Supernus Pharmaceuticals (SUPN) 10-K 9 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 29, 2016	Jun. 30, 2015
Document and Entity Information
Entity Registrant Name	SUPERNUS PHARMACEUTICALS INC
Entity Central Index Key	1,356,576
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 659,264,478
Entity Common Stock, Shares Outstanding		49,400,473
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 34,152	$ 36,396
Marketable securities	28,038	37,940
Accounts receivable, net	25,908	17,270
Inventories, net	12,587	13,441
Prepaid expenses and other current assets	5,292	3,845
Total current assets	105,977	108,892
Long term marketable securities	55,009	19,816
Property and equipment, net	3,874	2,448
Deferred legal fees	22,503	5,209
Intangible assets, net	976	225
Other non-current assets	391	918
Total assets	188,730	137,508
Current liabilities:
Accounts payable	4,314	1,863
Accrued sales deductions	26,794	8,461
Accrued expenses	24,813	17,026
Deferred licensing revenue	176	143
Total current liabilities	56,097	27,493
Deferred licensing revenue, net of current portion	1,390	1,274
Convertible notes, net of discount	7,189	26,947
Other non-current liabilities	4,325	3,876
Derivative liabilities	854	6,564
Total liabilities	69,855	66,154
Stockholders' equity:
Common stock, $0.001 par value, 130,000,000 shares authorized December 31, 2015 and 2014; 49,004,674 and 42,974,463 shares issued and outstanding at December 31, 2015 and 2014, respectively	49	43
Additional paid-in capital	263,955	230,122
Accumulated other comprehensive loss	(488)	(154)
Accumulated deficit	(144,641)	(158,657)
Total stockholders' equity	118,875	71,354
Total liabilities and stockholders' equity	$ 188,730	$ 137,508

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Consolidated Balance Sheets
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	130,000,000	130,000,000
Common stock, shares issued	49,004,674	42,974,463
Common stock, shares outstanding	49,004,674	42,974,463

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue
Net product sales	$ 143,526	$ 89,571	$ 11,552
Revenue from royalty agreement		30,000
Licensing revenue	901	2,474	467
Total revenue	144,427	122,045	12,019
Costs and expenses
Cost of product sales	8,423	5,758	1,104
Research and development	29,135	19,586	17,245
Selling, general and administrative	89,204	72,471	55,590
Total costs and expenses	126,762	97,815	73,939
Operating income (loss)	17,665	24,230	(61,920)
Other income (expense)
Interest income	643	348	299
Interest expense	(1,229)	(4,963)	(7,849)
Changes in fair value of derivative liabilities	193	2,809	(13,354)
Loss on extinguishment of debt	(2,338)	(2,592)	(9,550)
Other income	38	39	101
Total other expense	(2,693)	(4,359)	(30,353)
Earnings (loss) before income taxes	14,972	19,871	(92,273)
Income tax expense	956
Net income (loss)	$ 14,016	$ 19,871	$ (92,273)
Income (loss) per common share:
Basic (in dollars per share)	$ 0.30	$ 0.47	$ (2.90)
Diluted (in dollars per share)	$ 0.28	$ 0.32	$ (2.90)
Weighted-average number of common shares outstanding:
Basic (in shares)	47,485,258	42,260,896	31,848,299
Diluted (in shares)	51,160,380	50,583,511	31,848,299

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Comprehensive Income (Loss)
Net income (loss)	$ 14,016	$ 19,871	$ (92,273)
Other comprehensive (loss) income:
Unrealized net (loss) gain on marketable securities	(334)	(154)	57
Other comprehensive (loss) income:	(334)	(154)	57
Comprehensive income (loss)	$ 13,682	$ 19,717	$ (92,216)

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholder's Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Total
Beginning balance at Dec. 31, 2012	$ 31	$ 143,851	$ (57)	$ (86,255)	$ 57,570
Beginning balance (in shares) at Dec. 31, 2012	30,621,869
Increase (Decrease) in Stockholders' Equity
Exercise of over allotment from secondary offering		1,791			1,791
Exercise of over allotment from secondary offering (in shares)	239,432
Share-based compensation		1,913			1,913
Issuance of employee stock purchase plan shares		444			444
Issuance of employee stock purchase plan shares (in shares)	81,370
Exercise of stock options		78			78
Exercise of stock options (in shares)	62,513
Equity conversion feature on issuance of convertible notes, less issuance costs of $869		21,467			21,467
Equity issued on conversion of convertible notes	$ 9	42,408			42,417
Equity issued on conversion of convertible notes (in shares)	8,978,253
Net income (loss)				(92,273)	(92,273)
Other comprehensive income (loss)			57		57
Ending balance at Dec. 31, 2013	$ 40	211,952		(178,528)	33,464
Ending balance (in shares) at Dec. 31, 2013	39,983,437
Increase (Decrease) in Stockholders' Equity
Share-based compensation		2,716			2,716
Issuance of employee stock purchase plan shares		516			516
Issuance of employee stock purchase plan shares (in shares)	76,333
Exercise of stock options		54			54
Exercise of stock options (in shares)	17,627
Equity issued on conversion of convertible notes	$ 3	14,884			14,887
Equity issued on conversion of convertible notes (in shares)	2,897,066
Net income (loss)				19,871	19,871
Other comprehensive income (loss)			(154)		(154)
Ending balance at Dec. 31, 2014	$ 43	230,122	(154)	(158,657)	71,354
Ending balance (in shares) at Dec. 31, 2014	42,974,463
Increase (Decrease) in Stockholders' Equity
Share-based compensation		4,231			4,231
Issuance of employee stock purchase plan shares		930			930
Issuance of employee stock purchase plan shares (in shares)	98,986
Exercise of stock options		937			937
Exercise of stock options (in shares)	205,640
Equity issued on conversion of convertible notes	$ 6	27,083			27,089
Equity issued on conversion of convertible notes (in shares)	5,693,062
Exercise of warrants		652			652
Exercise of warrants (in shares)	32,523
Net income (loss)				14,016	14,016
Other comprehensive income (loss)			(334)		(334)
Ending balance at Dec. 31, 2015	$ 49	$ 263,955	$ (488)	$ (144,641)	$ 118,875
Ending balance (in shares) at Dec. 31, 2015	49,004,674

Consolidated Statements of Cha7

Consolidated Statements of Changes in Stockholder's Equity (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2013USD ($)
Consolidated Statements of Changes in Stockholder's Equity
Equity conversion feature on issuance of convertible notes, issuance costs	$ 869

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities
Net income (loss)	$ 14,016	$ 19,871	$ (92,273)
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Loss on extinguishment of debt	2,338	2,592	9,550
Change in fair value of derivative liability	(193)	(2,809)	13,354
Unrealized loss (gain) on marketable securities		(154)	57
Depreciation and amortization	921	928	742
Amortization of deferred financing costs and debt discount	748	2,090	3,033
Share-based compensation expense	4,231	2,716	1,913
Changes in operating assets and liabilities:
Accounts receivable	(8,638)	(12,216)	(5,043)
Inventories	854	(6,289)	(6,000)
Prepaid expenses and other assets	(1,582)	(1,144)	(889)
Accounts payable	2,061	(1,279)	336
Accrued sales deductions	18,333	7,461	1,000
Accrued expenses	(1,604)	2,854	7,156
Deferred product revenue, net		(7,882)	7,883
Deferred licensing revenue	149	(204)	803
Other non-current liabilities	489	1,198	429
Net cash provided by (used in) operating activities	32,123	7,733	(57,949)
Cash flows from investing activities
Purchases of marketable securities	(63,205)	(53,262)	(85,567)
Sales and maturities of marketable securities	37,581	53,473	75,806
Purchases of property and equipment	(2,104)	(593)	(1,646)
Deferred legal fees	(8,506)	(4,505)	(705)
Net cash used in investing activities	(36,234)	(4,887)	(12,112)
Cash flows from financing activities
Proceeds from issuance of common stock	1,867	571	2,437
Proceeds from convertible debt issuance			90,000
Cash settlement of debt to equity conversion		(1)	(1,727)
Repayment of secured notes payable			(24,344)
Financing costs and underwriters discounts			(3,627)
Net cash provided by financing activities	1,867	570	62,739
Net change in cash and cash equivalents	(2,244)	3,416	(7,322)
Cash and cash equivalents at beginning of year	36,396	32,980	40,302
Cash and cash equivalents at end of year	34,152	36,396	32,980
Supplemental cash flow information:
Cash paid for interest	825	2,854	4,313
Noncash financial activity:
Conversion of convertible notes and interest make-whole	27,089	$ 14,887	42,417
Initial value of interest make-whole derivative issued in connection with the convertible debt			9,270
Initial value of conversion option reported in equity			$ 22,336
Exercise of warrants	652
Deferred legal fees included in accrued expenses	$ 9,392

