Ironwood Pharmaceuticals (IRWD) 10-Q 6 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 01, 2018
Entity Registrant Name	IRONWOOD PHARMACEUTICALS INC
Entity Central Index Key	1,446,847
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Class A common stock
Entity Common Stock, Shares Outstanding		140,082,377
Class B common stock
Entity Common Stock, Shares Outstanding		13,976,855

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Current assets:
Cash and cash equivalents	$ 141,562	$ 125,736	$ 162,640
Available-for-sale securities	19,836	95,680
Accounts receivable, net	10,193	3,190
Related party accounts receivable, net	55,182	78,967
Inventory, net	76	735
Prepaid expenses and other current assets	21,699	7,288
Total current assets	248,548	311,596
Restricted cash	7,676	7,056
Property and equipment, net	16,161	17,274
Convertible note hedges	142,774	108,188
Intangible assets, net		159,905
Goodwill	785	785
Other assets	708	870
Total assets	416,652	605,674
Current liabilities:
Accounts payable and related party accounts payable, net	9,332	15,958
Accrued research and development costs	5,088	7,313
Accrued expenses and other current liabilities	44,958	38,237
Capital lease obligations	171	4,077
Current portion of deferred rent	247	195
Current portion of 2026 Notes	39,191
Current portion of contingent consideration	74	247
Deferred revenue	13,521
Total current liabilities	112,582	66,027
Deferred rent, net of current portion	6,113	5,449
Contingent consideration, net of current portion		31,011
Note hedge warrants	122,778	92,188
Convertible senior notes	261,355	249,193
2026 Notes, net of current portion	108,589	146,898
Other liabilities	2,530	5,060
Commitments and contingencies
Stockholders’ (deficit) equity:
Preferred stock, $0.001 par value, 75,000,000 shares authorized, no shares issued and outstanding
Additional paid-in capital	1,378,195	1,318,536
Accumulated deficit	(1,575,635)	(1,308,760)
Accumulated other comprehensive loss	(9)	(79)
Total stockholders' (deficit) equity	(197,295)	9,848
Total liabilities and stockholders’ (deficit) equity	416,652	605,674
Class A common stock
Stockholders’ (deficit) equity:
Common stock	140	137
Class B common stock
Stockholders’ (deficit) equity:
Common stock	$ 14	$ 14

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Preferred stock
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	75,000,000	75,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Class A common stock
Common stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	139,805,308	136,465,526
Common stock, shares outstanding	139,805,308	136,465,526
Class B common stock
Common stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	13,976,855	13,983,762
Common stock, shares outstanding	13,976,855	13,983,762

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Total revenues	$ 65,686	$ 86,825	$ 215,947	$ 204,068
Cost and expenses:
Cost of revenues, excluding amortization of acquired intangible assets	4,616	6,080	11,288	10,113
Write-down of commercial supply and inventory to net realizable value and (settlement) loss on non-cancellable purchase commitments	(1,589)	71	247	167
Research and development	46,794	37,065	122,231	108,111
Selling, general and administrative	55,248	61,774	183,112	175,170
Amortization of acquired intangible assets	1,159	1,897	8,111	2,738
(Gain) loss on fair value remeasurement of contingent consideration	(33,519)	(628)	(31,045)	7,919
Restructuring expenses	10,282		15,096
Impairment of finite-lived intangible assets	151,794		151,794
Total cost and expenses	234,785	106,259	460,834	304,218
Loss from operations	(169,099)	(19,434)	(244,887)	(100,150)
Other (expense) income:
Interest expense	(9,482)	(9,135)	(28,138)	(27,164)
Interest and investment income	741	601	2,154	1,492
Gain (loss) on derivatives	3,489	(4,329)	3,996	(1,191)
Loss on extinguishment of debt				(2,009)
Other expense, net	(5,252)	(12,863)	(21,988)	(28,872)
Net loss	$ (174,351)	$ (32,297)	$ (266,875)	$ (129,022)
Net loss per share—basic and diluted	$ (1.14)	$ (0.22)	$ (1.75)	$ (0.87)
Weighted average number of common shares used in net loss per share—basic and diluted:	153,227	149,502	152,143	148,695
Collaborative arrangements
Revenues:
Total revenues	$ 54,194	$ 76,652	$ 188,487	$ 187,156
Product
Revenues:
Total revenues	1,235	682	2,966	1,436
Active pharmaceutical ingredient
Revenues:
Total revenues	$ 10,257	$ 9,491	$ 24,494	$ 15,476

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Condensed Consolidated Statements of Comprehensive Loss
Net loss	$ (174,351)	$ (32,297)	$ (266,875)	$ (129,022)
Other comprehensive income:
Unrealized gains on available-for-sale securities	35	18	70	1
Total other comprehensive income	35	18	70	1
Comprehensive loss	$ (174,316)	$ (32,279)	$ (266,805)	$ (129,021)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net loss	$ (266,875)	$ (129,022)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	4,847	6,602
Amortization of acquired intangible assets	8,111	2,738
Impairment of finite-lived intangible assets	151,794
(Gain) loss on disposal of property and equipment	(1,591)	703
Share-based compensation expense	32,762	25,116
Change in fair value of note hedge warrants	30,590	(9,494)
Change in fair value of convertible note hedges	(34,586)	10,685
Write-down of commercial supply and inventory to net realizable value and (settlement) loss on non-cancellable purchase commitments	247	167
Write-down of excess non-cancellable ZURAMPIC and DUZALLO sample purchase commitments	390	1,353
Gain on facility subleases		(1,579)
Accretion of discount/premium on investment securities	(157)	31
Non-cash interest expense	13,044	11,918
Non-cash change in fair value of contingent consideration	(31,045)	7,919
Loss on extinguishment of debt		2,009
Changes in assets and liabilities:
Accounts receivable and related party accounts receivable	16,782	(15,229)
Prepaid expenses and other current assets	(13,164)	1,020
Inventory, net	(713)	1,081
Other assets	163	185
Accounts payable, related party accounts payable and accrued expenses	(2,766)	(6,659)
Accrued research and development costs	(2,225)	935
Deferred revenue	13,521
Deferred rent	716	(2,018)
Net cash used in operating activities	(80,155)	(91,539)
Cash flows from investing activities:
Purchases of available-for-sale securities	(3,241)	(130,728)
Sales and maturities of available-for-sale securities	79,312	319,133
Purchases of property and equipment	(5,320)	(3,209)
Proceeds from sale of property and equipment	627	117
Net cash provided by investing activities	71,378	185,313
Cash flows from financing activities:
Proceeds from issuance of 2026 Notes, net of discount to lender		146,250
Costs associated with issuance of 2026 Notes		(235)
Proceeds from exercise of stock options and employee stock purchase plan	27,152	19,379
Payments on capital leases	(1,822)	(2,406)
Principal payments on PhaRMA notes		(134,258)
Payments on contingent purchase price consideration	(107)	(15,058)
Net cash provided by financing activities	25,223	13,672
Net increase in cash, cash equivalents and restricted cash	16,446	107,446
Cash, cash equivalents and restricted cash, beginning of period	132,792	62,251
Cash, cash equivalents and restricted cash, end of period	$ 149,238	$ 169,697

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Reconciliation of cash, cash equivalents, and restricted cash to the condensed consolidated balance sheets
Restricted cash	$ 7,676	$ 7,057
Total cash, cash equivalents, and restricted cash	$ 149,238	$ 169,697

