Collegium Pharmaceutical (COLL) 10-Q 7 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 31, 2019
Document and Entity Information
Entity Registrant Name	Collegium Pharmaceutical, Inc.
Entity Central Index Key	0001267565
Document Type	10-Q
Document Period End Date	Jun. 30, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		33,470,530
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-37372
Entity Incorporation, State or Country Code	VA
Entity Tax Identification Number	03-0416362
Entity Address, Address Line One	100 Technology Center Drive
Entity Address, City or Town	Stoughton
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02072
City Area Code	781
Local Phone Number	713-3699
Title of 12(b) Security	Common Stock
Trading Symbol	COLL
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Entity Shell Company	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 148,713	$ 146,633
Accounts receivable	81,279	77,946
Inventory	9,953	7,817
Prepaid expenses and other current assets	4,618	5,116
Total current assets	244,563	237,512
Property and equipment, net	10,367	9,274
Operating lease assets	9,574
Intangible assets, net	36,879	44,255
Other noncurrent assets	198	204
Total assets	301,581	291,245
Current liabilities
Accounts payable	10,941	12,150
Accrued expenses	24,517	30,551
Accrued rebates, returns and discounts	158,264	144,783
Current portion of term loan payable	1,917	1,642
Current portion of operating lease liabilities	633
Total current liabilities	196,272	189,126
Term loan payable, net of current portion	9,583	9,858
Operating lease liabilities, net of current portion	9,903
Other noncurrent liabilities		676
Total liabilities	215,758	199,660
Commitments and contingencies (see Note 14)
Shareholders' equity:
Preferred stock, $0.001 par value; authorized shares - 5,000,000 at June 30, 2019 and December 31, 2018; issued and outstanding shares - none at June 30, 2019 and December 31, 2018
Common stock, $0.001 par value; authorized shares - 100,000,000 at June 30, 2019 and December 31, 2018; issued and outstanding shares - 33,416,553 at June 30, 2019 and 33,265,629 at December 31, 2018	33	33
Additional paid-in capital	437,379	428,729
Accumulated deficit	(351,589)	(337,177)
Total shareholders' equity	85,823	91,585
Total liabilities and shareholders' equity	$ 301,581	$ 291,245

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 30, 2019	Dec. 31, 2018
CONDENSED CONSOLIDATED BALANCE SHEETS
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, authorized shares	5,000,000	5,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized shares	100,000,000	100,000,000
Common stock, issued shares	33,416,553	33,265,629
Common stock, outstanding shares	33,416,553	33,265,629

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues
Product revenues, net	$ 75,040	$ 73,061	$ 149,556	$ 136,810
Costs and expenses
Cost of product revenues	48,654	46,838	97,818	89,944
Research and development	2,459	2,237	5,451	4,505
Selling, general and administrative	28,935	31,279	61,287	62,861
Total costs and expenses	80,048	80,354	164,556	157,310
Loss from operations	(5,008)	(7,293)	(15,000)	(20,500)
Interest expense	(236)	(6,158)	(470)	(11,858)
Interest income	532	391	1,058	646
Net loss	$ (4,712)	$ (13,060)	$ (14,412)	$ (31,712)
Loss per share - basic and diluted	$ (0.14)	$ (0.40)	$ (0.43)	$ (0.96)
Weighted-average shares - basic and diluted	33,397,709	32,967,718	33,338,243	32,935,873

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating activities
Net loss	$ (14,412)	$ (31,712)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Amortization expense for Nucynta asset acquisition	7,376	61,933
Depreciation and amortization, excluding Nucynta asset acquisition	355	578
Stock-based compensation expense	8,425	6,254
Non-cash lease expense	229
Non-cash interest expense for Nucynta asset acquisition		11,471
Changes in operating assets and liabilities:
Accounts receivable	(3,333)	(58,411)
Inventory	(2,136)	(508)
Prepaid expenses and other assets	509	(608)
Accounts payable	(1,209)	13,008
Accrued expenses	(3,285)	13,917
Accrued rebates, returns and discounts	13,481	69,346
Operating lease asset and liabilities	734
Other long-term liabilities	(676)
Net cash provided by operating activities	6,058	85,268
Investing activities
Upfront cash paid for Nucynta asset acquisition		(18,877)
Purchases of property and equipment	(4,198)	(987)
Net cash used in investing activities	(4,198)	(19,864)
Financing activities
Cash paid for common stock offerings costs		(30)
Proceeds from issuances of common stock from employee stock purchase plans	444	510
Proceeds from term loan amendment, net of repayment of amended term loan		10,020
Repayment of asset acquisition obligations		(64,500)
Proceeds from the exercise of stock options	299	3,905
Payments made for employee restricted stock tax withholdings	(523)	(356)
Net cash provided by (used in) financing activities	220	(50,451)
Net increase in cash, cash equivalents and restricted cash	2,080	14,953
Cash, cash equivalents and restricted cash at beginning of period	146,633	118,794
Cash, and cash equivalents and restricted cash at end of period	148,713	133,747
Supplemental disclosure of cash flow information
Cash paid for offering costs		30
Cash paid for interest	362	242
Supplemental disclosure of non-cash activities
Offering costs in accrued expenses		25
Receivable from stock option exercises in other current assets	5
Acquisition of property and equipment in accounts payable and accrued expenses	512	1,184
Operating lease assets assumed	9,957
Operating lease liabilities assumed	$ 10,691
Liabilities assumed from Nucynta asset acquisition included in accrued rebates, returns and discounts		22,406
Liabilities assumed from Nucynta asset acquisition included as a reduction to accounts receivable		$ 254

Nature of Business

Nature of Business	6 Months Ended
	Jun. 30, 2019
Nature of Business
Nature of Business	1. Nature of Business ​ Collegium Pharmaceutical, Inc. (the “Company”) was incorporated in Delaware in April 2002 and then reincorporated in Virginia in July 2014. The Company has its principal operations in Stoughton, Massachusetts. The Company is a specialty pharmaceutical company committed to being the leader in responsible pain management. The Company’s first product, Xtampza ER® (“Xtampza ER”) is an abuse-deterrent, extended-release, oral formulation of oxycodone. In April 2016, the U.S. Food and Drug Administration (“FDA”) approved the Company’s new drug application (“NDA”) for Xtampza ER for the management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate. In June 2016, the Company announced the commercial launch of Xtampza ER. The Company’s product portfolio also includes Nucynta ER and Nucynta IR (the “Nucynta Products”). In December 2017, the Company entered into a Commercialization Agreement (the “Nucynta Commercialization Agreement”) with Assertio Therapeutics, Inc. (formerly known as Depomed) (“Assertio”), pursuant to which the Company acquired the right to commercialize the Nucynta Products in the United States. The Company began shipping and recognizing product sales on the Nucynta Products on January 9, 2018 and began marketing the Nucynta Products in February 2018. Nucynta ER is an extended-release formulation of tapentadol that is indicated for the management of pain severe enough to require daily, around-the-clock, long-term opioid treatment, including neuropathic pain associated with diabetic peripheral neuropathy in adults, and for which alternate treatment options are inadequate. Nucynta IR is an immediate-release formulation of tapentadol that is indicated for the management of acute pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate in adults. The Company’s operations are subject to certain risks and uncertainties. The principal risks include inability to successfully commercialize products, changing market conditions for products and development of competing products, changing regulatory environment and reimbursement landscape, litigation related to opioid marketing and distribution practices, manufacture of adequate commercial inventory, inability to secure adequate supplies of active pharmaceutical ingredients, key personnel retention, protection of intellectual property, patent infringement litigation and the availability of additional capital financing on terms acceptable to the Company. The Company believes that its cash and cash equivalents at June 30, 2019, together with expected cash inflows from the commercialization of its products, will enable the Company to fund its operating expenses, debt service and capital expenditure requirements under its current business plan for the foreseeable future.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2019
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies ​ Basis of Presentation ​ The accompanying unaudited Condensed Consolidated Financial Statements include the accounts of Collegium Pharmaceutical, Inc. (a Virginia corporation) as well as the accounts of Collegium Securities Corp. (a Massachusetts corporation), incorporated in December 2015, and Collegium NF, LLC (a Delaware limited liability company), organized in December 2017, both wholly owned subsidiaries requiring consolidation. The consolidated financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial reporting and as required by Regulation S-X, Rule 10-01. Accordingly, they do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. ​ In the opinion of the Company’s management, the accompanying unaudited Condensed Consolidated Financial Statements contain all adjustments (consisting of items of a normal and recurring nature) necessary to fairly present the financial position of the Company as of June 30, 2019, the results of operations for the three and six months ended June 30, 2019 and 2018, and cash flows for the six months ended June 30, 2019 and 2018. The results of operations for the six months ended June 30, 2019 are not necessarily indicative of the results to be expected for the full year. ​ When preparing financial statements in conformity with GAAP, the Company must make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s financial statements and accompanying notes. The most significant estimates in the Company’s financial statements relate to revenue recognition, including the estimates of product returns, units prescribed, discounts and allowances related to commercial sales of its products, estimates of useful lives with respect to intangible assets, accounting for stock-based compensation, contingencies, impairment of intangible assets, and tax valuation reserves. The Company bases estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis. The Company’s actual results may differ from these estimates under different assumptions or conditions. The consolidated interim financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018 (the “Annual Report”). ​ Significant Accounting Policies ​ The Company’s significant accounting policies are described in Note 2, “Summary of Significant Accounting Policies,” in the Company’s Annual Report. There have been no material changes in the Company’s significant accounting policies, other than the adoption of accounting pronouncements below, as compared to the significant accounting policies described in the Annual Report. ​ Recently Adopted Accounting Pronouncements ​ New accounting pronouncements are issued periodically by the Financial Accounting Standards Board (“FASB”) and are adopted by the Company as of the specified effective dates. ​ The Company adopted Accounting Standard Updated (“ASU”) 2016-02, Leases (ASC Topic 842 he Company utilized the package of practical expedients permitted within the transition guidance, which, among other things, allowed the Company to carryforward the historical lease classification. Upon adoption, the new standard resulted in the Company recording material operating lease assets and corresponding operating lease liabilities on its balance sheet. As of June 30, 2019, the Company had operating lease assets of Recently Issued Accounting Pronouncements Not Yet Adopted ​ In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, ​

Revenue from Contracts with Cus

Revenue from Contracts with Customers	6 Months Ended
	Jun. 30, 2019
Revenue from Contracts with Customers
Revenue from Contracts with Customers	3. Revenue from Contracts with Customers ​ The Company’s only source of revenue to date has been generated by sales of the Company’s products, which are primarily sold to distributors (“customers”), which in turn sell the product to pharmacies for the treatment of patients. ​ Revenue Recognition ​ In accordance with Accounting Standards Codification Topic 606, Revenue from Contracts with Customers (“ASC Topic 606”), revenue recognition for arrangements that an entity determines are within the scope of 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) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. ​ Performance Obligations ​ The Company determined that performance obligations are satisfied and revenue is recognized when a customer takes control of the Company’s product, which occurs at a point in time. This generally occurs upon delivery of the products to customers, at which point the Company recognizes revenue and records accounts receivable, which represents the Company’s only contract asset. Payment is typically received 30 to 60 days after satisfaction of the Company’s performance obligations and generally does not have an effect on contract asset and contract liability balances. Under the practical expedients permitted by the rules of the adoption, the Company expenses incremental costs of obtaining a contract as and when incurred if the expected amortization period of the assets is one year or less. ​ Transaction Price and Variable Consideration ​ Revenue is measured as the amount of consideration the Company expects to receive in exchange for transferring products or services to a customer (“transaction price”). The transaction price for product sales includes variable consideration related to chargebacks, rebates, sales incentives and allowances, distribution service fees, and returns. The Company estimates the amount of variable consideration that should be included in the transaction price under the expected value method. These estimates take into consideration a range of possible outcomes that are probability-weighted for relevant factors such as the Company’s historical experience, current contractual and statutory requirements, specific known market events and trends, industry data and forecasted customer buying and payment patterns. These provisions reflect the Company’s best estimates of the amount of consideration to which it is entitled based on the terms of the contract. The amount of variable consideration that is included in the transaction price may be constrained and is included in net sales only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. In general, performance obligations do not include any estimated amounts of variable consideration that are constrained. Actual amounts of consideration ultimately received may differ from the Company’s estimates. If actual results in the future vary from the Company’s estimates, the Company will adjust these estimates, which would affect net product revenue and earnings in the period such variances become known. ​ The following table summarizes activity in each of the Company’s product revenue provision and allowance categories for the six months ended June 30, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Trade ​ ​ Rebates and ​ Product ​ Allowances and ​ ​ Incentives (1) ​ Returns (2) ​ Chargebacks (3) Balance at December 31, 2018 ​ $ 129,318 ​ $ 15,465 ​ $ 14,841 Provision related to current period sales ​ ​ 128,509 ​ ​ 9,150 ​ ​ 31,988 Changes in estimate related to prior period sales ​ ​ (3,017) ​ ​ — ​ ​ — Credits/payments made ​ ​ (119,659) ​ ​ (1,502) ​ ​ (32,673) Balance at June 30, 2019 ​ $ 135,151 ​ $ 23,113 ​ $ 14,156 ​ ​ ​ (1) Rebates and incentives includes managed care rebates, government rebates, co-pay program incentives, and sales incentives and allowances. Provisions for rebates and discounts are deducted from gross revenues at the time revenues are recognized and are included in accrued rebates, returns and discounts in the Company’s Condensed Consolidated Balance Sheets. ​ (2) Provisions for product returns are deducted from gross revenues at the time revenues are recognized and are included in accrued rebates, returns and discounts in the Company’s Condensed Consolidated Balance Sheets. ​ (3) ​ Trade allowances and chargebacks include fees for distribution service fees, prompt pay discounts, and chargebacks. Trade allowances and chargebacks are deducted from gross revenue at the time revenues are recognized and are recorded as a reduction to accounts receivable in the Company’s Condensed Consolidated Balance Sheets. ​ As of June 30, 2019, the Company did not have any transaction price allocated to remaining performance obligations and any costs to obtain contracts with customers, including pre-contract costs and set up costs, were immaterial. ​ Disaggregation of Revenue ​ Product revenues, net consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, ​ Six months ended June 30, ​ 2019 ​ 2018 ​ 2019 ​ 2018 Xtampza ER $ 26,018 $ 18,116 ​ $ 51,152 ​ $ 33,911 Nucynta Products 49,022 ​ 54,945 ​ 98,404 ​ 102,899 Total product revenues, net $ 75,040 ​ $ 73,061 ​ $ 149,556 ​ $ 136,810 ​