Organization and Nature of Oper

Organization and Nature of Operations	12 Months Ended
	Dec. 31, 2015
Organization and Nature of Operations
Organization and Nature of Operations	1. Organization and Nature of Operations Supernus Pharmaceuticals, Inc. (the Company) was incorporated in Delaware on March 30, 2005, and commenced operations on December 22, 2005. The Company is a specialty pharmaceutical company focused on developing and commercializing products for the treatment of central nervous system (CNS) diseases, including neurological and psychiatric disorders. The Company markets two epilepsy products, Oxtellar XR and Trokendi XR, and has several proprietary product candidates in clinical development that address the psychiatry market. The Company commenced the commercialization of Oxtellar XR and Trokendi XR in 2013.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The Company's consolidated financial statements include the accounts of Supernus Pharmaceuticals, Inc. and Supernus Europe Ltd., collectively referred to herein as "Supernus" or "the Company." All significant intercompany transactions and balances have been eliminated in consolidation. The Company's consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (U.S. GAAP). The Company, which is primarily located in the United States, operates in one operating segment. Use of Estimates The preparation of the financial statements in accordance with U.S. GAAP requires the Company to make estimates and judgments in certain circumstances that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. In preparing these consolidated financial statements, management has made its best estimates and judgments of certain amounts included in the financial statements, giving due consideration to materiality. On an ongoing basis, the Company evaluates its estimates, including those related to revenue recognition, accrued sales deductions, fair value of financial assets and liabilities, derivative liabilities, common stock options, income taxes, preclinical study and clinical trial accruals, and other contingencies. Management bases its estimates on historical experience or on various other assumptions, including information received from its service providers and independent valuation consultants, which it believes to be reasonable under the circumstances. Actual results could differ from these estimates. Cash and Cash Equivalents The Company considers all investments in highly liquid financial instruments with an original maturity of three months or less to be cash equivalents. Marketable Securities Marketable securities consist of investments in U.S. Treasuries, various U.S. governmental agency debt securities, corporate bonds and other fixed income securities. The Company's investments are classified as available for sale. Such securities are carried at estimated fair value, with any unrealized holding gains or losses reported, net of any tax effects reported, as accumulated other comprehensive income, which is a separate component of stockholders' equity. Realized gains and losses, and declines in value judged to be other-than-temporary, if any, are included in consolidated results of operations. A decline in the market value of any available for sale security below cost that is deemed to be other-than-temporary results in a reduction in fair value, which is charged to earnings in that period, and a new cost basis for the security is established. Dividend and interest income is recognized when earned. The cost of securities sold is calculated using the specific identification method. The Company places all investments with government, industrial, or financial institutions whose debt is rated as investment grade. The Company classifies all available-for-sale marketable securities with maturities greater than one year from the balance sheet date as non-current assets. The Company established the Supernus Supplemental Executive Retirement Plan (SERP) for the sole purpose of receiving funds for executives from a previous SERP and providing a continuing deferral program under the Supernus SERP. As of December 31, 2015 and 2014, the estimated fair value of the mutual fund investment securities within the SERP was approximately $263,000 and $305,000, respectively. The fair value of these assets is included within other non-current assets on the consolidated balance sheets. A corresponding noncurrent liability is also included in the consolidated balance sheets to reflect the Company's obligation for the SERP. The Company has not made, and has no plans to make, contributions to the SERP. The securities are restricted in nature and can only be used for purposes of paying benefits under the SERP. Accounts Receivable, net Accounts receivable are reported on the consolidated balance sheets at outstanding amounts, less an allowance for doubtful accounts and discounts. The Company extends credit without requiring collateral. The Company writes off uncollectible receivables when the likelihood of collection is remote. The Company evaluates the collectability of accounts receivable on a regular basis. An allowance, when needed, is based upon various factors including the financial condition and payment history of customers, an overall review of collections experience on other accounts, and economic factors or events expected to affect future collections experience. No accounts have been written off in 2015 and 2014. No allowance for uncollectible receivables is recorded at December 31, 2015 or December 31, 2014. The Company recorded an allowance of approximately $3.8 million and $4.1 million for expected sales discounts as of December 31, 2015 and December 31, 2014, respectively. The following table includes those customers that represent more than 10% of total net product sales for 2015 and more than 10% of the accounts receivable balance on the consolidated balance sheet as of December 31, 2015: Percent of Net Product Sales Percent of Accounts Receivable, net Customer A % % Customer B % % Customer C % % ​ ​ ​ ​ ​ ​ ​ ​ % % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash, cash equivalents, accounts receivable and marketable securities. The counterparties are various corporations and financial institutions of high credit standing. Substantially all of the Company's cash and cash equivalents are maintained with well known, U.S. and non U.S. financial institutions, government agencies, and corporations. Deposits held with banks may exceed the amount of insurance provided on such deposits. Generally, these deposits may be redeemed upon demand and, therefore, management believes they bear minimal risk. Inventory Inventories, which are recorded at the lower of cost or market, include materials, labor, and other direct and indirect costs and are valued using the first-in, first-out method. The Company capitalizes inventories produced in preparation for commercial launches when it becomes probable that the related product candidates will receive regulatory approval and that the related costs will be recoverable through the commercial sale of the product. Property and Equipment Property and equipment are stated at cost. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is credited or charged to operations. Repairs and maintenance costs are expensed as incurred. Depreciation and amortization are computed using the straight-line method over the following average useful lives: Computer equipment 3 years Software 3 years Lab equipment and furniture 5 - 10 years Leasehold improvements Shorter of lease term or useful life Deferred Legal Fees Deferred legal fees have been incurred in connection with legal proceedings related to patents for Oxtellar XR and Trokendi XR (see Note 6). Amortization of the deferred legal fees will begin upon successful outcome of the on-going litigation. Deferred legal fees will be charged to expense in the event of an unsuccessful outcome of the on-going litigation. Intangible Assets Intangible assets consist primarily of purchased patents and deferred legal fees. Patents are carried at cost less accumulated amortization, which is calculated on a straight-line basis over the estimated useful lives of the patents, generally estimated to be ten years. The carrying value of the patents is assessed for impairment annually during the fourth quarter of each year, or more frequently if impairment indicators exist. There were no indicators of impairment identified at December 31, 2015, 2014 or 2013. Impairment of Long-Lived Assets Long-lived assets consist primarily of purchased patents, deferred legal fees, and property and equipment. The Company assesses the recoverability of its long-lived assets whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If indications of impairment exist, projected future undiscounted cash flows associated with the asset are compared to the carrying amount to determine whether the asset's value is recoverable. Evaluating for impairment requires judgment, including the estimation of future cash flows, future growth rates and profitability and the expected life over which cash flows will occur. Changes in the Company's business strategy or adverse changes in market conditions could impact impairment analyses and require the recognition of an impairment charge equal to the excess of the carrying value of the long-lived assets over its estimated fair value. For the years ended December 31, 2015, 2014, and 2013, the Company determined that there was no impairment of the Company's long-lived assets. Deferred Financing Costs Deferred financing costs consist of financing costs incurred by the Company in connection with the closing of the Company's 7.50% Convertible Senior Secured Notes and Secured Notes Payable (see Note 8). The Company amortizes deferred financing costs over the term of the related debt using the effective interest method. When extinguishing debt, the related deferred financing costs are written off. Preclinical Study and Clinical Trial Accruals The Company estimates preclinical study and clinical trial expenses based on the services performed pursuant to contracts with research institutions, investigators, and clinical research organizations (CROs) that conduct these activities on our behalf. In recording service fees, the Company estimates the time period over which the related services will be performed and compares the level of effort expended through the end of each period to the cumulative expenses recorded and payments made for such services and, as appropriate, accrues additional service fees or defers any non-refundable advance payments until the related services are performed. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust its accrual or deferred advance payment accordingly. If the Company later determines that it no longer expects the services associated with a nonrefundable advance payment to be rendered, the advance payment will be charged to expense in the period that such determination is made. Revenue Recognition Revenue from product sales is recognized when persuasive evidence of an arrangement exists; delivery has occurred and title to the product and associated risk of loss has passed to the customer; the price is fixed or determinable; collection from the customer has been reasonably assured; all performance obligations have been met; and returns and allowances can be reasonably estimated. Product sales are recorded net of estimated rebates, chargebacks, discounts, co-pay assistance and other deductions as well as estimated product returns (collectively, "sales deductions"). Our products are distributed through wholesalers and pharmaceutical distributors. Each of these wholesalers and distributors will take title and ownership to the product upon physical receipt of the product and then distribute our products to pharmacies. Beginning in the fourth quarter of 2013, the Company began recognizing revenue for Oxtellar XR, net of estimated sales deductions, at the time of shipment to wholesalers. Prior to this time, the Company recognized revenue for Oxtellar XR upon fulfillment of prescriptions, net of all known or estimated sales deductions. Beginning in the second quarter of 2014, the Company began recognizing revenue for Trokendi XR, net of estimated sales deductions, at the time of shipment to wholesalers. Prior to this time, the Company recognized revenue for Trokendi XR upon fulfillment of prescriptions to patients, net of all known or estimated sales deductions. For the year ended December 31, 2015, the revenue for Oxtellar XR and Trokendi XR was recognized contemporaneously upon shipment of finished products to wholesalers, net of allowances for estimated sales deductions and returns. During the year ended December 31, 2015, the Company recorded a $2.9 million reduction to net revenue related to a change in estimate associated with its accrued sales deductions of $26.8 million at December 31, 2015. The change in estimate reflects returns experience associated with our initial launch shipments, which have now passed their expiry dating. Revenue from Product Sales The Company launched Oxtellar XR on February 4, 2013 and launched Trokendi XR on August 26, 2013. During the fourth quarter of 2013, we began to recognize revenue for Oxtellar XR contemporaneously upon shipment of finished product to wholesalers less allowances for estimated sales deductions and, during the second quarter of 2014, we began to recognize revenue for Trokendi XR contemporaneously upon shipment of finished product to wholesalers less allowances for estimated sales deductions. Through December 31, 2013, the Company recorded shipments of Trokendi XR to wholesalers as deferred revenue i.e., sales price net of known sales deductions (e.g. prompt pay discounts and other similar charges defined below). At the time, we lacked the experiential data which would allow us to estimate all remaining sales rebates, allowances and returns. Accordingly, when this data became available to the Company, we moved to contemporaneous revenue recognition in the second quarter of 2014. Sales Deductions Allowances for estimated sales deductions are provided for the following: · Rebates. Rebates include mandated discounts under the Medicaid Drug Rebate Program, the Medicare coverage gap program, as well as negotiated discounts with commercial healthcare providers. Rebates are amounts owed after the final dispensing of products to a benefit plan participant and are based upon contractual agreements or legal requirements with the public sector (e.g. Medicaid) and with private sector benefit providers. The allowance for rebates is based on statutory and contractual discount rates and expected claimed rebates paid based on a plan provider's utilization. Rebates are generally invoiced and paid quarterly in arrears so that the accrual balance consists of an estimate of the amount expected to be incurred for the current quarter's activity, plus an accrual balance for known or estimated prior quarters' unpaid rebates. If actual future rebates vary from estimates, we may need to adjust prior period accruals, which would affect revenue in the period of adjustment. · Chargebacks. Chargebacks are discounts that occur when contracted customers purchase directly from an intermediary distributor or wholesaler. Contracted customers, which currently consist primarily of Public Health Service institutions and federal government entities purchasing via the Federal Supply Schedule, generally purchase the product at a discounted price. The distributor or wholesaler, in turn, charges back the difference between the price initially paid by the distributor or wholesaler and the discounted price paid to the distributor or wholesaler by the customer. The allowance for distributor/wholesaler chargebacks is based on known sales to contracted customers. · Distributor/Wholesaler deductions and discounts. U.S. specialty distributors and wholesalers are offered various forms of consideration including allowances, service fees and prompt payment discounts as consideration for distributing our products. Distributor allowances and service fees arise from contractual agreements with distributors and are generally a percentage of the purchase price paid by the distributors and wholesalers. Wholesale customers are offered a prompt pay discount for payment within a specified period. · Co-pay assistance. Patients who pay in cash or have commercial insurance and meet certain eligibility requirements may receive co-pay assistance from the Company. The intent of this program is to reduce the patient's out of pocket costs. · Liabilities for co-pay assistance are based on actual program participation and estimates of program redemption using data provided by third-party administrators. · Returns. Sales of our products are not subject to a general right of return; however, the Company will accept product that is damaged or defective when shipped directly from our warehouse and expired product six months prior and up to 12 months subsequent to its expiry date. Product that has been used to fill patient prescriptions is no longer subject to any right of return. Revenue from Royalty Agreement In the third quarter of 2014, the Company recognized $30.0 million in revenue from a royalty agreement related to HealthCare Royalty Partners III, L.P.'s purchase of certain of the Company's rights under the Royalty Interest Acquisition Agreement with United Therapeutics Corporation related to the commercialization of Orenitram. The Company determined to recognize this revenue immediately because (1) the executed contract constituted persuasive evidence of an arrangement, (2) the delivery of the license occurred and the Company has no current or future performance obligations, (3) the total consideration for the license agreement was fixed and known at the time of its execution and there were no rights of return, and (4) the cash was received and is non-refundable. Revenue Recognition of License Revenue License and Collaboration Agreements We have entered into collaboration agreements to have both Oxtellar XR and Trokendi XR commercialized outside of the U.S. These agreements generally include an up-front license fee and ongoing milestone payments upon the achievement of specific events. We believe the milestones meet all of the necessary criteria to be considered substantive and therefore should be recognized as revenue when achieved. For up-front license fees, we have estimated the service period of the contract and are recognizing this payment as revenue on a straight-line basis over the respective service period. Milestone Payments Milestone payments on licensing agreements are recognized as revenue when the collaborative partner acknowledges completion of the milestone and substantive effort was necessary to achieve the milestone. Management may recognize revenue contingent upon the achievement of a milestone in its entirety in the period in which the milestone is achieved only if the milestone meets all the criteria to be considered substantive. Substantive milestone payments are recognized upon achievement of the milestone only if all of the following conditions are met: · the milestone payments are non-refundable; · achievement of the milestone involves a degree of risk and was not reasonably assured at the inception of the arrangement; · substantive effort on the partner's part is involved in achieving the milestone; and · the amount of the milestone payment is reasonable in relation to the effort expended or the risk associated with achievement of the milestone. Determination as to whether a payment meets the aforementioned conditions involves management's judgment. If any of these conditions are not met, the resulting payment would not be considered a substantive milestone, and therefore the resulting payment would be considered part of the consideration for the single unit of accounting and amortized over the appropriate period. The Company recorded milestone revenues of $0.8 million and $2.0 million during the years ended December 31, 2015 and 2014, respectively. There was no revenue generated from the achievement of milestones in the year ended December 31, 2013. Cost of Product Sales The cost of product sales consist primarily of materials, third-party manufacturing costs, freight and distribution costs, allocation of labor, quality control and assurance, and other manufacturing overhead costs. Research and Development Costs Research and development costs are expensed as incurred. Research and development costs primarily consist of employee-related expenses, including salaries and benefits; share-based compensation expense; expenses incurred under agreements with clinical research organizations (CROs), investigative sites, and consultants that conduct the Company's clinical trials; the cost of acquiring and manufacturing clinical trial materials; the cost of manufacturing materials used in process validation, to the extent that those materials are manufactured prior to receiving regulatory approval for those products and are not expected to be sold commercially, facilities costs that do not have an alternative future use; related depreciation and other allocated expenses; license fees for and milestone payments related to in-licensed products and technologies; and costs associated with animal testing activities and regulatory approvals. Advertising Expense The Company records the cost of its advertising efforts when services are performed or goods are delivered. The Company incurred approximately $19.3 million, $14.8 million, and $14.6 million in advertising costs for the years ended December 31, 2015, 2014, and 2013, respectively and are recorded in the sales, general and administrative expense line of the Statement of Operations. Share-Based Compensation Employee share-based compensation is measured based on the estimated fair value on the grant date. The grant date fair value is calculated using the Black-Scholes option-pricing model, which requires the use of subjective assumptions including volatility, expected term, risk-free rate, and the fair value of the underlying common stock. The Company recognizes expense using the straight-line method less estimated forfeitures. The Company records the expense for stock option grants to non-employees based on the estimated fair value of the stock option using the Black-Scholes option-pricing model. The fair value of non-employee awards is re-measured at each reporting period. As a result, stock compensation expense for non-employee awards with vesting is affected by subsequent changes in the fair value of the Company's common stock. Income Taxes The Company utilizes the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on differences between financial reporting and tax reporting bases of assets and liabilities and are measured using enacted tax rates and laws that are expected to be in effect when the differences are expected to reverse. Valuation allowances are established to reduce deferred tax assets to the amounts expected to be realized. The Company accounts for uncertain tax positions in its consolidated financial statements when it is more-likely-than-not that the position will be sustained upon examination by the tax authorities. Such tax positions must initially and subsequently be measured as the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon ultimate settlement with the tax authority assuming full knowledge of the position and relevant facts. The Company's policy is to recognize any interest and penalties related to income taxes in income tax expense. Recently Issued Accounting Pronouncements In November 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2015-17, "Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes". The standard requires that deferred tax assets and liabilities be classified as noncurrent on the balance sheet rather than being separated into current and noncurrent. ASU 2015-17 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early adoption is permitted and the standard may be applied either retrospectively or on a prospective basis to all deferred tax assets and liabilities. We early adopted ASU 2015-17 during our fourth quarter of fiscal year 2015 on a prospective basis. Accordingly, we reclassified the current deferred taxes to noncurrent on our December 31, 2015 Consolidated Balance Sheet, eliminating the presentation of the offsetting $0.2 million current deferred tax asset and non-current deferred tax liability. In July 2015, the FASB issued ASU No. 2015-11, "Inventory (Topic 330): Simplifying the Measurement of Inventory." Under this new guidance, entities that measure inventory using any method other than last-in, first-out or the retail inventory method will be required to measure inventory at the lower of cost and net realizable value. The amendments in this ASU, which should be applied prospectively, are effective for annual and interim periods beginning after December 15, 2016. Early adoption is permitted. The Company is currently in the process of evaluating the impact of adoption of ASU No. 2015-11 on our consolidated financial statements and related disclosures. In April 2015, the FASB issued ASU No. 2015-05, "Customer's Accounting for Fees Paid in a Cloud Computing Arrangement." This ASU provides guidance about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, then the software license element of the arrangement is consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, then it should account for the arrangement as a service contract. The amendments in this ASU are effective for financial statements issued for annual periods, including interim periods within those annual periods, beginning after December 15, 2015. The Company has elected to adopt the amendment early. The adoption of this standard had no impact on the Company's financial results. In April 2015, the FASB issued ASU No. 2015-03, "Simplifying the Presentation of Debt Issuance Costs." This ASU more closely aligns the treatment of debt issuance costs with debt discounts and premiums and requires debt issuance costs be presented as a direct deduction from the carrying amount of the related debt. The amendments in this ASU are effective for financial statements issued for fiscal years beginning after December 15, 2015 and interim periods within those fiscal years. This guidance should be applied on a retrospective basis and the Company will be required to comply with the applicable disclosures for a change in accounting principle. Presently, the Company does not expect the adoption of ASU 2015-03 to have a material impact on our consolidated financial statements and accompanying notes. In August 2014, the FASB issued ASU No. 2014-15, "Disclosure of Uncertainties About an Entity's Ability to Continue as a Going Concern". The new standard requires management to perform interim and annual assessments of an entity's ability to continue to meet its obligations as they become due within one year after the date that the financial statements are issued. ASU 2014-15 is effective for annual periods ending after December 15, 2016, and interim periods thereafter, with early adoption permitted. We do not believe the adoption of the new standard will have a significant impact on our consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, "Revenue from Contracts with Customers". ASU 2014-09 will eliminate transaction-and industry-specific revenue recognition guidance under current U.S. GAAP and replace it with a principles-based approach for determining revenue recognition. ASU 2014-09 will require that companies recognize revenue based on the value of transferred goods or services as they occur in the contract. The ASU also will require additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016. The FASB has voted to approve a one-year deferral, changing the effective date to annual reporting periods beginning after December 15, 2017, with early adoption being permitted for periods ending after December 15, 2016. Entities can transition to the standard either retrospectively or as a cumulative effect adjustment as of the date of adoption. Presently, the Company is assessing what effect the adoption of ASU 2014-09 will have on our consolidated financial statements and accompanying notes and has not yet selected a method of adoption. The Company has evaluated all other ASUs issued through the date the consolidated financials were issued and believes that no other ASU will have a material impact on the Company's consolidated financial statements.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2015
Fair Value of Financial Instruments
Fair Value of Financial Instruments	3. Fair Value of Financial Instruments The fair value of an asset or liability should represent the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Such transactions to sell an asset or transfer a liability are assumed to occur in the principal or most advantageous market for the asset or liability. Accordingly, fair value is determined based on a hypothetical transaction at the measurement date, considered from the perspective of a market participant rather than from a reporting entity's perspective. The Company reports assets and liabilities that are measured at fair value using a three level fair value hierarchy that prioritizes the inputs used to measure fair value. This hierarchy maximizes the use of observable inputs and minimizes the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: · Level 1—Inputs are unadjusted quoted prices in active markets for identical assets that the Company has the ability to access at the measurement date. · Level 2—Inputs are quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (interest rates, yield curves, etc.) and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs). · Level 3—Unobservable inputs that reflect the Company's own assumptions, based on the best information available, including the Company's own data. In accordance with the fair value hierarchy described above, the following tables show the fair value of the Company's financial assets and liabilities that are required to be measured at fair value, in thousands: Fair Value Measurements at December 31, 2015 Total Carrying Value at December 31, 2015 Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash and cash equivalents $ $ $ — $ — Marketable securities — — Long term marketable securities — — Marketable securities—restricted (SERP) — — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total assets at fair value $ $ $ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivative liabilities $ $ — $ — $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements at December 31, 2014 Total Carrying Value at December 31, 2014 Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash and cash equivalents $ $ $ — $ — Marketable securities — — Long term marketable securities — — Marketable securities—restricted (SERP) — — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total assets at fair value $ $ $ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivative liabilities $ $ — $ — $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The fair value of the restricted marketable securities is included within other non-current assets in the consolidated balance sheets. The Company's Level 1 assets include cash held with banks and money market funds. Level 2 assets include the SERP (Supplemental Executive Retirement Plan) assets, commercial paper and investment grade corporate bonds and other fixed income securities. Level 2 securities are valued using third-party pricing sources that apply applicable inputs and other relevant data into their models to estimate fair value. Level 3 liabilities include the estimated fair value of the interest make-whole liability associated with the Company's 7.50% Convertible Senior Secured Notes due 2019 (the Notes) and the outstanding warrants to purchase Common Stock, which are recorded as derivative liabilities. As of December 31, 2015, no warrants remained outstanding. The fair value of the interest make-whole liability of the Notes was calculated using a binomial-lattice model with the following key assumptions as of December 31 2015: Volatility 45% Stock Price as of December 31, 2015 $13.44 per share Credit Spread 2363 bps Term 1.33 years Dividend Yield 0.0% Significant changes to these assumptions could result in increases/decreases to the fair value of the derivative liabilities. Changes in the fair value of the warrants and the interest make-whole liability are recognized as a component of Other Income (Expense) in the Consolidated Statements of Operations. The following table presents information about the Company's Level 3 liabilities as of December 31, 2014 and December 31, 2015 that are included in the Non-Current Liabilities section of the Consolidated Balance Sheets, in thousands: Year Ended December 31, 2014 and 2015 Balance at December 31, 2013 $ Changes in fair value of derivative liabilities included in earnings ) Reduction due to conversion of debt to equity ) ​ ​ ​ ​ ​ Balance at December 31, 2014 ​ ​ ​ ​ ​ Changes in fair value of derivative liabilities included in earnings ) Reduction due to conversion of debt to equity ) Cashless exercise of common stock warrants ) ​ ​ ​ ​ ​ Balance at December 31, 2015 $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The carrying value, face value and estimated fair value of the Notes was approximately $7.2 million, $8.5 million and $22.6 million, respectively, as of December 31, 2015. The fair value was estimated based on actual trade information as well as quoted prices provided by bond traders, which would be characterized within Level 2 of the fair value hierarchy. This fair value amount gives recognition to the value of the interest make-whole liability and the value of the conversion option. These items have been accounted for as derivative liabilities and additional paid-in-capital, respectively. The carrying amounts of other financial instruments, including accounts receivable, accounts payable and accrued expenses approximate fair value due to their short-term maturities. Unrestricted marketable securities held by the Company were as follows, in thousands: At December 31, 2015: Available for Sale Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Corporate debt securities $ ) $ At December 31, 2014: Available for Sale Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Corporate debt securities $ ) $ The contractual maturities of the unrestricted available for sale marketable securities held by the Company were as follows, in thousands: December 31, 2015 Less Than 1 Year $ 1 - 5 years Greater Than 5 Years — ​ ​ ​ ​ ​ Total $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The Company has not experienced any other-than-temporary losses on its marketable securities and restricted marketable securities. The cost of securities sold is calculated using the specific identification method.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2015
Inventories
Inventories	4. Inventories Inventories consist of the following, in thousands: December 31, 2015 December 31, 2014 Raw materials $ $ Work in process Finished goods ​ ​ ​ ​ ​ ​ ​ ​ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2015
Property and Equipment
Property and Equipment	5. Property and Equipment Property and equipment consist of the following, in thousands: December 31, 2015 December 31, 2014 Computer equipment $ $ Software Lab equipment and furniture Leasehold improvements Construction in progress — ​ ​ ​ ​ ​ ​ ​ ​ Less accumulated depreciation and amortization ) ) ​ ​ ​ ​ ​ ​ ​ ​ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and amortization expense on property and equipment was approximately $678,000, $699,000, and $512,000 for the years ended December 31, 2015, 2014 and 2013, respectively.