Nature of Business

Nature of Business	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block
Nature of Business	1. Nature of Business Overview Ironwood Pharmaceuticals, Inc. (the “Company”) is a commercial biotechnology company leveraging its proven development and commercial capabilities as it seeks to bring multiple medicines to patients. The Company is advancing innovative product opportunities in areas of large unmet need, based upon the Company’s target-to-disease approach to development and leveraging the Company’s core areas of expertise in gastrointestinal (“GI”) and primary care, as well as in guanylate cyclase (“GC”) pathways. The Company’s first commercial product, linaclotide, is available to adult men and women suffering from irritable bowel syndrome with constipation (“IBS-C”), or chronic idiopathic constipation (“CIC”), in certain countries around the world. Linaclotide is available under the trademarked name LINZESS ® to adult men and women suffering from IBS-C or CIC in the United States (the “U.S.”) and Mexico, and to adult men and women suffering from IBS-C in Japan. Linaclotide is available under the trademarked name CONSTELLA ® to adult men and women suffering from IBS-C or CIC in Canada, and to adult men and women suffering from IBS-C in certain European countries. The Company and its partner Allergan plc (together with its affiliates, “Allergan”) began commercializing LINZESS in the U.S. in December 2012. Under the Company’s collaboration with Allergan for North America, total net sales of LINZESS in the U.S., as recorded by Allergan, are reduced by commercial costs incurred by each party, and the resulting amount is shared equally between the Company and Allergan. Allergan also has an exclusive license from the Company to develop and commercialize linaclotide in all countries other than China, Hong Kong, Macau, Japan and the countries and territories of North America (the “Allergan License Territory”). On a country-by-country and product-by-product basis in the Allergan License Territory, Allergan pays the Company a royalty as a percentage of net sales of products containing linaclotide as an active ingredient. In addition, Allergan has exclusive rights to commercialize linaclotide in Canada as CONSTELLA and in Mexico as LINZESS. Astellas Pharma Inc. (“Astellas”), the Company’s partner in Japan, has an exclusive license to develop and commercialize linaclotide in Japan. In March 2017, Astellas began commercializing LINZESS for the treatment of adults with IBS-C in Japan, and in September 2018, Astellas began commercializing LINZESS for the treatment of adults with chronic constipation in Japan. The Company has a collaboration agreement with AstraZeneca AB (together with its affiliates, “AstraZeneca”), to co-develop and co-commercialize linaclotide in China, Hong Kong and Macau, with AstraZeneca having primary responsibility for the local operational execution. In December 2015, the Company and AstraZeneca filed for approval with the China Food and Drug Administration (“CFDA”) to market linaclotide in China. The Company’s and Allergan’s linaclotide life cycle management strategy in the U.S. includes the objective of strengthening the clinical profile of linaclotide by obtaining additional abdominal symptom claims and expanding the clinical utility of linaclotide by demonstrating the pain-relieving effect of a delayed release formulation, through the advancement of MD-7246 (linaclotide delayed release) in all forms of IBS. The Company and Allergan are also continuing to explore ways to enhance the clinical profile of LINZESS by studying linaclotide in additional indications, populations and formulations to assess its potential to treat various conditions. In July 2018, the Company announced the initiation of a Phase IIIb trial evaluating the efficacy and safety of linaclotide 290 mcg on multiple abdominal symptoms in addition to pain, including bloating and discomfort, in adult patients with IBS-C. The Company is advancing another GI development program, IW-3718, a gastric retentive formulation of a bile acid sequestrant for the potential treatment of persistent gastroesophageal reflux disease (“GERD”). The Company’s clinical research has demonstrated that reflux of bile from the intestine into the stomach and esophagus plays a key role in the ongoing symptoms of persistent GERD. IW-3718 is a novel formulation of a bile acid sequestrant designed to release in the stomach over an extended period of time, bind to bile that refluxes into the stomach, and potentially provide symptomatic relief in patients with persistent GERD. In June 2018, the Company initiated two Phase III clinical trials evaluating the safety and efficacy of IW-3718 in patients with persistent GERD. In June 2016, the Company closed a transaction with AstraZeneca (the “Lesinurad Transaction”) pursuant to which the Company received an exclusive license to develop, manufacture, and commercialize in the U.S. products containing lesinurad as an active ingredient (the “Lesinurad License”), including ZURAMPIC ® and DUZALLO ® . Lesinurad 200mg tablets were approved as ZURAMPIC by the U.S. Food and Drug Administration (“FDA”) in December 2015 for use in combination with a xanthine oxidase inhibitor for the treatment of hyperuricemia associated with uncontrolled gout (“uncontrolled gout”). In October 2016, the Company began commercializing ZURAMPIC in the U.S. The FDA approved DUZALLO, a fixed-dose combination product of lesinurad and allopurinol in August 2017 The Company is also leveraging its pharmacological expertise in GC pathways gained through the discovery and development of linaclotide, a GC-C agonist, to develop and advance a pipeline of sGC stimulators, including praliciguat and olinciguat. The Company is advancing olinciguat, one of its lead clinical sGC stimulators in a Phase II trial for the potential treatment of sickle cell disease. In June 2018, the FDA granted Orphan Drug Designation to olinciguat for the treatment of patients with sickle cell disease. The Company is not pursuing additional clinical studies of olinciguat in achalasia at this time, and instead is focused on completing the ongoing Phase II trial of olinciguat in patients with sickle cell disease. The Company is also advancing praliciguat, another of its lead clinical sGC stimulators, in Phase II trials, for the potential treatment of diabetic nephropathy and for the potential treatment of heart failure with preserved ejection fraction (“HFpEF”). In September 2018, the FDA granted Fast Track Designation for praliciguat for the treatment of patients with HFpEF. In May 2018, the Company announced its intent, as authorized by its Board of Directors, to separate its sGC business from its commercial and GI business, resulting in two independent, publicly traded companies, Ironwood and a new company (“R&D Co”). Following the separation, Ironwood is expected to focus on accelerating growth of its in-market products, including LINZESS, and advance development programs targeting treatments for GI diseases and abdominal pain. The separated R&D Co. is expected to focus on the sGC pipeline development programs for the treatment of serious and orphan diseases. The separation is expected to be completed in the first half of 2019 and is anticipated to be tax-free. The Company has periodically entered into co-promotion agreements to maximize its salesforce productivity. As part of this strategy, in August 2015, the Company and Allergan entered into an agreement for the co-promotion of VIBERZI ® (eluxadoline) in the U.S., Allergan’s treatment for adults suffering from IBS with diarrhea (“IBS-D”). In January 2017, the Company and Allergan entered into a commercial agreement under which adjustments to the Company’s or Allergan’s share of the net profits under the share adjustment provision of the collaboration agreement for linaclotide in North America are eliminated, in full, in 2018 and all subsequent years. As part of this agreement, Allergan appointed the Company, on a non-exclusive basis, to promote CANASA ® (mesalamine), approved for the treatment of ulcerative proctitis, and DELZICOL ® (mesalamine), approved for the treatment of ulcerative colitis, in the U.S. for approximately two years. In December 2017, this agreement was amended to include and extend the promotion of VIBERZI through December 31, 2018 and discontinue the promotion of DELZICOL effective January 1, 2018. These agreements are more fully described in Note 3, Goodwill and Intangible Assets, and Note 4, Collaboration, License, Co-Promotion and Other Commercial Agreements, to these condensed consolidated financial statements. In September 2016, the Company closed a direct private placement, pursuant to which the Company issued $150.0 million in aggregate principal amount of 8.375% notes due 2026 (the “2026 Notes”) on January 5, 2017 (the “Funding Date”). The Company received net proceeds of approximately $11.2 million from the 2026 Notes, after redemption of the PhaRMA Notes outstanding balance and accrued interest of approximately $135.1 million and deducting fees and expenses of approximately $3.7 million. The proceeds from the issuance of the 2026 Notes were used to redeem the outstanding principal balance of the 11% PhaRMA Notes due 2024 (the “PhaRMA Notes”) on the Funding Date. These transactions are more fully described in Note 9, Notes Payable , to these condensed consolidated financial statements. Basis of Presentation The accompanying condensed consolidated financial statements and the related disclosures are unaudited and have been prepared in accordance with accounting principles generally accepted in the U.S. Additionally, certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017, which was filed with the Securities and Exchange Commission on February 22, 2018 (the “2017 Annual Report on Form 10-K”). The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all normal recurring adjustments considered necessary for a fair presentation of the Company’s financial position as of September 30, 2018, and the results of its operations for the three and nine months ended September 30, 2018 and 2017, and its cash flows for the nine months ended September 30, 2018 and 2017. The results of operations for the three and nine months ended September 30, 2018 and 2017 are not necessarily indicative of the results that may be expected for the full year or any other subsequent interim period. Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of Ironwood Pharmaceuticals, Inc. and its wholly owned subsidiaries. All intercompany transactions and balances are eliminated in consolidation. Reclassifications and Revisions to Prior Period Financial Statements Certain prior period financial statement items, such as Sale of Active Pharmaceutical Ingredient and Restricted Cash, have been reclassified to conform to current period presentation. Use of Estimates The preparation of condensed consolidated financial statements in accordance with U.S. generally accepted accounting principles requires the Company’s management to make estimates and judgments that may affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the amounts of revenues and expenses during the reported periods. On an on-going basis, the Company’s management evaluates its estimates, judgments and methodologies. Significant estimates and assumptions in the condensed consolidated financial statements include those related to revenue recognition, including returns, rebates, and other pricing adjustments; available-for-sale securities; inventory valuation, and related reserves; impairment of long-lived assets, including its acquired intangible assets and goodwill; initial valuation procedures for the issuance of convertible notes; fair value of derivatives; balance sheet classification of notes payable and convertible notes; income taxes, including the valuation allowance for deferred tax assets; research and development expenses; contingent consideration; contingencies and share-based compensation. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ materially from these estimates under different assumptions or conditions. Changes in estimates are reflected in reported results in the period in which they become known. Summary of Significant Accounting Policies The Company’s significant accounting policies are described in Note 2, Summary of Significant Accounting Policies , in the 2017 Annual Report on Form 10-K. During the nine months ended September 30, 2018, the Company adopted the following additional significant accounting policies: Revenue Recognition Effective January 1, 2018, the Company adopted Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers (“ASC 606”) using the modified retrospective transition method. The adoption of ASC 606 represents a change in accounting principle that aims to more closely align revenue recognition with the delivery of the Company's services and will provide financial statement readers with enhanced disclosures. In accordance with ASC 606, the Company recognizes revenue when the customer obtains control of a promised good or service, in an amount that reflects the consideration which the Company expects to receive in exchange for the good or service. The reported results for the three and nine months ended September 30, 2018 reflect the application of ASC 606 guidance, while the reported results for prior periods were prepared in accordance with ASC 605, Revenue Recognition (“ASC 605”). Upon adoption of ASC 606, the Company concluded that no cumulative adjustment to the accumulated deficit as of January 1, 2018 was necessary. There were no remaining or ongoing deliverables or unrecognized consideration as of December 31, 2017 that required an adjustment to accumulated deficit. The adoption of ASC 606 had no impact on the Company’s statement of operations, balance sheets, or statement of cash flows. As part of the ASC 606 adoption, the Company has utilized certain practical expedients outlined in the guidance. These practical expedients include: · Expensing as incurred incremental costs of obtaining a contract, such as sales commissions, if the amortization period of the asset would be less than one year. · Recognizing revenue in the amount that the Company has the right to invoice, when consideration from the customer corresponds directly with the value to the customer of the Company’s performance completed to date. · For contracts that were modified before the beginning of the earliest reporting period presented in accordance with the pending content that links to this paragraph, an entity need not retrospectively restate the contract for those contract modifications in accordance with paragraphs ASC 606-10-25-12 through 25-13. Instead, an entity shall reflect the aggregate effect of all modifications that occur before the beginning of the earliest period presented in accordance with the pending content that links to this paragraph when: a. Identifying the satisfied and unsatisfied performance obligations b. Determining the transaction price and c. Allocating the transaction price to the satisfied and unsatisfied performance obligations. Prior to the adoption of ASC 606, the Company recognized revenue when there was persuasive evidence that an arrangement existed, services had been rendered or delivery had occurred, the price was fixed or determinable, and collection was reasonably assured. The Company’s revenues are generated primarily through collaborative arrangements and license agreements related to the research and development and commercialization of linaclotide, as well as co-promotion arrangements in the U.S. and product revenue related to the commercial sale of ZURAMPIC and DUZALLO in the U.S. The terms of the collaborative research and development, license, co-promotion and other agreements contain multiple performance obligations which may include (i) licenses, (ii) research and development activities, including participation on joint steering committees, (iii) the manufacture of finished drug product, active pharmaceutical ingredient (“API”), or development materials for a partner, which are reimbursed at a contractually determined rate, and (iv) co-promotion activities by the Company’s clinical sales specialists. Non-refundable payments to the Company under these agreements may include (i) up-front license fees, (ii) payments for research and development activities, (iii) payments for the manufacture of finished drug product, API, or development materials, (iv) payments based upon the achievement of certain milestones, (v) payments for sales detailing, promotional support services and medical education initiatives, and (vi) royalties on product sales. Additionally, the Company may receive its share of the net profits or bear its share of the net losses from the sale of linaclotide in the U.S. and for China, Hong Kong and Macau through its collaborations with Allergan and AstraZeneca, respectively. The Company has adopted a policy to recognize revenue net of tax withholdings, as applicable. Revenue recognition under ASC 606 Upon executing a revenue generating arrangement, the Company assesses whether it is probable the Company will collect consideration in exchange for the good or service it transfers to the customer. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, it performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies the performance obligations. The Company must develop assumptions that require significant judgment to determine the stand-alone selling price for each performance obligation identified in the contract. The assumptions that are used to determine the stand-alone selling price may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success. Collaboration, License, Co-Promotion and Other Commercial Agreements Upon licensing intellectual property to a customer, the Company determines if the license is distinct from the other performance obligations identified in the arrangement. The Company recognizes revenues from the transaction price, including non-refundable, up-front fees allocated to the license when the license is transferred to the customer if the license has distinct benefit to the customer. For licenses that are combined with other promises, the Company assesses the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time. For performance obligations that are satisfied over time, the Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. The Company’s license and collaboration agreements include milestone payments, such as development and other milestones. The Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method at the inception of the agreement. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. The Company re-evaluates the probability of achievement of such milestones and any related constraint at each reporting period, and any adjustments are recorded on a cumulative catch-up basis. Agreements that include the supply API or drug product for either clinical development or commercial supply at the customer’s discretion are generally considered as options. The Company assesses if these options provide a material right to its partner, and if so, they are accounted for as separate performance obligations. If the Company is entitled to additional payments when the customer exercises these options, any additional payments are recorded as revenue when the customer obtains control of the goods, which is typically upon shipment for sales of API and upon delivery for sales of drug product. For agreements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue when the related sales occur in accordance with the sales-based royalty exception under ASC 606-10-55-65. Net Profit or Net Loss Sharing In accordance with ASC 808 Topic, Collaborative Arrangements (“ASC 808”), the Company considered the nature and contractual terms of the arrangement and the nature of the Company’s business operations to determine the classification of payments under the Company’s collaboration agreements. While ASC 808 provides guidance on classification, the standard is silent on matters of separation, initial measurement, and recognition. Therefore, the Company, consistent with its accounting policies prior to the adoption of ASC 606, applies the separation, initial measurement, and recognition principles of ASC 606 to its collaboration agreements. The Company’s collaborative arrangements revenues generated from sales of LINZESS in the U.S. are considered akin to sales-based royalties. In accordance with the sales-based royalty exception, the Company recognizes its share of the pre-tax commercial net profit or net loss generated from the sales of LINZESS in the U.S. in the period the product sales are earned, as reported by Allergan, and related cost of goods sold and selling, general and administrative expenses are incurred by the Company and its collaboration partner. These amounts are partially determined based on amounts provided by Allergan and involve the use of estimates and judgments, such as product sales allowances and accruals related to prompt payment discounts, chargebacks, governmental and contractual rebates, wholesaler fees, product returns, and co-payment assistance costs, which could be adjusted based on actual results in the future. The Company is highly dependent on Allergan for timely and accurate information regarding any net revenues realized from sales of LINZESS in the U.S. in accordance with both ASC 808 and ASC 606, and the costs incurred in selling it, in order to accurately report its results of operations. If the Company does not receive timely and accurate information or incorrectly estimates activity levels associated with the collaboration at a given point in time, the Company could be required to record adjustments in future periods. In accordance with ASC 606-10-55, Principal Agent Considerations, the Company records revenue transactions as net product revenue in its condensed consolidated statements of operations if it is deemed the principal in the transaction, which includes being the primary obligor, retaining inventory risk, and control over pricing. Given that the Company is not the primary obligor and does not have the inventory risks in the collaboration agreement with Allergan for North America, it records its share of the net profits or net losses from the sales of LINZESS in the U.S. on a net basis and presents the settlement payments to and from Allergan as collaboration expense or collaborative arrangements revenue, as applicable. The Company and Allergan settle the cost sharing quarterly, such that the Company’s statement of operations reflects 50% of the pre-tax net profit or loss generated from sales of LINZESS in the U.S. Product revenue, net Net product revenue is derived from sales of ZURAMPIC and DUZALLO (“the Lesinurad Products”) in the U.S. The Company sells the Lesinurad Products principally to a limited number of national wholesalers and selected regional wholesalers (the “Distributors”). The Distributors resell the Lesinurad Products to retail pharmacies and healthcare providers, who then sell to patients. Net product revenue is recognized when the Distributor obtains control of the Company’s product, which occurs at a point in time, typically upon shipment of Lesinurad Products to the Distributor. When the Company performs shipping and handling activities after the transfer of control to the Distributor (e.g., when control transfers prior to delivery), they are considered as fulfillment activities, and accordingly, the costs are accrued for when the related revenue is recognized. The Company expenses incremental costs of obtaining a contract as and when incurred if the expected amortization period of the asset that the Company would have recognized is one year or less. The Company evaluates the creditworthiness of each of its Distributors to determine whether it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur. The Company calculates its net product revenue based on the wholesale acquisition cost that the Company charges its Distributors for the Lesinurad Products less variable consideration. The product revenue variable consideration consists of estimates relating to (i) trade discounts and allowances, such as invoice discounts for prompt payment and distributor fees, (ii) estimated government and private payor rebates, chargebacks and discounts, such as Medicaid reimbursements, (iii) reserves for expected product returns and (iv) estimated costs of incentives offered to certain indirect customers including patients. These estimates could be adjusted based on actual results in the period such variances become known. Trade Discounts and Allowances: The Company generally provides invoice discounts on sales of Lesinurad Products to its Distributors for prompt payment and pays fees for distribution services and for certain data that Distributors provide to the Company. Consistent with historical industry practice, the Company expects its Distributors to earn these discounts and fees, and accordingly deducts the full amount of these discounts and fees from its gross product revenues at the time such revenues are recognized. Rebates, Chargebacks and Discounts: The Company contracts with Medicaid, other government agencies and various private organizations ("Third-party Payors") to allow for eligible purchases of the Lesinurad Products at partial or full reimbursement from such Third-party Payors. The Company estimates the rebates, chargebacks and discounts it will be obligated to provide to Third-party Payors and deducts these estimated amounts from its gross product revenue at the time the revenue is recognized. Based upon (i) the Company's contracts with these Third-party Payors, (ii) the government-mandated discounts applicable to government-funded programs, (iii) information obtained from the Company's Distributors and third-parties regarding the payor mix for Lesinurad Products and (iv) historical industry information regarding the payor mix for analog products, the Company estimates the rebates, chargebacks and discounts that it will be obligated to provide to Third-party Payors. Product Returns: The Company estimates the amount of Lesinurad Products that will be returned and deducts these estimated amounts from its gross revenue at the time the revenue is recognized. The Company's Distributors have the right to return unopened, unprescribed Lesinurad Products beginning six months prior to the labeled expiration date and ending twelve months after the labeled expiration date. The expiration date for the Lesinurad Products is at least 24 months after it has been converted into tablet form, which is the last step in the manufacturing process for Lesinurad Products and generally occurs within a few months before Lesinurad Products are delivered to the Company. The Company currently estimates product returns based on data provided to the Company by its Distributors and by other third parties, historical industry information regarding rates for similar pharmaceutical products, the estimated remaining shelf life of the Lesinurad Products previously shipped and currently being shipped to Distributors, and contractual agreements with the Company's Distributors intended to limit the amount of inventory they maintain. Reporting from the Distributors includes Distributor sales and inventory held by Distributors, which provides the Company with visibility into the distribution channel in order to determine which products, if any, were eligible to be returned. Other Incentives: Incentives that the Company offers include voluntary patient assistance programs, such as co-pay assistance programs which are intended to provide financial assistance to qualified commercially insured patients with prescription drug co-payments required by payors. The calculation of the accrual for co-pay assistance is based on an estimate of claims and the cost per claim that the Company expects to receive associated with product that has been recognized as revenue. Product revenue is recorded net of the trade discounts, allowances, rebates, chargebacks, discounts, product returns, and other incentives. Certain of these adjustments are recorded as an accounts receivable reserve. Other The Company produces linaclotide finished drug product, API and development materials for certain of its partners. The Company recognizes revenue on linaclotide finished drug product, API and development materials when control have transferred to the partner, which generally occurs upon shipment for sales of API and upon delivery for sales of drug product, after the material has passed all quality testing required for collaborator acceptance. As it relates to development materials and API produced for Astellas, the Company is reimbursed at a contracted rate. Such reimbursements are considered as part of revenue generated pursuant to the Astellas license agreement and are presented as collaborative arrangements revenue. Any linaclotide finished drug product, API and development materials currently produced for Allergan for the U.S. or AstraZeneca for China, Hong Kong and Macau are recognized in accordance with the cost-sharing provisions of the Allergan and AstraZeneca collaboration agreements, respectively. Revenue recognition prior to the adoption of ASC 606 Agreements Entered into Prior to January 1, 2011 For arrangements that include multiple deliverables and were entered into prior to January 1, 2011, the Company followed the provisions of ASC Topic 605-25, Revenue Recognition—Multiple-Element Arrangements (‘‘ASC 605-25’’), in accounting for these agreements. Under ASC 605‑25, the Company was required to identify the deliverables included within the agreement and evaluate which deliverables represent separate units of accounting. Collaborative research and development and licensing agreements that contained multiple deliverables were divided into separate units of accounting when the following criteria were met: · Delivered element(s) had value to the collaborator on a standalone basis, · There was objective and reliable evidence of the fair value of the undelivered obligation(s), and · If the arrangement included a general right of return relative to the delivered item(s), delivery or performance of the undelivered item(s) was considered probable and substantially within the Company’s control. The Company allocated arr