License Agreements

License Agreements	6 Months Ended
	Jun. 30, 2019
License Agreements
License Agreements	4. License Agreements The Company periodically enters into license and development agreements to develop and commercialize its products. The Company’s license and development agreements as of June 30, 2019 are as follows: Nucynta Commercialization Agreement On January 9, 2018 (the “Nucynta Commercialization Closing Date”), the Company consummated the transactions contemplated by the Nucynta Commercialization Agreement, pursuant to which Assertio agreed to grant a sublicense of certain of its intellectual property related to the Nucynta Products for commercialization in the United States. The Company began recording revenues from sales of the Nucynta Products on the Nucynta Commercialization Closing Date and began commercial promotion of the Nucynta Products in February 2018. Pursuant to the Nucynta Commercialization Agreement, the Company paid a one-time, non-refundable license fee of $10,000 to Assertio on the Nucynta Commercialization Closing Date, $6,223 for transferred inventory and $1,987 as reimbursement for prepaid expenses. The Company also assumed the existing liabilities of the Nucynta Products, including $22,660 related to sales of Nucynta Products that occurred prior to the Nucynta Commercialization Closing Date. The Nucynta Commercialization Agreement initially required the Company to pay a guaranteed minimum royalty of $135,000 per year through December 2021, payable in quarterly payments of $33,750, prorated in 2018 for the Nucynta Commercialization Closing Date, as well as a variable royalty based on annual net sales over $233,000. Beginning January 2022 and for each year of the Nucynta Commercialization Agreement term thereafter, the Company was required to pay a variable royalty on annual net sales of the Nucynta Products, but without a guaranteed minimum. Effective August 2018, the Company entered into a Second Amendment to the Nucynta Commercialization Agreement to clarify the mechanism for transferring title of products to be sold by the Company pursuant to the agreement and various related matters. The Second Amendment did not have an impact on the Company’s financial statements. Effective November 2018, the Company entered into the Third Amendment to the Nucynta Commercialization Agreement to adjust the royalty structure and termination clauses. Pursuant to the amended Nucynta Commercialization Agreement, the $135,000 guaranteed minimum annual royalties are eliminated, and the Company is no longer required to secure its royalty payment obligations with a standby letter of credit. Beginning on January 1, 2019 and thereafter, the Company will be conditionally obligated to make royalty payments to Assertio conditional upon net sales and based on the following royalty structure for the period between January 1, 2019 and December 31, 2021: (i) (ii) (iii) (iv) (v) The Amendment does not modify the royalties payable on sales of the Nucynta Products on and after January 1, 2022, which will remain as contemplated by the Nucynta Commercialization Agreement as in effect on January 9, 2018, based on the following royalty structure: (i) (ii) (iii) In addition, prior to January 1, 2022, if the annual net sales of the Nucynta Products are in the range of $180,000 to $243,000, the Company will be required to pay a supplemental royalty to Assertio, for ultimate payment to Grünenthal GmbH, not to exceed a maximum of 4.9% of net sales of the Nucynta Products. If annual net sales of Products are less than $180,000 in any 12-month period through January 1, 2022, or if they are less than $170,000 in any 12-month period commencing on January 1, 2022, then Assertio will have the right to terminate the Nucynta Commercialization Agreement without penalty. The Amendment further provides that the Company does not have a right to terminate the Nucynta Commercialization Agreement prior to December 31, 2021. The Company will be required to pay a $5,000 termination fee to Assertio in connection with any termination by the Company with an effective date between December 31, 2021 and December 31, 2022. In connection with execution of the Third Amendment to the Nucynta Commercialization Agreement, the Company issued a warrant to Assertio to purchase 1,041,667 shares of common stock of the Company (the “Warrant”) at an exercise price of $19.20 per share. The Warrant will expire in November 2022 and includes customary adjustments for changes in the Company’s capitalization. The assets acquired, liabilities assumed, and equity interests issued by the Company in connection with the Nucynta Commercialization Agreement are further described in Note 8.

Loss per Common Share

Loss per Common Share	6 Months Ended
	Jun. 30, 2019
Loss per Common Share
Loss per Common Share	5. Loss per Common Share ​ The following table presents the computations of basic and dilutive net loss per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, ​ Six months ended June 30, ​ ​ 2019 ​ 2018 ​ ​ 2019 ​ 2018 Loss attributable to common shareholders — basic and diluted $ (4,712) ​ $ (13,060) ​ $ (14,412) ​ $ (31,712) Weighted-average number of common shares used in net loss per share - basic and diluted ​ 33,397,709 ​ ​ 32,967,718 ​ ​ 33,338,243 ​ ​ 32,935,873 Loss per share - basic and diluted $ (0.14) ​ $ (0.40) ​ $ (0.43) ​ $ (0.96) ​ The following potentially dilutive securities, which represent all outstanding potentially dilutive securities, were excluded from the calculation of diluted net loss per share due to their anti-dilutive effect (in common stock equivalent shares): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, Six months ended June 30, ​ 2019 2018 2019 2018 Outstanding stock options 4,190,116 ​ 3,665,459 ​ 4,190,116 ​ 3,665,459 Warrants 1,041,667 ​ — ​ 1,041,667 ​ — Unvested restricted stock (1) — ​ 12,072 ​ — ​ 12,072 Restricted stock units 892,237 ​ 522,190 ​ 892,237 ​ 522,190 Performance share units 99,400 ​ — ​ 99,400 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (1) - Includes shares of unvested restricted stock remaining from the early exercise of stock options. ​

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2019
Fair Value of Financial Instruments
Fair Value of Financial Instruments	6. Fair Value of Financial Instruments ​ Disclosures of fair value information about financial instruments are required, whether or not recognized in the balance sheet, for financial instruments with respect to which it is practicable to estimate that value. Fair value measurements and disclosures describe the fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, that may be used to measure fair value, as follows: ​ ​ ​ Level 1 inputs: Quoted prices (unadjusted) in active markets for identical assets or liabilities Level 2 inputs: Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly Level 3 inputs: Unobservable inputs that reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability ​ Transfers are calculated on values as of the transfer date. There were no transfers between Levels 1, 2 and 3 during the six months ended June 30, 2019 and 2018. ​ The following tables present the Company’s financial instruments carried at fair value using the lowest level input applicable to each financial instrument at June 30, 2019 and December 31, 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Significant ​ ​ ​ ​ ​ ​ ​ ​ ​ Quoted Prices ​ ​ other ​ ​ Significant ​ ​ ​ ​ ​ ​ in active ​ ​ observable ​ ​ unobservable ​ ​ ​ ​ ​ ​ markets ​ ​ inputs ​ ​ inputs June 30, 2019 ​ Total ​ (Level 1) ​ (Level 2) ​ (Level 3) Money market funds, included in cash equivalents ​ $ 93,968 ​ $ 93,968 ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds, included in cash equivalents ​ $ 92,914 ​ $ 92,914 ​ $ — ​ $ — ​ As of June 30, 2019, the carrying amounts of the Company’s other assets and liabilities approximated their estimated fair values.

Inventory

Inventory	6 Months Ended
	Jun. 30, 2019
Inventory
Inventory	7. Inventory ​ Inventory consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, ​ As of December 31, ​ ​ 2019 ​ 2018 Raw materials ​ $ 1,664 ​ $ 496 Work in process ​ ​ 848 ​ ​ 671 Finished goods ​ ​ 7,441 ​ ​ 6,650 Total inventory ​ $ 9,953 ​ $ 7,817 ​ The aggregate charges related to excess inventory for the three and six months ended June 30, 2019 and 2018 were immaterial. These expenses were recorded as a component of cost of product revenues.

Intangible Assets

Intangible Assets	6 Months Ended
	Jun. 30, 2019
Intangible Assets
Intangible Assets	8. Intangible Assets ​ As of June 30, 2019 and December 31, 2018, the Company’s only intangible asset is related to the Nucynta Intangible Asset. Nucynta Intangible Asset The Company determined the Nucynta Commercialization Agreement should be accounted for as an asset acquisition in accordance with ASC Topic 805-50 as substantially all of the fair value of the gross assets acquired is concentrated in the sublicense of the Nucynta Products, which is a single identifiable asset. The Company concluded that the fair value estimates of the assets surrendered, liabilities incurred, and equity interests issued were more clearly evident than the fair value of the assets received, and therefore followed a cost accumulation model to determine the consideration transferred in the asset acquisition. The table below represents the costs accumulated to acquire the sublicense of the Nucynta Products based on the terms of the Nucynta Commercialization Agreement, as amended: ​ ​ ​ ​ ​ Acquisition consideration: ​ ​ ​ Upfront cash paid ​ $ 18,877 Minimum royalty payment obligation (1) ​ ​ 112,719 Rebates, incentives, trade allowances and chargebacks assumed ​ ​ 22,660 Warrant issued ​ ​ 8,043 Total acquisition consideration: ​ $ 162,299 ​ (1) Represents $132,000 of minimum royalty payments owed under the Nucynta Commercialization Agreement discounted for present value adjustments of $19,281 . ​ The Company then allocated the consideration transferred to the individual assets acquired on a relative fair value basis as summarized in the table below: ​ ​ ​ ​ Assets acquired: ​ ​ Nucynta Intangible Asset $ 154,089 Inventory ​ 6,223 Prepaid expenses ​ 1,987 Total consideration allocated to assets acquired: $ 162,299 ​ Under the original terms of the Nucynta Commercialization Agreement, the Company was obligated to make guaranteed annual minimum royalty payments of $537,000 to Assertio, which consisted of scheduled payments of $132,000 in 2018, $135,000 in 2019, $135,000 in 2020, and $135,000 in 2021. Due to the nature of the guaranteed minimum royalty payment obligation and the fact that it was required to be settled in cash, the Company determined that the future minimum royalty payments represented a liability that should be recorded at its fair value as of the Nucynta Commercialization Closing Date. The Company calculated the fair value of the future minimum royalty payments to be $482,300 using a discount rate of 5.7%. The discount rate was determined based on a review of observable market data relating to similar liabilities. The fair value of the future minimum royalty payments was recorded as a component of the intangible asset. The Company determined the $54,700 discount should be recognized as interest expense in the Statement of Operations using the effective interest method and over the repayment period from January 9, 2018 through December 2021. Prior to the Third Amendment to the Nucynta Commercialization Agreement in November 2018, the Company recognized interest expense of $19,281 relating to the minimum royalty payments and amortization expense of $107,662 related to the intangible asset. ​ Effective November 8, 2018 (the “Third Amendment Date”), the Company entered into the Third Amendment to the Nucynta Commercialization Agreement, which eliminated the guaranteed minimum royalty payment obligations for years 2019, 2020 and 2021. As a result, the Company remeasured the remaining contractual obligation as of the Third Amendment Date and recorded a reduction of the acquired intangible asset and obligation. ​ ​ The gross carrying amount and accumulated amortization of the Nucynta Intangible Asset were as follows: ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, ​ As of December 31, ​ 2019 2018 Gross carrying amount $ 154,089 ​ $ 154,089 Accumulated amortization ​ (117,210) ​ (109,834) Intangible assets, net $ 36,879 ​ $ 44,255 ​ Warrant ​ In November 2018, in connection with the Third Amendment to the Nucynta Commercialization Agreement, the Company issued a warrant to Assertio to purchase 1,041,667 shares of common stock of the Company at an exercise price of $19.20 per share. The terms of the warrant are fixed, with the exception of customary adjustments for changes in the Company’s capitalization. The warrant may only be settled with the issuance of shares of common stock upon exercise and will expire in November 2022. The Company has recorded the relative fair value of the warrant as a component of equity interest issued by the Company as consideration transferred in the cost accumulation model for the asset acquisition. The Company estimated the fair value of the warrant on the date of issuance to be approximately $8,043 using the Black-Scholes option-pricing model. The Company concluded that the warrant met the definition of an equity instrument and was recorded as a component of additional paid-in capital in the Company’s Condensed Consolidated Balance Sheet as of the issuance date. ​ Amortization ​ The Company has been amortizing the Nucynta Intangible Asset over its useful life, which is the period over which the asset is expected to contribute directly or indirectly to the future cash flows of the Company. The Company determined that the useful life for the intangible asset was approximately 4.0 years from the Nucynta Commercialization Closing Date. The Company recognizes amortization expense as a component of cost of product revenues in the Statement of Operations on a straight-line basis over its useful life as it approximates the period of economic benefits expected to be realized from future cash inflows from sales of the Nucynta Products. Prior to the Third Amendment to the Nucynta Commercialization Agreement, the Company had recognized $107,662 of amortization expense. As the accumulated cost basis of the intangible asset was reduced with the Third Amendment to the Nucynta Commercialization Agreement, the Company will continue to prospectively amortize the residual net intangible asset on a straight-line basis over the remaining useful life. For the three months ended June 30, 2019 and 2018, the Company recognized amortization expenses of $3,688 and $32,407 respectively. For the six months ended ended June 30, 2019 and 2018, the Company recognized amortization expenses of $7,376 and $61,933 respectively. As of June 30, 2019, the remaining amortization period is approximately 2.5 years and the remaining estimated amortization for 2019, 2020 and 2021 is expected to be $7,376 , $14,752 , and $14,751 , respectively.