Intangible Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2015
Intangible Assets
Intangible Assets	6. Intangible Assets The Company purchased certain patents from Shire Laboratories, Inc. pursuant to a 2005 purchase agreement. These patents are being amortized over the weighted average life of the patents purchased in that transaction. Deferred legal fees have been incurred in connection with litigation related to patents for Oxtellar XR and Trokendi XR. The following sets forth the gross carrying amount and related accumulated amortization of these intangible assets, in thousands: December 31, 2015 December 31, 2014 Weighted- Average Life Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Purchased patents $ $ $ $ Capitalized patent defense costs $ $ $ — $ — Deferred legal fees will be capitalized as part of the patents upon successful outcome of the on-going litigation related to these patents, at which point amortization of those costs will begin. The Company reached an agreement to settle certain litigation related to Trokendi XR in October 2015, at which time the Company capitalized the costs associated with that litigation and began amortization. The net book value of intangible assets was $1.0 million as of December 31, 2015 and was $0.2 million as of December 31, 2014. Amortization expense on intangible assets was approximately $243,000, $229,000, and $229,000 for the years ended December 31, 2015, 2014 and 2013, respectively. There were no indicators of impairment identified at December 31, 2015 or December 31, 2014.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2015
Accrued Expenses
Accrued Expenses	7. Accrued Expenses Accrued expenses are comprised of the following, in thousands: December 31, 2015 December 31, 2014 Accrued compensation $ $ Accrued professional fees Accrued clinical trial and clinical supply costs Accrued sales and marketing expenses Accrued product costs Accrued interest expense Other accrued expenses ​ ​ ​ ​ ​ ​ ​ ​ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Convertible Senior Secured Note

Convertible Senior Secured Notes	12 Months Ended
	Dec. 31, 2015
Convertible Senior Secured Notes
Convertible Senior Secured Notes	8. Convertible Senior Secured Notes On May 3, 2013, the Company issued $90.0 million aggregate principal amount of Notes. The Company completed this private placement offering in reliance on Section 4(a)(2) under the Securities Act of 1933, as amended (the Securities Act). The notes were available for resale in transactions exempt from the registration requirements of the Securities Act to persons reasonably believed by the initial purchasers to be "qualified institutional buyers" as defined in Rule 144A under the Securities Act. Aggregate offering expenses in connection with the transaction, including the underwriters' fee of $3.0 million, were approximately $3.5 million, resulting in net proceeds of approximately $86.5 million. The Company used approximately $19.6 million to repay in full its borrowings under and terminate its then existing secured credit facility. The Company issued the Notes under an Indenture, dated May 3, 2013 (the Indenture), between the Company and U.S. Bank National Association, as Trustee and Collateral Agent. The Notes provide for 7.50% interest per annum on the principal amount of the Notes, payable semi-annually in arrears on May 1 and November 1 of each year, beginning on November 1, 2013. Interest will accrue on the Notes from and including May 3, 2013 and the Notes will mature on May 1, 2019, unless earlier converted, redeemed or repurchased by the Company. The Notes are convertible into the Company's common stock (Common Stock) as described below. The Notes are the Company's senior secured obligations and (i) rank senior in right of payment to any of the indebtedness that is expressly subordinated in right of payment to the Notes; (ii) rank effectively senior to any of the unsecured indebtedness to the extent of the value of the collateral securing the Notes; (iii) rank equal in right of payment with all of the Company's indebtedness that is not subordinated to the Notes; and (iv) are structurally subordinated to all indebtedness and liabilities, including trade payables, of the Company's existing and future subsidiaries. The Notes are secured by a first-priority lien, other than customary permitted liens, on substantially all of the Company's and its domestic subsidiaries' assets, whether now owned or hereafter acquired, including license agreements, general intangibles, accounts, instruments, investment property, intellectual property and any proceeds of the foregoing pursuant to that certain Security and Pledge Agreement, dated May 3, 2013 (the Security Agreement), between the Company and U.S. Bank National Association, as Collateral Agent. The Indenture restricts the ability of the Company and its existing and future subsidiaries to make investments, including transfers of the Company's assets that constitute collateral securing the Notes, in its existing and future foreign subsidiaries. The Company is entitled to the release of property and other assets constituting collateral from the liens securing the Notes and the obligations thereunder (i) to enable the Company to consummate the sale, transfer, license, monetization or other disposition of such property or assets; (ii) with the consent of the holders of at least 66 2 / 3 % of the aggregate principal amount of the Notes then outstanding and affected; or (iii) pursuant to a modification or amendment of the Indenture, the Notes or the Security Agreement. Prior to the close of business on the business day immediately preceding November 1, 2018, a holder of Notes may convert all or a portion of its Notes, in principal amounts equal to $1,000 or an integral multiple thereof, only if one or more of the following conditions has been satisfied: (1) if, for at least 20 trading days (whether or not consecutive) during the 30 consecutive trading day period ending within five trading days prior to a conversion date, the last reported sale price of the Company's Common Stock exceeds the conversion price on each such trading day; (2) during the five consecutive business day period immediately following any five consecutive trading day period (the Measurement Period), in which, for each trading day of that Measurement Period, the trading price (as defined in the Indenture) per $1,000 principal amount of Notes for such trading day was less than 98% of the product of the last reported sale price of the Company's Common Stock on such trading day and the applicable conversion rate on such trading day; (3) upon the occurrence of specified corporate transactions; or (4) if the Company calls the Notes for redemption, at any time prior to the close of business on the business day immediately preceding the redemption date. On and after November 1, 2018, a holder of Notes may convert all or a portion of its Notes, in principal amounts equal to $1,000 or an integral multiple thereof, at any time prior to the close of business on the business day immediately preceding the maturity date of the Notes, regardless of the foregoing circumstances. The Company will settle conversion of the Notes through payment or delivery, as the case may be of cash, shares of Common Stock or a combination thereof, at its election. The conversion rate for the Notes is equal to 188.7059 shares of Common Stock per $1,000 principal amount of notes (which is equivalent to an initial conversion price of approximately $5.30 per share of Common Stock). The conversion rate is subject to adjustment upon the occurrence of certain specified events but will not be adjusted for accrued and unpaid interest. In addition, upon the occurrence of a "make-whole fundamental change" (as defined in the Indenture), the Company will, in certain circumstances, increase the conversion rate by a number of additional shares for a holder that elects to convert its notes in connection with such make-whole fundamental change as described in the Indenture. Effective November 1, 2013, if, for at least 20 trading days (whether or not consecutive) during the 30 consecutive trading day period ending within five trading days prior to a conversion date, the last reported sale price of the Company's common stock exceeds the conversion price on each such trading day, the Company became required, in certain circumstances, to make an interest make-whole payment to converting holders equal to the sum of the present value of the remaining scheduled payments of interest that would have been made on the Notes to be converted had such notes remained outstanding until May 1, 2017 computed using a discount rate equal to 2%. The Company may pay an interest make-whole payment either in cash or in Common Stock, at its election. If the Company elects to pay an interest make-whole payment in Common Stock, then the stock will be valued at 95% of the simple average of the daily volume- weighted average price (VWAP) per share for the 10 trading days ending on and including the trading day immediately preceding the conversion date. Notwithstanding the foregoing, the number of shares the Company may deliver in connection with an interest make-whole payment and repayment of principal will not exceed 221.7294 shares per $1,000 principal amount of Notes, subject to adjustment. If, pursuant to its election to deliver Common Stock in connection with the payment of the interest make-whole amount, the Company would be required to deliver a number of shares of Common Stock in excess of such threshold, the Company would deliver cash in lieu of shares otherwise deliverable upon conversions in excess thereof (based on the simple average of the daily VWAP for the 10 trading days ending on and including the trading day immediately preceding the conversion date). Upon (i) the occurrence of a fundamental change (as defined in the Indenture) or (ii) if the Company calls the Notes for redemption as described below (either event, a "make-whole fundamental change") and a holder elects to convert its Notes in connection with such make-whole fundamental change, the Company will, in certain circumstances, increase the conversion rate by a number of additional shares (the "Additional Shares") as described below. The Company will notify holders within one business day after the first public announcement by it or a third party of an event or transaction that the Company reasonably determines would, if consummated, constitute a make-whole fundamental change. Upon receiving notice or otherwise becoming aware of a potential make-whole fundamental change described, the Company will use commercially reasonable efforts to announce or cause the announcement of such potential make-whole fundamental change in time to deliver such notice at least 50 scheduled trading days prior to the anticipated effective date for such transaction. The Company will notify the Trustee and holders of the effective date of any make-whole fundamental change no later than one business day after such effective date. The number of additional shares by which the Company will increase the conversion rate will be determined based on the date on which the make-whole fundamental change occurs or becomes effective (the Effective Date) and the price (the Stock Price) paid (or deemed paid) per share of the Company's Common Stock in the fundamental change. If the holders of the Company's common stock receive only cash in a make-whole fundamental change (i) the Stock Price shall be the cash amount paid per share and (ii) the Company will satisfy its conversion obligation to a holder that converts its Notes any time after such make-whole fundamental change by delivering to such holder, on the third business day immediately following the relevant conversion date, an amount of cash, for each $1,000 principal amount of Notes converted, equal to the product of (x) the conversion rate in effect on the relevant conversion date (as increased by the Additional Shares, if any) and (y) the Stock Price. Otherwise, (i) the Stock Price will equal the average of the last reported sale prices of the Company's Common Stock over the five trading day period ending on, and including, the trading day immediately preceding the Effective Date of the make-whole fundamental change and (ii) the Company will satisfy its conversion obligation to a holder that converts its Notes in connection with such make-whole fundamental change based on the conversion rate as increased by the number of Additional Shares. In connection with a make-whole fundamental change triggered by redemption of the Notes, the Effective Date of such make-whole fundamental change will be the date on which the Company delivers notice of the redemption. Notwithstanding the foregoing, in no event will the conversion rate exceed the maximum conversion rate, which is 221.7294 shares per $1,000 principal amount of Notes, which amount is inclusive of repayment of the principal of the Notes. If a fundamental change occurs at any time, holders will have the right, at their option, to require the Company to purchase for cash any or all of the Notes, or any portion of the principal amount thereof, that is equal to $1,000 or an integral multiple of $1,000 in excess thereof, on a date of the Company's choosing that is not less than 20 calendar days nor more than 35 calendar days after the date on which it delivers a fundamental change notice. The price the Company is required to pay for a Note is equal to 100% of the principal amount of such Note plus accrued and unpaid interest, if any, to, but excluding, the fundamental change purchase date. Any Notes purchased by the Company will be paid for in cash. The Company may not redeem the Notes prior to May 1, 2017. On or after May 1, 2017, the Company may redeem for cash all, but not less than all, of the Notes if the last reported sale price of the Company's Common Stock equals or exceeds 140% of the applicable conversion price for at least 20 trading days during the 30 consecutive trading day period ending on the trading day immediately prior to the date the Company delivers written notice of the redemption. The redemption price will be equal to 100% of the principal amount of the Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. If the Company calls the Notes for redemption, a make- whole fundamental change will be deemed to occur and the Company will, in certain circumstances, increase the conversion rate for holders who convert their notes in connections with such make-whole fundamental change as described in the Indenture. The Company incurred approximately $3.5 million of financing costs (including the underwriters' fee) in connection with the issuance of the Notes. Approximately $0.9 million of this amount was allocated to additional paid-in capital and the remaining $2.6 million is recorded as a deferred cost being amortized over the term of the Notes. As of December 31, 2015, approximately $0.1 million remained unamortized, of which $0.03 million is current and $0.07 million is long term. The table below summarizes activity related to the Notes from issuance on May 3, 2013 through December 31, 2015, in thousands: Gross proceeds $ Initial value of interest make-whole derivative reported as debt discount ) Conversion option reported as debt discount and APIC ) Conversion of debt to equity—principal ) Conversion of debt to equity—accretion of debt discount Accretion of debt discount ​ ​ ​ ​ ​ December 31, 2014 carrying value Conversion of debt to equity—principal ) Conversion of debt to equity—accretion of debt discount Accretion of debt discount ​ ​ ​ ​ ​ December 31, 2015 carrying value $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ During the year ended December 31, 2015, approximately $27.5 million of the Notes were presented to the Company for conversion. Accordingly, the Company issued approximately 5.2 million shares of common stock in conversion of the principal amount of the Notes. The Company issued an additional 0.5 million shares of common stock in settlement of the interest make-whole provision related to the converted Notes. As a result of the conversions, the Company incurred a loss on extinguishment of debt of approximately $2.3 million during the period ended December 31, 2015. During the year ended December 31, 2014, approximately $13.4 million of the Notes were presented to the Company for conversion. Accordingly, the Company issued approximately 2.5 million shares of common stock in conversion of the principal amount of the Notes. The Company issued an additional 0.4 million shares of common stock in settlement of the interest make-whole provision related to the converted Notes. As a result of the conversions, the Company incurred a loss on extinguishment of debt of approximately $2.6 million during the period ended December 31, 2014. Secured Notes Payable In January 2011, the Company entered into a secured credit facility pursuant to a loan and security agreement with certain lenders, which was subsequently amended in December 2011, providing for term loans of up to an aggregate of $30.0 million. On January 26, 2011 and December 30, 2011, the Company drew down $15.0 million and $15.0 million, respectively, of term loans under this secured credit facility. The Company used approximately $19.6 million of the Convertible Note proceeds to repay in full its borrowings under and terminate this secured credit facility in May 2013. Upon repayment of the secured notes payable, the Company incurred an approximately $1.2 million loss on extinguishment of debt during the period ended December 31, 2013.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity
Stockholders' Equity	9. Stockholders' Equity Common Stock The holders of the Common Stock are entitled to one vote for each share of Common Stock held. On May 1, 2012, the Company completed its IPO, in which 10 million shares of the Company's Common Stock were sold at a price of $5 per share. Additionally, the underwriters of the Company's IPO exercised the full amount of their over-allotment option resulting in the sale of an additional 449,250 shares of the Company's Common Stock at a price of $5 per share, resulting in cash proceeds to the Company of $52.3 million. The Company realized net proceeds of $47.6 million from the IPO, after issuance costs of approximately $4.7 million. On December 5, 2012, the Company completed a follow-on offering, in which 6 million shares of the Company's Common Stock were sold at a price of $8 per share. Additionally, the underwriters of the Company's follow-on offering exercised their over-allotment options in January 2013 resulting in the sale of an additional 239,432 shares of the Company's Common Stock at a price of $8 per share, resulting in total cash proceeds to the Company of $49.9 million. The Company realized net proceeds of $46.6 million from the follow-on offering, after issuance costs of approximately $3.3 million. During the period from November 1, 2013 through December 31, 2015, the Company issued 15,372,477 shares of common stock as a result of the conversion of approximately $81.5 million of Convertible Notes and approximately 2,195,904 shares of common stock in settlement of the interest-make whole associated with those conversions.