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block
Net Loss Per Share	2. Net Loss Per Share Basic and diluted net loss per common share is computed by dividing net loss by the weighted average number of common shares outstanding during the period. In June 2015, in connection with the issuance of approximately $335.7 million in aggregate principal amount of the 2022 Notes, the Company entered into convertible note hedge transactions (the “Convertible Note Hedges”). The Convertible Note Hedges are generally expected to reduce the potential dilution to the Company’s Class A common stockholders upon a conversion of the 2022 Notes and/or offset any cash payments the Company is required to make in excess of the principal amount of converted 2022 Notes in the event that the market price per share of the Company’s Class A common stock, as measured under the terms of the Convertible Note Hedges, is greater than the conversion price of the 2022 Notes (Note 9). The Convertible Note Hedges are not considered for purposes of calculating the number of diluted weighted average shares outstanding, as their effect would be antidilutive. Concurrently with entering into the Convertible Note Hedges, the Company also entered into certain warrant transactions in which it sold note hedge warrants (the “Note Hedge Warrants”) to the Convertible Note Hedge counterparties to acquire 20,249,665 shares of the Company’s Class A common stock, subject to customary anti-dilution adjustments. The Note Hedge Warrants could have a dilutive effect on the Company’s Class A common stock to the extent that the market price per share of the Class A common stock exceeds the applicable strike price of such warrants (Note 9). The Note Hedge Warrants are not considered for purposes of calculating the number of diluted weighted averages shares outstanding, as their effect would be antidilutive. The following potentially dilutive securities have been excluded from the computation of diluted weighted average shares outstanding as their effect would be anti-dilutive (in thousands): Nine Months Ended September 30, 2018 2017 Options to purchase common stock Shares subject to repurchase Restricted stock units 3,238 2,205 Shares subject to issuance under Employee Stock Purchase Plan 59 74 Note hedge warrants 20,250 20,250 2022 Notes 20,250 20,250

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block
Goodwill and Intangible Assets	3. Goodwill and Intangible Assets The Company closed the Lesinurad Transaction on June 2, 2016 (the “Acquisition Date”) with AstraZeneca pursuant to which the Company received an exclusive license to develop, manufacture and commercialize in the U.S. products containing lesinurad as an active ingredient, including ZURAMPIC and DUZALLO. On August 2, 2018, the Company delivered to AstraZeneca a notice of termination of the lesinurad license agreement, which termination is made with respect to all products under the lesinurad license agreement and expected to be effective no later than 180 days from the notice (the “Effective Termination Date”). In connection with the Lesinurad License, the Company is required to perform certain post-marketing activities required by the FDA. These post-marketing requirements for lesinurad are estimated to be less than $100.0 million over up to ten years from the Acquisition Date. The Company concluded that the Lesinurad Transaction included inputs and processes that have the ability to create outputs and accordingly accounted for the transaction as a business combination in accordance with ASC 805. The purchase price consisted of the up-front payment to AstraZeneca of $100.0 million, which was made in June 2016, and the fair value of contingent consideration of approximately $67.9 million. In addition to the up-front payment, the Company will also pay a tiered royalty to AstraZeneca in the single-digits as a percentage of net sales of the Products in the U.S. through the Effective Termination Date of the Lesinurad License. During the year ended December 31, 2017, the Company paid a $15.0 million milestone to AstraZeneca related to the approval of DUZALLO by the FDA. In connection with the Company’s revised forecast and subsequent notice of termination of the lesinurad license agreement, the Company reduced its projected revenue and net cash flow assumptions associated with the value of its developed technology – ZURAMPIC and developed technology – DUZALLO intangible assets. Accordingly, the Company evaluated its developed technology – ZURAMPIC and developed technology – DUZALLO intangible assets for impairment. As a result of the triggering event requiring an impairment assessment, the Company recorded an approximately $151.8 million impairment charge during the three months ended September 30, 2018 related to the write-down of the developed technology – ZURAMPIC and developed technology – DUZALLO intangible assets. The impairment assessment performed utilized the revised projected revenue and net cash flows assumed through the Effective Termination Date, resulting in an impairment of the full carrying value of the intangible assets. The impairment charge was recorded as impairment of intangible assets in the Company’s condensed consolidated statement of operations. The Company tests its goodwill for impairment annually as of October 1st, or more frequently if events or changes in circumstances indicate an impairment may have occurred. As of September 30, 2018, there was no impairment of goodwill.