Accrued Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2019
Accrued Expenses
Accrued Expenses	9. Accrued Expenses ​ Accrued expenses consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, ​ As of December 31, ​ 2019 2018 Accrued royalties $ 15,463 ​ $ 15,138 Accrued bonuses ​ 2,008 ​ 4,286 Accrued incentive compensation ​ 1,566 ​ ​ 1,806 Accrued payroll and related benefits ​ 1,230 ​ ​ 1,544 Accrued inventory ​ 1,175 ​ ​ 3,745 Accrued audit and legal 674 ​ ​ 480 Accrued sales and marketing ​ 690 ​ ​ 2,193 Accrued interest 382 ​ 274 Accrued other operating costs ​ 1,329 ​ ​ 1,085 Total accrued expenses $ 24,517 ​ $ 30,551 ​

Term Loan Payable

Term Loan Payable	6 Months Ended
	Jun. 30, 2019
Term Loan Payable
Term Loan Payable	10. Term Loan Payable On August 28, 2012, the Company entered into a loan agreement with Silicon Valley Bank (“SVB”) to borrow up to a maximum amount of $1,000. The loan agreement was subsequently amended in 2014 and 2015 to provide for additional borrowings (as amended, the “Existing Term Loan”). In January 2018, in connection with, and as a condition to, consummation of the transactions contemplated by the Nucynta Commercialization Agreement with Assertio, the Company entered into a Consent and Amendment to Loan and Security Agreement (the “Consent and Amendment”) with SVB to amend the Existing Term Loan. The Consent and Amendment provided the Company with a new term loan facility in an original principal amount of $11,500, which replaced the Existing Term Loan and the proceeds of which were used by the Company to finance certain payment obligations under the Nucynta Commercialization Agreement and to repay the balance of the Existing Term Loan. The Existing Term Loan also provided SVB’s consent with respect to the Nucynta Commercialization Agreement. The Consent and Amendment bears interest at a rate per annum of 0.75% above the prime rate (as defined in the Consent and Amendment). The Company will repay the Consent and Amendment in equal consecutive monthly installments of principal plus monthly payments of accrued interest, commencing in July 2019, provided that, if the Company achieves EBITDA (as defined in the Consent and Amendment) in excess of $2,500 for two (2) consecutive calendar quarters prior to June 2019, such payments will commence in January 2020. All outstanding principal and accrued and unpaid interest under the Consent and Amendment, and all other outstanding obligations with respect to the Consent and Amendment, are due and payable in full in December 2022. The Company may prepay the Consent and Amendment, in full but not in part, with a prepayment fee of (i) 3.0% of the outstanding principal balance prior to the first anniversary of the Consent and Amendment, (ii) 2.0% of the outstanding principal balance following the first anniversary of the Consent and Amendment and prior to the second anniversary of the Consent and Amendment and (iii) 1.0% of the outstanding principal balance following the second anniversary of the Consent and Amendment, plus, in each case, a final payment fee of $719 . In November 2018, the Company entered into an amended and restated Loan and Security Agreement (“New Term Loan”) with SVB, that supersedes the Company’s original loan agreement and subsequent amendments with SVB. The New Term Loan amended and restated the loan documentation between the Company and SVB and modified the minimum liquidity ratio to be at least The Company achieved EBITDA in excess of $2,500 for two (2) consecutive calendar quarters prior to June 2019. Therefore, in accordance with the Loan and Security Agreement, the monthly installments of principal payments plus monthly payments of accrued interest will commence in January 2020. As of June 30, 2019, scheduled principle repayments under the Company’s term loan are as follows: ​ ​ ​ ​ 2020 ​ 3,833 2021 ​ 3,833 2022 ​ 3,834 Balance $ 11,500 ​

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases
Leases	11. Leases ​ In accordance with ASC Topic 842, Lease Accounting, the Company records lease assets and liabilities for lease arrangements exceeding a 12-month initial term. For operating leases, the Company records a beginning lease liability equal to the present value of minimum lease payments to be made over the lease term discounted using the Company’s incremental borrowing rate and a corresponding lease asset adjusted for incentives received and indirect costs. After lease commencement, the Company remeasures the operating liability at the present value of the remaining lease payments discounted using the original incremental borrowing rate and corresponding lease asset adjusted for incentives received, indirect costs and uneven lease payments. T in the Statements of Operations Leases with an initial term of 12 months or less, or short-term leases, are not recorded on the balance sheet. Short-term lease expense is recognized on a straight-line basis over the lease term. The Company does not have any financing lease arrangements. ​ As of June 30, 2019, the Company had operating lease assets of $9,574 and operating lease liabilities of $10,536 primarily related to operating lease agreements for its corporate headquarters. ​ Adoption of ASC Topic 842, Lease Accounting ​ The Company adopted ASC Topic 842, as amended, on January 1, 2019, which supersedes the lease accounting requirements in ASC Topic 840, Leases Adoption of the new standard resulted in the Company initially recording operating lease assets of $9,957 and corresponding operating lease liabilities of $10,690 on its Condensed Consolidated Balance Sheet, primarily related to the operating lease agreement for its corporate headquarters. In addition, the Company identified an embedded operating lease arrangement that was accounted as a service contract in prior years, as accounting for operating leases and service contracts was similar under legacy GAAP and the accounting for the embedded lease did not result in a material impact to the financial statements. The Company has also implemented new accounting policies, processes and controls to identify and account for leases, including embedded leases, going forward. Operating Lease Arrangements ​ In March 2018, the Company entered into an operating lease for its new corporate headquarters (the “Stoughton Lease”) pursuant to which the Company leases approximately 50,678 of rentable square feet of space, in Stoughton, Massachusetts. The Stoughton Lease commenced in August 2018 when the Company took possession of the space. After the initial four-month free rent period following possession of the space, the operating lease will continue for a term of 10 years. The Company has the right to extend the term of the Stoughton Lease for two additional five-year terms, provided that written notice is provided to the landlord no later than 12 months prior to the expiration of the then current Stoughton Lease term. The Company does not believe the exercise of the extension to be reasonably certain as of the balance sheet date and therefore did not include the extension as part of its recognized lease asset and lease liability. The annual base rent is $1,214, or $23.95 per rentable square foot, and will increase annually by 2.5% to 3.1% over the subsequent years. ​ The Company continues to lease 9,660 square feet of office and research space at its former corporate headquarters located in Canton, Massachusetts (the “Canton Lease”). The Canton Lease terminates in August 2020 and may be extended for an additional five years at the Company’s election. The Company does not believe the exercise of the extension to be reasonably certain as of the balance sheet date and therefore did not include the extension as part of its recognized lease asset and lease liability. ​ In January 2016, the Company entered a non-cancellable contract with the contract manufacturing organization (“CMO”) of Xtampza ER. The initial contract term continues through December 2020 and automatically renews for successive two-year terms unless either party gives written notice of termination two-years in advance. Xtampza ER production is currently conducted in an area of the manufacturing plant that is shared with other clients. Pursuant to the terms of the agreement, since 2016 the CMO has reserved 3,267 square feet of existing manufacturing space for a dedicated production suite for Xtampza ER, which is currently under construction. Upon adoption of ASC Topic 842, the Company determined that this arrangement has an embedded operating lease arrangement as the Company can direct the use of the dedicated space and obtain substantially all the economic benefits. The Company expects the lease term to continue at least through December 2026 and separated the agreement’s lease and non-lease components in determining the operating lease assets and liabilities. The Company determined its best estimate of stand-alone prices for each of the lease and nonlease components by considering observable information including gross margins expected to be recovered from the Company’s service provider and terms of similar lease contracts. ​ Short-Term Lease Arrangements ​ In December 2018, the Company began entering into 12-month, non-cancelable vehicle leases for its field-based employees. Each vehicle lease is executed separately and will expire at varying times with automatic renewal options that are cancelable at any time. The rent expense for these leases will therefore be recognized on a straight-line basis over the lease term. ​ Variable lease payments associated with non-lease components of these arrangements were immaterial and expensed as incurred. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, ​ Six months ended June 30, ​ ​ 2019 ​ 2019 Lease Cost ​ ​ ​ ​ ​ ​ Operating lease cost ​ $ 353 ​ $ 705 Short-term lease cost ​ ​ 144 ​ ​ 312 Total lease cost ​ $ 497 ​ $ 1,017 ​ ​ ​ ​ ​ ​ ​ As of June 30, Lease Term and Discount Rate: ​ 2019 Weighted-average remaining lease term — operating leases (years) ​ ​ 10.1 Weighted-average discount rate — operating leases ​ ​ 6.1% ​ ​ ​ ​ ​ ​ ​ Six months ended June 30, Other Information: ​ 2019 Cash paid for amounts included in the measurement of operating leases liabilities ​ $ 476 Leased assets obtained in exchange for new operating lease liabilities ​ ​ — ​ ​ Under ASC Topic 842, the Company’s aggregate future minimum lease payments for its operating leases, including embedded operating lease arrangements, as of June 30, 2019, are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ 2019 ​ $ 578 2020 ​ 1,328 2021 ​ ​ 1,284 2022 ​ ​ 1,322 2023 ​ ​ 1,360 After 2023 ​ ​ 8,490 Total minimum lease payments ​ $ 14,362 Less: Present value discount ​ ​ 3,826 Present value of lease liabilities ​ $ 10,536 ​ Under legacy GAAP, the Company’s aggregate future minimum lease payments for its operating leases as of December 31, 2018 were as follows: ​ ​ ​ ​ ​ 2019 ​ $ 1,032 2020 ​ ​ 1,305 2021 ​ ​ 1,261 2022 ​ ​ 1,299 2023 ​ ​ 1,337 After 2023 ​ ​ 8,423 Total minimum lease payments ​ $ 14,657 ​