Share-Based Payments

Share-Based Payments	12 Months Ended
	Dec. 31, 2015
Share-Based Payments
Share-Based Payments	10. Share-Based Payments Stock Option Plans The Company has adopted the Supernus Pharmaceuticals, Inc. 2012 Equity Incentive Plan (the 2012 Plan), which is stockholder approved, and provides for the grant of stock options and certain other awards, including stock appreciation rights (SAR), restricted and unrestricted stock, stock units, performance awards, cash awards and other awards that are convertible into or otherwise based on the Company's common stock, to the Company's key employees, directors, and consultants and advisors. The 2012 Plan is administered by the Company's Board of Directors and provides for the issuance of up to 4,000,000 shares of the Company's Common Stock. Option awards are granted with an exercise price equal to the estimated fair value of the Company's Common Stock at the grant date; those option awards generally vest in four annual installments, starting on the first anniversary of the date of grant and have ten-year contractual terms. Share-based compensation recognized related to the grant of employee and non-employee stock options, SAR, potential Employee Stock Purchase Plan (ESPP) awards and non-vested stock was as follows, in thousands: Year Ended December 31, 2015 2014 2013 Research and development $ $ $ Selling, general and administrative ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model using the assumptions in the following table: Year Ended December 31, 2015 2014 2013 Fair value of common stock $9.13 - $21.21 $7.63 - $10.02 $5.40 - $7.90 Expected volatility 60.9% - 64.6% 64.5% - 68.3% 69.5% - 70.9% Dividend Yield 0% 0% 0% Expected term 6.25 years 6.25 years 6.25 - 9.60 years Risk-free interest rate 1.54% - 1.74% 1.67% - 1.97% 1.20% - 2.94% Expected forfeiture rate 5% 5% 5% Fair Value of Common Stock —For option grants that occurred after the Company's IPO on May 1, 2012, the fair value of the Common Stock underlying the option grants was determined based on observable market prices of the Company's Common Stock. Expected Volatility —Volatility is a measure of the amount by which a financial variable such as a share price has fluctuated (historical volatility) or is expected to fluctuate (expected volatility) during a period. The Company has identified several public entities of similar size, complexity, and stage of development and, accordingly, historical volatility has been calculated using the volatility of these companies, as well as taking into consideration the Company's actual volatility since our IPO. As our historical experience is not sufficient to calculate volatility for our option grants, the Company will continue to use guideline peer group volatility information until the historical volatility of its own Common Stock is sufficient on its own to measure expected volatility for future option grants. Dividend Yield —The Company has never declared or paid dividends and has no plans to do so in the foreseeable future. Expected Term —This is the period of time that the options granted are expected to remain unexercised. Options granted have a maximum term of ten years. The Company determines the average expected life of stock options according to the "simplified method" as described in Staff Accounting Bulletin 110, which is the mid-point between the vesting date and the end of the contractual term. Over time, management will track estimates of the expected life of the option term so that estimates will approximate actual behavior for similar options. Risk-Free Interest Rate —This is the U.S. Treasury rate for the week of each option grant during the year, having a term that most closely resembles the expected term of the option. Expected Forfeiture Rate —The forfeiture rate is the estimated percentage of options granted that are expected to be forfeited or canceled on an annual basis before becoming fully vested. The following table summarizes stock option and SAR activity: Number of Options Weighted- Average Exercise Price Weighted-Average Remaining Contractual Term (in years) Outstanding, December 31, 2013 $ Granted $ Exercised ) $ Forfeited ) $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding, December 31, 2014 $ Granted $ Exercised ) $ Forfeited ) $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding, December 31, 2015 $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2015: Vested and expected to vest $ Exercisable $ The aggregate intrinsic value of options outstanding, vested and expected to vest, and exercisable as of December 31, 2015 is approximately $12.6 million, $12.4 million and $5.0 million, respectively. The aggregate intrinsic value of options outstanding, vested and expected to vest, and exercisable as of December 31, 2014 is approximately $2.0 million, $2.0 million and $1.5 million, respectively. The aggregate intrinsic value of options outstanding, vested and expected to vest, and exercisable as of December 31, 2013 is approximately $1.4 million, $1.4 million and $1.0 million, respectively. The weighted-average, grant-date fair value of options granted for the years ended December 31, 2015, 2014, and 2013 was $6.05, $5.79, and $4.98 per share, respectively. The total fair value of the underlying Common Stock related to shares that vested during the years ended December 31, 2015, 2014, and 2013 was approximately $2.6 million, $1.9 million, and $0.5 million, respectively. The total intrinsic value of options exercised amounted to approximately $1.6 million, $0.1 million, and $0.4 million, respectively, during the years ended December 31, 2015, 2014, and 2013. As of December 31, 2015 and 2014, the total unrecognized compensation expense, net of estimated forfeitures, was approximately $7.2 million, and $5.9 million, respectively, which the Company expects to recognize over a weighted-average period of 2.54 and 2.56 years, respectively.

Earnings per Share

Earnings per Share	12 Months Ended
	Dec. 31, 2015
Earnings per Share
Earnings per Share	11. Earnings per Share Basic income (loss) per common share is determined by dividing income (loss) attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration of common stock equivalents. Diluted income (loss) per share is computed by dividing the income (loss) attributable to common stockholders by the weighted-average number of common share equivalents outstanding for the period. The treasury stock method is used to determine the dilutive effect of the Company's stock option grants, SAR, and potential Employee Stock Purchase Plan (ESPP) awards, and the if-converted method is used to determine the dilutive effect of the Company's Notes. The following common stock equivalents were excluded in the calculation of diluted loss per share because their effect would be anti-dilutive as applied to the loss from continuing operations applicable to common stockholders for the years ended December 31, 2015, 2014, and 2013: Year Ended December 31, 2015 2014 2013 Shares underlying Convertible Senior Secured Notes — — Warrants to purchase common stock — — Stock options, stock appreciation rights, non-vested stock options and ESPP awards — — The following table sets forth the computation of basic and diluted net income per share for the years ended December 31, 2015, 2014, and 2013, in thousands, except share and per share amounts: Year ended December 31, 2015 2014 2013 Numerator, in thousands: Net income (loss) used for calculation of basic EPS $ $ $ ) Interest expense on convertible debt — Changes in fair value of derivative liabilities ) ) — Loss on extinguishment of debt — Loss on extinguishment of outstanding debt, as if converted ) ) — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total adjustments ) — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income used for calculation of diluted EPS $ $ $ ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator: Weighted average shares outstanding, basic Effect of dilutive potential common shares: — Shares underlying Convertible Senior Secured Notes Shares issuable to settle interest make-whole derivatives — Warrants to purchase common stock — — Stock options, stock appreciation rights, and non-vested stock options — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total potential dilutive common shares — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average shares outstanding, diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) per share, basic $ $ $ ) Net income (loss) per share, diluted $ $ $ )

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Taxes
Income Taxes	12. Income Taxes The components of the income tax expense/ (benefit) for the years ended December 31, 2015, 2014, and 2013 were as follow, in thousands: Year Ended December 31, 2015 2014 2013 Current Federal $ $ — $ — State — — Deferred Federal — — — State — — — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total $ $ — $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, 2015, the expense (benefit) for US. Federal or state income taxes was $1.0 million. For the years ended December 31, 2014, and 2013, there was no expense (benefit) for U.S. Federal or state income taxes based on continuing operations, net operating loss carryforwards and the Company's valuation allowance against its deferred income tax asset. A reconciliation of the expected income tax expense/(benefit) computed using the U.S. Federal statutory income tax rate to the Company's effective income tax rate is as follows, in thousands: Year Ended December 31, 2015 2014 2013 Income tax expense/(benefit) computed at U.S. Federal statutory tax rate $ $ $ ) Permanent items State income taxes ) Change in valuation allowance ) ) Uncertain income tax position ) Research and development credits ) ) ) Other ) ) Deferred rate change — — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income tax expense (benefit) $ $ — $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The Company recorded a change in our deferred income tax rate due to changes in state apportionment factors. The deferred income tax expense/(benefit) have been entirely offset by the net change in valuation allowances. The significant components of the Company's deferred income tax assets (liabilities) were as follow, in thousands: As of December 31, 2015 2014 Deferred tax assets: Net operating loss carryforward $ $ Deferred rent credit Accrued compensation and non-qualified stock options Deferred financing costs Depreciation and amortization Research and development credits Capitalized overhead into inventory (UNICAP §263A) Other Valuation allowance ) ) ​ ​ ​ ​ ​ ​ ​ ​ Net deferred tax asset Deferred tax liability: Debt discount on convertible notes ) ) Depreciation ) — ​ ​ ​ ​ ​ ​ ​ ​ Net deferred taxes $ — $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ In assessing the realizability of deferred income tax assets, management considers whether it is more likely than not that some or all of the deferred income tax assets will not be realized. The ultimate realization of the deferred income tax assets is dependent upon the generation of future taxable income during the periods in which the net operating loss (NOL) and tax credit carryforwards are available. Management considers projected future taxable income, the scheduled reversal of deferred income tax liabilities, and available tax planning strategies that can be implemented by the Company in making this assessment. Based upon the level of historical taxable income and projections for future taxable income over the periods in which the NOL and credit carryforwards are available to reduce income taxes payable, management has established a full valuation allowance as the Company is not more likely than not to realize such net deferred tax assets. The net decrease during the year ended December 31, 2015 in total valuation allowance of approximately $2.5 million is due to the pretax book income which was generated in the current year and an adjustment in the Company's deferred income tax rate. As of December 31, 2015, the US Federal and state NOL carryforwards amounted to approximately $91.8 million ($34.6 million tax effected) and will expire in various years beginning in 2030. As of December 31, 2015, the Company has available research and development credit carryforwards of approximately $5.5 million, which expire, if unused, starting in 2026. The use of the Company's U.S. Federal and state NOL carryforwards and research and development credits are restricted in annual use due to changes in the Company's ownership. For the year ended December 31, 2015, the Company utilized NOL's of approximately $18.5 million and expects the remaining $91.8 million of NOL carryforwards to become available over the years from 2016 to 2020, in amounts ranging from $7.8 million to $20.3 million per year. In addition, the Company has available research and development credits of approximately $5.5 million expected to become available in 2020 to 2021. The Company's state NOL's will have a similar limitation to the amount noted for US Federal. Additionally, despite the NOL carryforwards, the Company may have a future tax liability due to state and local income tax requirements. The Company paid no Federal income taxes in the years ended December 31, 2015, 2014, or 2013. The Company accounts for uncertain income tax positions pursuant to the guidance in FASB ASC Topic 740, Income Taxes . The Company recognizes interest and penalties related to uncertain tax positions, if any, in income tax expense. As of December 31, 2015, the Company accrued interest of a nominal amount and penalties of $0.1 million related to uncertain tax positions. The Company's income taxes have not been subject to examination by any tax jurisdictions since its inception in 2005. Due to NOL and research and development credit carryforwards, all U.S. Federal and state income tax returns filed by the Company are subject to examination by the taxing jurisdictions. Any uncertain income tax position liability has been recorded to the Company's deferred income tax assets to offset such tax attribute carryforwards. A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows, in thousands: Year Ended December 31, 2015 2014 2013 Balance as of January 1 $ $ $ Gross (decreases) increases related to prior-year tax positions ) ) Gross increases related to current-year tax positions Gross decreases related to current-year tax positions ) — — Change in tax rates ) ) — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of December 31 $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The Company believes that most of its uncertain income tax positions would not result in adjustments to its effective income tax rate because a corresponding adjustments to deferred income tax assets would be offset by adjustments to recorded valuation allowances. As of December 31, 2015, the Company recorded $1.0 million of current tax expense on setting up an uncertain tax position related to the Alternative Minimum Tax. The Company does not anticipate a significant increase or decrease in the uncertain income tax benefits within the next 12 months.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies
Commitments and Contingencies	13. Commitments and Contingencies The Company has concurrent leases for office and lab space that extend through April 2020. The Company may elect to extend the term of the leases for an additional five-year term. The leases provide for a tenant improvement allowance of approximately $2.1 million in aggregate. During December 31, 2015, 2014, and 2013, approximately $0.2 million, $0.1 million, and $0.5 million, respectively, of the allowance was utilized and is included in fixed assets and deferred rent. As of December 31, 2015, $0.5 million is available for tenant improvements. Rent expense for the leased facilities and leased vehicles for the years ended December 31, 2015, 2014, and 2013 was approximately, $2.6 million, $2.3 million, and $1.6 million, respectively. Future minimum lease payments under non-cancelable operating leases as of December 31, 2015 are as follows, in thousands: Year ending December 31: 2016 $ 2017 2018 2019 Thereafter ​ ​ ​ ​ ​ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The Company has obtained exclusive licenses from third parties for proprietary rights to support the product candidates in the Company's psychiatry portfolio. Under license agreements with Afecta, the Company has an exclusive option to evaluate Afecta's CNS pipeline and to obtain exclusive worldwide rights to selected product candidates, including an exclusive license to SPN-810. The Company does not owe any future milestone payments for SPN-810. The Company is obligated to pay royalties to Afecta based on worldwide net product sales in the low-single digits. The Company has also entered into a purchase and sale agreement with Rune, where the Company obtained the exclusive worldwide rights to a product concept from Rune. There are no future milestone payments due to Rune under this agreement. If the Company receives approval to market and sell any products based on the Rune product concept for SPN-809, the Company is obligated to pay royalties to Rune based on net sales worldwide in the low single digits.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2015
Employee Benefit Plan
Employee Benefit Plan	14. Employee Benefit Plan On January 2, 2006, the Company established the Supernus Pharmaceuticals, Inc. 401(k) Profit Sharing Plan (the 401(k) Plan) for its employees under Section 401(k) of the Internal Revenue Code (Code). Under the 401(k) Plan, all full-time employees who are at least 21 years old are eligible to participate in the 401(k) Plan. Employees may participate starting on the first day of the month following employment. Employees may contribute up to the lesser of 90% of eligible compensation or the applicable limit established by the Code. Employees are 100% vested in their contributions to the 401(k) Plan. The Company matches 100% of a participant's contribution for the first 3% of their salary deferral and matches 50% of the next 2% of their salary deferral. As determined by the Board, the Company may elect to make a discretionary contribution not exceeding 60% of the annual compensation paid to all participating employees. The Company's contributions to the 401(k) Plan approximated $1.4 million, $1.1 million, and $0.6 million for the years ended December 31, 2015, 2014, and 2013, respectively.