Collaboration, License, Co-Prom

Collaboration, License, Co-Promotion and Other Commercial Agreements	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block
Collaboration, License, Co-Promotion and Other Commercial Agreements	4. Collaboration, License, Co-Promotion and Other Commercial Agreements For the three and nine months ended September 30, 2018, the Company had linaclotide collaboration agreements with Allergan for North America and AstraZeneca for China, Hong Kong and Macau, as well as linaclotide license agreements with Astellas for Japan and with Allergan for the Allergan License Territory. The Company also had agreements with Allergan to co-promote VIBERZI in the U.S. and to promote CANASA in the U.S. The following table provides amounts included in the Company’s condensed consolidated statements of operations as collaborative arrangements revenue and sale of API attributable to transactions from these arrangements (in thousands): Collaborative Arrangements Revenue Three Months Ended Nine Months Ended September 30, September 30, Collaborative Arrangements Revenue 2018 2017 2018 2017 Linaclotide Agreements: Allergan (North America) $ $ $ $ Allergan (Europe and other) AstraZeneca (China, Hong Kong and Macau) — — — 208 Co-Promotion and Other Agreements: Exact Sciences (Cologuard) (1) — — Allergan (VIBERZI) Other Total collaborative arrangements revenue $ $ $ $ Sale of API Linaclotide Agreements: Astellas (Japan) $ $ $ $ Other (2) — — Total sale of API $ $ $ $ (1) In August 2016, the Company terminated the Exact Sciences Co-Promotion Agreement for Cologuard. Under the terms of the agreement, the Company continued to receive royalty payments through July 2017. (2) During the three months ended September 30, 2018, the Company recorded approximately $0.8 million in revenue related to the sale of API to Allergan. Accounts receivable, net and related party accounts receivable, net totaled approximately $64.7 million related to collaborative arrangements revenue and sale of API as of September 30, 2018, net of approximately $6.6 million related to related party accounts payable. As of September 30, 2018, there were no impairment indicators for the accounts receivable recorded. During the three and nine months ended September 30, 2018, there was no significant unusual activity in accounts receivable. Linaclotide Agreements Collaboration Agreement for North America with Allergan In September 2007, the Company entered into a collaboration agreement with Allergan to develop and commercialize linaclotide for the treatment of IBS-C, CIC and other GI conditions in North America. Under the terms of this collaboration agreement, the Company received a non-refundable, upfront licensing fee and shares equally with Allergan all development costs as well as net profits or losses from the development and sale of linaclotide in the U.S. The Company receives royalties in the mid-teens percent based on net sales in Canada and Mexico. Allergan is solely responsible for the further development, regulatory approval and commercialization of linaclotide in those countries and funding any costs. The collaboration agreement for North America also includes contingent milestone payments, as well as a contingent equity investment, based on the achievement of specific development and commercial milestones. At September 30, 2018, $205.0 million in license fees and all six development milestone payments had been received by the Company, as well as a $25.0 million equity investment in the Company’s capital stock (Note 12). The Company can also achieve up to $100.0 million in a sales-related milestone if certain conditions are met, which will be recognized as collaborative arrangements revenue when it is probable that a significant reversal of revenue would not occur and the associated constraints have been lifted. As a result of the research and development cost-sharing provisions of the linaclotide collaboration for North America, the Company offset approximately $2.5 million and offset approximately $5.8 million in incremental research and development costs during the three and nine months ended September 30, 2018, respectively, and recognized an insignificant amount and approximately $0.5 million in research and development costs during the three and nine months ended September 30, 2017, respectively, to reflect the obligations of each party under the collaboration to bear half of the development costs incurred. The Company and Allergan began commercializing LINZESS in the U.S. in December 2012. The Company receives 50% of the net profits and bears 50% of the net losses from the commercial sale of LINZESS in the U.S. Net profits or net losses consist of net sales of LINZESS to third-party customers and sublicense income in the U.S. less the cost of goods sold as well as selling, general and administrative expenses. LINZESS net sales are calculated and recorded by Allergan and may include gross sales net of discounts, rebates, allowances, sales taxes, freight and insurance charges, and other applicable deductions. If either party provided fewer calls on physicians in a particular year than it was contractually required to provide, such party’s share of the net profits would be adjusted as set forth in the collaboration agreement for North America. During the year ended December 31, 2017, these adjustments to the share of the net profits were reduced or eliminated in connection with the co-promotion activities under the Company’s agreement with Allergan to co-promote VIBERZI in the U.S., as described below in Agreement with Allergan for VIBERZI . Additionally, these adjustments to the share of the net profits are eliminated, in full, in 2018 and all subsequent years under the terms of the Company’s commercial agreement with Allergan entered into in January 2017 under which the Company promotes Allergan’s CANASA product, as described below in Commercial Agreement with Allergan . In May 2014, CONSTELLA became commercially available in Canada and in June 2014, LINZESS became commercially available in Mexico. The Company evaluated this collaboration arrangement under ASC 606 and concluded that all development-period performance obligations had been satisfied as of September 2012. However, the Company has determined that there are three remaining commercial-period performance obligations, which include the sales detailing of LINZESS, participation in the joint commercialization committee, and approved additional trials. The consideration remaining includes cost reimbursements in the U.S., as well as commercial sales-based milestones and net profit and loss sharing payments based on net sales in the U.S. Additionally, the Company receives royalties in the mid-teens percent based on net sales in Canada and Mexico. Royalties, commercial sales-based milestones, and net profit and loss sharing payments will be recorded as collaborative arrangements revenue or expense in the period earned, in accordance with the sales-based royalty exception, as these payments relate predominately to the license granted to Allergan. The Company records royalty revenue in the period earned based on royalty reports from its partner, if available, or based on the projected sales and historical trends. The cost reimbursements received from Allergan during the commercialization period will be recognized as billed in accordance with the right-to-invoice exemption, as the Company’s right to consideration corresponds directly with the value of the services transferred during the commercialization period. Under the Company’s collaboration with Allergan for North America, LINZESS net sales are calculated and recorded by Allergan and include gross sales net of discounts, rebates, allowances, sales taxes, freight and insurance charges, and other applicable deductions, as noted above. These amounts include the use of estimates and judgments, which could be adjusted based on actual results in the future. The Company records its share of the net profits or net losses from the sales of LINZESS in the U.S. on a net basis less commercial expenses, and presents the settlement payments to and from Allergan as collaboration expense or collaborative arrangements revenue, as applicable. This is in accordance with the Company’s policy, given that the Company is not the primary obligor and does not have the inventory risks in the collaboration agreement with Allergan for North America. The Company relies on Allergan to provide accurate and complete information related to net sales of LINZESS in accordance with U.S. GAAP in order to calculate its settlement payments to and from Allergan and record collaboration expense or collaborative arrangements revenue, as applicable. From time to time, in accordance with the terms of the collaboration with Allergan for North America, the Company engages an independent certified public accounting firm to review the accuracy of the financial reporting from Allergan to the Company. In connection with the most recent of such reviews, during the three months ended September 30, 2018, Allergan reported to the Company an approximately $59.3 million negative adjustment to LINZESS net sales. Such adjustment relates to the cumulative difference between certain previously estimated LINZESS gross-to-net sales reserves and allowances made by Allergan during the years ended December 31, 2015, 2016 and 2017, and actual subsequent payments made. This adjustment is primarily associated with estimated governmental and contractual rebates, as reported by Allergan. Accordingly, upon receiving this information from Allergan, the Company recorded a change in accounting estimate to reduce collaborative arrangements revenue by approximately $29.7 million during the three months ended September 30, 2018 related to the Company’s share of this adjustment. The Company recognized collaborative arrangements revenue from the Allergan collaboration agreement for North America during the three and nine months ended September 30, 2018 and 2017 as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Collaborative arrangements revenue related to sales of LINZESS in the U.S. $ 52,261 $ 73,905 $ 182,675 $ 179,664 Royalty revenue 463 452 1,458 1,386 Other (1) — 1,677 — 1,677 Total collaborative arrangements revenue $ 52,724 $ 76,034 $ 184,133 $ 182,727 (1) The collaborative arrangements revenue recognized in the three and nine months ended September 30, 2018 and 2017 primarily represents the Company’s share of the net profits and net losses on the sale of LINZESS in the U.S. The following table presents the amounts recorded by the Company for commercial efforts related to LINZESS in the U.S. in the three and nine months ended September 30, 2018 and 2017 (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Collaborative arrangements revenue related to sales of LINZESS in the U.S. (1)(2) $ 52,261 $ 73,905 $ 182,675 $ 179,664 Selling, general and administrative costs incurred by the Company (1) (10,915) (10,457) (33,556) (34,062) The Company’s share of net profit $ 41,346 $ 63,448 $ 149,119 $ 145,602 (1) Includes only collaborative arrangement revenue or selling, general and administrative costs attributable to the cost-sharing arrangement with Allergan for the three and nine months ended September 30, 2018 and 2017. (2) Certain of the unfavorable adjustments to the Company’s share of the LINZESS net profits were reduced or eliminated during the nine months ended September 30, 2017 in connection with the co-promotion activities under the Company’s agreement with Allergan to co-promote VIBERZI in the U.S., as described below in Agreement with Allergan for VIBERZI . In May 2014, CONSTELLA became commercially available in Canada and in June 2014, LINZESS became commercially available in Mexico. In October 2015, Almirall and Allergan terminated the sublicense arrangement with respect to Mexico, returning the exclusive rights to commercialize CONSTELLA in Mexico to Allergan. CONSTELLA continues to be available to adult IBS-C patients in Mexico. The Company records royalties on sales of CONSTELLA in Canada and LINZESS in Mexico in the period earned. The Company recognized approximately $0.5 million and approximately $1.5 million of combined royalty revenues from Canada and Mexico during the three and nine months ended September 30, 2018, respectively. The Company recognized approximately $0.5 million and approximately $1.4 million of combined royalty revenues from Canada and Mexico during the three and nine months ended September 30, 2017, respectively. License Agreement with Allergan (All countries other than the countries and territories of North America, China, Hong Kong, Macau, and Japan) In April 2009, the Company entered into a license agreement with Almirall (the “European License Agreement”) to develop and commercialize linaclotide in Europe (including the Commonwealth of Independent States and Turkey) for the treatment of IBS-C, CIC and other GI conditions. In October 2015, Almirall transferred its exclusive license to develop and commercialize linaclotide in Europe to Allergan. In accordance with the European License Agreement, the Company granted Almirall a right to access its U.S. Phase III clinical trial data for the purposes of supporting European regulatory approval. Additionally, the Company was required to participate on a joint development committee during linaclotide’s development period and is required to participate in a joint commercialization committee while linaclotide is commercially available. Additionally, in October 2015, the Company and Allergan separately entered into an amendment to the European License Agreement relating to the development and commercialization of linaclotide in Europe. Pursuant to the terms of the amendment, (i) certain sales-based milestones payable to the Company under the European License Agreement were modified to increase the total milestone payments such that, when aggregated with certain commercial launch milestones, they could total up to $42.5 million, (ii) the royalties payable to the Company during the term of the European License Agreement were modified such that the royalties based on sales volume in Europe begin in the mid-single digit percent and escalate to the upper-teens percent by calendar year 2019, and (iii) Allergan assumed responsibility for the manufacturing of linaclotide API for Europe from the Company, as well as the associated costs. The Company concluded that the 2015 amendment to the European License Agreement was not a modification to the linaclotide collaboration agreement with Allergan for North America. In January 2017, concurrently with entering into the commercial agreement as described below in Commercial Agreement with Allergan , the Company and Allergan entered into an amendment to the European License Agreement. The European License Agreement, as amended (the “Allergan License Agreement”), extended the license to develop and commercialize linaclotide in all countries other than China, Hong Kong, Macau, Japan, and the countries and territories of North America. On a country-by-country and product-by-product basis in such additional territory, Allergan is obligated to pay the Company a royalty as a percentage of net sales of products containing linaclotide as an active ingredient in the upper-single digits for five years following the first commercial sale of a linaclotide product in a country, and in the low-double digits thereafter. The royalty rate for products in the expanded territory will decrease, on a country-by-country basis, to the lower-single digits, or cease entirely, following the occurrence of certain events. Allergan is also obligated to assume certain purchase commitments for quantities of linaclotide API under the Company’s agreements with third-party API suppliers. The amendment to the European License Agreement did not modify any of the milestones or royalty terms related to Europe. The Company concluded that the 2017 amendment was a material modification to the European License Agreement; however, this modification did not have a material impact on the Company's condensed consolidated financial statements as there was no deferred revenue associated with the European License Agreement. The Company also concluded that the 2017 amendment to the European License Agreement was not a material modification to the linaclotide collaboration agreement with Allergan for North America. The Company’s conclusions on deliverables under ASC Topic 605-25, Revenue Recognition—Multiple-Element Arrangements (“ASC 605-25”) are described below in Commercial Agreement with Allergan . The Company evaluated the European License Agreement under ASC 606. In evaluating the terms of the 2009 European License Agreement under ASC 606, the Company determined that there are no remaining performance obligations as of September 2012. However, the Company continues to be eligible to receive consideration in the form of commercial launch milestones, sales-based milestones, and royalties. The commercial launch milestones, sales-based milestones and royalties under the European License Agreement have historically been recognized as revenue as earned. Under ASC 606, the Company will apply the sales-based royalty exception to royalties and sales-based milestones, as these payments relate predominantly to the license granted to Allergan (formerly Almirall). Accordingly, the royalties and sales-based milestones will be recorded as revenue in the period earned. The Company records royalties on sales of CONSTELLA in Europe in the period earned based on royalty reports from its partner, if available, or the projected sales and historical trends. The commercial launch milestones will be recognized as revenue when it is probable that a significant reversal of revenue would not occur and the associated constraint has been lifted. Additionally, the Company evaluated the terms of the January 2017 amendment under ASC 606 and determined that it would be treated as a separate contract given that it adds a distinct good or service at an amount that reflects standalone selling price. The Company determined that all performance obligations in this amendment were satisfied in January 2017 when the license for the additional territory was transferred. The Company continues to receive royalties under this agreement, which are recorded in the period earned pursuant to the sales-based royalty exception, as they related predominantly to the license granted to Allergan. The Company recognized approximately $0.2 million and $0.8 million of royalty revenue during the three and nine months ended September 30, 2018, respectively, and an insignificant amount and approximately $0.3 million during the three and nine months ended September 30, 2017, respectively. License Agreement for Japan with Astellas In November 2009, the Company entered into a license agreement with Astellas, as amended, to develop and commercialize linaclotide for the treatment of IBS‑C, CIC and other GI conditions in Japan. Astellas is responsible for all activities relating to development, regulatory approval and commercialization in Japan as well as funding the associated costs and the Company is required to participate on a joint development committee over linaclotide’s development period. During the year ended December 31, 2017, the Company and Astellas entered into a commercial API supply agreement (the “Astellas Commercial Supply Agreement”). Pursuant to the Astellas Commercial Supply Agreement, the Company sells linaclotide API supply to Astellas at a contractually defined rate and recognizes related revenue as sale of API. Under the license agreement, the Company receives royalties which escalate based on sales volume, beginning in the low-twenties percent, less the transfer price paid for the API included in the product actually sold and other contractual deductions. In 2009, Astellas paid the Company a non‑refundable, up‑front licensing fee of $30.0 million, which was recognized as collaborative arrangements revenue on a straight‑line basis over the Company’s estimate of the period over which linaclotide was developed under the license agreement in accordance with ASC 605. The development period was completed in December 2016 upon approval of LINZESS by the Japanese Ministry of Health, Labor and Welfare at which point all previously deferred revenue under the agreement was recognized. The agreement also includes three development milestone payments that totaled up to $45.0 million, all of which were achieved and recognized as revenue through December 31, 2016 in accordance with ASC 605. The first milestone payment, consisting of $15.0 million upon enrollment of the first study subject in a Phase III study for linaclotide in Japan, was achieved in November 2014. The second milestone payment, consisting of $15.0 million upon filing of a New Drug Application (“NDA”) for linaclotide with the Japanese Ministry of Health, Labor and Welfare, was achieved in February 2016. The third development milestone payment consisting of $15.0 million upon approval of an NDA by the Japanese Ministry of Health, Labor and Welfare to market linaclotide in Japan was achieved in December 2016. The Company has evaluated the terms of the 2009 License Agreement with Astellas under ASC 606 and has determined that there are no remaining performance obligations as of December 2016. However, there continues to be consideration in the form of royalties on sales of LINZESS in Japan under the 2009 License Agreement. Upon adoption of ASC 606, the Company concluded that the royalties on sales of LINZESS in Japan relate predominantly to the license granted to Astellas. Accordingly, the Company applies the sales-based royalty exception and records royalties on sales of LINZESS in Japan in the period earned based on royalty reports from its partner, if available, or the projected sales and historical trends. Additionally, under the terms of the Astellas Commercial Supply Agreement, the Company continues to have an ongoing performance obligation to supply API. Upon adoption of ASC 606, product revenue is recognized when the customer obtains control of the Company’s product, which occurs at a point in time, typically upon shipment of the product to the customer. This results in earlier revenue recognition than the Company’s historical accounting. The royalty on sales of LINZESS in Japan during each of the three and nine months ended September 30, 2018 and September 30, 2017 relating to the quarters in arrears did not exceed the transfer price of API sold and other contractual deductions during the periods. During the three and nine months ended September 30, 2017, the Company recognized approximately $9.5 million and $15.5 million, respectively, from the sale of API to Astellas under the license agreement and the Astellas Commercial Supply Agreement. During the three and nine months ended September 30, 2018, the Company recognized approximately $9.5 million and $23.7 million, respectively, from the sale of API to Astellas under the license agreement and the Astellas Commercial Supply Agreement. Additionally, the Company recorded approximately $13.5 million as deferred revenue as of September 30, 2018 related to API transactions with Astellas for API sales where control had not yet passed. Collaboration Agreement for China, Hong Kong and Macau with AstraZeneca In October 2012, the Company entered into a collaboration agreement with AstraZeneca (the “AstraZeneca Collaboration Agreement”) to co‑develop and co‑commercialize linaclotide in China, Hong Kong and Macau (the “License Territory”). The collaboration provides AstraZeneca with an exclusive nontransferable license to exploit the underlying technology in the License Territory. The parties share responsibility for continued development and commercialization of linaclotide under a joint development plan and a joint commercialization plan, respectively, with AstraZeneca having primary responsibility for the local operational execution. The parties agreed to an Initial Development Plan (“IDP”) which includes the planned development of linaclotide in China, including the lead responsibility for each activity and the related internal and external costs. The IDP indicates that AstraZeneca is responsible for a multinational Phase III clinical trial (the “Phase III Trial”), the Company is responsible for nonclinical development and supplying clinical trial material and both parties are responsible for the regulatory submission process. The IDP indicates that the party specifically designated as being responsible for a particular development activity under the IDP shall implement and conduct such activities. The activities are governed by a Joint Development Committee (“JDC”), with equal representation from each party. The JDC is responsible for approving, by unanimous consent, the joint development plan and development budget, as well as approving protocols for clinical studies, reviewing and commenting on regulatory submissions, and providing an exchange of data and information. The AstraZeneca Collaboration Agreement will continue until there is no longer a development plan or commercialization plan in place, however, it can be terminated by AstraZeneca at any time upon 180 days’ prior written notice. Under certain circumstances, either party may terminate the AstraZeneca Collaboration Agreement in the event of bankruptcy or an uncured material breach of the other party. Upon certain change in control scenarios of AstraZeneca, the Company may elect to terminate the AstraZeneca Collaboration Agreement and may re‑acquire its product rights in a lump sum payment equal to the fair market value of such product rights. In connection with the AstraZeneca Collaboration Agreement, the Company and AstraZeneca also executed a co-promotion agreement (the “Co-Promotion Agreement”), pursuant to which the Company utilized its existing sales force to co-promote NEXIUM ® (esomeprazole magnesium), one of AstraZeneca’s products, in the U.S. The Co-Promotion Agreement expired in May 2014. There are no refund provisions in the AstraZeneca Collaboration Agreement and the Co‑Promotion Agreement (together, the “AstraZeneca Agreements”). Under the terms of the AstraZeneca Collaboration Agreement, the Company received a $25.0 million non‑refundable up-front payment upon execution. The Company is also eligible for $125.0 million in additional commercial milestone payments contingent on the achievement of certain sales targets. The parties will also share in the net profits and losses associated with the development and commercialization of linaclotide in the License Territory, with AstraZeneca receiving 55% of the net profits or incurring 55% of the net losses until a certain specified commercial milestone is achieved, at which time profits and losses will be shared equally thereafter. Activities under the AstraZeneca Agreements were evaluated in accordance with ASC 605-25, to determine if they represented a multiple element revenue arrangement. The Company identified the following deliverables in the AstraZeneca Agreements: · an exclusive license to develop and commercialize linaclotide in the License Territory (the “License Deliverable”) (the deliverable was completed upon execution and all associated revenue was recognized as of December 31, 2016), · research, development and regulatory services pursuant to the IDP, as modified from time to time (the “R&D Services”), · JDC services, · obligation to supply clinical trial material, and · co‑promotion services for AstraZeneca’s product (the “Co‑Promotion Deliverable”) (the deliverable was completed and all associated revenue was recognized as of December 31, 2013). Under ASC 605, the License Deliverable is nontransferable and has certain sublicense restrictions. The Company determined that the License Deliverable had standalone value as a result of AstraZeneca’s internal product development and commercialization capabilities, which would enable it to use the License Deliverable for its intended purposes without the involvement of the Company. The remaining deliverables were deemed to have standalone value based on their nature and all deliverables met the criteria to be accounted for as separate units of accounting under ASC 605‑25. Factors considered in this determination included, among other things, whether any other vendors sell the items separately and if the customer could use the delivered item for its intended purpose without the receipt of the remaining deliverables. The Company performs R&D Services and JDC services, and supplies clinical trial materials during the estimated development period. All consideration allocated to such services was being recognized as a reduction of research and development costs, using the proportional performance method, by which the amounts are recognized in proportion to the costs incurred in accordance with ASC 605. At the inception of the arrangement, the Company identified the supply of linaclotide drug product for commercial requirements and commercialization services as contingent deliverables under ASC 605 because these services are contingent upon the receipt of regulatory approval to commercialize linaclotide in the License Territory, and there were no binding commitments or firm purchase orders pending for commercial supply at the inception of the AstraZeneca Collaboration Agreement. In August 2014, the Company and AstraZeneca, through the JDC, modified the IDP and development budget to include approximately $14.0 million in additional activities over the remaining development period, to be shared by the Company and AstraZeneca under the terms of the AstraZeneca Collaboration Agreement. These additional activities serve to support the continued development of linaclotide in the License Territory, including the Phase III Trial. Pursuant to the terms of the modified IDP and development budget, certain of the Company’s deliverables were modified, specifically the R&D Services and the obligation to supply clinical trial material. The modification did not, however, have a material impact on the Company’s condensed consolidated financial statements. The total amount of the non‑contingent consideration allocable to the AstraZeneca Agreements was approximately $34.0 million (“Arrangement Consideration”) which includes the $25.0 million non‑refundable up-front payment and approximately $9.0 million representing 55% of the costs for clinical trial material supply services and research, development and regulatory activities allocated to the Company in the IDP or as approved by the JDC in subsequent periods. The Company allocated the Arrangement Consideration to the non-contingent deliverables based on management’s best estimated selling price (“BESP”) of each deliverable using the relative selling price method, as the Company did not have vendor-specific objective evidence or third-party evidence of selling price for such deliverables. Of the total Arrangement Consideration, approximately $29.7 million was allocated to the License Deliverable, approximately $1.8 million to the R&D Services, approximately $0.1 million to the JDC services, approximately $0.3 million to the clinical trial material supply services, and approximately $2.1 million to the Co-Promotion Deliverable in the relative selling price model. Because the Company shares development costs with AstraZeneca, payments from AstraZeneca with respect to both research and development and selling, general and administrative costs incurred by the Company prior to the commercialization of linaclotide in the License Territory are recorded as a reduction in expense, in accordance with the Company’s policy, which is consistent with the nature of the cost reimbursement. Development costs incurred by the Company that pertain to the joint development plan and subsequent amendments to the joint development plan, as approved by the JDC, are recorded as research and development expense as incurred. Payments to AstraZeneca are recorded as incremental research and development expense. As a result of the cost-sharing arrangements under the collaboration, the Company offset an insignificant amount and approximately $0.2 million in research and development costs during the three and nine months ended September 30, 2017 respectively. In March 2017, the Company began providing supply of linaclotide drug product and certain commercialization-related services pursuant to the AstraZeneca Collaboration Agreement. During the three and nine months ended September 30, 2017, the Company recognized no revenue and approximately $0.2 million, respectively, as collaborative arrangements revenue related to linaclotide drug prod