Equity

Equity	6 Months Ended
	Jun. 30, 2019
Equity
Equity	12. Equity ​ The changes in shareholder’s equity for the three and six months ended June 30, 2019 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Additional ​ ​ Total ​ Common Stock Paid- In Accumulated Shareholders’ ​ Shares ​ Amount Capital Deficit Equity (Deficit) Balance, December 31, 2018 33,265,629 ​ $ 33 ​ $ 428,729 ​ $ (337,177) ​ $ 91,585 Exercise of common stock options 18,693 ​ ​ — ​ ​ 246 ​ ​ — ​ ​ 246 Issuance for employee stock purchase plan 32,826 ​ ​ — ​ ​ 444 ​ ​ — ​ ​ 444 Vesting of restricted stock units ("RSUs") 101,483 ​ ​ — ​ ​ — ​ ​ — ​ ​ — Shares withheld for employee taxes upon vesting of RSUs (33,503) ​ ​ — ​ ​ (488) ​ ​ — ​ ​ (488) Stock-based compensation — ​ ​ — ​ ​ 4,263 ​ ​ — ​ ​ 4,263 Net loss — ​ ​ — ​ ​ — ​ ​ (9,700) ​ ​ (9,700) Balance, March 31, 2019 33,385,128 ​ $ 33 ​ $ 433,194 ​ $ (346,877) ​ $ 86,350 Exercise of common stock options 8,218 ​ ​ — ​ ​ 58 ​ ​ — ​ ​ 58 Vesting of RSUs 26,304 ​ ​ — ​ ​ — ​ ​ — ​ ​ — Shares withheld for employee taxes upon vesting of RSUs (3,097) ​ ​ — ​ ​ (35) ​ ​ — ​ ​ (35) Stock-based compensation — ​ ​ — ​ ​ 4,162 ​ ​ — ​ ​ 4,162 Net loss — ​ ​ — ​ ​ — ​ ​ (4,712) ​ ​ (4,712) Balance, June 30, 2019 33,416,553 ​ $ 33 ​ $ 437,379 ​ $ (351,589) ​ $ 85,823 ​ ​ The changes in shareholder’s equity for the three and six months ended June 30, 2018 ended were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Additional ​ ​ Total ​ Common Stock Paid- In Accumulated Shareholders’ ​ Shares ​ Amount Capital ​ Deficit Equity (Deficit) Balance, December 31, 2017 32,770,678 ​ $ 33 ​ $ 402,096 ​ $ (298,049) ​ $ 104,080 Exercise of common stock options 183,987 ​ ​ — ​ ​ 2,373 ​ ​ — ​ ​ 2,373 Issuance for employee stock purchase plan 50,151 ​ ​ — ​ ​ 510 ​ ​ — ​ ​ 510 Vesting of RSUs 32,573 ​ ​ — ​ ​ — ​ ​ — ​ ​ — Shares withheld for employee taxes upon vesting of RSUs (9,810) ​ ​ — ​ ​ (216) ​ ​ — ​ ​ (216) Stock-based compensation — ​ ​ — ​ ​ 2,728 ​ ​ — ​ ​ 2,728 Net loss — ​ ​ — ​ ​ — ​ ​ (18,652) ​ ​ (18,652) Balance, March 31, 2018 33,027,579 ​ $ 33 ​ $ 407,491 ​ $ (316,701) ​ $ 90,823 Exercise of common stock options 137,419 ​ ​ — ​ ​ 1,532 ​ ​ — ​ ​ 1,532 Vesting of RSUs 20,887 ​ ​ — ​ ​ — ​ ​ — ​ ​ — Shares withheld for employee taxes upon vesting of RSUs (6,205) ​ ​ — ​ ​ (140) ​ ​ — ​ ​ (140) Stock-based compensation — ​ ​ — ​ ​ 3,526 ​ ​ — ​ ​ 3,526 Net loss — ​ ​ — ​ ​ — ​ ​ (13,060) ​ ​ (13,060) Balance, June 30, 2018 33,179,680 ​ $ 33 ​ $ 412,409 ​ $ (329,761) ​ $ 82,681 ​ Controlled Equity Offering Sales Agreement ​ In March 2017, the Company entered into a Controlled Equity Offering Sales Agreement (the “ATM Sales Agreement”), with Cantor Fitzgerald & Co., as sales agent (“Cantor Fitzgerald”), pursuant to which the Company may issue and sell, from time to time, through Cantor Fitzgerald, shares of the Company’s common stock, up to an aggregate offering price of $60,000 (the “ATM Shares”). Under the ATM Sales Agreement, Cantor Fitzgerald may sell the ATM Shares by methods deemed to be an “at-the-market” offering as defined in Rule 415 promulgated under the Securities Act of 1933, as amended (the “Securities Act”), including sales made directly on The NASDAQ Global Select Market, on any other existing trading market for the ATM Shares or to or through a market maker. In addition, under the ATM Sales Agreement, Cantor Fitzgerald may sell the ATM Shares by any other method permitted by law, including in privately negotiated transactions. The Company is not obligated to make any sales of the ATM Shares under the ATM Sales Agreement. The Company or Cantor Fitzgerald may suspend or terminate the offering of ATM Shares upon notice to the other party and subject to other conditions. The Company will pay Cantor Fitzgerald a commission of up to 3.0% of the gross proceeds from the sale of the ATM Shares pursuant to the ATM Sales Agreement and has agreed to provide Cantor Fitzgerald with customary indemnification and contribution rights. ​ No shares were sold pursuant to the ATM Sales during the six months ended June 30, 2019 or the year ended December 31, 2018. ​ Warrants ​ As of June 30, 2019, the warrant issued to Assertio in November 2018 was the Company’s only outstanding warrant, which is described in greater detail in Note 8.