Collaboration Agreements

Collaboration Agreements	12 Months Ended
	Dec. 31, 2015
Collaboration Agreements
Collaboration Agreements	15. Collaboration Agreements The Company has a license agreement with United Therapeutics Corporation to use one of its proprietary technologies for an oral formulation of Remodulin for the treatment of pulmonary arterial hypertension and potentially for additional indications. The revenue generated in the year ended December 31, 2014 was $2.0 million for a milestone payment. During 2014, we entered into a Royalty Interest Acquisition Agreement with HC Royalty. Pursuant to this Agreement, HC Royalty made a $30.0 million cash payment to the Company in consideration for acquiring from the Company certain royalty and milestone rights related to the commercialization of Orenitram (treprostinil) Extended-Release Tablets. We will retain full ownership of the royalty rights after a certain threshold has been reached per the terms of the Agreement. Prior to that time, we will receive no revenue under this license agreement.

Quarterly Financial Information

Quarterly Financial Information (unaudited)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information (unaudited)
Quarterly Financial Information (unaudited)	16. Quarterly Financial Information (unaudited) Quarterly financial information for fiscal 2015 and 2014 are presented in the following table, in thousands, except per share data, unaudited: 1 st Quarter 2 nd Quarter 3 rd Quarter 4 th Quarter 2015 Revenue $ $ $ $ Total costs and expenses Operating income Net income Net income per share, basic Net income per share, diluted 2014 Revenue $ $ (2) $ (1) $ Total costs and expenses Operating loss ) Net loss ) Net loss per share, basic ) Net loss per share, diluted ) (1) The Company's results for the third quarter of 2014 include $30.0 million in revenue upon entering into a Royalty Interest Acquisition Agreement. (2) The Company's results for the second quarter of 2014 include the change in accounting estimate regarding revenue recognition on product sales for Trokendi XR from prescriptions filled to shipments to wholesalers.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2015
Subsequent Events
Subsequent Events	17. Subsequent Events Subsequent to December 31, 2015, holders of the Notes converted approximately $2.0 million of the Notes.We issued a total of approximately 0.4 million shares of common stock in conversion of the principal amount of the Notes and accrued interest thereon resulting in a remaining outstanding balance of $6.6 million. As of February 5, 2016, litigation with respect to Oxtellar XR was decided in favor of the Company pending appeal when a federal court ruled that three of our patents were found to be valid, and that Actavis infringed two of these three patents.

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation The Company's consolidated financial statements include the accounts of Supernus Pharmaceuticals, Inc. and Supernus Europe Ltd., collectively referred to herein as "Supernus" or "the Company." All significant intercompany transactions and balances have been eliminated in consolidation. The Company's consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (U.S. GAAP). The Company, which is primarily located in the United States, operates in one operating segment.
Use of Estimates	Use of Estimates The preparation of the financial statements in accordance with U.S. GAAP requires the Company to make estimates and judgments in certain circumstances that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. In preparing these consolidated financial statements, management has made its best estimates and judgments of certain amounts included in the financial statements, giving due consideration to materiality. On an ongoing basis, the Company evaluates its estimates, including those related to revenue recognition, accrued sales deductions, fair value of financial assets and liabilities, derivative liabilities, common stock options, income taxes, preclinical study and clinical trial accruals, and other contingencies. Management bases its estimates on historical experience or on various other assumptions, including information received from its service providers and independent valuation consultants, which it believes to be reasonable under the circumstances. Actual results could differ from these estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all investments in highly liquid financial instruments with an original maturity of three months or less to be cash equivalents.
Marketable Securities	Marketable Securities Marketable securities consist of investments in U.S. Treasuries, various U.S. governmental agency debt securities, corporate bonds and other fixed income securities. The Company's investments are classified as available for sale. Such securities are carried at estimated fair value, with any unrealized holding gains or losses reported, net of any tax effects reported, as accumulated other comprehensive income, which is a separate component of stockholders' equity. Realized gains and losses, and declines in value judged to be other-than-temporary, if any, are included in consolidated results of operations. A decline in the market value of any available for sale security below cost that is deemed to be other-than-temporary results in a reduction in fair value, which is charged to earnings in that period, and a new cost basis for the security is established. Dividend and interest income is recognized when earned. The cost of securities sold is calculated using the specific identification method. The Company places all investments with government, industrial, or financial institutions whose debt is rated as investment grade. The Company classifies all available-for-sale marketable securities with maturities greater than one year from the balance sheet date as non-current assets. The Company established the Supernus Supplemental Executive Retirement Plan (SERP) for the sole purpose of receiving funds for executives from a previous SERP and providing a continuing deferral program under the Supernus SERP. As of December 31, 2015 and 2014, the estimated fair value of the mutual fund investment securities within the SERP was approximately $263,000 and $305,000, respectively. The fair value of these assets is included within other non-current assets on the consolidated balance sheets. A corresponding noncurrent liability is also included in the consolidated balance sheets to reflect the Company's obligation for the SERP. The Company has not made, and has no plans to make, contributions to the SERP. The securities are restricted in nature and can only be used for purposes of paying benefits under the SERP.
Accounts Receivable, net	Accounts Receivable, net Accounts receivable are reported on the consolidated balance sheets at outstanding amounts, less an allowance for doubtful accounts and discounts. The Company extends credit without requiring collateral. The Company writes off uncollectible receivables when the likelihood of collection is remote. The Company evaluates the collectability of accounts receivable on a regular basis. An allowance, when needed, is based upon various factors including the financial condition and payment history of customers, an overall review of collections experience on other accounts, and economic factors or events expected to affect future collections experience. No accounts have been written off in 2015 and 2014. No allowance for uncollectible receivables is recorded at December 31, 2015 or December 31, 2014. The Company recorded an allowance of approximately $3.8 million and $4.1 million for expected sales discounts as of December 31, 2015 and December 31, 2014, respectively. The following table includes those customers that represent more than 10% of total net product sales for 2015 and more than 10% of the accounts receivable balance on the consolidated balance sheet as of December 31, 2015: Percent of Net Product Sales Percent of Accounts Receivable, net Customer A % % Customer B % % Customer C % % ​ ​ ​ ​ ​ ​ ​ ​ % % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash, cash equivalents, accounts receivable and marketable securities. The counterparties are various corporations and financial institutions of high credit standing. Substantially all of the Company's cash and cash equivalents are maintained with well known, U.S. and non U.S. financial institutions, government agencies, and corporations. Deposits held with banks may exceed the amount of insurance provided on such deposits. Generally, these deposits may be redeemed upon demand and, therefore, management believes they bear minimal risk.
Inventory	Inventory Inventories, which are recorded at the lower of cost or market, include materials, labor, and other direct and indirect costs and are valued using the first-in, first-out method. The Company capitalizes inventories produced in preparation for commercial launches when it becomes probable that the related product candidates will receive regulatory approval and that the related costs will be recoverable through the commercial sale of the product.
Property and Equipment	Property and Equipment Property and equipment are stated at cost. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is credited or charged to operations. Repairs and maintenance costs are expensed as incurred. Depreciation and amortization are computed using the straight-line method over the following average useful lives: Computer equipment 3 years Software 3 years Lab equipment and furniture 5 - 10 years Leasehold improvements Shorter of lease term or useful life
Deferred Legal Fees	Deferred Legal Fees Deferred legal fees have been incurred in connection with legal proceedings related to patents for Oxtellar XR and Trokendi XR (see Note 6). Amortization of the deferred legal fees will begin upon successful outcome of the on-going litigation. Deferred legal fees will be charged to expense in the event of an unsuccessful outcome of the on-going litigation.
Intangible Assets	Intangible Assets Intangible assets consist primarily of purchased patents and deferred legal fees. Patents are carried at cost less accumulated amortization, which is calculated on a straight-line basis over the estimated useful lives of the patents, generally estimated to be ten years. The carrying value of the patents is assessed for impairment annually during the fourth quarter of each year, or more frequently if impairment indicators exist. There were no indicators of impairment identified at December 31, 2015, 2014 or 2013.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets consist primarily of purchased patents, deferred legal fees, and property and equipment. The Company assesses the recoverability of its long-lived assets whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If indications of impairment exist, projected future undiscounted cash flows associated with the asset are compared to the carrying amount to determine whether the asset's value is recoverable. Evaluating for impairment requires judgment, including the estimation of future cash flows, future growth rates and profitability and the expected life over which cash flows will occur. Changes in the Company's business strategy or adverse changes in market conditions could impact impairment analyses and require the recognition of an impairment charge equal to the excess of the carrying value of the long-lived assets over its estimated fair value. For the years ended December 31, 2015, 2014, and 2013, the Company determined that there was no impairment of the Company's long-lived assets.
Deferred Financing Costs	Deferred Financing Costs Deferred financing costs consist of financing costs incurred by the Company in connection with the closing of the Company's 7.50% Convertible Senior Secured Notes and Secured Notes Payable (see Note 8). The Company amortizes deferred financing costs over the term of the related debt using the effective interest method. When extinguishing debt, the related deferred financing costs are written off.
Preclinical Study and Clinical Trial Accruals	Preclinical Study and Clinical Trial Accruals The Company estimates preclinical study and clinical trial expenses based on the services performed pursuant to contracts with research institutions, investigators, and clinical research organizations (CROs) that conduct these activities on our behalf. In recording service fees, the Company estimates the time period over which the related services will be performed and compares the level of effort expended through the end of each period to the cumulative expenses recorded and payments made for such services and, as appropriate, accrues additional service fees or defers any non-refundable advance payments until the related services are performed. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust its accrual or deferred advance payment accordingly. If the Company later determines that it no longer expects the services associated with a nonrefundable advance payment to be rendered, the advance payment will be charged to expense in the period that such determination is made.
Revenue Recognition	Revenue Recognition Revenue from product sales is recognized when persuasive evidence of an arrangement exists; delivery has occurred and title to the product and associated risk of loss has passed to the customer; the price is fixed or determinable; collection from the customer has been reasonably assured; all performance obligations have been met; and returns and allowances can be reasonably estimated. Product sales are recorded net of estimated rebates, chargebacks, discounts, co-pay assistance and other deductions as well as estimated product returns (collectively, "sales deductions"). Our products are distributed through wholesalers and pharmaceutical distributors. Each of these wholesalers and distributors will take title and ownership to the product upon physical receipt of the product and then distribute our products to pharmacies. Beginning in the fourth quarter of 2013, the Company began recognizing revenue for Oxtellar XR, net of estimated sales deductions, at the time of shipment to wholesalers. Prior to this time, the Company recognized revenue for Oxtellar XR upon fulfillment of prescriptions, net of all known or estimated sales deductions. Beginning in the second quarter of 2014, the Company began recognizing revenue for Trokendi XR, net of estimated sales deductions, at the time of shipment to wholesalers. Prior to this time, the Company recognized revenue for Trokendi XR upon fulfillment of prescriptions to patients, net of all known or estimated sales deductions. For the year ended December 31, 2015, the revenue for Oxtellar XR and Trokendi XR was recognized contemporaneously upon shipment of finished products to wholesalers, net of allowances for estimated sales deductions and returns. During the year ended December 31, 2015, the Company recorded a $2.9 million reduction to net revenue related to a change in estimate associated with its accrued sales deductions of $26.8 million at December 31, 2015. The change in estimate reflects returns experience associated with our initial launch shipments, which have now passed their expiry dating. Revenue from Product Sales The Company launched Oxtellar XR on February 4, 2013 and launched Trokendi XR on August 26, 2013. During the fourth quarter of 2013, we began to recognize revenue for Oxtellar XR contemporaneously upon shipment of finished product to wholesalers less allowances for estimated sales deductions and, during the second quarter of 2014, we began to recognize revenue for Trokendi XR contemporaneously upon shipment of finished product to wholesalers less allowances for estimated sales deductions. Through December 31, 2013, the Company recorded shipments of Trokendi XR to wholesalers as deferred revenue i.e., sales price net of known sales deductions (e.g. prompt pay discounts and other similar charges defined below). At the time, we lacked the experiential data which would allow us to estimate all remaining sales rebates, allowances and returns. Accordingly, when this data became available to the Company, we moved to contemporaneous revenue recognition in the second quarter of 2014. Sales Deductions Allowances for estimated sales deductions are provided for the following: · Rebates. Rebates include mandated discounts under the Medicaid Drug Rebate Program, the Medicare coverage gap program, as well as negotiated discounts with commercial healthcare providers. Rebates are amounts owed after the final dispensing of products to a benefit plan participant and are based upon contractual agreements or legal requirements with the public sector (e.g. Medicaid) and with private sector benefit providers. The allowance for rebates is based on statutory and contractual discount rates and expected claimed rebates paid based on a plan provider's utilization. Rebates are generally invoiced and paid quarterly in arrears so that the accrual balance consists of an estimate of the amount expected to be incurred for the current quarter's activity, plus an accrual balance for known or estimated prior quarters' unpaid rebates. If actual future rebates vary from estimates, we may need to adjust prior period accruals, which would affect revenue in the period of adjustment. · Chargebacks. Chargebacks are discounts that occur when contracted customers purchase directly from an intermediary distributor or wholesaler. Contracted customers, which currently consist primarily of Public Health Service institutions and federal government entities purchasing via the Federal Supply Schedule, generally purchase the product at a discounted price. The distributor or wholesaler, in turn, charges back the difference between the price initially paid by the distributor or wholesaler and the discounted price paid to the distributor or wholesaler by the customer. The allowance for distributor/wholesaler chargebacks is based on known sales to contracted customers. · Distributor/Wholesaler deductions and discounts. U.S. specialty distributors and wholesalers are offered various forms of consideration including allowances, service fees and prompt payment discounts as consideration for distributing our products. Distributor allowances and service fees arise from contractual agreements with distributors and are generally a percentage of the purchase price paid by the distributors and wholesalers. Wholesale customers are offered a prompt pay discount for payment within a specified period. · Co-pay assistance. Patients who pay in cash or have commercial insurance and meet certain eligibility requirements may receive co-pay assistance from the Company. The intent of this program is to reduce the patient's out of pocket costs. · Liabilities for co-pay assistance are based on actual program participation and estimates of program redemption using data provided by third-party administrators. · Returns. Sales of our products are not subject to a general right of return; however, the Company will accept product that is damaged or defective when shipped directly from our warehouse and expired product six months prior and up to 12 months subsequent to its expiry date. Product that has been used to fill patient prescriptions is no longer subject to any right of return.
Revenue from Royalty Agreement	Revenue from Royalty Agreement In the third quarter of 2014, the Company recognized $30.0 million in revenue from a royalty agreement related to HealthCare Royalty Partners III, L.P.'s purchase of certain of the Company's rights under the Royalty Interest Acquisition Agreement with United Therapeutics Corporation related to the commercialization of Orenitram. The Company determined to recognize this revenue immediately because (1) the executed contract constituted persuasive evidence of an arrangement, (2) the delivery of the license occurred and the Company has no current or future performance obligations, (3) the total consideration for the license agreement was fixed and known at the time of its execution and there were no rights of return, and (4) the cash was received and is non-refundable.
Revenue Recognition of License Revenue	Revenue Recognition of License Revenue License and Collaboration Agreements We have entered into collaboration agreements to have both Oxtellar XR and Trokendi XR commercialized outside of the U.S. These agreements generally include an up-front license fee and ongoing milestone payments upon the achievement of specific events. We believe the milestones meet all of the necessary criteria to be considered substantive and therefore should be recognized as revenue when achieved. For up-front license fees, we have estimated the service period of the contract and are recognizing this payment as revenue on a straight-line basis over the respective service period. Milestone Payments Milestone payments on licensing agreements are recognized as revenue when the collaborative partner acknowledges completion of the milestone and substantive effort was necessary to achieve the milestone. Management may recognize revenue contingent upon the achievement of a milestone in its entirety in the period in which the milestone is achieved only if the milestone meets all the criteria to be considered substantive. Substantive milestone payments are recognized upon achievement of the milestone only if all of the following conditions are met: · the milestone payments are non-refundable; · achievement of the milestone involves a degree of risk and was not reasonably assured at the inception of the arrangement; · substantive effort on the partner's part is involved in achieving the milestone; and · the amount of the milestone payment is reasonable in relation to the effort expended or the risk associated with achievement of the milestone. Determination as to whether a payment meets the aforementioned conditions involves management's judgment. If any of these conditions are not met, the resulting payment would not be considered a substantive milestone, and therefore the resulting payment would be considered part of the consideration for the single unit of accounting and amortized over the appropriate period. The Company recorded milestone revenues of $0.8 million and $2.0 million during the years ended December 31, 2015 and 2014, respectively. There was no revenue generated from the achievement of milestones in the year ended December 31, 2013.
Cost of Product Sales	Cost of Product Sales The cost of product sales consist primarily of materials, third-party manufacturing costs, freight and distribution costs, allocation of labor, quality control and assurance, and other manufacturing overhead costs.
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred. Research and development costs primarily consist of employee-related expenses, including salaries and benefits; share-based compensation expense; expenses incurred under agreements with clinical research organizations (CROs), investigative sites, and consultants that conduct the Company's clinical trials; the cost of acquiring and manufacturing clinical trial materials; the cost of manufacturing materials used in process validation, to the extent that those materials are manufactured prior to receiving regulatory approval for those products and are not expected to be sold commercially, facilities costs that do not have an alternative future use; related depreciation and other allocated expenses; license fees for and milestone payments related to in-licensed products and technologies; and costs associated with animal testing activities and regulatory approvals.
Advertising Expense	Advertising Expense The Company records the cost of its advertising efforts when services are performed or goods are delivered. The Company incurred approximately $19.3 million, $14.8 million, and $14.6 million in advertising costs for the years ended December 31, 2015, 2014, and 2013, respectively and are recorded in the sales, general and administrative expense line of the Statement of Operations.
Share-Based Compensation	Share-Based Compensation Employee share-based compensation is measured based on the estimated fair value on the grant date. The grant date fair value is calculated using the Black-Scholes option-pricing model, which requires the use of subjective assumptions including volatility, expected term, risk-free rate, and the fair value of the underlying common stock. The Company recognizes expense using the straight-line method less estimated forfeitures. The Company records the expense for stock option grants to non-employees based on the estimated fair value of the stock option using the Black-Scholes option-pricing model. The fair value of non-employee awards is re-measured at each reporting period. As a result, stock compensation expense for non-employee awards with vesting is affected by subsequent changes in the fair value of the Company's common stock.
Income Taxes	Income Taxes The Company utilizes the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on differences between financial reporting and tax reporting bases of assets and liabilities and are measured using enacted tax rates and laws that are expected to be in effect when the differences are expected to reverse. Valuation allowances are established to reduce deferred tax assets to the amounts expected to be realized. The Company accounts for uncertain tax positions in its consolidated financial statements when it is more-likely-than-not that the position will be sustained upon examination by the tax authorities. Such tax positions must initially and subsequently be measured as the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon ultimate settlement with the tax authority assuming full knowledge of the position and relevant facts. The Company's policy is to recognize any interest and penalties related to income taxes in income tax expense.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In November 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2015-17, "Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes". The standard requires that deferred tax assets and liabilities be classified as noncurrent on the balance sheet rather than being separated into current and noncurrent. ASU 2015-17 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early adoption is permitted and the standard may be applied either retrospectively or on a prospective basis to all deferred tax assets and liabilities. We early adopted ASU 2015-17 during our fourth quarter of fiscal year 2015 on a prospective basis. Accordingly, we reclassified the current deferred taxes to noncurrent on our December 31, 2015 Consolidated Balance Sheet, eliminating the presentation of the offsetting $0.2 million current deferred tax asset and non-current deferred tax liability. In July 2015, the FASB issued ASU No. 2015-11, "Inventory (Topic 330): Simplifying the Measurement of Inventory." Under this new guidance, entities that measure inventory using any method other than last-in, first-out or the retail inventory method will be required to measure inventory at the lower of cost and net realizable value. The amendments in this ASU, which should be applied prospectively, are effective for annual and interim periods beginning after December 15, 2016. Early adoption is permitted. The Company is currently in the process of evaluating the impact of adoption of ASU No. 2015-11 on our consolidated financial statements and related disclosures. In April 2015, the FASB issued ASU No. 2015-05, "Customer's Accounting for Fees Paid in a Cloud Computing Arrangement." This ASU provides guidance about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, then the software license element of the arrangement is consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, then it should account for the arrangement as a service contract. The amendments in this ASU are effective for financial statements issued for annual periods, including interim periods within those annual periods, beginning after December 15, 2015. The Company has elected to adopt the amendment early. The adoption of this standard had no impact on the Company's financial results. In April 2015, the FASB issued ASU No. 2015-03, "Simplifying the Presentation of Debt Issuance Costs." This ASU more closely aligns the treatment of debt issuance costs with debt discounts and premiums and requires debt issuance costs be presented as a direct deduction from the carrying amount of the related debt. The amendments in this ASU are effective for financial statements issued for fiscal years beginning after December 15, 2015 and interim periods within those fiscal years. This guidance should be applied on a retrospective basis and the Company will be required to comply with the applicable disclosures for a change in accounting principle. Presently, the Company does not expect the adoption of ASU 2015-03 to have a material impact on our consolidated financial statements and accompanying notes. In August 2014, the FASB issued ASU No. 2014-15, "Disclosure of Uncertainties About an Entity's Ability to Continue as a Going Concern". The new standard requires management to perform interim and annual assessments of an entity's ability to continue to meet its obligations as they become due within one year after the date that the financial statements are issued. ASU 2014-15 is effective for annual periods ending after December 15, 2016, and interim periods thereafter, with early adoption permitted. We do not believe the adoption of the new standard will have a significant impact on our consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, "Revenue from Contracts with Customers". ASU 2014-09 will eliminate transaction-and industry-specific revenue recognition guidance under current U.S. GAAP and replace it with a principles-based approach for determining revenue recognition. ASU 2014-09 will require that companies recognize revenue based on the value of transferred goods or services as they occur in the contract. The ASU also will require additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016. The FASB has voted to approve a one-year deferral, changing the effective date to annual reporting periods beginning after December 15, 2017, with early adoption being permitted for periods ending after December 15, 2016. Entities can transition to the standard either retrospectively or as a cumulative effect adjustment as of the date of adoption. Presently, the Company is assessing what effect the adoption of ASU 2014-09 will have on our consolidated financial statements and accompanying notes and has not yet selected a method of adoption. The Company has evaluated all other ASUs issued through the date the consolidated financials were issued and believes that no other ASU will have a material impact on the Company's consolidated financial statements.