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block
Fair Value of Financial Instruments	5. Fair Value of Financial Instruments The tables below present information about the Company’s assets that are measured at fair value on a recurring basis as of September 30, 2018 and December 31, 2017 and indicate the fair value hierarchy of the valuation techniques the Company utilized to determine such fair value. In general, fair values determined by Level 1 inputs utilize observable inputs such as quoted prices in active markets for identical assets or liabilities. Fair values determined by Level 2 inputs utilize data points that are either directly or indirectly observable, such as quoted prices for similar instruments in active markets, interest rates and yield curves. Fair values determined by Level 3 inputs utilize unobservable data points in which there is little or no market data, which require the Company to develop its own assumptions for the asset or liability. The Company’s investment portfolio includes fixed income securities that do not always trade on a daily basis. As a result, the pricing services used by the Company apply other available information as applicable through processes such as benchmark yields, benchmarking of like securities, sector groupings and matrix pricing to prepare valuations. In addition, model processes are used to assess interest rate impact and develop prepayment scenarios. These models take into consideration relevant credit information, perceived market movements, sector news and economic events. The inputs into these models may include benchmark yields, reported trades, broker-dealer quotes, issuer spreads and other relevant data. The Company validates the prices provided by its third-party pricing services by obtaining market values from other pricing sources and analyzing pricing data in certain instances. The Company also invests in certain reverse repurchase agreements which are collateralized by deposits in the form of Government Securities and Obligations for an amount not less than 102% of their principal amount. The Company does not record an asset or liability for the collateral as the Company is not permitted to sell or re-pledge the collateral. The collateral has at least the prevailing credit rating of U.S. Government Treasuries and Agencies. The Company utilizes a third-party custodian to manage the exchange of funds and ensure the collateral received is maintained at 102% of the reverse repurchase agreements principal amount on a daily basis. The following tables present the assets and liabilities the Company has measured at fair value on a recurring basis (in thousands): Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Other Significant Active Markets for Observable Unobservable Identical Assets Inputs Inputs September 30, 2018 (Level 1) (Level 2) (Level 3) Assets: Cash and cash equivalents: Money market funds $ 116,037 $ 116,037 $ — $ — Repurchase agreements 30,000 30,000 — — Available-for-sale securities: U.S. Treasury securities 6,740 6,740 — — U.S. government-sponsored securities 13,096 — 13,096 — Convertible Note Hedges 142,774 — — 142,774 Total assets measured at fair value $ 308,647 $ 152,777 $ 13,096 $ 142,774 Liabilities: Note Hedge Warrants $ 122,778 $ — $ — $ 122,778 Contingent Consideration 74 — — 74 Total liabilities measured at fair value $ 122,852 $ — $ — $ 122,852 Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Other Significant Active Markets for Observable Unobservable Identical Assets Inputs Inputs December 31, 2017 (Level 1) (Level 2) (Level 3) Assets: Cash and cash equivalents: Money market funds $ $ $ — $ — U.S. Treasury securities — — Repurchase agreements — — Available-for-sale securities: U.S. Treasury securities — — U.S. government-sponsored securities — — Convertible Note Hedges 108,188 — — 108,188 Total assets measured at fair value $ $ $ $ Liabilities: Note Hedge Warrants $ 92,188 $ — $ — $ 92,188 Contingent Consideration 31,258 — — 31,258 Total liabilities measured at fair value $ 123,446 $ — $ — $ 123,446 There were no transfers between fair value measurement levels during the three and nine months ended September 30, 2018 or 2017. Cash equivalents, accounts receivable, related party accounts receivable, prepaid expenses and other current assets, accounts payable, related party accounts payable, accrued expenses and the current portion of capital lease obligations at September 30, 2018 and December 31, 2017 are carried at amounts that approximate fair value due to their short-term maturities. Convertible Note Hedges and Note Hedge Warrants The Company’s Convertible Note Hedges and the Note Hedge Warrants are recorded as derivative assets and liabilities, and are classified as Level 3 under the fair value hierarchy. These derivatives are not actively traded and are valued using the Black-Scholes option-pricing model which requires the use of subjective assumptions. Significant inputs used to determine the fair value as of September 30, 2018 included the price per share of the Company’s Class A common stock, time to maturity of the derivative instruments, the strike prices of the derivative instruments, the risk-free interest rate, and the volatility of the Company’s Class A common stock. The Company has not paid and does not anticipate paying cash dividends on its shares of common stock in the foreseeable future; therefore, the expected dividend yield is assumed to be zero. Changes to these inputs could materially affect the valuation of the Convertible Note Hedges and Note Hedge Warrants. The following inputs were used in the fair market valuation of the Convertible Note Hedges and Note Hedge Warrants as of September 30, 2018 and December 31, 2017: Nine Months Ended Year Ended September 30, December 31, 2018 2017 Convertible Note Hedge Convertible Note Hedge Note Hedges Warrants Note Hedges Warrants Risk-free interest rate (1) 2.9 % 2.9 % 2.1 % 2.2 % Time to maturity 3.7 4.4 4.5 5.0 Stock price (2) $ 18.46 $ 18.46 $ 14.99 $ 14.99 Strike price (3) $ 16.58 $ 21.50 $ 16.58 $ 21.50 Common stock volatility (4) 40.7 % 41.6 % 44.1 % 44.1 % Dividend yield — % — % — % — % (1) Based on U.S. Treasury yield curve, with terms commensurate with the terms of the Convertible Note Hedges and the Note Hedge Warrants. (2) The closing price of the Company’s Class A common stock on the last trading day of the quarter ended September 30, 2018 and December 31, 2017, respectively. (3) As per the respective agreements for the Convertible Note Hedges and Note Hedge Warrants. (4) Selected volatility based on historical volatility of the Company’s Class A common stock. The Convertible Note Hedges and the Note Hedge Warrants are recorded at fair value at each reporting period and changes in fair value are recorded in other expense, net within the Company’s condensed consolidated statements of operations. Gains and losses for these derivative financial instruments are presented separately in the Company’s condensed consolidated statements of cash flows. The following table reflects the change in the Company’s Level 3 convertible note derivatives from December 31, 2017 through September 30, 2018 (in thousands): Convertible Note Hedge Note Hedges Warrants Balance at December 31, 2017 $ 108,188 $ (92,188) Change in fair value, recorded as a component of gain (loss) on derivatives 34,586 (30,590) Balance at September 30, 2018 $ 142,774 $ (122,778) Contingent Consideration In connection with the Lesinurad Transaction, the Company recorded a liability of $67.9 million as of the Acquisition Date. This valuation was based on a Monte-Carlo simulation, which includes significant estimates related to probability weighted net cash outflow projections, primarily comprised of estimated future royalty and milestone payments to AstraZeneca, discounted using a yield curve equivalent to the Company’s credit risk, which was the estimated cost of debt financing for market participants. Adjustments are recorded when there are changes in significant assumptions, including net sales projections, probability weighted net cash outflow projections, the discount rate, passage of time, and the yield curve equivalent to the Company’s credit risk, which is based on the estimated cost of debt for market participants. This estimate represents the probability weighted analysis of expected future milestone and royalty payments based on net sales to be made to AstraZeneca. Changes to these inputs are re-evaluated each reporting period and could materially affect the valuation of the contingent consideration. During the three months ended September 30, 2018, the Company reduced its projected revenue assumptions associated with the sales of ZURAMPIC and DUZALLO and delivered to AstraZeneca a notice of termination of the Lesinurad License. Accordingly, the Company recognized a gain on fair value remeasurement of contingent consideration of approximately $33.5 million during the three months ended September 30, 2018 due to the reduction in projected royalty payments. The estimated fair value of contingent consideration was approximately $0.1 million as of September 30, 2018. The following table reflects the change in the Company’s Level 3 contingent consideration payable from December 31, 2017 through September 30, 2018 (in thousands): Contingent Consideration Fair Value at December 31, 2017 31,258 Changes in fair value (31,045) Payments/transfers to accrued expenses and other current liabilities (139) Fair value at September 30, 2018 $ 74 2.25% Convertible Senior Notes In June 2015, the Company issued approximately $335.7 million of its 2022 Notes. The Company separately accounted for the liability and equity components of the 2022 Notes by allocating the proceeds between the liability component and equity component (Note 9). The fair value of the 2022 Notes, which differs from their carrying value, is influenced by interest rates, the price of the Company’s Class A common stock and the volatility thereof, and the prices for the 2022 Notes observed in market trading, which are Level 2 inputs. The estimated fair value of the 2022 Notes was approximately $433.7 million and approximately $392.8 million as of September 30, 2018 and December 31, 2017, respectively. 8.375% Notes Due 2026 In September 2016, the Company closed a direct private placement pursuant to which the Company issued $150.0 million in aggregate principal amount of the 2026 Notes in January 2017. Nonrecurring fair value measurements – Intangible Assets The Company’s acquired intangible assets are analyzed for impairment on a nonrecurring basis using fair value measurements with unobservable inputs (Level 3). During the three months ended September 30, 2018, the Company recorded an approximately $151.8 million impairment charge related to its acquired intangible assets. The impairment assessment performed utilized the revised projected revenue and net cash flows assumed through the Effective Termination Date, resulting in an impairment of the full carrying value of the intangible assets (Note 3).

Available-for-Sale Securities

Available-for-Sale Securities	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block
Available-for-Sale Securities	6. Available-for-Sale Securities The following tables summarize the available-for-sale securities held at September 30, 2018 and December 31, 2017 (in thousands): Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value September 30, 2018 U.S. Treasury securities $ 6,744 $ — $ (4) $ 6,740 U.S. government-sponsored securities 13,101 — (5) 13,096 Total $ 19,845 $ — $ (9) $ 19,836 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value December 31, 2017 U.S. Treasury securities $ 64,378 $ — $ (35) $ 64,343 U.S. government-sponsored securities 31,384 — (47) 31,337 Total $ 95,762 $ — $ (82) $ 95,680 The contractual maturities of all securities held at September 30, 2018 are one year or less. There were 7 and 29 available-for-sale securities in an unrealized loss position at September 30, 2018 and December 31, 2017, respectively, none of which had been in an unrealized loss position for more than twelve months. The aggregate fair value of these securities at September 30, 2018 and December 31, 2017 was approximately $19.8 million and approximately $95.7 million, respectively. The Company reviews its investments for other-than-temporary impairment whenever the fair value of an investment is less than amortized cost and evidence indicates that an investment’s carrying amount is not recoverable within a reasonable period of time. To determine whether an impairment is other-than-temporary, the Company considers whether it has the ability and intent to hold the investment until a market price recovery and considers whether evidence indicating the cost of the investment is recoverable outweighs evidence to the contrary. The Company does not intend to sell the investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases, which may be maturity. The Company did not hold any securities with other-than-temporary impairment at September 30, 2018. There were no sales of available-for-sale securities during each of the three and nine months ended September 30, 2018 or 2017. Net unrealized holding gains or losses for the period that have been included in accumulated other comprehensive loss were not material to the Company’s condensed consolidated results of operations.

Inventory

Inventory	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block
Inventory	7. Inventory Inventory consisted of the following (in thousands): September 30, 2018 December 31, 2017 Finished Goods $ 76 $ 735 $ 76 $ 735 The Company’s inventory represents linaclotide API and drug product and Lesinurad Products finished goods that are available for commercial sale. The Company evaluates inventory levels quarterly and any inventory that has a cost basis in excess of its expected net realizable value, inventory that becomes obsolete, inventory in excess of expected sales requirements, inventory that fails to meet commercial sale specifications or is otherwise impaired is written down with a corresponding charge to the statement of operations in the period that the impairment is first identified. No impairment of linaclotide API inventory was recorded during the three or nine months ended September 30, 2018 or 2017. The Company wrote down approximately $0.6 million and approximately $2.5 million related to lesinurad inventory and commercial supply purchase commitments during the three and nine months ended September 30, 2018, respectively, as a result of revised demand forecasts and the notice of termination of the Lesinurad License. The adjustment was recorded as write-down of lesinurad commercial supply to net realizable value and (settlement) loss on non-cancelable purchase commitments. During the three months ended September 30, 2018, the Company assigned to Allergan certain linaclotide excess non-cancelable purchase commitments that the Company had previously accrued for. Accordingly, the Company relieved the previous accrual of approximately $2.5 million, which was recorded as write-down of lesinurad commercial supply to net realizable value and (settlement) loss on non-cancelable purchase commitments on the Company’s condensed consolidated statement of operations.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block
Accrued Expenses and Other Current Liabilities	8. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, 2018 December 31, 2017 Salaries $ 1,750 $ Accrued vacation 3,835 Accrued incentive compensation 12,342 Other employee benefits 2,602 Professional fees 2,681 Accrued interest 2,761 Workforce reduction charges 7,853 — Other 11,134 $ 44,958 $ As of September 30, 2018, other accrued expenses of approximately $11.1 million includes approximately $2.5 million related to linaclotide excess purchase commitments, approximately $2.1 million related to a portion of the activities associated with the Company’s intent to separate into two independent publicly traded companies, and During the three months ended September 30, 2018, the Company relieved approximately $2.5 million related to linaclotide excess non-cancelable purchase commitment accruals that were assigned to Allergan during the period. This amount was recorded as write-down of lesinurad commercial supply to net realizable value and (settlement) loss on non-cancelable purchase commitments on the Company’s condensed consolidated statements of operations. As of December 31, 2017, other accrued expenses of approximately $12.2 million included approximately $3.4 million related to linaclotide excess purchase commitments , approximately $1.3 million related to excess non-cancelable ZURAMPIC sample purchase commitments, and approximately $0.2 million related to ZURAMPIC finished goods inventory.