Stock-based Compensation

Stock-based Compensation	6 Months Ended
	Jun. 30, 2019
Stock-based Compensation
Stock-based Compensation	13. Stock-based Compensation ​ A summary of the Company’s stock-based compensation expense included in the Condensed Consolidated Statements of Operations are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, ​ Six months ended June 30, ​ 2019 ​ 2018 ​ 2019 ​ 2018 Research and development expenses $ 514 $ 380 ​ $ 1,081 $ 703 Selling, general and administrative expenses 3,648 ​ 3,146 ​ 7,344 ​ 5,551 Total stock-based compensation expense $ 4,162 ​ $ 3,526 ​ $ 8,425 ​ $ 6,254 ​ At June 30, 2019, there was approximately $34,447 of unrecognized compensation expense related to unvested options, restricted stock units and performance stock units, which is expected to be recognized as expense over a weighted average period of approximately 2.7 years. ​ Restricted Stock Units, Performance Share Units, and Stock Options ​ In May 2015, the Company adopted the Amended and Restated 2014 Stock Incentive Plan (the “Plan”), under which an aggregate of 2,700,000 shares of common stock were authorized for issuance to employees, officers, directors, consultants and advisors of the Company, plus an annual increase on the first day of each fiscal year until the expiration of the Plan equal to 4% of the total number of outstanding shares of common stock on December 31 st following the termination date, while unvested options are forfeited immediately upon termination. ​ In January 2019, the Company granted performance share units (“PSUs”) to certain members of the Company's senior management team. The PSUs will vest following a three-year performance period, subject to the satisfaction of annual and cumulative performance criteria and the executive’s continued employment through the performance period. No shares will be issued if the minimum applicable performance metric is not achieved. The Company recognizes compensation expense ratably over the required service period based on its estimate of the number of shares that will vest based upon the probability of achieving performance metrics. If there is a change in the estimate of the number of shares that are likely to vest, the Company will cumulatively adjust compensation expense in the period that the change in estimate is made. Achievement of the annual and cumulative performance criteria for PSU grants will be determined by the compensation committee. For PSUs granted in 2019, the performance criteria relate to Xtampza ER 2019, 2020, 2021 and ​ A summary of the Company’s performance share units activity for the six months ended June 30, 2019 and related information is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ Shares ​ Grant Date Fair Value Outstanding at December 31, 2018 ​ — ​ $ — Granted ​ 99,400 ​ ​ 15.90 Outstanding at June 30, 2019 ​ 99,400 ​ $ 15.90 ​ A summary of the Company’s restricted stock units activity for the six months ended June 30, 2019 and related information is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ Shares ​ Grant Date Fair Value Outstanding at December 31, 2018 ​ 514,603 ​ $ 20.67 Granted ​ 590,205 ​ ​ 15.78 Vested ​ (127,787) ​ ​ 21.54 Forfeited ​ (84,784) ​ ​ 18.26 Outstanding at June 30, 2019 ​ 892,237 ​ $ 17.54 ​ A summary of the Company’s stock option activity for the six months ended June 30, 2019 and related information is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ Weighted- Average ​ ​ ​ ​ ​ ​ ​ Average Remaining ​ ​ Aggregate ​ ​ ​ ​ ​ Exercise Price Contractual ​ ​ Intrinsic ​ Shares ​ per Share Term (in years) ​ Value Outstanding at December 31, 2018 3,585,856 ​ $ 16.20 8.0 ​ $ 11,170 Granted 897,312 ​ 15.67 ​ ​ ​ ​ ​ Exercised (26,911) ​ ​ 11.30 ​ ​ ​ ​ ​ Cancelled (266,141) ​ 17.61 ​ ​ ​ ​ ​ Outstanding at June 30, 2019 4,190,116 ​ $ 16.03 7.7 ​ $ 5,248 Exercisable at June 30, 2019 2,113,346 ​ $ 14.45 6.6 ​ $ 4,285 ​ The fair value of each stock option is estimated on the grant date using the Black-Scholes option-pricing model using the following assumptions: ​ ​ ​ ​ ​ ​ ​ ​ Six months ended June 30, ​ 2019 ​ 2018 Risk-free interest rate 2.6 % ​ 2.6 % Volatility 63.3 % ​ 65.0 % Expected term (years) 6.06 ​ ​ 6.11 ​ Expected dividend yield — % ​ — % ​ Employee Stock Purchase Plan ​ The Company’s 2015 Employee Stock Purchase Plan allows employees to purchase shares of the Company’s common stock. The purchase price is equal to 85% of the lower of the closing price of the Company’s common stock on (1) the first day of the purchase period or (2) the last day of the purchase period. During the three and six months ended June 30, 2019, 32,826 shares of common stock were purchased for total proceeds of $444. The expense for the three months ended June 30, 2019 and 2018 was $73 and $120, respectively. The expense for the six months ended June 30, 2019 and 2018 was $173 and $242, respectively.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies
Commitments and Contingencies	14. Commitments and Contingencies ​ Legal Proceedings ​ From time to time, the Company may face legal claims or actions in the normal course of business. Except as disclosed below, the Company is not currently a party to any litigation and, accordingly, does not have any amounts recorded for any litigation related matters. ​ Xtampza ER Litigation The Company filed the NDA for Xtampza ER as a 505(b)(2) application, which allows the Company to reference data from an approved drug listed in the FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations (commonly known as the Orange Book), in this case OxyContin OP. The 505(b)(2) process requires that the Company certifies to the FDA and notify Purdue Pharma, L.P (“Purdue”), as the holder of the NDA and any other Orange Book-listed patent owners, that the Company does not infringe any of the patents listed for OxyContin OP in the Orange Book, or that the patents are invalid. The Company made such certification and provided such notice on February 11, 2015 and such certification documented why Xtampza ER does not infringe any of the 11 Orange Book listed patents for OxyContin OP, five of which have been invalidated in court proceedings. Under the Hatch-Waxman Act of 1984, Purdue had the option to sue the Company for infringement and receive a stay of up to 30 months before the FDA could issue a final approval for Xtampza ER, unless the stay was earlier terminated. ​ Purdue exercised its option and elected to sue the Company for infringement in the District of Delaware on March 24, 2015 asserting infringement of three of Purdue’s Orange Book-listed patents (Patent Nos. 7,674,799, 7,674,800, and 7,683,072) and a non-Orange Book-listed patent (Patent No. 8,652,497), and accordingly, received a 30-month stay of FDA approval. The Delaware court transferred the case to the District of Massachusetts. After the Company filed a partial motion for judgment on the pleadings relating to the Orange Book-listed patents, the District Court of Massachusetts ordered judgment in the Company’s favor on those three patents, and dismissed the claims asserting infringement of those patents with prejudice. Upon dismissal of those claims, the 30-month stay of FDA approval was lifted. As a result, the Company was able to obtain final approval for Xtampza ER and launch the product commercially. In November 2015, Purdue filed a follow-on suit asserting infringement of another patent, Patent No. 9,073,933, which was late-listed in the Orange Book and therefore could not trigger any stay of FDA approval. In June 2016, Purdue filed another follow-on suit asserting infringement of another non-Orange Book listed patent, Patent No. 9,155,717. In April 2017, Purdue filed another follow-on suit asserting infringement of another patent, Patent No. 9,522,919, which was late-listed in the Orange Book and therefore could not trigger any stay of FDA approval. Then, in September 2017, Purdue filed another follow-on suit asserting infringement of another non-Orange Book listed patent, Patent No. 9,693,961. ​ On March 13, 2018, the Company filed a Petition for Post-Grant Review (“PGR”) of the ʼ961 patent with the Patent Trial and Appeal Board (“PTAB”). The PGR argues that the ʼ961 patent is invalid for lack of a written description, for lack of enablement, for indefiniteness, and as being anticipated by prior art. Purdue filed its Patent Owner Preliminary Response on July 10, 2018. The PTAB entered an order to institute post-grant review of all claims of the ’961 patent on October 4, 2018, upon a finding that it is more likely than not that the claims of the ʼ961 patent are unpatentable. Purdue filed its Patent Owner Response on January 30, 2019. The Company filed its reply on April 12, 2019, and Purdue filed a sur-reply on May 10, 2019. The PTAB held oral argument on the proceedings on July 10, 2019 and, absent special circumstances, will issue a decision on the patentability of the ʼ961 patent by no later than October 4, 2019. ​ In October 2017, and in response to the filing of the Company’s Supplemental NDA (“sNDA”) seeking to update the drug abuse and dependence section of the Xtampza ER label, Purdue filed another suit asserting infringement of the ʼ933 and ʼ919 patent. The Company filed a motion to dismiss that action, and the Court granted its motion on January 16, 2018. The current suits have been consolidated by the District of Massachusetts, where Purdue asserted infringement of five patents: the ʼ497 patent, the ʼ933 patent, the ʼ717 patent, the ʼ919 patent, and the ʼ961 patent. The Court issued an order on September 28, 2018 in which it granted in part a motion for summary judgment filed by the Company, and in which the Court ruled that the ʼ497 and ʼ717 patents are not infringed by the Company. As a result, only the ʼ933, the ʼ919, and the ʼ961 patents remain in dispute. On October 16, 2018, the Company filed a motion to stay proceedings in the district court on the ‘961 patent pending the PGR. None of these suits are associated with any stay of FDA approval for Xtampza ER. Purdue has made a demand for monetary relief but has not quantified its alleged damages. Purdue has also requested a judgment of infringement, an adjustment of the effective date of FDA approval, and an injunction on the sale of the Company’s products accused of infringement. The Company has denied all claims and seeks a judgment that the patents are invalid and/or not infringed by the Company; the Company is also seeking a judgment that the case is exceptional, with an award to the Company of its fees for defending the case. The parties are in the early stages of fact discovery. Written discovery has commenced with depositions expected to commence during 2019. A claim construction hearing was held on June 1, 2017. On November 21, 2017, the Court issued its claim construction ruling, construing certain claims of the ʼ933, ʼ497, and ʼ717 patents. No trial date has been scheduled. The Company is, and plans to continue, defending this case vigorously. At this stage, the Company is unable to evaluate the likelihood of an unfavorable outcome or estimate the amount or range of potential loss, if any. ​ Nucynta Litigation On February 7, 2018, Purdue filed a patent infringement suit against the Company in the District of Delaware. Specifically, Purdue argues that the Company’s sale of immediate-release and extended-release Nucynta infringes U.S. Patent Nos. 9,861,583, 9,867,784, and 9,872,836. Purdue has made a demand for monetary relief in its complaint but has not quantified its alleged damages. ​ On December 6, 2018, the Company filed an Amended Answer asserting an affirmative defense for patent exhaustion. On December 10, 2018, the Court granted the parties’ stipulation for resolution of the Company’s defense of patent exhaustion and stayed the action, with the exception of briefing on and resolution of the Company’s Motion for Judgment on the Pleadings and any discovery related to that Motion. On December 12, 2018, the Company filed a Rule 12(c) Motion for Judgment on the Pleadings, arguing that the Purdue’s claims were barred by the doctrine of patent exhaustion. Purdue filed its response on January 11, 2019 and the Company filed a reply on January 25, 2019. On June 18, 2019, the court heard oral argument on the Company’s Rule 12(c) Motion for Judgment on the Pleadings. On June 19, 2019, the court issued an order stating that “judgment in Collegium’s favor is warranted under the doctrine of patent exhaustion to the extent Collegium’s alleged infringing activities resulted from sales that fall within the scope of that covenant.” The court explained, however, that based on the current record, it was not possible “to determine whether title of the Nucynta Products was transferred to Collegium” from sales authorized by Purdue’s covenant not to sue. The court ordered discovery on this issue and the case remains “stayed with the exception of discovery and briefing on and resolution of the Company’s anticipated motion for summary judgment based on patent exhaustion.” ​ The Company plans to defend this case vigorously. At this stage, the Company is unable to evaluate the likelihood of an unfavorable outcome or estimate the amount or range of potential loss, if any. Teva Litigation The Company has fifteen patents listed in the FDA Orange Book as covering the Company’s abuse-deterrent product and methods of using it to treat patients: Patents Nos. 7,399,488; 7,771,707; 8,449,909; 8,557,291; 8,758,813; 8,840,928; 9,044,398; 9,248,195; 9,592,200; 9,682,075; 9,737,530, 9,763,883; 9,968,598; 10,004,729; and 10,188,644 (the “Orange Book Patents”). Teva Pharmaceuticals USA, Inc. (“Teva”) filed Notice Letters of Patent Certification against all of the fifteen listed Orange Book Patents alleging that they were invalid and/or not infringed by the proposed oxycodone products that are the subject of ​ The Company filed a second lawsuit in the District of Delaware, asserting two additional Orange Book Patents, on November 30, 2018. Teva responded to the Company’s complaint on January 11, 2019, alleging that the asserted patents are invalid and are not infringed by Teva’s proposed ANDA products, and asserting counterclaims of non-infringement and invalidity of the asserted patents. The Company answered Teva’s counterclaims on February 1, 2019. The court consolidated the second suit with the first suit, and thus both suits are proceeding on the same schedule. ​ The Company filed a third lawsuit in the District of Delaware, asserting one additional Orange Book Patent, on May 9, 2019. Teva responded to the Company’s complaint on June 6, 2019, alleging that the asserted patent is invalid and is not infringed by Teva’s proposed ANDA products, and asserting counterclaims of non-infringement and invalidity of the asserted patent. The Company answered Teva’s counterclaims on June 27, 2019. No schedule has been entered in the third lawsuit. ​ Opioid Litigation ​ On March 19, 2018, a lawsuit was filed by multiple local governments in the Circuit Court of Crittenden County, Arkansas, against the Company and other pharmaceutical manufacturers and distributors alleging a variety of claims related to opioid marketing and distribution practices. On January 29, 2019, the Company was dismissed from this litigation without prejudice. ​ On March 21, 2018, the Company, along with other pharmaceutical manufacturers and distributors, were named in a class-action lawsuit filed in the Eastern District of Kentucky by a family practice clinic, on behalf of other similarly-situated healthcare providers. The action alleges violations of the Racketeer Influenced and Corrupt Organizations Act (“RICO”) relating to opioid marketing and distribution practices. On April 14, 2018, the lawsuit was conditionally transferred by the Judicial Panel on Multi-District Litigation to the federal Prescription Opiate Multi District Litigation (the “MDL”) in the Southern District of Ohio. On April 10, 2018, the conditional transfer was finalized and the lawsuit was docketed in the MDL on April 11, 2018. On May 4, 2018, the Company, along with other pharmaceutical manufacturers and distributors, were named in two lawsuits filed in the MDL by the Fiscal Court of Bourbon County, Kentucky and the Fiscal Court of Owen County, Kentucky, relating to opioid marketing and distribution practices. On June 11 and 12, 2018, the Company was named in four lawsuits filed in the MDL by a health system and various member hospitals. On September 26, 2018, the Company was named in two lawsuits filed in the MDL by the Fiscal Court of Lee County, Kentucky and the Fiscal Court of Wolfe County, Kentucky. On March 15, 2019, the Company was named in an additional lawsuit in the MDL by the City of Paterson, New Jersey. The lawsuits all seek, generally, penalties and/or injunctive relief. On March 15, 2019, the plaintiffs in all of the MDL cases in which the Company was named, except for the City of Paterson case, filed amended complaints which no longer name the Company as a defendant, effectively terminating these lawsuits as to the Company. The City of Paterson lawsuit is not designated as a representative case in the MDL and, therefore, is effectively currently stayed. In April 2019, the City of Norwich, Connecticut and the Town of Enfield, Connecticut filed lawsuits in Connecticut Superior Court. The lawsuits allege violations of fraud, public nuisance, negligent misrepresentation, and violations of state consumer protection laws. On June 28, 2019, both cases were transferred to the MDL, where they are effectively stayed. ​ On May 29, 2018, a lawsuit was filed by Bucks County, Pennsylvania against the Company and other pharmaceutical manufacturers and on June 12, 2018, a lawsuit was filed by Clinton County, Pennsylvania, against the Company and other pharmaceutical manufacturers and distributors. On June 6, 2018, a lawsuit was filed by Mercer County, Pennsylvania, against the Company and other pharmaceutical manufacturers and distributors. These lawsuits allege claims related to opioid marketing and distribution, including negligence, fraud, unjust enrichment, public nuisance, and violations of state consumer protections laws. These cases have been consolidated for discovery purposes in the Delaware County Court of Common Pleas as part of a consolidated proceeding of similar lawsuits brought by numerous Pennsylvania counties against other pharmaceutical manufacturers and distributors. In March 2019, three additional cases were filed in Pennsylvania by two payor groups and Warminster Township. In July 2019, the Company learned of additional lawsuits alleging similar claims which were filed by Warrington Township in the Bucks County Court of Common Pleas, and filed by the City of Lock Haven in the Clinton County Court of Common Pleas. The City of Lock Haven case has been coordinated into the consolidated proceeding before the Delaware County Court of Common Pleas; the Warrington Township case is pending transfer. None of these cases have been designated a Track One case in which discovery would commence, and therefore are effectively stayed at present. ​ On July 30, 2018, a lawsuit was filed by the City of Worcester, Massachusetts against the Company and other pharmaceutical manufacturers and distributors. The action alleges a variety of claims related to opioid marketing and distribution practices including public nuisance, common law fraud, negligent misrepresentation, negligence, violations of Mass Gen. Laws ch. 93A, Section 11 City of Cambridge and the Town of Randolph, each of these additional lawsuits has been coordinated before the Business Litigation Session; the City of Cambridge and Town of Randolph are pending transfer into the Business Litigation Session. The case brought by the City of Springfield has been selected to advance for the purpose of motions practice. The other cases pending before the Business Litigation Session are effectively stayed at present. ​ On January 11, 2019, the City of Portsmouth filed a lawsuit in Virginia Circuit Court against the Company and other pharmaceutical manufacturers and distributors. The lawsuit alleges a variety of claims related to opioid marketing and distribution practices including public nuisance, common law fraud, negligent misrepresentation, negligence, and violations of state consumer protection laws. On June 24, 2019, the case was removed to the Eastern District of Virginia federal court, where it awaits either coordination in the federal MDL or remand to state court. The plaintiff has filed its opposition to coordination and requested remand to Virginia Circuit Court. ​ On June 14, 2019, the City of Trenton filed a lawsuit in New Jersey Superior Court against the Company and other pharmaceutical manufacturers and distributors. The lawsuit alleges a variety of claims related to opioid marketing and distribution practices including public nuisance, common law fraud, negligent misrepresentation, negligence, and violations of state consumer protection laws and the New Jersey Drug Dealer Liability Act. ​ The Company disputes the allegations in these lawsuits and intends to vigorously defend these actions. At this stage, the Company is unable to evaluate the likelihood of an unfavorable outcome or estimate the amount or range of potential loss, if any. ​ Opioid-Related Request and Subpoenas The Company, like a number of other pharmaceutical companies, has received subpoenas or civil investigative demands related to opioid sales and marketing. The Company has received such subpoenas or civil investigative demands from the Offices of the Attorney General of each of Washington, New Hampshire, and Massachusetts. The Company is currently cooperating with each of the foregoing states in their respective investigations.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2019
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation ​ The accompanying unaudited Condensed Consolidated Financial Statements include the accounts of Collegium Pharmaceutical, Inc. (a Virginia corporation) as well as the accounts of Collegium Securities Corp. (a Massachusetts corporation), incorporated in December 2015, and Collegium NF, LLC (a Delaware limited liability company), organized in December 2017, both wholly owned subsidiaries requiring consolidation. The consolidated financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial reporting and as required by Regulation S-X, Rule 10-01. Accordingly, they do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. ​ In the opinion of the Company’s management, the accompanying unaudited Condensed Consolidated Financial Statements contain all adjustments (consisting of items of a normal and recurring nature) necessary to fairly present the financial position of the Company as of June 30, 2019, the results of operations for the three and six months ended June 30, 2019 and 2018, and cash flows for the six months ended June 30, 2019 and 2018. The results of operations for the six months ended June 30, 2019 are not necessarily indicative of the results to be expected for the full year. ​ When preparing financial statements in conformity with GAAP, the Company must make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s financial statements and accompanying notes. The most significant estimates in the Company’s financial statements relate to revenue recognition, including the estimates of product returns, units prescribed, discounts and allowances related to commercial sales of its products, estimates of useful lives with respect to intangible assets, accounting for stock-based compensation, contingencies, impairment of intangible assets, and tax valuation reserves. The Company bases estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis. The Company’s actual results may differ from these estimates under different assumptions or conditions. The consolidated interim financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018 (the “Annual Report”).
Recent Accounting Pronouncements	Recently Adopted Accounting Pronouncements ​ New accounting pronouncements are issued periodically by the Financial Accounting Standards Board (“FASB”) and are adopted by the Company as of the specified effective dates. ​ The Company adopted Accounting Standard Updated (“ASU”) 2016-02, Leases (ASC Topic 842 he Company utilized the package of practical expedients permitted within the transition guidance, which, among other things, allowed the Company to carryforward the historical lease classification. Upon adoption, the new standard resulted in the Company recording material operating lease assets and corresponding operating lease liabilities on its balance sheet. As of June 30, 2019, the Company had operating lease assets of

