party Transactions
Number of executive officers affiliated with counterparty | item	3
Direct sublease agreement | NST, LLC [Member]
Related Party Transactions
Lease termination charge	$ 590
Expenses incurred under related party transactions	570	$ 75
Services agreement | General and administrative expense.
Related Party Transactions
Net expenses (revenues) from related party transactions		45
Services agreement | NST, LLC [Member]
Related Party Transactions
Amount due to related party	$ 0		$ 570
Payments to related party		135
Services agreement | NST, LLC [Member] | General and administrative expense.
Related Party Transactions
Expenses incurred under related party transactions		56
Other revenue earned from related party transactions		$ (11)

Agreements Related to Intelle52

Agreements Related to Intellectual Property (Details) - USD ($) $ in Thousands	1 Months Ended
	Apr. 30, 2017	Feb. 29, 2016	Aug. 31, 2012
Assignment Agreement and Finder's Services Agreement [Member]
Agreements Related to Intellectual Property
Term of agreement, minimum			15 years
Assignment Agreement and Finder's Services Agreement [Member] | Achievement Of Dosing Of First Subject With A101
Agreements Related to Intellectual Property
Milestone payment		$ 300
Assignment Agreement and Finder's Services Agreement [Member] | Achievement Of Specified Regulatory Milestones [Member]
Agreements Related to Intellectual Property
Milestone payment	$ 1,000
Finders Services Agreement | Achievement Of Specified Commercial Milestones | Maximum
Agreements Related to Intellectual Property
Potential future milestone payments			$ 4,500

Income Taxes - Rate reconciliat

Income Taxes - Rate reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Taxes
Federal income tax benefit	$ 0	$ 0
State income tax benefit	$ 0	$ 0

Segments (Details)

Segments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)item	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | item	2
Revenue	$ 1,118
Cost of revenue	967
Research and development	13,606	$ 7,772
Sales and marketing	11,233	1,438
General and administrative	6,260	3,720
Loss from operations	(30,948)	(12,930)
UNITED KINGDOM
Segment Reporting Information [Line Items]
Net assets	142		$ 175
Dermatology Therapeutics Segment [Member]
Segment Reporting Information [Line Items]
Research and development	13,606	7,772
Sales and marketing	11,221	1,438
General and administrative		93
Loss from operations	(24,827)	(9,303)
Contract Research Segment [Member]
Segment Reporting Information [Line Items]
Revenue	2,502
Cost of revenue	2,120
Sales and marketing	12
General and administrative	472
Loss from operations	(102)
Corporate and Other
Segment Reporting Information [Line Items]
Revenue	(1,384)
Cost of revenue	(1,153)
General and administrative	5,788	3,627
Loss from operations	(6,019)	$ (3,627)
Intersegment Eliminations [Member] | Contract Research Segment [Member]
Segment Reporting Information [Line Items]
Revenue	$ (1,384)