Notes Payable

Notes Payable	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block
Notes Payable	9. Notes Payable 8.375% Notes due 2026 On September 23, 2016, the Company closed a direct private placement, pursuant to which the Company issued $150.0 million in aggregate principal amount of 8.375% notes due 2026 on the Funding Date, January 5, 2017. The proceeds from the issuance of the 2026 Notes were used to redeem the outstanding principal balance of the PhaRMA Notes on the Funding Date. The Company capitalized approximately $0.5 million of debt issuance costs, which were netted against the carrying value of the 2026 Notes. The 2026 Notes bear an annual interest rate of 8.375%, with interest payable March 15, June 15, September 15 and December 15 of each year (each an “8.375% Payment Date”) which began on June 15, 2017. Principal of the 2026 Notes will be payable on the 8.375% Payment Dates beginning March 15, 2019. From March 15, 2019, the Company will make quarterly payments on the 2026 Notes equal to the greater of (i) 7.5% of net sales of linaclotide in the U.S. for the preceding quarter (the “8.375% Synthetic Royalty Amount”) and (ii) accrued and unpaid interest on the 2026 Notes (the “8.375% Required Interest Amount”). Principal on the 2026 Notes will be repaid in an amount equal to the 8.375% Synthetic Royalty Amount minus the 8.375% Required Interest Amount, when this is a positive number, until the principal has been paid in full. Given the principal payments on the 2026 Notes are based on the 8.375% Synthetic Royalty Amount, which will vary from quarter to quarter, the 2026 Notes may be repaid prior to September 15, 2026, the final legal maturity date. The Company expects to pay approximately $39.2 million of the principal within twelve months following September 30, 2018. The 2026 Notes are secured by a security interest in a segregated bank account established to receive the required quarterly payments as well as certain limited accounts receivables, payment intangibles or other rights to payment or proceeds, in each case, up to the 8.375% Synthetic Royalty Amount or estimated equivalent thereto, as applicable. Up to the amount of the required quarterly payments under the 2026 Notes, Allergan deposits its quarterly profit (loss) sharing payments due to the Company related to net sales of linaclotide in the U.S. pursuant to the collaboration agreement for North America, if any, into the segregated bank account. If the funds deposited by Allergan into the segregated bank account are insufficient to make a required payment of interest or principal on a particular 8.375% Payment Date, the Company is obligated to deposit such shortfall out of the Company’s general funds into the segregated bank account. The 2026 Notes may be redeemed at any time prior to maturity, in whole or in part, at the option of the Company. If applicable, the Company will pay a redemption price equal to the percentage of outstanding principal balance of the 2026 Notes being redeemed specified below for the period in which the redemption occurs (plus the accrued and unpaid interest to the redemption date on the 2026 Notes being redeemed): Redemption Payment Dates Percentage From and including March 15, 2018 to and including March 14, 2019 108.00 % From and including March 15, 2019 to and including March 14, 2020 105.50 % From and including March 15, 2020 to and including March 14, 2021 102.75 % From and including March 15, 2021 and thereafter 100.00 % The 2026 Notes contain certain covenants related to the Company’s obligations with respect to the commercialization of linaclotide and the related collaboration agreement with Allergan for North America, as well as certain customary covenants, including covenants that limit or restrict the Company’s ability to incur certain liens, merge or consolidate or make dispositions of assets. The 2026 Notes also specify a number of events of default (some of which are subject to applicable cure periods), including, among other things, covenant defaults, other non-payment defaults, and bankruptcy and insolvency defaults. Upon the occurrence of an event of default, subject to cure periods in certain circumstances, all amounts outstanding may become immediately due and payable. The accounting for the 2026 Notes requires the Company to make certain estimates and assumptions about the future net sales of linaclotide in the U.S. Linaclotide has been marketed as LINZESS in the U.S. since December 2012 and the estimates of the magnitude and timing of linaclotide net sales are subject to significant variability and uncertainty. These estimates and assumptions are likely to change, which may result in future adjustments to the portion of the 2026 Notes that is classified as a current liability, the amortization of debt issuance costs and discounts as well as the accretion of the interest expense. Any such adjustments could be material to the Company’s condensed consolidated financial statements. 2.25% Convertible Senior Notes due 2022 In June 2015, the Company issued approximately $335.7 million aggregate principal amount of the 2022 Notes. The Company received net proceeds of approximately $324.0 million from the sale of the 2022 Notes, after deducting fees and expenses of approximately $11.7 million. The Company used approximately $21.1 million of the net proceeds from the sale of the 2022 Notes to pay the net cost of the Convertible Note Hedges (after such cost was partially offset by the proceeds to the Company from the sale of the Note Hedge Warrants), as described below. The 2022 Notes are governed by an indenture (the “Indenture”) between the Company and U.S. Bank National Association, as the trustee. The 2022 Notes are senior unsecured obligations and bear cash interest at the annual rate of 2.25%, payable on June 15 and December 15 of each year, which began on December 15, 2015. The 2022 Notes will mature on June 15, 2022, unless earlier converted or repurchased. The Company may settle conversions of the 2022 Notes through payment or delivery, as the case may be, of cash, shares of Class A common stock of the Company or a combination of cash and shares of Class A common stock, at the Company’s option (subject to, and in accordance with, the settlement provisions of the Indenture). The initial conversion rate for the 2022 Notes is 60.3209 shares of Class A common stock (subject to adjustment as provided for in the Indenture) per $1,000 principal amount of the 2022 Notes, which is equal to an initial conversion price of approximately $16.58 per share and 20,249,665 shares. Holders of the 2022 Notes may convert their 2022 Notes at their option at any time prior to the close of business on the business day immediately preceding December 15, 2021 in multiples of $1,000 principal amount, only under the following circumstances: · during any calendar quarter commencing after the calendar quarter ending on September 30, 2015 (and only during such calendar quarter), if the last reported sale price of the Company’s Class A common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price for the 2022 Notes on each applicable trading day; · during the five business day period after any five consecutive trading day period (the “measurement period”) in which the “trading price” (as defined in the Indenture) per $1,000 principal amount of the 2022 Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s Class A common stock and the conversion rate for the 2022 Notes on each such trading day; or · upon the occurrence of specified corporate events described in the Indenture. On or after December 15, 2021, until the close of business on the second scheduled trading day immediately preceding June 15, 2022, holders may convert their 2022 Notes, in multiples of $1,000 principal amount, at the option of the holder regardless of the foregoing circumstances. If a make-whole fundamental change, as described in the Indenture, occurs and a holder elects to convert its 2022 Notes in connection with such make-whole fundamental change, such holder may be entitled to an increase in the conversion rate as described in the Indenture. The Company may not redeem the 2022 Notes prior to the maturity date and no “sinking fund” is provided for by the 2022 Notes, which means that the Company is not required to periodically redeem or retire the 2022 Notes. Upon the occurrence of certain fundamental changes involving the Company, holders of the 2022 Notes may require the Company to repurchase for cash all or part of their 2022 Notes at a repurchase price equal to 100% of the principal amount of the 2022 Notes to be repurchased, plus accrued and unpaid interest. The Indenture does not contain any financial covenants or restrict the Company’s ability to repurchase the Company’s securities, pay dividends or make restricted payments in the event of a transaction that substantially increases the Company’s level of indebtedness. The Indenture provides for customary events of default. In the case of an event of default with respect to the 2022 Notes arising from specified events of bankruptcy or insolvency, all outstanding 2022 Notes will become due and payable immediately without further action or notice. If any other event of default with respect to the 2022 Notes under the Indenture occurs or is continuing, the trustee or holders of at least 25% in aggregate principal amount of the then outstanding 2022 Notes may declare the principal amount of the 2022 Notes to be immediately due and payable. Notwithstanding the foregoing, the Indenture provides that, upon the Company’s election, and for up to 180 days, the sole remedy for an event of default relating to certain failures by the Company to comply with certain reporting covenants in the Indenture consists exclusively of the right to receive additional interest on the 2022 Notes. In accordance with accounting guidance for debt with conversion and other options, the Company separately accounted for the liability and equity components of the 2022 Notes by allocating the proceeds between the liability component and the embedded conversion option, or equity component, due to the Company’s ability to settle the 2022 Notes in cash, its Class A common stock, or a combination of cash and Class A common stock at the option of the Company. The carrying amount of the liability component was calculated by measuring the fair value of a similar liability that does not have an associated convertible feature. The allocation was performed in a manner that reflected the Company’s non-convertible debt borrowing rate for similar debt. The equity component of the 2022 Notes was recognized as a debt discount and represents the difference between the gross proceeds from the issuance of the 2022 Notes and the fair value of the liability of the 2022 Notes on their respective dates of issuance. The excess of the principal amount of the liability component over its carrying amount, or debt discount, is amortized to interest expense using the effective interest method over seven years, or the life of the 2022 Notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. The Company’s outstanding Convertible Note balances as of September 30, 2018 and December 31, 2017 consisted of the following (in thousands): September 30, 2018 December 31, 2017 Liability component: Principal $ 335,699 $ 335,699 Less: unamortized debt discount (69,080) (80,530) Less: unamortized debt issuance costs (5,264) (5,976) Net carrying amount $ 261,355 $ 249,193 Equity component $ 114,199 $ 114,199 In connection with the issuance of the 2022 Notes, the Company incurred approximately $11.7 million of debt issuance costs, which primarily consisted of initial purchasers’ discounts and legal and other professional fees. The Company allocated these costs to the liability and equity components based on the allocation of the proceeds. The portion of these costs allocated to the equity components totaling approximately $4.0 million were recorded as a reduction to additional paid-in capital. The portion of these costs allocated to the liability components totaling approximately $7.7 million were recorded as a reduction in the carrying value of the debt on the balance sheet and are amortized to interest expense using the effective interest method over the expected life of the 2022 Notes. The Company determined the expected life of the 2022 Notes was equal to their seven-year term. The effective interest rate on the liability components of the 2022 Notes for the period from the date of issuance through September 30, 2018 was 9.34%. The following table sets forth total interest expense recognized related to the 2022 Notes during the three and nine months ended September 30, 2018 and 2017 (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Contractual interest expense $ 1,889 $ 1,888 $ 5,665 $ 5,665 Amortization of debt issuance costs 249 206 712 590 Amortization of debt discount 3,900 3,574 11,450 10,492 Total interest expense $ 6,038 $ 5,668 $ 17,827 $ 16,747 Convertible Note Hedge and Warrant Transactions with Respect to 2022 Notes To minimize the impact of potential dilution to the Company’s Class A common stockholders upon conversion of the 2022 Notes, the Company entered into the Convertible Note Hedges covering 20,249,665 shares of the Company’s Class A common stock in connection with the issuance of the 2022 Notes. The Convertible Note Hedges have an exercise price of approximately $16.58 per share and are exercisable when and if the 2022 Notes are converted. If upon conversion of the 2022 Notes, the price of the Company’s Class A common stock is above the exercise price of the Convertible Note Hedges, the counterparties are obligated to deliver shares of the Company’s Class A common stock and/or cash with an aggregate value approximately equal to the difference between the price of the Company’s Class A common stock at the conversion date and the exercise price, multiplied by the number of shares of the Company’s Class A common stock related to the Convertible Note Hedge being exercised. Concurrently with entering into the Convertible Note Hedges, the Company also sold Note Hedge Warrants to the Convertible Note Hedge counterparties to acquire 20,249,665 shares of the Company’s Class A common stock, subject to customary anti-dilution adjustments. The strike price of the Note Hedge Warrants is initially $21.50 per share, subject to adjustment, and such warrants are exercisable over the 150 trading day period beginning on September 15, 2022. The Note Hedge Warrants could have a dilutive effect on the Class A common stock to the extent that the market price per share of the Company’s Class A common stock exceeds the applicable strike price of such warrants. The Convertible Note Hedges and the Note Hedge Warrants are separate transactions entered into by the Company and are not part of the terms of the 2022 Notes. Holders of the 2022 Notes and the Note Hedge Warrants do not have any rights with respect to the Convertible Note Hedges. The Company paid approximately $91.9 million for the Convertible Note Hedges and recorded this amount as a long-term asset on the condensed consolidated balance sheet. The Company received approximately $70.8 million for the Note Hedge Warrants and recorded this amount as a long-term liability, resulting in a net cost to the Company of approximately $21.1 million. The Convertible Note Hedges and Note Hedge Warrants are accounted for as derivative assets and liabilities, respectively, in accordance with ASC Topic 815, “Derivatives and Hedging” (Note 5). 11% PhaRMA Notes due 2024 In January 2013, the Company closed a private placement of $175.0 million in aggregate principal amount of notes due on or before June 15, 2024. The PhaRMA Notes were redeemed at par on the 2026 Notes’ Funding Date, January 5, 2017, resulting in a loss on extinguishment of debt related to the write-off of the remaining PhaRMA Notes unamortized debt issuance costs of approximately $2.0 million.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block
Commitments and Contingencies	10. Commitments and Contingencies Lease Commitments During the year ended December 31, 2015, the Company entered into 12-month capital leases (the "2015 Vehicle Leases") for certain vehicles within its vehicle fleet for its field-based sales force and medical science liaisons. The 2015 Vehicle Leases expire at varying times through December 2018. During the six months ended June 30, 2018, the Company entered into new 12-month operating leases (the "2018 Vehicle Leases") for certain vehicles within its vehicle fleet for its field-based sales force and medical science liaisons. In connection with entering into the 2018 Vehicle Leases, all of the 2015 Vehicle Leases will be terminated through December 31, 2018. The 2018 Vehicle Leases expire at varying times beginning in April 2019 with an automatic one-month renewal provision. In accordance with the terms of the 2018 Vehicle Leases, the Company maintains a letter of credit securing its obligations under the lease agreements of $1.3 million, which is recorded as restricted cash. At September 30, 2018, the weighted average interest rate on the outstanding 2018 Vehicle Lease obligations was approximately 3.3% and the weighted average interest rate on the outstanding 2015 Vehicle Lease obligations was approximately 2.6%.

Employee Stock Benefit Plans

Employee Stock Benefit Plans	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block
Employee Stock Benefit Plans	11. Employee Stock Benefit Plans The Company has several share-based compensation plans under which stock options, restricted stock awards, restricted stock units (“RSUs”), and other share-based awards are available for grant to employees, directors and consultants of the Company. The following table summarizes share-based compensation expense reflected in the condensed consolidated statements of operations for the three and nine months ended September 30, 2018 and 2017 (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Research and development $ $ $ $ Selling, general and administrative Restructuring expenses — — $ $ $ $ During the three months ended March 31, 2018, the Company reduced its field-based workforce by approximately 60 employees, primarily consisting of field-based sales representatives that promoted DUZALLO or ZURAMPIC in the first position, resulting in a modification to certain share-based payment awards. As a result of the modification, the Company recorded stock-based compensation expense of approximately $0.2 million to restructuring expenses during the three months ended March 31, 2018. During the three months ended June 30, 2018, the Company initiated a reduction in headquarter-based workforce by approximately 40 employees associated with the Company’s intent to separate. Certain share-based payment awards were modified in connection with the reduction in workforce. As a result of the modifications, the Company recorded share-based compensation expense of approximately $1.0 million and $1.4 million to restructuring expenses during the three and nine months ended September 30, 2018, respectively. During the three months ended September 30, 2018, the Company reduced its workforce by approximately 100 employees, primarily consisting of field-based sales representatives as a result of the termination of the Lesinurad License. Certain share-based payment awards were modified in connection with the reduction in workforce. As a result of the modifications, the Company recorded share-based compensation expense of approximately $0.6 million to restructuring expenses during the three months ended September 30, 2018. A summary of stock option activity for the nine months ended September 30, 2018 is as follows: Weighted- Average Number of Shares Fair Value (in thousands) Outstanding at December 31, 2017 21,086 $ 12.90 Granted 3,168 14.93 Exercised (2,430) 10.32 Cancelled (964) 14.93 Outstanding at September 30, 2018 20,860 $ 13.42 The weighted-average assumptions used to estimate the fair value of the stock options using the Black-Scholes option-pricing model were as follows for the three and nine months ended September 30, 2018 and 2017: Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Expected volatility 44.1 % 45.2 % 43.6 % 46.0 % Expected term (in years) 6.0 6.0 Risk-free interest rate 2.8 % % 2.7 % % Expected dividend yield — % — % — % — % The Company utilizes RSUs in addition to stock options as part of the equity compensation it provides to its employees, each RSU representing the right to receive one share of the Company’s Class A Common Stock pursuant to the terms of the applicable award agreement and granted pursuant to the terms of the Company’s 2010 Equity Plan. The RSUs generally vest 25% per year on the approximate anniversary of the date of grant until fully vested, provided the employee remains continuously employed with the Company through each vesting date. Shares of the Company’s Class A Common Stock are delivered to the employee upon vesting, subject to payment of applicable withholding taxes. The fair value of all RSUs is based on the market value of the Company’s Class A Common Stock on the date of grant. Compensation expense, including the effect of estimated forfeitures, is recognized over the applicable service period. A summary of RSU activity for the nine months ended September 30, 2018 is as follows: Weighted- Average Number Grant Date of Shares Fair Value Unvested as of December 31, 2017 2,277 $ 15.08 Granted 2,017 $ 15.64 Vested (594) $ 15.07 Forfeited (462) $ 15.14 Unvested as of September 30, 2018 3,238 $ 15.42

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block
Related Party Transactions	12. Related Party Transactions In September 2009, Allergan became a related party when the Company sold to Allergan 2,083,333 shares of the Company’s convertible preferred stock. Amounts due to and due from Allergan are reflected as related party accounts payable and related party accounts receivable, respectively. These balances are reported net of any balances due to or from the related party. The Company had approximately $55.2 million and approximately $79.0 million in related party accounts receivable, net of related party accounts payable, associated with Allergan as of September 30, 2018 and December 31, 2017, respectively. The Company has and currently obtains health insurance services for its employees from an insurance provider whose President and Chief Executive Officer became a member of the Company’s Board of Directors in April 2016. The Company paid approximately $2.9 million and approximately $9.2 million in insurance premiums to this insurance provider during the three and nine months ended September 30, 2018, respectively, and approximately $3.0 million and approximately $9.0 million during the three and nine months ended September 30, 2017, respectively. At September 30, 2018 and December 31, 2017, the Company had an insignificant amount and no accounts payable due to this related party, respectively.