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	6 Months Ended
	Jun. 30, 2019
Revenue from Contracts with Customers
Summary of product revenue provision and allowance	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Trade ​ ​ Rebates and ​ Product ​ Allowances and ​ ​ Incentives (1) ​ Returns (2) ​ Chargebacks (3) Balance at December 31, 2018 ​ $ 129,318 ​ $ 15,465 ​ $ 14,841 Provision related to current period sales ​ ​ 128,509 ​ ​ 9,150 ​ ​ 31,988 Changes in estimate related to prior period sales ​ ​ (3,017) ​ ​ — ​ ​ — Credits/payments made ​ ​ (119,659) ​ ​ (1,502) ​ ​ (32,673) Balance at June 30, 2019 ​ $ 135,151 ​ $ 23,113 ​ $ 14,156 ​ ​ ​ (1) Rebates and incentives includes managed care rebates, government rebates, co-pay program incentives, and sales incentives and allowances. Provisions for rebates and discounts are deducted from gross revenues at the time revenues are recognized and are included in accrued rebates, returns and discounts in the Company’s Condensed Consolidated Balance Sheets. ​ (2) Provisions for product returns are deducted from gross revenues at the time revenues are recognized and are included in accrued rebates, returns and discounts in the Company’s Condensed Consolidated Balance Sheets. ​ (3) ​ Trade allowances and chargebacks include fees for distribution service fees, prompt pay discounts, and chargebacks. Trade allowances and chargebacks are deducted from gross revenue at the time revenues are recognized and are recorded as a reduction to accounts receivable in the Company’s Condensed Consolidated Balance Sheets. ​
Schedule of disaggregation of revenue	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, ​ Six months ended June 30, ​ 2019 ​ 2018 ​ 2019 ​ 2018 Xtampza ER $ 26,018 $ 18,116 ​ $ 51,152 ​ $ 33,911 Nucynta Products 49,022 ​ 54,945 ​ 98,404 ​ 102,899 Total product revenues, net $ 75,040 ​ $ 73,061 ​ $ 149,556 ​ $ 136,810 ​

Loss per Common Share (Tables)

Loss per Common Share (Tables)	6 Months Ended
	Jun. 30, 2019
Loss per Common Share
Schedule of computations of basic and diluted net loss per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, ​ Six months ended June 30, ​ ​ 2019 ​ 2018 ​ ​ 2019 ​ 2018 Loss attributable to common shareholders — basic and diluted $ (4,712) ​ $ (13,060) ​ $ (14,412) ​ $ (31,712) Weighted-average number of common shares used in net loss per share - basic and diluted ​ 33,397,709 ​ ​ 32,967,718 ​ ​ 33,338,243 ​ ​ 32,935,873 Loss per share - basic and diluted $ (0.14) ​ $ (0.40) ​ $ (0.43) ​ $ (0.96)
Schedule of potentially dilutive securities excluded from computations of diluted weighted-average shares outstanding	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, Six months ended June 30, ​ 2019 2018 2019 2018 Outstanding stock options 4,190,116 ​ 3,665,459 ​ 4,190,116 ​ 3,665,459 Warrants 1,041,667 ​ — ​ 1,041,667 ​ — Unvested restricted stock (1) — ​ 12,072 ​ — ​ 12,072 Restricted stock units 892,237 ​ 522,190 ​ 892,237 ​ 522,190 Performance share units 99,400 ​ — ​ 99,400 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (1) - Includes shares of unvested restricted stock remaining from the early exercise of stock options. ​

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value of Financial Instruments
Schedule of financial instruments measured at fair value by level within fair value hierarchy	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Significant ​ ​ ​ ​ ​ ​ ​ ​ ​ Quoted Prices ​ ​ other ​ ​ Significant ​ ​ ​ ​ ​ ​ in active ​ ​ observable ​ ​ unobservable ​ ​ ​ ​ ​ ​ markets ​ ​ inputs ​ ​ inputs June 30, 2019 ​ Total ​ (Level 1) ​ (Level 2) ​ (Level 3) Money market funds, included in cash equivalents ​ $ 93,968 ​ $ 93,968 ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds, included in cash equivalents ​ $ 92,914 ​ $ 92,914 ​ $ — ​ $ —

Inventory (Tables)

Inventory (Tables)	6 Months Ended
	Jun. 30, 2019
Inventory
Schedule of Inventory	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, ​ As of December 31, ​ ​ 2019 ​ 2018 Raw materials ​ $ 1,664 ​ $ 496 Work in process ​ ​ 848 ​ ​ 671 Finished goods ​ ​ 7,441 ​ ​ 6,650 Total inventory ​ $ 9,953 ​ $ 7,817

Intangible Assets (Tables)

Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2019
Intangible Assets
Costs accumulated to acquire assets and consideration allocated to assets	The table below represents the costs accumulated to acquire the sublicense of the Nucynta Products based on the terms of the Nucynta Commercialization Agreement, as amended: ​ ​ ​ ​ ​ Acquisition consideration: ​ ​ ​ Upfront cash paid ​ $ 18,877 Minimum royalty payment obligation (1) ​ ​ 112,719 Rebates, incentives, trade allowances and chargebacks assumed ​ ​ 22,660 Warrant issued ​ ​ 8,043 Total acquisition consideration: ​ $ 162,299 ​ (1) Represents $132,000 of minimum royalty payments owed under the Nucynta Commercialization Agreement discounted for present value adjustments of $19,281 . ​ The Company then allocated the consideration transferred to the individual assets acquired on a relative fair value basis as summarized in the table below: ​ ​ ​ ​ Assets acquired: ​ ​ Nucynta Intangible Asset $ 154,089 Inventory ​ 6,223 Prepaid expenses ​ 1,987 Total consideration allocated to assets acquired: $ 162,299 ​
Carrying amount of Nucynta intangible	​ ​ ​ ​ ​ ​ ​ ​ As of June 30, ​ As of December 31, ​ 2019 2018 Gross carrying amount $ 154,089 ​ $ 154,089 Accumulated amortization ​ (117,210) ​ (109,834) Intangible assets, net $ 36,879 ​ $ 44,255

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2019
Accrued Expenses
Schedule of components of accrued expenses	​ ​ ​ ​ ​ ​ ​ ​ As of June 30, ​ As of December 31, ​ 2019 2018 Accrued royalties $ 15,463 ​ $ 15,138 Accrued bonuses ​ 2,008 ​ 4,286 Accrued incentive compensation ​ 1,566 ​ ​ 1,806 Accrued payroll and related benefits ​ 1,230 ​ ​ 1,544 Accrued inventory ​ 1,175 ​ ​ 3,745 Accrued audit and legal 674 ​ ​ 480 Accrued sales and marketing ​ 690 ​ ​ 2,193 Accrued interest 382 ​ 274 Accrued other operating costs ​ 1,329 ​ ​ 1,085 Total accrued expenses $ 24,517 ​ $ 30,551 ​

Term Loan Payable (Tables)

Term Loan Payable (Tables)	6 Months Ended
	Jun. 30, 2019
Term Loan Payable
Schedule of future payments under debt agreements	​ ​ ​ ​ 2020 ​ 3,833 2021 ​ 3,833 2022 ​ 3,834 Balance $ 11,500 ​

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases
Schedule of lease cost	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, ​ Six months ended June 30, ​ ​ 2019 ​ 2019 Lease Cost ​ ​ ​ ​ ​ ​ Operating lease cost ​ $ 353 ​ $ 705 Short-term lease cost ​ ​ 144 ​ ​ 312 Total lease cost ​ $ 497 ​ $ 1,017
Schedule of lease quantitative details	​ ​ ​ ​ ​ ​ ​ As of June 30, Lease Term and Discount Rate: ​ 2019 Weighted-average remaining lease term — operating leases (years) ​ ​ 10.1 Weighted-average discount rate — operating leases ​ ​ 6.1%
Schedule of other information	​ ​ ​ ​ ​ ​ ​ Six months ended June 30, Other Information: ​ 2019 Cash paid for amounts included in the measurement of operating leases liabilities ​ $ 476 Leased assets obtained in exchange for new operating lease liabilities ​ ​ —
Schedule of future minimum lease payments - ASC Topic 842	​ ​ ​ ​ ​ ​ ​ ​ ​ 2019 ​ $ 578 2020 ​ 1,328 2021 ​ ​ 1,284 2022 ​ ​ 1,322 2023 ​ ​ 1,360 After 2023 ​ ​ 8,490 Total minimum lease payments ​ $ 14,362 Less: Present value discount ​ ​ 3,826 Present value of lease liabilities ​ $ 10,536
Schedule of future minimum lease payments - legacy GAAP	​ ​ ​ ​ ​ 2019 ​ $ 1,032 2020 ​ ​ 1,305 2021 ​ ​ 1,261 2022 ​ ​ 1,299 2023 ​ ​ 1,337 After 2023 ​ ​ 8,423 Total minimum lease payments ​ $ 14,657 ​

Equity (Tables)

Equity (Tables)	6 Months Ended
	Jun. 30, 2019
Equity
Summary of Changes in Shareholders' Equity	The changes in shareholder’s equity for the three and six months ended June 30, 2019 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Additional ​ ​ Total ​ Common Stock Paid- In Accumulated Shareholders’ ​ Shares ​ Amount Capital Deficit Equity (Deficit) Balance, December 31, 2018 33,265,629 ​ $ 33 ​ $ 428,729 ​ $ (337,177) ​ $ 91,585 Exercise of common stock options 18,693 ​ ​ — ​ ​ 246 ​ ​ — ​ ​ 246 Issuance for employee stock purchase plan 32,826 ​ ​ — ​ ​ 444 ​ ​ — ​ ​ 444 Vesting of restricted stock units ("RSUs") 101,483 ​ ​ — ​ ​ — ​ ​ — ​ ​ — Shares withheld for employee taxes upon vesting of RSUs (33,503) ​ ​ — ​ ​ (488) ​ ​ — ​ ​ (488) Stock-based compensation — ​ ​ — ​ ​ 4,263 ​ ​ — ​ ​ 4,263 Net loss — ​ ​ — ​ ​ — ​ ​ (9,700) ​ ​ (9,700) Balance, March 31, 2019 33,385,128 ​ $ 33 ​ $ 433,194 ​ $ (346,877) ​ $ 86,350 Exercise of common stock options 8,218 ​ ​ — ​ ​ 58 ​ ​ — ​ ​ 58 Vesting of RSUs 26,304 ​ ​ — ​ ​ — ​ ​ — ​ ​ — Shares withheld for employee taxes upon vesting of RSUs (3,097) ​ ​ — ​ ​ (35) ​ ​ — ​ ​ (35) Stock-based compensation — ​ ​ — ​ ​ 4,162 ​ ​ — ​ ​ 4,162 Net loss — ​ ​ — ​ ​ — ​ ​ (4,712) ​ ​ (4,712) Balance, June 30, 2019 33,416,553 ​ $ 33 ​ $ 437,379 ​ $ (351,589) ​ $ 85,823 ​ ​ The changes in shareholder’s equity for the three and six months ended June 30, 2018 ended were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Additional ​ ​ Total ​ Common Stock Paid- In Accumulated Shareholders’ ​ Shares ​ Amount Capital ​ Deficit Equity (Deficit) Balance, December 31, 2017 32,770,678 ​ $ 33 ​ $ 402,096 ​ $ (298,049) ​ $ 104,080 Exercise of common stock options 183,987 ​ ​ — ​ ​ 2,373 ​ ​ — ​ ​ 2,373 Issuance for employee stock purchase plan 50,151 ​ ​ — ​ ​ 510 ​ ​ — ​ ​ 510 Vesting of RSUs 32,573 ​ ​ — ​ ​ — ​ ​ — ​ ​ — Shares withheld for employee taxes upon vesting of RSUs (9,810) ​ ​ — ​ ​ (216) ​ ​ — ​ ​ (216) Stock-based compensation — ​ ​ — ​ ​ 2,728 ​ ​ — ​ ​ 2,728 Net loss — ​ ​ — ​ ​ — ​ ​ (18,652) ​ ​ (18,652) Balance, March 31, 2018 33,027,579 ​ $ 33 ​ $ 407,491 ​ $ (316,701) ​ $ 90,823 Exercise of common stock options 137,419 ​ ​ — ​ ​ 1,532 ​ ​ — ​ ​ 1,532 Vesting of RSUs 20,887 ​ ​ — ​ ​ — ​ ​ — ​ ​ — Shares withheld for employee taxes upon vesting of RSUs (6,205) ​ ​ — ​ ​ (140) ​ ​ — ​ ​ (140) Stock-based compensation — ​ ​ — ​ ​ 3,526 ​ ​ — ​ ​ 3,526 Net loss — ​ ​ — ​ ​ — ​ ​ (13,060) ​ ​ (13,060) Balance, June 30, 2018 33,179,680 ​ $ 33 ​ $ 412,409 ​ $ (329,761) ​ $ 82,681