Summary of Significant Accoun27

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Summary of Significant Accounting Policies
Schedule of customers that represent more than 10% total revenue	Percent of Net Product Sales Percent of Accounts Receivable, net Customer A % % Customer B % % Customer C % % ​ ​ ​ ​ ​ ​ ​ ​ % % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of average useful lives used to compute depreciation and amortization	Computer equipment 3 years Software 3 years Lab equipment and furniture 5 - 10 years Leasehold improvements Shorter of lease term or useful life

Fair Value of Financial Instr28

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value of Financial Instruments
Schedule of fair value of the financial assets and liabilities	In accordance with the fair value hierarchy described above, the following tables show the fair value of the Company's financial assets and liabilities that are required to be measured at fair value, in thousands: Fair Value Measurements at December 31, 2015 Total Carrying Value at December 31, 2015 Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash and cash equivalents $ $ $ — $ — Marketable securities — — Long term marketable securities — — Marketable securities—restricted (SERP) — — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total assets at fair value $ $ $ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivative liabilities $ $ — $ — $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements at December 31, 2014 Total Carrying Value at December 31, 2014 Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash and cash equivalents $ $ $ — $ — Marketable securities — — Long term marketable securities — — Marketable securities—restricted (SERP) — — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total assets at fair value $ $ $ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivative liabilities $ $ — $ — $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of assumptions used to calculate fair value of make-whole liability	Volatility 45% Stock Price as of December 31, 2015 $13.44 per share Credit Spread 2363 bps Term 1.33 years Dividend Yield 0.0%
Schedule of Level 3 liabilities included in Non-current Liabilities on the Balance Sheet	The following table presents information about the Company's Level 3 liabilities as of December 31, 2014 and December 31, 2015 that are included in the Non-Current Liabilities section of the Consolidated Balance Sheets, in thousands: Year Ended December 31, 2014 and 2015 Balance at December 31, 2013 $ Changes in fair value of derivative liabilities included in earnings ) Reduction due to conversion of debt to equity ) ​ ​ ​ ​ ​ Balance at December 31, 2014 ​ ​ ​ ​ ​ Changes in fair value of derivative liabilities included in earnings ) Reduction due to conversion of debt to equity ) Cashless exercise of common stock warrants ) ​ ​ ​ ​ ​ Balance at December 31, 2015 $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of unrestricted marketable securities	Unrestricted marketable securities held by the Company were as follows, in thousands: At December 31, 2015: Available for Sale Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Corporate debt securities $ ) $ At December 31, 2014: Available for Sale Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Corporate debt securities $ ) $
Schedule of contractual maturities of the unrestricted marketable securities held	The contractual maturities of the unrestricted available for sale marketable securities held by the Company were as follows, in thousands: December 31, 2015 Less Than 1 Year $ 1 - 5 years Greater Than 5 Years — ​ ​ ​ ​ ​ Total $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2015
Inventories
Schedule of inventories	Inventories consist of the following, in thousands: December 31, 2015 December 31, 2014 Raw materials $ $ Work in process Finished goods ​ ​ ​ ​ ​ ​ ​ ​ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property and Equipment
Schedule of property and equipment	Property and equipment consist of the following, in thousands: December 31, 2015 December 31, 2014 Computer equipment $ $ Software Lab equipment and furniture Leasehold improvements Construction in progress — ​ ​ ​ ​ ​ ​ ​ ​ Less accumulated depreciation and amortization ) ) ​ ​ ​ ​ ​ ​ ​ ​ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Intangible Assets (Tables)

Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Intangible Assets
Schedule of gross carrying amount and related accumulated amortization of the intangible assets	The following sets forth the gross carrying amount and related accumulated amortization of these intangible assets, in thousands: December 31, 2015 December 31, 2014 Weighted- Average Life Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Purchased patents $ $ $ $ Capitalized patent defense costs $ $ $ — $ —

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2015
Accrued Expenses
Schedule of accrued expenses	Accrued expenses are comprised of the following, in thousands: December 31, 2015 December 31, 2014 Accrued compensation $ $ Accrued professional fees Accrued clinical trial and clinical supply costs Accrued sales and marketing expenses Accrued product costs Accrued interest expense Other accrued expenses ​ ​ ​ ​ ​ ​ ​ ​ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Convertible Senior Secured No33

Convertible Senior Secured Notes (Tables)	12 Months Ended
	Dec. 31, 2015
Convertible Senior Secured Notes
Summary of issuance of Notes reflected in balance sheet	The table below summarizes activity related to the Notes from issuance on May 3, 2013 through December 31, 2015, in thousands: Gross proceeds $ Initial value of interest make-whole derivative reported as debt discount ) Conversion option reported as debt discount and APIC ) Conversion of debt to equity—principal ) Conversion of debt to equity—accretion of debt discount Accretion of debt discount ​ ​ ​ ​ ​ December 31, 2014 carrying value Conversion of debt to equity—principal ) Conversion of debt to equity—accretion of debt discount Accretion of debt discount ​ ​ ​ ​ ​ December 31, 2015 carrying value $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Share-Based Payments (Tables)

Share-Based Payments (Tables)	12 Months Ended
	Dec. 31, 2015
Share-Based Payments
Schedule of share-based compensation recognized related to the grant of employee and non-employee stock options, SARS and non-vested stock	Share-based compensation recognized related to the grant of employee and non-employee stock options, SAR, potential Employee Stock Purchase Plan (ESPP) awards and non-vested stock was as follows, in thousands: Year Ended December 31, 2015 2014 2013 Research and development $ $ $ Selling, general and administrative ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of assumptions used in estimation of fair value of each award option on the date of grant using Black-Scholes option-pricing model	Year Ended December 31, 2015 2014 2013 Fair value of common stock $9.13 - $21.21 $7.63 - $10.02 $5.40 - $7.90 Expected volatility 60.9% - 64.6% 64.5% - 68.3% 69.5% - 70.9% Dividend Yield 0% 0% 0% Expected term 6.25 years 6.25 years 6.25 - 9.60 years Risk-free interest rate 1.54% - 1.74% 1.67% - 1.97% 1.20% - 2.94% Expected forfeiture rate 5% 5% 5%
Summary of stock option and SAR activity	Number of Options Weighted- Average Exercise Price Weighted-Average Remaining Contractual Term (in years) Outstanding, December 31, 2013 $ Granted $ Exercised ) $ Forfeited ) $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding, December 31, 2014 $ Granted $ Exercised ) $ Forfeited ) $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding, December 31, 2015 $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2015: Vested and expected to vest $ Exercisable $

Earnings per Share (Tables)

Earnings per Share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings per Share
Schedule of common stock equivalents excluded in the calculation of diluted loss per share	Year Ended December 31, 2015 2014 2013 Shares underlying Convertible Senior Secured Notes — — Warrants to purchase common stock — — Stock options, stock appreciation rights, non-vested stock options and ESPP awards — —
Schedule of computation of basic and diluted net income per share	The following table sets forth the computation of basic and diluted net income per share for the years ended December 31, 2015, 2014, and 2013, in thousands, except share and per share amounts: Year ended December 31, 2015 2014 2013 Numerator, in thousands: Net income (loss) used for calculation of basic EPS $ $ $ ) Interest expense on convertible debt — Changes in fair value of derivative liabilities ) ) — Loss on extinguishment of debt — Loss on extinguishment of outstanding debt, as if converted ) ) — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total adjustments ) — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income used for calculation of diluted EPS $ $ $ ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator: Weighted average shares outstanding, basic Effect of dilutive potential common shares: — Shares underlying Convertible Senior Secured Notes Shares issuable to settle interest make-whole derivatives — Warrants to purchase common stock — — Stock options, stock appreciation rights, and non-vested stock options — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total potential dilutive common shares — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average shares outstanding, diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) per share, basic $ $ $ ) Net income (loss) per share, diluted $ $ $ )