Workforce Reduction

Workforce Reduction	9 Months Ended
	Sep. 30, 2018
Disclosure Text Block
Workforce Reduction	13. Workforce Reduction On January 30, 2018, the Company commenced an initiative to evaluate the optimal mix of investments for the lesinurad franchise. As part of this effort, the Company reduced its field-based workforce by approximately 60 employees, primarily consisting of field-based sales representatives that promoted DUZALLO or ZURAMPIC in the first position. During the three months ended March 31, 2018, the Company substantially completed the implementation of this reduction in field-based workforce and, in accordance with ASC 420, Exit or Disposal Activities , recorded approximately $2.4 million of costs including employee severance, benefits and related costs. These costs are reflected in the condensed consolidated statement of operations as approximately $2.4 million in restructuring expenses. On June 27, 2018, the Company determined the initial organizational designs of the two new businesses, including employees’ roles and responsibilities, in connection with the Company’s intent to separate its sGC business from its commercial and GI business. As part of this process, the Company has initiated a reduction in its headquarter-based workforce by approximately 40 employees and expects to substantially complete the reduction in its workforce during the year ending December 31, 2018. The Company anticipates total costs related to the reduction in workforce to be approximately $5.2 million and will incur substantially all expenses through the end of 2018. During the three months ended September 30, 2018, the Company recorded approximately $2.7 million of costs, including employee severance, benefits and related costs, in connection with the reduction in workforce associated with the Company’s intent to separate in accordance with ASC 420, Exit and Disposal Activities . These costs are reflected in the condensed consolidated statement of operations as restructuring expenses. On August 16, 2018, the Company initiated a reduction in its workforce by approximately 100 employees, primarily consisting of field-based sales representatives in connection with the termination of the Lesinurad License and expects to substantially complete the reduction in its workforce and record associated costs during the year ending December 31, 2018. The Company anticipates total costs related to the reduction in workforce to be approximately $7.8 million, which are comprised of approximately $5.6 million of employee severance, benefits and related costs and approximately $2.2 million of contract-related costs. During the three months ended September 30, 2018, the Company recorded approximately $7.6 million of costs, including approximately $5.4 million of severance, benefits and related costs and approximately $2.2 million of contract-related costs, including the write-down of certain prepaid assets and deposits, in accordance with ASC 420, Exit and Disposal Activities . These costs are reflected in the condensed consolidated statement of operations as restructuring expenses. The following table summarizes the accrued liabilities activity recorded in connection with the reduction in workforce for the nine months ended September 30, 2018 (in thousands): Amounts Accrued at Charges Amount Paid Adjustments September 30, 2018 Employee severance, benefits and related costs January 2018 Reduction $ 2,228 $ (2,184) $ (13) $ 31 June 2018 Reduction 3,877 (1,727) 14 2,164 August 2018 Reduction 5,212 (553) 11 4,670 Total $ 11,317 $ (4,464) $ 12 $ 6,865 Contract related costs August 2018 Reduction $ 988 $ — $ — $ 988 Total $ 988 $ — $ — $ 988 During the three month and nine months ended September 30, 2018, the Company recorded approximately $10.3 million and approximately $15.1 million, respectively, in restructuring expenses.

Nature of Business (Policies)