Stock-based Compensation (Table

Stock-based Compensation (Tables)	6 Months Ended
	Jun. 30, 2019
Summary of stock-based compensation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, ​ Six months ended June 30, ​ 2019 ​ 2018 ​ 2019 ​ 2018 Research and development expenses $ 514 $ 380 ​ $ 1,081 $ 703 Selling, general and administrative expenses 3,648 ​ 3,146 ​ 7,344 ​ 5,551 Total stock-based compensation expense $ 4,162 ​ $ 3,526 ​ $ 8,425 ​ $ 6,254
Summary of restricted stock units activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ Shares ​ Grant Date Fair Value Outstanding at December 31, 2018 ​ 514,603 ​ $ 20.67 Granted ​ 590,205 ​ ​ 15.78 Vested ​ (127,787) ​ ​ 21.54 Forfeited ​ (84,784) ​ ​ 18.26 Outstanding at June 30, 2019 ​ 892,237 ​ $ 17.54
Summary of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ Weighted- Average ​ ​ ​ ​ ​ ​ ​ Average Remaining ​ ​ Aggregate ​ ​ ​ ​ ​ Exercise Price Contractual ​ ​ Intrinsic ​ Shares ​ per Share Term (in years) ​ Value Outstanding at December 31, 2018 3,585,856 ​ $ 16.20 8.0 ​ $ 11,170 Granted 897,312 ​ 15.67 ​ ​ ​ ​ ​ Exercised (26,911) ​ ​ 11.30 ​ ​ ​ ​ ​ Cancelled (266,141) ​ 17.61 ​ ​ ​ ​ ​ Outstanding at June 30, 2019 4,190,116 ​ $ 16.03 7.7 ​ $ 5,248 Exercisable at June 30, 2019 2,113,346 ​ $ 14.45 6.6 ​ $ 4,285
Schedule of fair value assumption using Black-Scholes option-pricing model	​ ​ ​ ​ ​ ​ ​ ​ Six months ended June 30, ​ 2019 ​ 2018 Risk-free interest rate 2.6 % ​ 2.6 % Volatility 63.3 % ​ 65.0 % Expected term (years) 6.06 ​ ​ 6.11 ​ Expected dividend yield — % ​ — %
Performance share units
Summary of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ Shares ​ Grant Date Fair Value Outstanding at December 31, 2018 ​ — ​ $ — Granted ​ 99,400 ​ ​ 15.90 Outstanding at June 30, 2019 ​ 99,400 ​ $ 15.90

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) $ in Thousands	Jun. 30, 2019USD ($)
Summary of Significant Accounting Policies
Operating lease assets	$ 9,574
Operating lease liabilities	$ 10,536

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Narrative (Details)	6 Months Ended
	Jun. 30, 2019
Revenue from Contracts with Customers
Practical expedient incremental cost	true

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Contract Liabilities (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Rebates and Incentives
Allowance categories
Balance at beginning of the period	$ 129,318
Provision related to current period sales	128,509
Changes in estimate related to prior period sales	(3,017)
Credits/payments made	(119,659)
Balance at end of the period	135,151
Product Returns
Allowance categories
Balance at beginning of the period	15,465
Provision related to current period sales	9,150
Credits/payments made	(1,502)
Balance at end of the period	23,113
Trade Allowances and Chargebacks
Allowance categories
Balance at beginning of the period	14,841
Provision related to current period sales	31,988
Credits/payments made	(32,673)
Balance at end of the period	$ 14,156

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue
Revenue	$ 75,040	$ 73,061	$ 149,556	$ 136,810
Xtampza
Disaggregation of Revenue
Revenue	26,018	18,116	51,152	33,911
Nucynta
Disaggregation of Revenue
Revenue	$ 49,022	$ 54,945	$ 98,404	$ 102,899

License Agreements (Details)

License Agreements (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 09, 2018	Nov. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
License Agreements [Line Items]
Cost of product revenues			$ 48,654	$ 46,838	$ 97,818	$ 89,944
Annual net sales			$ 75,040	$ 73,061	$ 149,556	$ 136,810
Exercise price of warrant		$ 19.20
Nucynta Commercialization Agreement | Assertio
License Agreements [Line Items]
Cost of product revenues	$ 10,000
Annual net sales	135,000
Nucynta Commercialization Agreement | Nucynta | Assertio
License Agreements [Line Items]
Payment for inventory	6,223
Reimbursement for prepaid expenses	1,987
Liability relating to sales	22,660
Variable royalty payment based on net sales	233,000
Quarterly royalty payable	$ 33,750
Nucynta Commercialization Agreement | Nucynta | Assertio | Sales Royalty Structure 1 [member]
License Agreements [Line Items]
Royalty payment as percentage of annual net sales on and after January 1, 2022		58.00%
Nucynta Commercialization Agreement | Nucynta | Assertio | Sales Royalty Structure 2 [member]
License Agreements [Line Items]
Royalty payment as percentage of annual net sales on and after January 1, 2022		25.00%
Nucynta Commercialization Agreement | Nucynta | Assertio | Sales Royalty Structure 3 [member]
License Agreements [Line Items]
Royalty payment as percentage of annual net sales on and after January 1, 2022		17.50%
Royalty payment limit on and after January 1, 2022		$ 258,000
Nucynta Commercialization Agreement | Nucynta | Assertio | Minimum | Sales Royalty Structure 2 [member]
License Agreements [Line Items]
Royalty payment limit on and after January 1, 2022		233,000
Nucynta Commercialization Agreement | Nucynta | Assertio | Maximum | Sales Royalty Structure 1 [member]
License Agreements [Line Items]
Royalty payment limit on and after January 1, 2022		233,000
Nucynta Commercialization Agreement | Nucynta | Assertio | Maximum | Sales Royalty Structure 2 [member]
License Agreements [Line Items]
Royalty payment limit on and after January 1, 2022		$ 258,000
Third Amendment to the Commercialization Agreement
License Agreements [Line Items]
Number of shares that can be purchased		1,041,667
Exercise price of warrant		$ 19.20
Third Amendment to the Commercialization Agreement | Nucynta
License Agreements [Line Items]
Minimum royalty payment eliminated		$ 135,000
Third Amendment to the Commercialization Agreement | Nucynta | Maximum | Any 12-month period through January 1, 2022
License Agreements [Line Items]
Net sales limit upon which Counterparty can terminate without penalty		180,000
Third Amendment to the Commercialization Agreement | Nucynta | Maximum | Any 12-month period commencing on January 1, 2022
License Agreements [Line Items]
Net sales limit upon which Counterparty can terminate without penalty		170,000
Third Amendment to the Commercialization Agreement | Nucynta | Assertio
License Agreements [Line Items]
Termination fee owed if Company terminates		$ 5,000
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Sales Royalty Structure 1 [member]
License Agreements [Line Items]
Royalty payment as percentage of annual net sales between January 1, 2019 and December 31, 2021		65.00%
Royalty payment limit between January 1, 2019 and December 31, 2021		$ 180,000
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Sales Royalty Structure 2 [member]
License Agreements [Line Items]
Royalty payment as percentage of annual net sales between January 1, 2019 and December 31, 2021		14.00%
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Sales Royalty Structure 3 [member]
License Agreements [Line Items]
Royalty payment as percentage of annual net sales between January 1, 2019 and December 31, 2021		58.00%
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Sales Royalty Structure 4 [member]
License Agreements [Line Items]
Royalty payment as percentage of annual net sales between January 1, 2019 and December 31, 2021		20.00%
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Sales Royalty Structure 5 [member]
License Agreements [Line Items]
Royalty payment as percentage of annual net sales between January 1, 2019 and December 31, 2021		15.00%
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Minimum | Sales Royalty Structure 2 [member]
License Agreements [Line Items]
Royalty payment limit between January 1, 2019 and December 31, 2021		$ 180,000
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Minimum | Sales Royalty Structure 3 [member]
License Agreements [Line Items]
Royalty payment limit between January 1, 2019 and December 31, 2021		210,000
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Minimum | Sales Royalty Structure 4 [member]
License Agreements [Line Items]
Royalty payment limit between January 1, 2019 and December 31, 2021		233,000
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Minimum | Sales Royalty Structure 5 [member]
License Agreements [Line Items]
Royalty payment limit between January 1, 2019 and December 31, 2021		258,000
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Minimum | Sales Royalty Structure 6 [member]
License Agreements [Line Items]
Sales threshold where supplemental royalty payment is due		$ 180,000
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Maximum
License Agreements [Line Items]
Percentage of supplemental royalty based on net sales		4.90%
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Maximum | Sales Royalty Structure 2 [member]
License Agreements [Line Items]
Royalty payment limit between January 1, 2019 and December 31, 2021		$ 210,000
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Maximum | Sales Royalty Structure 3 [member]
License Agreements [Line Items]
Royalty payment limit between January 1, 2019 and December 31, 2021		233,000
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Maximum | Sales Royalty Structure 4 [member]
License Agreements [Line Items]
Royalty payment limit between January 1, 2019 and December 31, 2021		258,000
Third Amendment to the Commercialization Agreement | Nucynta | Assertio | Maximum | Sales Royalty Structure 6 [member]
License Agreements [Line Items]
Sales threshold where supplemental royalty payment is due		$ 243,000

Loss per Common Share - Computa

Loss per Common Share - Computation of Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Loss per Common Share
Loss attributable to common shareholders - basic and diluted	$ (4,712)	$ (13,060)	$ (14,412)	$ (31,712)
Weighted-average number of common shares used in net loss per share - basic and diluted	33,397,709	32,967,718	33,338,243	32,935,873
Loss per share - basic and diluted	$ (0.14)	$ (0.40)	$ (0.43)	$ (0.96)

Loss per Common Share - Summary

Loss per Common Share - Summary of Potentially Dilutive Securities (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Outstanding stock option
Anti-dilutive securities
Potentially dilutive securities excluded from the computations of diluted weighted-average shares outstanding	4,190,116	3,665,459	4,190,116	3,665,459
Warrants
Anti-dilutive securities
Potentially dilutive securities excluded from the computations of diluted weighted-average shares outstanding	1,041,667		1,041,667
Unvested restricted stock
Anti-dilutive securities
Potentially dilutive securities excluded from the computations of diluted weighted-average shares outstanding		12,072		12,072
Restricted stock units
Anti-dilutive securities
Potentially dilutive securities excluded from the computations of diluted weighted-average shares outstanding	892,237	522,190	892,237	522,190
Performance share units
Anti-dilutive securities
Potentially dilutive securities excluded from the computations of diluted weighted-average shares outstanding	99,400		99,400

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Transfer of Assets From Level 1 to Level 2	$ 0	$ 0
Transfer of Assets From Level 2 to Level 1	0	0
Transfer of Liabilities From Level 1 to Level 2	0	0
Transfer of Liabilities From Level 2 to Level 1	0	0
Transfer of Assets Into Level 3	0	0
Transfer of Assets Out of Level 3	0	0
Transfer of Liabilities Into Level 3	0	0
Transfer of Liabilities Out of Level 3	0	$ 0
Money market funds
Cash equivalents	93,968		$ 92,914
Quoted Prices in active markets (Level 1) | Money market funds
Cash equivalents	$ 93,968		$ 92,914

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Inventory
Raw materials	$ 1,664	$ 496
Work in process	848	671
Finished goods	7,441	6,650
Total inventory	$ 9,953	$ 7,817

Intangible Assets - Costs Accum

Intangible Assets - Costs Accumulated to Acquire Intangible Asset; and Consideration Transferred (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Acquisition consideration:
Upfront cash paid	$ 18,877
Minimum royalty payment obligation	112,719
Rebates, incentives, trade allowances and chargebacks assumed	22,660
Warrant issued	8,043
Total acquisition consideration	162,299
Consideration transferred to assets acquired:
Nucynta Intangible Asset	154,089
Inventory	6,223
Prepaid expenses	1,987
Total consideration allocated to assets acquired	$ 162,299

Intangible Assets - Minimum Roy

Intangible Assets - Minimum Royalty Payments - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	6 Months Ended
	Nov. 30, 2018	Jun. 30, 2019
Intangible Assets
Total remaining minimum royalty payments due		$ 537,000
2018		132,000
2019		135,000
2020		135,000
2021		135,000
Fair Value of royalty payments		$ 482,300
Discounted cash flow rate		5.70%
Interest expense recognized		$ 54,700
Interest expense recognized, relating to royalty payments, prior to third amendment	$ 19,281
Amortization expense recognized prior to third amendment	$ 107,662

Intangible Assets - Gross carry

Intangible Assets - Gross carrying amount and accumulated amortization (Details) - Nucynta - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Gross carrying amount	$ 154,089	$ 154,089
Accumulated amortization	(117,210)	(109,834)
Intangible assets, net	$ 36,879	$ 44,255

Intangible Assets - Warrant and

Intangible Assets - Warrant and Amortization - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 09, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Nov. 30, 2018
Intangible Assets
Common stock that may be purchased upon exercise of warrant (in shares)						1,041,667
Exercise price of warrant (in dollars per share)						$ 19.20
Useful life	4 years			2 years 6 months
Amortization expense recognized prior to third amendment				$ 107,662
Amortization expense for Nucynta asset acquisition		$ 3,688	$ 32,407	7,376	$ 61,933
2019		7,376		7,376
2020		14,752		14,752
2021		$ 14,751		$ 14,751