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Taxes
Schedule of components of the income tax expense/(benefit)	The components of the income tax expense/ (benefit) for the years ended December 31, 2015, 2014, and 2013 were as follow, in thousands: Year Ended December 31, 2015 2014 2013 Current Federal $ $ — $ — State — — Deferred Federal — — — State — — — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total $ $ — $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of reconciliation of the expected income tax benefit computed using the federal statutory income tax rate to the entity's effective income tax rate	A reconciliation of the expected income tax expense/(benefit) computed using the U.S. Federal statutory income tax rate to the Company's effective income tax rate is as follows, in thousands: Year Ended December 31, 2015 2014 2013 Income tax expense/(benefit) computed at U.S. Federal statutory tax rate $ $ $ ) Permanent items State income taxes ) Change in valuation allowance ) ) Uncertain income tax position ) Research and development credits ) ) ) Other ) ) Deferred rate change — — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income tax expense (benefit) $ $ — $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of Significant components of the entity's deferred tax assets (liabilities)	The significant components of the Company's deferred income tax assets (liabilities) were as follow, in thousands: As of December 31, 2015 2014 Deferred tax assets: Net operating loss carryforward $ $ Deferred rent credit Accrued compensation and non-qualified stock options Deferred financing costs Depreciation and amortization Research and development credits Capitalized overhead into inventory (UNICAP §263A) Other Valuation allowance ) ) ​ ​ ​ ​ ​ ​ ​ ​ Net deferred tax asset Deferred tax liability: Debt discount on convertible notes ) ) Depreciation ) — ​ ​ ​ ​ ​ ​ ​ ​ Net deferred taxes $ — $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of reconciliation of the beginning and ending amount of gross unrecognized tax benefits	A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows, in thousands: Year Ended December 31, 2015 2014 2013 Balance as of January 1 $ $ $ Gross (decreases) increases related to prior-year tax positions ) ) Gross increases related to current-year tax positions Gross decreases related to current-year tax positions ) — — Change in tax rates ) ) — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of December 31 $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies
Schedule of future minimum lease payments under non-cancelable operating leases	Future minimum lease payments under non-cancelable operating leases as of December 31, 2015 are as follows, in thousands: Year ending December 31: 2016 $ 2017 2018 2019 Thereafter ​ ​ ​ ​ ​ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Quarterly Financial Informati38

Quarterly Financial Information (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information (unaudited)
Schedule of quarterly financial information	Quarterly financial information for fiscal 2015 and 2014 are presented in the following table, in thousands, except per share data, unaudited: 1 st Quarter 2 nd Quarter 3 rd Quarter 4 th Quarter 2015 Revenue $ $ $ $ Total costs and expenses Operating income Net income Net income per share, basic Net income per share, diluted 2014 Revenue $ $ (2) $ (1) $ Total costs and expenses Operating loss ) Net loss ) Net loss per share, basic ) Net loss per share, diluted ) (1) The Company's results for the third quarter of 2014 include $30.0 million in revenue upon entering into a Royalty Interest Acquisition Agreement. (2) The Company's results for the second quarter of 2014 include the change in accounting estimate regarding revenue recognition on product sales for Trokendi XR from prescriptions filled to shipments to wholesalers.

Organization and Nature of Op39

Organization and Nature of Operations (Details)	12 Months Ended
	Dec. 31, 2015item
Organization and Nature of Operations
Number of proprietary products in clinical development	2

Summary of Significant Accoun40

Summary of Significant Accounting Policies - Segments (Details)	12 Months Ended
	Dec. 31, 2015item
Basis of Presentation
Number of operating segments	1

Summary of Significant Accoun41

Summary of Significant Accounting Policies - SERP (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
SERP | Other Non-current Assets
Marketable Securities - Restricted
Marketable securities - restricted	$ 263,000	$ 305,000

Summary of Significant Accoun42

Summary of Significant Accounting Policies - Accounts Receivable, net (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Accounts Receivable, net
Allowance for uncollectible receivables	$ 0	$ 0
Allowance for expected sales deductions	$ 3,800,000	$ 4,100,000
Revenues | Customer Concentration Risk
Concentration risk percentage
Concentration risk percentage	96.00%
Revenues | Customer Concentration Risk | Customer A
Concentration risk percentage
Concentration risk percentage	26.00%
Revenues | Customer Concentration Risk | Customer B
Concentration risk percentage
Concentration risk percentage	32.00%
Revenues | Customer Concentration Risk | Customer C
Concentration risk percentage
Concentration risk percentage	38.00%
Accounts Receivable | Customer Concentration Risk
Concentration risk percentage
Concentration risk percentage	97.00%
Accounts Receivable | Customer Concentration Risk | Customer A
Concentration risk percentage
Concentration risk percentage	40.00%
Accounts Receivable | Customer Concentration Risk | Customer B
Concentration risk percentage
Concentration risk percentage	28.00%
Accounts Receivable | Customer Concentration Risk | Customer C
Concentration risk percentage
Concentration risk percentage	29.00%

Summary of Significant Accoun43

Summary of Significant Accounting Policies - Property and Equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Intangible Assets
Estimated useful lives of the patents	10 years
Impairment of Long-Lived Assets
Impairment of long-lived assets	$ 0	$ 0	$ 0
Computer Equipment
Property and equipment
Average useful lives	3 years
Software
Property and equipment
Average useful lives	3 years
Lab Equipment and Furniture | Minimum
Property and equipment
Average useful lives	5 years
Lab Equipment and Furniture | Maximum
Property and equipment
Average useful lives	10 years

Summary of Significant Accoun44

Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	May. 03, 2013
Revenue Recognition
Reduction in net revenues		$ 144,427	$ 122,045	$ 12,019
Accrued sales deductions		$ 26,794	8,461
Sales return period prior to expiry date		6 months
Sales return period subsequent to expiry date		12 months
Revenue From Royalty Agreement	$ 30,000		30,000
Milestone revenues recorded		$ 800	2,000	0
Selling, General and Administrative
Advertising Expense
Advertising costs		$ 19,300	$ 14,800	$ 14,600
7.50% Convertible Senior Secured Notes due 2019
Notes payable
Fixed interest rate (as a percent)		7.50%			7.50%
Sales deductions
Revenue Recognition
Reduction in net revenues		$ 2,900
Accrued sales deductions		$ 26,800

Summary of Significant Accoun45

Summary of Significant Accounting Policies - Recently Issued Accounting Pronouncements (Details) - Retrospective early adoption - Accounting Standards Update ("ASU") 2015-17 - Income Taxes: Balance Sheet Classification of Deferred Taxes $ in Millions	Dec. 31, 2015USD ($)
Recent Accounting Pronouncements
Current deferred tax asset	$ (0.2)
Non-current deferred tax liability	$ (0.2)

Fair Value of Financial Instr46

Fair Value of Financial Instruments - Carrying Value (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Assets:
Marketable securities	$ 28,038,000	$ 37,940,000
Long term marketable securities	55,009,000	19,816,000
Liabilities:
Derivative liabilities	854,000	6,564,000
Quoted Prices in Active Markets (Level 1) | Recurring
Assets:
Cash and cash equivalents	34,152,000	36,396,000
Total assets at fair value	34,152,000	36,396,000
Significant Other Observable Inputs (Level 2) | Recurring
Assets:
Marketable securities	28,038,000	37,940,000
Long term marketable securities	55,009,000	19,816,000
Marketable securities - restricted (SERP)	263,000	305,000
Total assets at fair value	83,310,000	58,061,000
Significant Unobservable Inputs (Level 3) | Recurring
Liabilities:
Derivative liabilities	854,000	6,564,000
Warrants outstanding	0
Total Carrying Value | Recurring
Assets:
Cash and cash equivalents	34,152,000	36,396,000
Marketable securities	28,038,000	37,940,000
Long term marketable securities	55,009,000	19,816,000
Marketable securities - restricted (SERP)	263,000	305,000
Total assets at fair value	117,462,000	94,457,000
Liabilities:
Derivative liabilities	$ 854,000	$ 6,564,000

Fair Value of Financial Instr47

Fair Value of Financial Instruments - Fair Value Assumptions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	May. 03, 2013
Assumptions used to calculate fair value of interest make-whole liability using Monte-Carlo simulation with a Black-Scholes lattice model
Volatility (as a percent)	45.00%
Stock Price (in dollars per share)	$ 13.44
Credit Spread (as a percent)	23.63%
Term	1 year 3 months 29 days
Dividend Yield (as a percent)	0.00%
7.50% Convertible Senior Secured Notes due 2019
Assumptions used to calculate fair value of interest make-whole liability using Monte-Carlo simulation with a Black-Scholes lattice model
Interest rate (as a percent)	7.50%	7.50%

Fair Value of Financial Instr48

Fair Value of Financial Instruments - Level 3 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Warrant and Interest Make-Whole Liability
Carrying value of the convertible notes	$ 7,189	$ 26,947
Face value of the convertible notes	8,500
Estimated fair value of the convertible notes	22,600
Significant Unobservable Inputs (Level 3) | Derivative Financial Instruments, Liabilities
Warrant and Interest Make-Whole Liability
Balance at the beginning of the period	6,564	12,644
Changes in fair value of derivative liabilities included in earnings	(193)	(2,809)
Reduction due to conversion of debt to equity	(4,865)	(3,271)
Cashless exercise of common stock warrants	(652)
Balance at the end of the period	$ 854	$ 6,564

Fair Value of Financial Instr49

Fair Value of Financial Instruments - Unrestricted Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value of Financial Instruments
Corporate debt securities, Amortized Cost	$ 83,535	$ 57,910
Corporate debt securities, Gross Unrealized Gains	5	4
Corporate debt securities, Gross Unrealized Losses	(493)	(158)
Corporate debt securities, Fair Value	83,047	57,756
Contractual maturities of the unrestricted marketable securities held
Less Than 1 Year	28,038
1-5 years	55,009
Corporate debt securities, Fair Value	$ 83,047	$ 57,756

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventories
Raw materials	$ 2,887	$ 2,491
Work in process	3,946	6,328
Finished goods	5,754	4,622
Total inventories	$ 12,587	$ 13,441

Property and Equipment (Details

Property and Equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property and equipment
Property and equipment, gross	$ 10,842,000	$ 8,738,000
Less accumulated depreciation and amortization	(6,968,000)	(6,290,000)
Property and equipment, net	3,874,000	2,448,000
Depreciation and amortization expense	678,000	699,000	$ 512,000
Computer Equipment
Property and equipment
Property and equipment, gross	1,112,000	862,000
Software
Property and equipment
Property and equipment, gross	307,000	254,000
Lab Equipment and Furniture
Property and equipment
Property and equipment, gross	5,667,000	5,194,000
Leasehold Improvements
Property and equipment
Property and equipment, gross	2,642,000	$ 2,428,000
Construction in progress
Property and equipment
Property and equipment, gross	$ 1,114,000

Intangible Assets (Details)

Intangible Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite lived intangible assets disclosures
Weighted-Average Life	10 years
Additional disclosures
Net book value of intangible assets	$ 976,000	$ 225,000
Amortization expense	$ 243,000	229,000	$ 229,000
Purchased Patents
Finite lived intangible assets disclosures
Weighted-Average Life	10 years
Gross Carrying Amount	$ 2,292,000	2,292,000
Accumulated Amortization	$ 2,292,000	$ 2,067,000
Patent defense costs
Finite lived intangible assets disclosures
Weighted-Average Life	9 years 6 months
Gross Carrying Amount	$ 994,000
Accumulated Amortization	$ 18,000

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued Expenses
Accrued compensation	$ 7,519	$ 5,784
Accrued professional fees	10,057	2,049
Accrued clinical trial and clinical supply costs	3,677	2,942
Accrued sales and marketing expenses	434	1,017
Accrued product costs	113	3,014
Accrued interest expense	295	639
Other accrued expenses	2,718	1,581
Total	$ 24,813	$ 17,026

Convertible Senior Secured No54

Convertible Senior Secured Notes (Details)	May. 03, 2013USD ($)	May. 31, 2013USD ($)	Dec. 31, 2015USD ($)item$ / sharesshares	Dec. 31, 2014USD ($)shares	Dec. 31, 2013USD ($)shares	Dec. 31, 2014USD ($)	Dec. 31, 2015USD ($)$ / sharesshares
Notes payable
Amount issued			$ 8,500,000				$ 8,500,000
Proceeds from convertible debt issuance					$ 90,000,000
Details of Notes reflected in balance sheet
Initial value of interest make-whole derivative reported as debt discount					(9,270,000)
Remaining outstanding balance			7,189,000	$ 26,947,000		$ 26,947,000	7,189,000
Loss on extinguishment of debt			2,338,000	2,592,000	$ 9,550,000
Occurrence of fundamental change
Notes payable
Conversion ratio, principal amount			$ 1,000				$ 1,000
Required notice period for notification of fundamental change			1 day
Redemption price (as a percent)			100.00%
Occurrence of fundamental change | Minimum
Notes payable
Period from notice date within which note holders can exercise their right to exchange the notes			20 days
Occurrence of fundamental change | Maximum
Notes payable
Period from notice date within which note holders can exercise their right to exchange the notes			35 days
Occurrence of make-whole fundamental change
Notes payable
Required notice period for notification of fundamental change			50 days
Company redeems Notes on or after May 1, 2017
Notes payable
Threshold trading days (whether or not consecutive) | item			20
Consecutive trading day period			30 days
Redemption price (as a percent)			100.00%
Threshold percentage of common stock price to determine eligibility of conversion			140.00%
7.50% Convertible Senior Secured Notes due 2019
Notes payable
Gross proceeds						90,000,000
Amount issued	$ 90,000,000
Fixed interest rate (as a percent)	7.50%		7.50%				7.50%
Amount of underwriters' fee	$ 3,000,000
Offering expenses	3,500,000
Proceeds from convertible debt issuance	$ 86,500,000
Minimum percentage of debt holder's consent require to transfer property collateral for notes	66.67%
Conversion ratio, principal amount			$ 1,000				$ 1,000
Conversion rate for the Notes (in shares) | shares					188.7059
Conversion price, per share of Common Stock | $ / shares			$ 5.30				$ 5.30
Details of Notes reflected in balance sheet
Gross proceeds						90,000,000
Initial value of interest make-whole derivative reported as debt discount						(9,270,000)
Conversion option reported as debt discount and APIC	$ 900,000					(22,336,000)
Conversion of debt to equity - principal			$ (27,522,000)	(13,400,000)		(53,941,000)	$ (81,500,000)
Conversion of debt to equity - accretion of debt discount			7,077,000	17,926,000		17,926,000	7,077,000
Accretion of debt discount			687,000			4,568,000
Remaining outstanding balance			7,189,000	26,947,000		26,947,000	7,189,000
Unamortized debt issuance costs	2,600,000		100,000				100,000
Deferred financing costs, current			30,000				30,000
Deferred financing costs, long-term			70,000				70,000
Principal amount of the Notes converted			$ 27,522,000	$ 13,400,000		$ 53,941,000	$ 81,500,000
Shares of common stock issued in conversion of Notes | shares			5,200,000	2,500,000			15,372,477
Shares of common stock issued in settlement of the interest make-whole provision | shares			500,000	400,000			2,195,904
Loss on extinguishment of debt			$ 2,300,000	$ 2,600,000
7.50% Convertible Senior Secured Notes due 2019 | Company obtains stockholder approval prior to day before November 1, 2018
Notes payable
Conversion ratio, principal amount			$ 1,000				$ 1,000
Threshold trading days (whether or not consecutive) | item			20
Consecutive trading day period			30 days
Number of trading days prior to a conversion date within which threshold trading days should complete | item			5
Threshold trading days period prior to a conversion date during which principal amount of notes for such trading day was less than 98% of the product of the last reported sale price of common stock | item			5
Consecutive trading day period prior to a conversion date during which principal amount of notes for such trading day was less than 98% of the product of the last reported sale price of common stock			5 days
Maximum ratio of trading price for each day in measurement period to last reported sales price of Company's stock on each day of measurement period (as a percent)					98.00%
7.50% Convertible Senior Secured Notes due 2019 | Company calls Notes for redemption prior to day before redemption date and Note holder converts on or after November 1, 2018
Notes payable
Conversion ratio, principal amount			$ 1,000				1,000
7.50% Convertible Senior Secured Notes due 2019 | On or after November 1, 2013, Company makes interest make-whole payments
Notes payable
Conversion ratio, principal amount			$ 1,000				$ 1,000
Threshold trading days (whether or not consecutive) | item			20
Consecutive trading day period			30 days
Number of trading days prior to a conversion date within which threshold trading days should complete | item			5
Discount rate (as a percent)			2.00%
Stock value as percentage of simple average of the daily volume-weighted average price if the company elects to pay an interest make-whole payment in common stock			95.00%				95.00%
Number of trading days ending on and including the trading day immediately preceding the conversion date use to determine daily volume weighted average price | item			10
7.50% Convertible Senior Secured Notes due 2019 | On or after November 1, 2013, Company makes interest make-whole payments | Maximum
Notes payable
Conversion rate for the Notes (in shares) | shares			221.7294
Term loans
Notes payable
Repayment of debt	$ 19,600,000	$ 19,600,000
Details of Notes reflected in balance sheet
Loss on extinguishment of debt					$ 1,200,000