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Accrued Expenses
Accrued royalties	$ 15,463	$ 15,138
Accrued inventory	1,175	3,745
Accrued sales and marketing	690	2,193
Accrued payroll and related benefits	1,230	1,544
Accrued incentive compensation	1,566	1,806
Accrued bonuses	2,008	4,286
Accrued audit and legal	674	480
Accrued interest	382	274
Accrued other operating costs	1,329	1,085
Total accrued expenses	$ 24,517	$ 30,551

Term Loan Payable (Details)

Term Loan Payable (Details) $ in Thousands	1 Months Ended	6 Months Ended
	Nov. 30, 2018	Jun. 30, 2019USD ($)	Aug. 12, 2012USD ($)
Loan and Security Agreements
Maximum borrowing capacity			$ 1,000
New Term Loan | Silicon Valley Bank Loan Agreement Consent and Sixth Amendment
Loan and Security Agreements
Variable interest rate margin (as a percent)		0.75%
Original principal amount		$ 11,500
Threshold limit of EDITDA to repay principal and interest prior to specific date		2,500
Final payment fee		$ 719
Minimum liquidity ratio	1.5	1
Additional interest rate in event of default		5
Prior to first anniversary | New Term Loan | Silicon Valley Bank Loan Agreement Consent and Sixth Amendment
Loan and Security Agreements
Prepayment fee (as a percent)		3
Between first anniversary and second anniversary | New Term Loan | Silicon Valley Bank Loan Agreement Consent and Sixth Amendment
Loan and Security Agreements
Prepayment fee (as a percent)		2
Following second anniversary | New Term Loan | Silicon Valley Bank Loan Agreement Consent and Sixth Amendment
Loan and Security Agreements
Prepayment fee (as a percent)		1

Term Loan Payable - Future Paym

Term Loan Payable - Future Payments (Details) $ in Thousands	Jun. 30, 2019USD ($)
Future payments under term loan
2020	$ 3,833
2021	3,833
2022	3,834
Balance	$ 11,500

Leases (Details)

Leases (Details) $ in Thousands	Jun. 30, 2019USD ($)
Leases
Operating lease assets	$ 9,574
Operating lease liabilities	$ 10,536

Leases - Operating Lease Arrang

Leases - Operating Lease Arrangements (Details) $ in Thousands	1 Months Ended
	Mar. 31, 2018USD ($)ft²item$ / ft²	Jan. 31, 2016ft²	Dec. 31, 2018
CMO
Lessee, Lease, Description [Line Items]
Square of feet of space		3,267
Term of lease extension option		2 years
Advance written notice termination period		2 years
Vehicle leases
Lessee, Lease, Description [Line Items]
Lease term			12 months
Stoughton, Massachusetts
Lessee, Lease, Description [Line Items]
Rent-free term	4 months
Square of feet of space	50,678
Lease term	10 years
Number of renewal periods | item	2
Term of lease extension option	5 years
Base rent | $	$ 1,214
Annual base rent per rentable square foot | $ / ft²	23.95
Canton, Massachusetts
Lessee, Lease, Description [Line Items]
Square of feet of space	9,660
Term of lease extension option	5 years
Maximum | Stoughton, Massachusetts
Lessee, Lease, Description [Line Items]
Increase in annual base rent	3.10%
Minimum | Stoughton, Massachusetts
Lessee, Lease, Description [Line Items]
Increase in annual base rent	2.50%

Leases - Practical expedients (

Leases - Practical expedients (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jan. 01, 2019
Lessee, Lease, Description [Line Items]
Practical expedients - package	true
Operating lease assets	$ 9,574
Operating lease liabilities, net of current portion	$ 9,903
ASU 2016-02 | Adjustment
Lessee, Lease, Description [Line Items]
Operating lease assets		$ 9,957
Operating lease liabilities, net of current portion		$ 10,690

Leases - Lease Cost (Details)

Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Lease Cost
Operating lease cost	$ 353	$ 705
Short-term lease cost	144	312
Total lease cost	$ 497	$ 1,017

Leases - Other Information (Det

Leases - Other Information (Details) $ in Thousands	3 Months Ended
	Jun. 30, 2019USD ($)
Leases
Cash paid for amounts included in the measurement of operating lease liabilities	$ 476
Weighted-average remaining lease term - operating leases (years)	10 years 1 month 6 days
Weighted-average discount rate - operating leases	6.10%

Leases - Future minimum lease p

Leases - Future minimum lease payments - ASC Topic 842 (Details) $ in Thousands	Jun. 30, 2019USD ($)
Future minimum lease payments
2019	$ 578
2020	1,328
2021	1,284
2022	1,322
2023	1,360
After 2023	8,490
Total minimum lease payments	14,362
Less: Present value discount	3,826
Present value of lease liabilities	$ 10,536

Leases - Future minimum lease_2

Leases - Future minimum lease payments - legacy GAAP (Details) $ in Thousands	Dec. 31, 2018USD ($)
Future minimum lease payments
2019	$ 1,032
2020	1,305
2021	1,261
2022	1,299
2023	1,337
After 2023	8,423
Total minimum lease payments	$ 14,657

Equity - Changes in Shareholder

Equity - Changes in Shareholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Balance at beginning of period	$ 86,350	$ 91,585	$ 90,823	$ 104,080	$ 91,585	$ 104,080
Exercise of common stock options	58	246	1,532	2,373
Exercise of common stock options, shares					26,911
Issuance for employee stock purchase plan		444		510
Issuance for employee stock purchase plan, shares					32,826
Shares withheld for employee taxes upon vesting of RSUs	(35)	(488)	(140)	(216)
Stock-based compensation expense	4,162	4,263	3,526	2,728
Net loss	(4,712)	(9,700)	(13,060)	(18,652)	$ (14,412)	(31,712)
Balance at end of period	85,823	86,350	82,681	90,823	85,823	82,681
Common Stock
Balance at beginning of period	$ 33	$ 33	$ 33	$ 33	$ 33	$ 33
Balance at beginning of year, shares	33,385,128	33,265,629	33,027,579	32,770,678	33,265,629	32,770,678
Exercise of common stock options, shares	8,218	18,693	137,419	183,987
Issuance for employee stock purchase plan, shares		32,826		50,151
Vesting of restricted stock units, shares	26,304	101,483	20,887	32,573
Shares withheld for employee taxes upon vesting of RSUs, shares	(3,097)	(33,503)	(6,205)	(9,810)
Balance at end of period	$ 33	$ 33	$ 33	$ 33	$ 33	$ 33
Balance at end of year, shares	33,416,553	33,385,128	33,179,680	33,027,579	33,416,553	33,179,680
Additional Paid-In Capital
Balance at beginning of period	$ 433,194	$ 428,729	$ 407,491	$ 402,096	$ 428,729	$ 402,096
Exercise of common stock options	58	246	1,532	2,373
Issuance for employee stock purchase plan		444		510
Shares withheld for employee taxes upon vesting of RSUs	(35)	(488)	(140)	(216)
Stock-based compensation expense	4,162	4,263	3,526	2,728
Balance at end of period	437,379	433,194	412,409	407,491	437,379	412,409
Accumulated Deficit
Balance at beginning of period	(346,877)	(337,177)	(316,701)	(298,049)	(337,177)	(298,049)
Net loss	(4,712)	(9,700)	(13,060)	(18,652)
Balance at end of period	$ (351,589)	$ (346,877)	$ (329,761)	$ (316,701)	$ (351,589)	$ (329,761)

Equity - Narrative (Details)

Equity - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	6 Months Ended	12 Months Ended
	Mar. 31, 2017	Jun. 30, 2019	Dec. 31, 2018
Equity
Common stock sold (in shares)		0	0
Sale of Stock, Consideration Received if Additional Shares are Issued	$ 60,000
Commission fee percentage on gross proceeds from sale of ATM shares	3.00%

Stock-based Compensation - Narr

Stock-based Compensation - Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	May 31, 2015
Stock-based compensation
Shares of common stock authorized for issuance outstanding (in shares)		4,190,116		4,190,116		3,585,856
Employee Stock Purchase Plan, Purchase Price Percentage				85.00%
Issuance for employee stock purchase plan, shares				32,826
Proceeds from issuances of common stock from employee stock purchase plans				$ 444,000	$ 510,000
Employee Stock Purchase Plan, Compensation Expense		$ 73,000	$ 120,000	173,000	242,000
Share-based Compensation				$ 8,425,000	$ 6,254,000
Maximum
Stock-based compensation
Period following termination date vested options are exercisable				3 months
Performance share units
Stock-based compensation
Vesting period	3 years
Share-based Compensation		27,000		$ 42,000
Restricted Stock Awards And Restricted Stock Units
Stock-based compensation
Unrecognized compensation cost related to outstanding options		$ 34,447		$ 34,447
Period over which unrecognized compensation cost is expected to be recognized as expense				2 years 8 months 12 days
2014 Stock Incentive Plan
Stock-based compensation
Shares of common stock authorized for issuance (in shares)							2,700,000
Shares of common stock remaining available for future grant		1,261,162		1,261,162
Increase in number of authorized shares on the first day of each fiscal year, as a percentage of outstanding common stock (as a percent)				4.00%
Vesting period				4 years
Contractual life				10 years
2014 Stock Incentive Plan | Minimum
Stock-based compensation
Period following termination date vested options are exercisable				1 year

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Stock-Based Compensation Included in Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Stock-based compensation
Total stock-based compensation expense	$ 4,162	$ 3,526	$ 8,425	$ 6,254
Research and development expenses
Stock-based compensation
Total stock-based compensation expense	514	380	1,081	703
Selling, general and administrative expenses
Stock-based compensation
Total stock-based compensation expense	$ 3,648	$ 3,146	$ 7,344	$ 5,551

Stock-based Compensation - Su_2

Stock-based Compensation - Summary of Restricted Stock and Performance Share Activity (Details)	6 Months Ended
	Jun. 30, 2019$ / sharesshares
Performance share units
Restricted stock awards
Granted | shares	99,400
Balance | shares	99,400
Weighted-average purchase price per share
Granted | $ / shares	$ 15.90
Balance | $ / shares	$ 15.90
Restricted stock units
Restricted stock awards
Balance | shares	514,603
Granted | shares	590,205
Vested | shares	(127,787)
Forfeited | shares	(84,784)
Balance | shares	892,237
Weighted-average purchase price per share
Balance | $ / shares	$ 20.67
Granted | $ / shares	15.78
Vested | $ / shares	21.54
Forfeited | $ / shares	18.26
Balance | $ / shares	$ 17.54

Stock-based Compensation - Su_3

Stock-based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares
Stock option activity
Outstanding | shares	3,585,856
Granted | shares	897,312
Exercised | shares	(26,911)
Cancelled | shares	(266,141)
Outstanding | shares	4,190,116	3,585,856
Exercisable at end of period | shares	2,113,346
Weighted average exercise price per share
Outstanding | $ / shares	$ 16.20
Granted | $ / shares	15.67
Exercised | $ / shares	11.30
Cancelled | $ / shares	17.61
Outstanding | $ / shares	16.03	$ 16.20
Exercisable at end of period | $ / shares	$ 14.45
Stock option activity, additional information
Outstanding Weighted-Average Remaining Contractual Term	7 years 8 months 12 days	8 years
Outstanding Aggregate Intrinsic Value | $	$ 5,248	$ 11,170
Exercisable at end of period, Weighted-Average Remaining Contractual Term	6 years 7 months 6 days
Exercisable at end of period, Aggregate Intrinsic Value | $	$ 4,285

Stock-based Compensation - Su_4

Stock-based Compensation - Summary of Valuation Assumptions Used (Details)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee stock option grants
Risk-free interest rate	2.60%	2.60%
Volatility	63.30%	65.00%
Expected term (in years)	6 years 21 days	6 years 1 month 9 days

Commitments and Contingencies (

Commitments and Contingencies (Details)	May 09, 2019patent	Nov. 30, 2018patent	Sep. 26, 2018lawsuit	Jun. 12, 2018lawsuit	May 24, 2018lawsuit	Mar. 24, 2015patent	Jun. 30, 2019patentlawsuit
Contingencies
Stay period before FDA can issue a final approval unless it is terminated							30 months
Number of lawsuits filed | lawsuit			2	4	2
Number of patents listed in FDA Orange Book							15
Purdue Pharma, L. P. patent infringement suit, District of Delaware
Contingencies
Number of patents allegedly infringed						3	5
Purdue Pharma, L. P. patent infringement suit, District of Massachusetts
Contingencies
Number of patents found not infringed							3
Teva Litigation [member]
Contingencies
Stay period before FDA can issue a final approval unless it is terminated							30 months
Number of patents allegedly infringed							11
Number of Orange Book patents asserted to have been infringed	1	2
Payor Groups and Warminister Township [Member]
Contingencies
Number of lawsuits filed | lawsuit							3