Convertible Senior Secured No55

Convertible Senior Secured Notes - Term Loans (Details) - USD ($) $ in Thousands	May. 03, 2013	Dec. 30, 2011	Jan. 26, 2011	May. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011
Notes payable
Loss on extinguishment of debt					$ 2,338	$ 2,592	$ 9,550
Term loans
Notes payable
Aggregate amount								$ 30,000
Repayment of debt	$ 19,600			$ 19,600
Loss on extinguishment of debt							$ 1,200
Initial term loan facility
Notes payable
Drawdown under the secured credit facility			$ 15,000
Additional term loan facility
Notes payable
Drawdown under the secured credit facility		$ 15,000

Stockholders' Equity (Details)

Stockholders' Equity (Details) $ / shares in Units, $ in Thousands	Dec. 05, 2012USD ($)$ / sharesshares	May. 01, 2012USD ($)$ / sharesshares	Jan. 31, 2013$ / sharesshares	Dec. 31, 2015USD ($)itemshares	Dec. 31, 2014USD ($)shares	Dec. 31, 2013USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2015USD ($)itemshares
Stockholders' equity
Expenses incurred in connection with offering						$ 869
Gross cash proceeds from sale of common stock in a follow-on offering				$ 1,867	$ 571	$ 2,437
7.50% Convertible Senior Secured Notes due 2019
Stockholders' equity
Shares of common stock issued in conversion of Notes | shares				5,200,000	2,500,000			15,372,477
Principal amount of the Notes converted				$ 27,522	$ 13,400		$ 53,941	$ 81,500
Shares of common stock issued in settlement of the interest make-whole provision | shares				500,000	400,000			2,195,904
Common Stock
Stockholders' equity
Number of votes to which holders of common shares are entitled for each share held | item				1				1
Number of shares sold | shares	6,000,000	10,000,000
Selling price (in dollars per share) | $ / shares	$ 8	$ 5	$ 8
Expenses incurred in connection with offering	$ 3,300	$ 4,700
Shares of common stock sold upon exercise of full amount of over-allotment option by the underwriters | shares		449,250	239,432
Gross proceeds from issuance of common stock		$ 52,300
Net cash proceeds from sale of common stock		$ 47,600
Gross cash proceeds from sale of common stock in a follow-on offering	49,900
Net cash proceeds from sale of common stock in a follow-on offering	$ 46,600

Share-Based Payments - 2012 Pla

Share-Based Payments - 2012 Plan (Details) - 2012 Plan	12 Months Ended
	Dec. 31, 2015itemshares
Share-based payments
Maximum number of shares of common stock provided for issuance | shares	4,000,000
Stock Option
Share-based payments
Number of annual installments in which the awards would generally vest starting on the first anniversary of the date of grant | item	4
Contractual term	10 years

Share-Based Payments - Share-ba

Share-Based Payments - Share-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Payments
Share-based compensation recognized	$ 4,231	$ 2,716	$ 1,913
Research and Development
Share-based Payments
Share-based compensation recognized	874	728	493
Selling, General and Administrative
Share-based Payments
Share-based compensation recognized	$ 3,357	$ 1,988	$ 1,420

Share-Based Payments - Activity

Share-Based Payments - Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assumptions used in estimating the fair value of each option award using the Black-Scholes option-pricing model
Fair value of common stock (in dollars per share)	$ 13.44
Stock Option Stock Appreciation Rights
Number of Options
Outstanding at the beginning of the period (in shares)	2,080,749	1,463,043
Granted (in shares)	971,500	686,235
Exercised (in shares)	(205,640)	(17,627)
Forfeited (in share)	(147,602)	(50,902)
Outstanding at the end of the period (in shares)	2,699,007	2,080,749	1,463,043
Vested and expected to vest (in shares)	2,654,381
Exercisable (in shares)	901,672
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 7.93	$ 7.27
Granted (in dollars per share)	10.12	9.20
Exercised (in dollars per share)	4.56	3.08
Forfeited (in dollars per share)	8.60	7.79
Outstanding at the end of the period (in dollars per share)	8.94	$ 7.93	$ 7.27
Vested and expected to vest (in dollars per share)	8.93
Exercisable (in dollars per share)	$ 7.95
Stock Option
Assumptions used in estimating the fair value of each option award using the Black-Scholes option-pricing model
Expected volatility, minimum (as a percent)	60.90%	64.50%	69.50%
Expected volatility, maximum (as a percent)	64.60%	68.30%	70.90%
Dividend Yield (as a percent)	0.00%	0.00%	0.00%
Expected term	6 years 3 months	6 years 3 months
Risk-free interest rate, minimum (as a percent)	1.54%	1.67%	1.20%
Risk-free interest rate, maximum (as a percent)	1.74%	1.97%	2.94%
Expected forfeiture rate (as a percent)	5.00%	5.00%
Weighted-Average Remaining Contractual Term
Outstanding at the end of the period	7 years 11 months 1 day	8 years 15 days	8 years 6 months 4 days
Vested and expected to vest	7 years 10 months 24 days
Exercisable	6 years 10 months 10 days
Share-based payments, additional disclosure
Aggregate intrinsic value of options outstanding	$ 12.6	$ 2	$ 1.4
Aggregate intrinsic value of options vested and expected to vest	12.4	2	1.4
Aggregate intrinsic value of options exercisable	$ 5	$ 1.5	$ 1
Weighted-average, grant-date fair value of options granted (in dollars per share)	$ 6.05	$ 5.79	$ 4.98
Total fair value of the common stock vested	$ 2.6	$ 1.9	$ 0.5
Total intrinsic value of options exercised	1.6	0.1	$ 0.4
Total unrecognized compensation expense, net of estimated forfeitures	$ 7.2	$ 5.9
Weighted-average period over which total unrecognized compensation expense is expected to be recognized	2 years 6 months 15 days	2 years 6 months 22 days
Stock Option | Minimum
Assumptions used in estimating the fair value of each option award using the Black-Scholes option-pricing model
Fair value of common stock (in dollars per share)	$ 9.13	$ 7.63	$ 5.40
Expected term			6 years 3 months
Expected forfeiture rate (as a percent)			5.00%
Stock Option | Maximum
Assumptions used in estimating the fair value of each option award using the Black-Scholes option-pricing model
Fair value of common stock (in dollars per share)	$ 21.21	$ 10.02	$ 7.90
Expected term			9 years 7 months 6 days

Earnings per Share (Details)

Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Numerator, in thousands
Net income (loss) used for calculation of basic EPS									$ 14,016	$ 19,871	$ (92,273)
Interest expense on convertible debt									1,229	4,963
Change in fair value of derivative liabilities									(589)	(2,809)
Loss on extinguishment of debt									2,338	2,592
Loss on extinguishment of outstanding debt, as if converted									(2,494)	(8,315)
Total adjustments									484	(3,569)
Net income used for calculation of diluted EPS									$ 14,500	$ 16,302	$ (92,273)
Denominator
Weighted average shares outstanding, basic									47,485,258	42,260,896	31,848,299
Effect of dilutive potential common shares
Shares underlying Convertible Senior Secured Notes									2,459,009	7,090,722
Shares issuable to settle interest make-whole derivatives									804,507	904,618
Warrants to purchase common stock										20,499
Stock options, stock appreciation rights, and non-vested stock options									411,606	306,776
Total potential dilutive common shares									3,675,122	8,322,615
Weighted average shares outstanding, diluted									51,160,380	50,583,511	31,848,299
Net income (loss) per share, basic	$ 0.14	$ 0.09	$ 0.04	$ 0.02	$ 0.10	$ 0.65	$ 0.08	$ (0.38)	$ 0.30	$ 0.47	$ (2.90)
Net income (loss) per share, diluted	$ 0.14	$ 0.08	$ 0.03	$ 0.02	$ 0.10	$ 0.39	$ 0.08	$ (0.38)	$ 0.28	$ 0.32	$ (2.90)
7.50% Convertible Senior Secured Notes due 2019
Loss Per Share
Common stock equivalents excluded in the calculation of diluted loss per share											6,219,782
Warrants to purchase common stock.
Loss Per Share
Common stock equivalents excluded in the calculation of diluted loss per share											13,388
Stock Options, Stock Appreciation Rights and Non-Vested Stock Options and ESPP awards
Loss Per Share
Common stock equivalents excluded in the calculation of diluted loss per share											151,737

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current
Federal	$ 914
State	42
Income tax expense (benefit)	956
Reconciliation of the expected income tax benefit computed using the federal statutory income tax rate to the Company's effective income tax rate
Income tax expense/(benefit) computed at U.S federal statutory tax rate	5,240	$ 6,955	$ (32,286)
Permanent items	601	610	340
State income taxes	50	627	(4,772)
Change in valuation allowance	(4,849)	(10,604)	31,526
Uncertain income tax position	833	(960)	5,411
Research and development credits	(979)	(535)	(156)
Other	60	(125)	(63)
Deferred rate change		4,032
Income tax expense (benefit)	956
NOL carryforwards	91,800
NOL carryforwards after tax effect	34,600
Research and development credit carryforwards	5,500
Available NOL's	18,500
Available from 2015 to 2019	91,800
Research and development credit carryforward available in 2020 to 2021	5,500
Federal income taxes paid	0	0	0
Accrued penalties related to uncertain tax positions	100
Deferred tax assets:
Net operating loss carryforward	34,676	42,800
Deferred rent credit	532	506
Accrued compensation and non-qualified stock options	5,891	3,392
Deferred financing costs	188	244
Depreciation and amortization	291	474
Research and development credits	5,529	4,725
Capitalized overhead into inventory (UNICAP 263A)	543	675
Other	495	552
Valuation allowance	(47,526)	(49,914)
Net deferred tax asset	619	3,454
Deferred tax liability:
Debt discount on convertible notes	(509)	(3,454)
Depreciation	(110)
Net change in total valuation allowance	2,500
Reconciliation of the beginning and ending amount of gross unrecognized tax benefits
Balance at the beginning of the period	8,342	9,828	688
Gross (decreases) increases related to prior-year tax positions	(5)	(1,040)	23
Gross increases related to current-year tax positions	984	80	9,117
Gross decreases related to current-year tax prositions	(244)
Change in tax rates	(21)	(526)
Balance at the end of the period	9,056	$ 8,342	$ 9,828
Income tax expense	956
Minimum
Reconciliation of the expected income tax benefit computed using the federal statutory income tax rate to the Company's effective income tax rate
Available NOL's utilized per year in future years	7,800
Maximum
Reconciliation of the expected income tax benefit computed using the federal statutory income tax rate to the Company's effective income tax rate
Available NOL's utilized per year in future years	$ 20,300

Commitments and Contingencies62

Commitments and Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies
Additional period for which the entity may elect to extend the term of the lease	5 years
Additional tenant improvement allowance	$ 2,100
Tenant improvement allowance utilized and included in fixed assets and deferred rent	200	$ 100	$ 500
Amount available for tenant improvements	500
Rent expense	2,600	$ 2,300	$ 1,600
Future minimum lease payments under non-cancelable operating leases
2,016	1,430
2,017	1,290
2,018	1,314
2,019	1,341
Thereafter	454
Total	$ 5,829

Employee Benefit Plan (Details)

Employee Benefit Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee Benefit Plan
Minimum age requirement for employees to participate in the plan	21 years
Maximum contribution by employee (as a percent)	90.00%
Vesting percentage of contributions by employee to the 401(k) Plan	100.00%
Employer match of employee contributions on the first level of salary deferral (as a percent)	100.00%
Percentage of eligible compensation, first level, matched by employer	3.00%
Employer match of employee contributions on the second level of salary deferral (as a percent)	50.00%
Percentage of eligible compensation, second level, partially matched by employer	2.00%
Maximum percentage of participating employee annual compensation that the company may elect to make a discretionary contribute towards	60.00%
Company's contribution to the 401(k) Plan	$ 1.4	$ 1.1	$ 0.6

Collaboration Agreements (Detai

Collaboration Agreements (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Collaboration agreement
Milestone revenue generated		$ 800	$ 2,000	$ 0
Revenue From Royalty Agreement	$ 30,000		30,000
Collaborative Arrangement | United Therapeutics
Collaboration agreement
Milestone revenue generated			$ 2,000
Revenue From Royalty Agreement		$ 30,000

Quarterly Financial Informati65

Quarterly Financial Information (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information (unaudited)
Revenue	$ 42,655	$ 38,587	$ 35,052	$ 28,133	$ 30,801	$ 52,488	$ 29,675	$ 9,081	$ 143,526	$ 89,571	$ 11,552
Total costs and expenses	35,806	34,277	31,976	24,703	26,072	23,321	25,919	22,503	126,762	97,815	73,939
Operating income (loss)	6,849	4,310	3,076	3,430	4,729	29,167	3,756	(13,422)
Net income (loss)	$ 6,872	$ 4,222	$ 2,005	$ 917	$ 4,354	$ 27,858	$ 3,202	$ (15,543)	$ 14,016	$ 19,871	$ (92,273)
Net income (loss) per share, basic	$ 0.14	$ 0.09	$ 0.04	$ 0.02	$ 0.10	$ 0.65	$ 0.08	$ (0.38)	$ 0.30	$ 0.47	$ (2.90)
Net income (loss) per share, diluted	$ 0.14	$ 0.08	$ 0.03	$ 0.02	$ 0.10	$ 0.39	$ 0.08	$ (0.38)	$ 0.28	$ 0.32	$ (2.90)
Revenue From Royalty Agreement						$ 30,000				$ 30,000

Subsequent Events (Details)

Subsequent Events (Details) $ in Thousands	Feb. 05, 2016patent	Mar. 07, 2016USD ($)shares	Dec. 31, 2015USD ($)shares	Dec. 31, 2014USD ($)shares	Dec. 31, 2014USD ($)	Dec. 31, 2015USD ($)shares
Subsequent events
Remaining outstanding balance			$ 7,189	$ 26,947	$ 26,947	$ 7,189
7.50% Convertible Senior Secured Notes due 2019
Subsequent events
Principal amount of the Notes converted			$ 27,522	$ 13,400	53,941	$ 81,500
Shares of common stock issued in conversion of Notes and accrued interest thereon | shares			5,200,000	2,500,000		15,372,477
Remaining outstanding balance			$ 7,189	$ 26,947	$ 26,947	$ 7,189
Subsequent Events | Oxtellar XR Litigation
Subsequent events
Number of patents found infringed upon | patent	2
Number of patents allegedly infringed upon | patent	3
Subsequent Events | 7.50% Convertible Senior Secured Notes due 2019
Subsequent events
Principal amount of the Notes converted		$ 2,000
Shares of common stock issued in conversion of Notes and accrued interest thereon | shares		400,000
Remaining outstanding balance		$ 6,600