Nature of Business (Policies)	9 Months Ended
	Sep. 30, 2018
Policy Text Blocks
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements and the related disclosures are unaudited and have been prepared in accordance with accounting principles generally accepted in the U.S. Additionally, certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017, which was filed with the Securities and Exchange Commission on February 22, 2018 (the “2017 Annual Report on Form 10-K”). The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all normal recurring adjustments considered necessary for a fair presentation of the Company’s financial position as of September 30, 2018, and the results of its operations for the three and nine months ended September 30, 2018 and 2017, and its cash flows for the nine months ended September 30, 2018 and 2017. The results of operations for the three and nine months ended September 30, 2018 and 2017 are not necessarily indicative of the results that may be expected for the full year or any other subsequent interim period.
Principles of Consolidation	Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of Ironwood Pharmaceuticals, Inc. and its wholly owned subsidiaries. All intercompany transactions and balances are eliminated in consolidation.
Reclassifications and Revisions to Prior Period Financial Statements	Reclassifications and Revisions to Prior Period Financial Statements Certain prior period financial statement items, such as Sale of Active Pharmaceutical Ingredient and Restricted Cash, have been reclassified to conform to current period presentation.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in accordance with U.S. generally accepted accounting principles requires the Company’s management to make estimates and judgments that may affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the amounts of revenues and expenses during the reported periods. On an on-going basis, the Company’s management evaluates its estimates, judgments and methodologies. Significant estimates and assumptions in the condensed consolidated financial statements include those related to revenue recognition, including returns, rebates, and other pricing adjustments; available-for-sale securities; inventory valuation, and related reserves; impairment of long-lived assets, including its acquired intangible assets and goodwill; initial valuation procedures for the issuance of convertible notes; fair value of derivatives; balance sheet classification of notes payable and convertible notes; income taxes, including the valuation allowance for deferred tax assets; research and development expenses; contingent consideration; contingencies and share-based compensation. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ materially from these estimates under different assumptions or conditions. Changes in estimates are reflected in reported results in the period in which they become known.
Revenue Recognition	Revenue Recognition Effective January 1, 2018, the Company adopted Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers (“ASC 606”) using the modified retrospective transition method. The adoption of ASC 606 represents a change in accounting principle that aims to more closely align revenue recognition with the delivery of the Company's services and will provide financial statement readers with enhanced disclosures. In accordance with ASC 606, the Company recognizes revenue when the customer obtains control of a promised good or service, in an amount that reflects the consideration which the Company expects to receive in exchange for the good or service. The reported results for the three and nine months ended September 30, 2018 reflect the application of ASC 606 guidance, while the reported results for prior periods were prepared in accordance with ASC 605, Revenue Recognition (“ASC 605”). Upon adoption of ASC 606, the Company concluded that no cumulative adjustment to the accumulated deficit as of January 1, 2018 was necessary. There were no remaining or ongoing deliverables or unrecognized consideration as of December 31, 2017 that required an adjustment to accumulated deficit. The adoption of ASC 606 had no impact on the Company’s statement of operations, balance sheets, or statement of cash flows. As part of the ASC 606 adoption, the Company has utilized certain practical expedients outlined in the guidance. These practical expedients include: · Expensing as incurred incremental costs of obtaining a contract, such as sales commissions, if the amortization period of the asset would be less than one year. · Recognizing revenue in the amount that the Company has the right to invoice, when consideration from the customer corresponds directly with the value to the customer of the Company’s performance completed to date. · For contracts that were modified before the beginning of the earliest reporting period presented in accordance with the pending content that links to this paragraph, an entity need not retrospectively restate the contract for those contract modifications in accordance with paragraphs ASC 606-10-25-12 through 25-13. Instead, an entity shall reflect the aggregate effect of all modifications that occur before the beginning of the earliest period presented in accordance with the pending content that links to this paragraph when: a. Identifying the satisfied and unsatisfied performance obligations b. Determining the transaction price and c. Allocating the transaction price to the satisfied and unsatisfied performance obligations. Prior to the adoption of ASC 606, the Company recognized revenue when there was persuasive evidence that an arrangement existed, services had been rendered or delivery had occurred, the price was fixed or determinable, and collection was reasonably assured. The Company’s revenues are generated primarily through collaborative arrangements and license agreements related to the research and development and commercialization of linaclotide, as well as co-promotion arrangements in the U.S. and product revenue related to the commercial sale of ZURAMPIC and DUZALLO in the U.S. The terms of the collaborative research and development, license, co-promotion and other agreements contain multiple performance obligations which may include (i) licenses, (ii) research and development activities, including participation on joint steering committees, (iii) the manufacture of finished drug product, active pharmaceutical ingredient (“API”), or development materials for a partner, which are reimbursed at a contractually determined rate, and (iv) co-promotion activities by the Company’s clinical sales specialists. Non-refundable payments to the Company under these agreements may include (i) up-front license fees, (ii) payments for research and development activities, (iii) payments for the manufacture of finished drug product, API, or development materials, (iv) payments based upon the achievement of certain milestones, (v) payments for sales detailing, promotional support services and medical education initiatives, and (vi) royalties on product sales. Additionally, the Company may receive its share of the net profits or bear its share of the net losses from the sale of linaclotide in the U.S. and for China, Hong Kong and Macau through its collaborations with Allergan and AstraZeneca, respectively. The Company has adopted a policy to recognize revenue net of tax withholdings, as applicable. Revenue recognition under ASC 606 Upon executing a revenue generating arrangement, the Company assesses whether it is probable the Company will collect consideration in exchange for the good or service it transfers to the customer. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, it performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies the performance obligations. The Company must develop assumptions that require significant judgment to determine the stand-alone selling price for each performance obligation identified in the contract. The assumptions that are used to determine the stand-alone selling price may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success. Collaboration, License, Co-Promotion and Other Commercial Agreements Upon licensing intellectual property to a customer, the Company determines if the license is distinct from the other performance obligations identified in the arrangement. The Company recognizes revenues from the transaction price, including non-refundable, up-front fees allocated to the license when the license is transferred to the customer if the license has distinct benefit to the customer. For licenses that are combined with other promises, the Company assesses the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time. For performance obligations that are satisfied over time, the Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. The Company’s license and collaboration agreements include milestone payments, such as development and other milestones. The Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method at the inception of the agreement. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. The Company re-evaluates the probability of achievement of such milestones and any related constraint at each reporting period, and any adjustments are recorded on a cumulative catch-up basis. Agreements that include the supply API or drug product for either clinical development or commercial supply at the customer’s discretion are generally considered as options. The Company assesses if these options provide a material right to its partner, and if so, they are accounted for as separate performance obligations. If the Company is entitled to additional payments when the customer exercises these options, any additional payments are recorded as revenue when the customer obtains control of the goods, which is typically upon shipment for sales of API and upon delivery for sales of drug product. For agreements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue when the related sales occur in accordance with the sales-based royalty exception under ASC 606-10-55-65. Net Profit or Net Loss Sharing In accordance with ASC 808 Topic, Collaborative Arrangements (“ASC 808”), the Company considered the nature and contractual terms of the arrangement and the nature of the Company’s business operations to determine the classification of payments under the Company’s collaboration agreements. While ASC 808 provides guidance on classification, the standard is silent on matters of separation, initial measurement, and recognition. Therefore, the Company, consistent with its accounting policies prior to the adoption of ASC 606, applies the separation, initial measurement, and recognition principles of ASC 606 to its collaboration agreements. The Company’s collaborative arrangements revenues generated from sales of LINZESS in the U.S. are considered akin to sales-based royalties. In accordance with the sales-based royalty exception, the Company recognizes its share of the pre-tax commercial net profit or net loss generated from the sales of LINZESS in the U.S. in the period the product sales are earned, as reported by Allergan, and related cost of goods sold and selling, general and administrative expenses are incurred by the Company and its collaboration partner. These amounts are partially determined based on amounts provided by Allergan and involve the use of estimates and judgments, such as product sales allowances and accruals related to prompt payment discounts, chargebacks, governmental and contractual rebates, wholesaler fees, product returns, and co-payment assistance costs, which could be adjusted based on actual results in the future. The Company is highly dependent on Allergan for timely and accurate information regarding any net revenues realized from sales of LINZESS in the U.S. in accordance with both ASC 808 and ASC 606, and the costs incurred in selling it, in order to accurately report its results of operations. If the Company does not receive timely and accurate information or incorrectly estimates activity levels associated with the collaboration at a given point in time, the Company could be required to record adjustments in future periods. In accordance with ASC 606-10-55, Principal Agent Considerations, the Company records revenue transactions as net product revenue in its condensed consolidated statements of operations if it is deemed the principal in the transaction, which includes being the primary obligor, retaining inventory risk, and control over pricing. Given that the Company is not the primary obligor and does not have the inventory risks in the collaboration agreement with Allergan for North America, it records its share of the net profits or net losses from the sales of LINZESS in the U.S. on a net basis and presents the settlement payments to and from Allergan as collaboration expense or collaborative arrangements revenue, as applicable. The Company and Allergan settle the cost sharing quarterly, such that the Company’s statement of operations reflects 50% of the pre-tax net profit or loss generated from sales of LINZESS in the U.S. Product revenue, net Net product revenue is derived from sales of ZURAMPIC and DUZALLO (“the Lesinurad Products”) in the U.S. The Company sells the Lesinurad Products principally to a limited number of national wholesalers and selected regional wholesalers (the “Distributors”). The Distributors resell the Lesinurad Products to retail pharmacies and healthcare providers, who then sell to patients. Net product revenue is recognized when the Distributor obtains control of the Company’s product, which occurs at a point in time, typically upon shipment of Lesinurad Products to the Distributor. When the Company performs shipping and handling activities after the transfer of control to the Distributor (e.g., when control transfers prior to delivery), they are considered as fulfillment activities, and accordingly, the costs are accrued for when the related revenue is recognized. The Company expenses incremental costs of obtaining a contract as and when incurred if the expected amortization period of the asset that the Company would have recognized is one year or less. The Company evaluates the creditworthiness of each of its Distributors to determine whether it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur. The Company calculates its net product revenue based on the wholesale acquisition cost that the Company charges its Distributors for the Lesinurad Products less variable consideration. The product revenue variable consideration consists of estimates relating to (i) trade discounts and allowances, such as invoice discounts for prompt payment and distributor fees, (ii) estimated government and private payor rebates, chargebacks and discounts, such as Medicaid reimbursements, (iii) reserves for expected product returns and (iv) estimated costs of incentives offered to certain indirect customers including patients. These estimates could be adjusted based on actual results in the period such variances become known. Trade Discounts and Allowances: The Company generally provides invoice discounts on sales of Lesinurad Products to its Distributors for prompt payment and pays fees for distribution services and for certain data that Distributors provide to the Company. Consistent with historical industry practice, the Company expects its Distributors to earn these discounts and fees, and accordingly deducts the full amount of these discounts and fees from its gross product revenues at the time such revenues are recognized. Rebates, Chargebacks and Discounts: The Company contracts with Medicaid, other government agencies and various private organizations ("Third-party Payors") to allow for eligible purchases of the Lesinurad Products at partial or full reimbursement from such Third-party Payors. The Company estimates the rebates, chargebacks and discounts it will be obligated to provide to Third-party Payors and deducts these estimated amounts from its gross product revenue at the time the revenue is recognized. Based upon (i) the Company's contracts with these Third-party Payors, (ii) the government-mandated discounts applicable to government-funded programs, (iii) information obtained from the Company's Distributors and third-parties regarding the payor mix for Lesinurad Products and (iv) historical industry information regarding the payor mix for analog products, the Company estimates the rebates, chargebacks and discounts that it will be obligated to provide to Third-party Payors. Product Returns: The Company estimates the amount of Lesinurad Products that will be returned and deducts these estimated amounts from its gross revenue at the time the revenue is recognized. The Company's Distributors have the right to return unopened, unprescribed Lesinurad Products beginning six months prior to the labeled expiration date and ending twelve months after the labeled expiration date. The expiration date for the Lesinurad Products is at least 24 months after it has been converted into tablet form, which is the last step in the manufacturing process for Lesinurad Products and generally occurs within a few months before Lesinurad Products are delivered to the Company. The Company currently estimates product returns based on data provided to the Company by its Distributors and by other third parties, historical industry information regarding rates for similar pharmaceutical products, the estimated remaining shelf life of the Lesinurad Products previously shipped and currently being shipped to Distributors, and contractual agreements with the Company's Distributors intended to limit the amount of inventory they maintain. Reporting from the Distributors includes Distributor sales and inventory held by Distributors, which provides the Company with visibility into the distribution channel in order to determine which products, if any, were eligible to be returned. Other Incentives: Incentives that the Company offers include voluntary patient assistance programs, such as co-pay assistance programs which are intended to provide financial assistance to qualified commercially insured patients with prescription drug co-payments required by payors. The calculation of the accrual for co-pay assistance is based on an estimate of claims and the cost per claim that the Company expects to receive associated with product that has been recognized as revenue. Product revenue is recorded net of the trade discounts, allowances, rebates, chargebacks, discounts, product returns, and other incentives. Certain of these adjustments are recorded as an accounts receivable reserve. Other The Company produces linaclotide finished drug product, API and development materials for certain of its partners. The Company recognizes revenue on linaclotide finished drug product, API and development materials when control have transferred to the partner, which generally occurs upon shipment for sales of API and upon delivery for sales of drug product, after the material has passed all quality testing required for collaborator acceptance. As it relates to development materials and API produced for Astellas, the Company is reimbursed at a contracted rate. Such reimbursements are considered as part of revenue generated pursuant to the Astellas license agreement and are presented as collaborative arrangements revenue. Any linaclotide finished drug product, API and development materials currently produced for Allergan for the U.S. or AstraZeneca for China, Hong Kong and Macau are recognized in accordance with the cost-sharing provisions of the Allergan and AstraZeneca collaboration agreements, respectively. Revenue recognition prior to the adoption of ASC 606 Agreements Entered into Prior to January 1, 2011 For arrangements that include multiple deliverables and were entered into prior to January 1, 2011, the Company followed the provisions of ASC Topic 605-25, Revenue Recognition—Multiple-Element Arrangements (‘‘ASC 605-25’’), in accounting for these agreements. Under ASC 605‑25, the Company was required to identify the deliverables included within the agreement and evaluate which deliverables represent separate units of accounting. Collaborative research and development and licensing agreements that contained multiple deliverables were divided into separate units of accounting when the following criteria were met: · Delivered element(s) had value to the collaborator on a standalone basis, · There was objective and reliable evidence of the fair value of the undelivered obligation(s), and · If the arrangement included a general right of return relative to the delivered item(s), delivery or performance of the undelivered item(s) was considered probable and substantially within the Company’s control. The Company allocated arrangement consideration among the separate units of accounting either on the basis of each unit’s respective fair value or using the residual method, and applied the applicable revenue recognition criteria to each of the separate units. If the separation criteria were not met, revenue of the combined unit of accounting was recorded based on the method appropriate for the last delivered item. Agreements Entered into or Materially Modified on or after January 1, 2011 and prior to January 1, 2018 The Company evaluated revenue from multiple element agreements entered into on or after January 1, 2011 under ASU No. 2009‑13, Multiple-Deliverable Revenue Arrangements (“ASU 2009‑13”), or ASC 605, until the adoption of ASC 606. The Company also evaluated whether amendments to its multiple element arrangements were considered material modifications that were subject to the application of ASU 2009‑13. This evaluation required management to assess all relevant facts and circumstances and to make subjective determinations and judgments. When evaluating multiple element arrangements under ASU 2009‑13, the Company considered whether the deliverables under the arrangement represented separate units of accounting. This evaluation required subjective determinations and required management to make judgments about the individual deliverables and whether such deliverables were separable from the other aspects of the contractual relationship. In determining the units of accounting, management evaluated certain criteria, including whether the deliverables had standalone value, based on the consideration of the relevant facts and circumstances for each arrangement. Factors considered in this determination included the research, manufacturing and commercialization capabilities of the partner and the availability of relevant research and manufacturing expertise in the general marketplace. In addition, the Company considered whether the collaborator can use the license or other deliverables for their intended purpose without the receipt of the remaining elements, and whether the value of the deliverable was dependent on the undelivered items and whether there were other vendors that could provide the undelivered items. The consideration received was allocated among the separate units of accounting using the relative selling price method, and the applicable revenue recognition criteria were applied to each of the separate units. The Company determined the estimated selling price for deliverables using vendor‑specific objective evidence (“VSOE”) of selling price, if available, third‑party evidence (“TPE”) of selling price if VSOE was not available, or best estimate of selling price (“BESP”) if neither VSOE nor TPE was available. Up‑Front License Fees prior to January 1, 2018 When management believed the license to its intellectual property had stand-alone value, the Company generally recognized revenue attributed to the license upon delivery. When management believed the license to its intellectual property did not have stand‑alone value from the other deliverables to be provided in the arrangement, it was combined with other deliverables and the revenue of the combined unit of accounting was recorded based on the method appropriate for the last delivered item. Milestones prior to January 1, 2018 At the inception of each arrangement that included pre-commercial milestone payments, the Company evaluated whether each pre-commercial milestone was substantive, in accordance with ASU No. 2010-17, Revenue Recognition—Milestone Method (“ASU 2010-17”), prior to the adoption of ASC 606. This evaluation included an assessment of whether (a) the consideration was commensurate with either (1) the entity’s performance to achieve the milestone, or (2) the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the entity’s performance to achieve the milestone, (b) the consideration relates solely to past performance and (c) the consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. The Company evaluated factors such as the scientific, clinical, regulatory, commercial and other risks that must be overcome to achieve the respective milestone, the level of effort and investment required and whether the milestone consideration is reasonable relative to all deliverables and payment terms in the arrangement in making this assessment. At December 31, 2017, the Company had no pre-commercial milestones that were deemed substantive. Commercial milestones were accounted for as royalties and are recorded as revenue upon achievement of the milestone, assuming all other revenue recognition criteria are met. Net Profit or Net Loss Sharing prior to January 1, 2018 In accordance with ASC 808 Topic, Collaborative Arrangements , and ASC 605‑45, Principal Agent Considerations , the Company considered the nature and contractual terms of the arrangement and the nature of the Company’s business operations to determine the classification of the transactions under the Company’s collaboration agreements. The Company recorded revenue transactions gross in the condensed consolidated statements of operations if it is deemed the principal in the transaction, which includes being the primary obligor and having the risks and rewards of ownership. The Company recognized its share of the pre‑tax commercial net profit or net loss generated from the sales of LINZESS in the U.S. in the period the product sales are reported by Allergan and related cost of goods sold and selling, general and administrative expenses are incurred by the Company and its collaboration partner. These amounts were partially determined based on amounts provided by Allergan and involve the use of estimates and judgments, such as product sales allowances and accruals related to prompt payment discounts, chargebacks, governmental and contractual rebates, wholesaler fees, product returns, and co‑payment assistance costs, which could be adjusted based on actual results. For the periods covered in the condensed consolidated financial statements presented, there have been no material changes to prior period estimates of revenues, cost of goods sold or selling, general and administrative expenses associated with the sales of LINZESS in the U.S. The Company records its share of the net profits or net losses from the sales of LINZESS in the U.S. on a net basis and presents the settlement payments to and from Allergan as collaboration expense or collaborative arrangements revenue, as applicable, as the Company is not the primary obligor and does not have the risks and rewards of ownership in the collaboration agreement with Allergan for North America. The Company and Allergan settle the cost sharing quarterly, such that the Company’s statement of operations reflects 50% of the pre‑tax net profit or loss generated from sales of LINZESS in the U.S. Royalties on Product Sales prior to January 1, 2018 The Company received royalty revenues under certain of the Company’s license or collaboration agreements. The Company recorded these revenues as earned. Product Revenue, Net prior to January 1, 2018 As noted above, net product revenue is derived from sales of the Lesinurad Products in the U.S. The Company recognized net product revenue from sales of the Lesinurad Products in accordance with ASC 605, when persuasive evidence of an arrangement exists, delivery has occurred and title of the product and associated risk of loss has passed to the customer, the price is fixed or determinable, and collection from the customer has been reasonably assured. ASC 605 required, among other criteria, that future returns could be reasonably estimated in order to recognize revenue. The Company began commercializing ZURAMPIC in October 2016 and DUZALLO in October 2017 in the U.S. Initially, upon the product launch of each of the Lesinurad Products, the Company determined that it was not able to reliably make certain estimates, including returns, necessary to recognize product revenue upon delivery to Distributors. As a result, through September 30, 2017, the Company recorded net product revenue for the Lesinurad Products using a deferred revenue recognition model (sell-through). Under the deferred revenue model, the Company did not recognize revenue until the respective product was prescribed to an end-user. Accordingly, the Company recognized net product revenue when the Lesinurad Products were prescribed to the end-user, using estimated prescription demand and pharmacy demand from third party sources and the Company’s analysis of third party market research data, as well as other third-party information through September 30, 2017. During the three months ended December 31, 2017, the Company concluded it had sufficient volume of historical activity and visibility into the distribution channel, in order to reasonably make all estimates required under ASC 605 to recognize product revenue upon delivery to the Distributor. During the three months and year ended December 31, 2017, product revenue is recognized upon delivery of the Lesinurad Products to the Distributors. The Company evaluated the creditworthiness of each of its Distributors to determine whether revenue can be recognized upon delivery, subject to satisfaction of the other requirements, or whether recognition was required to be delayed until receipt of payment. In order to conclude that the price is fixed or determinable, the Company must be able to (i) calculate its gross product revenue from the sales to Distributors and (ii) reasonably estimate its net product revenue. The Company calculated gross product revenue based on the wholesale acquisition cost that the Company charged its Distributors for ZURAMPIC and DUZALLO. The Company estimated its net product revenue by deducting from its gross product revenue (i) trade discounts and allowances, such as invoice discounts for prompt payment and distributor fees, (ii) estimated government and private payor rebates, chargebacks and discounts, such as Medicaid reimbursements, (iii) reserves for expected product returns and (iv) estimated costs of incentives offered to certain indirect customers including patients. These estimates could be adjusted based on actual results in the period such variances become known. Other The Company supplies linaclotide finished drug product, API and development materials for certain of its partners. The Company recognized revenue on linaclotide finished drug product, API and development materials when the material had passed all quality testing required for collaborator acceptance, delivery had occurred, title and risk of loss had transferred to the partner, the price was fixed or determinable, and collection was reasonably assured.
New Accounting Pronouncements	New Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (the “FASB”) or other standard setting bodies that are adopted by the Company as of the specified effective date. Except as set forth below, the Company did not adopt any new accounting pronouncements during the three and nine months ended September 30, 2018 and 2017 that had a material effect on its condensed consolidated financial statements. In May 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which supersedes the revenue recognition requirements in ASC 605, and most industry-specific guidance. The new standard requires that an entity recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. The update also requires 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. In April 2016, the FASB issued ASU No. 2016-10, Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing (“ASU 2016-10”), which clarifies certain aspects of identifying performance obligations and licensing implementation guidance. In May 2016, the FASB issued ASU No. 2016-12, Revenue from Contracts with Customers: Narrow-Scope Improvements and Practical Expedients (“ASU 2016-12”), related to disclosures of remaining performance obligations, as well as other amendments to guidance on collectability, non-cash consideration and the presentation of sales and other similar taxes collected from customers. The Company adopted these ASUs using the modified retrospective transition approach effective January 1, 2018. The adoption of these ASUs did not have a material impact on the Company’s financial position or results of operations; however, adoption did result in significant changes to the Company’s financial statement disclosures. In February 2016, the FASB issued ASU No. 2016-02, Leases (“ASU 2016-02”), which supersedes the lease accounting requirements in ASC Topic 840, Leases , and most industry-specific guidance with ASC Topic 842, Leases . ASU 2016-02 requires the identification of arrangements that should be accounted for as leases by lessees. In general, for lease arrangements exceeding a 12-month term, these arrangements must now be recognized as assets and liabilities on the balance sheet of the lessee. Under ASU 2016-02, a right-of-use asset and lease obligation will be recorded for all leases, whether operating or financing, while the income statement will reflect lease expense for operating leases and amortization and interest expense for financing leases. The balance sheet amount recorded for existing leases at the date of adoption of ASU 2016-02 must be calculated using the applicable incremental borrowing rate at the date of adoption. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. In July 2018, the FASB issued ASU No. 2018-10, Leases (Topic 842) (“ASU 2018-10”) , Codification Improvements and ASU No. 2018-11, Leases (Topic 842), Targeted Improvements (“ASU 2018-11”) , to provide additional guidance for the adoption of Topic 842 . ASU 2018-10 clarifies certain provisions and corrects unintended applications of the guidance, such as the rate implicit in a lease, impairment of the net investment in a lease, lessee reassessment of lease classifications, lessor reassessment of lease term and purchase options, variable payments that depend on an index or rate and certain transition adjustments. The amendments in ASU 2018-11 allow for an additional transition method, whereby at the adoption date the entity recognizes a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption, while the comparative period disclosures continue recognition under ASC Topic 840. Additionally, ASU 2018-11 includes a practical expedient for separating contract components for lessors . The Company is evaluating the potential impact that the adoption of ASU 2016-02, ASU 2018-10, and ASU 2018-11 may have on the Company’s financial position and results of operations. The Company’s analysis includes, but is not limited to, reviewing existing leases, reviewing other service agreements for embedded leases, establishing policies and procedures, assessing potential disclosures and evaluating the impact of adoption on the Company’s condensed consolidated financial statements. The Company anticipates adopting ASC Topic 842 using the additional transition method outlined in ASU 2018-11 as of January 1, 2019. In October 2016, the FASB issued ASU No. 2016-16, Accounting for Income Taxes: Intra-Entity Asset Transfers of Assets Other than Inventory (“ASU 2016-16”). ASU 2016-16 eliminates the ability to defer the tax expense related to intra-entity asset transfers other than Inventory. Under the new standard, entities should recognize the income tax consequences on an intra-entity transfer of an asset other than inventory when the transfer occurs. ASU 2016-16 is effective for fiscal periods beginning after December 15, 2018. Early adoption is permitted. The Company continues to evaluat e the potential impact that the adoption of ASU 2016-16 will have on the Company’s financial position or results of operations. The Company does not expect the adoption of ASU 2016-16 to have a material impact on the Company’s financial position or results of operations. In October 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230) Restricted Cash (“ASU 2016-18”), which requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and restricted cash or restricted cash equivalents. Therefore, amounts described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-18 is effective for fiscal years beginning after December 15, 2017, and interim periods within those years. The Company adopted this standard during the three months ended March 31, 2018. Adoption of this standard did not have a material impact on the Company’s financial position or results of operations. As a result of adopting ASU 2016-18, the Company adjusted the condensed consolidated statements of cash flows from previously reported amounts as follows: Nine Months Ended September 30, 2017 As previously reported Adjustments As adjusted Cash flows from Operating Activities: Net decrease (increase) in restricted cash related to lease obligations $ 1,190 $ (1,190) $ — Net cash flows used in operating activities (90,349) (1,190) (91,539) Net change in cash, cash equivalents, and restricted cash 108,636 (1,190) 107,446 Cash, cash equivalents, and restricted cash, beginning of period 54,004 8,247 62,251 Cash, cash equivalents, and restricted cash, end of period $ 162,640 $ 7,057 $ 169,697 In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business (“ASU 2017-01”), to clarify the definition of a business by adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions or disposals of assets versus businesses. ASU 2017-01 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company adopted this standard during the three months ended March 31, 2018. The adoption of this standard did not have a material impact on the Company’s financial position or results of operations. In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other (Topic 350) (“ASU 2017-04”) to simplify the accounting for goodwill impairment by removing Step 2 of the goodwill impairment test. ASU 2017-04 is effective for fiscal years beginning after December 15, 2019. Early adoption is permitted. The Company is evaluating the potential impact that the adoption of ASU 2017-04 may have on the Company’s financial position and results of operations. In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation (Topic 708) Scope of Modification Accounting (“ASU 2017-09”) which provides guidance that clarifies when changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. Adoption of ASU 2017-09 is required for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The Company adopted this standard during the three months ended March 31, 2018. The adoption of this standard did not have a material impact on the Company’s financial position and results of operations. In June 2018, the FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting (“ASU 2018-07”) . This ASU expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from non-employees, and as a result, the accounting for share-based payments to non-employees will be substantially aligned. ASU 2018-07 is effective for fiscal years beginning after December 15, 2-18, including interim periods within that fiscal year. Early adoption is permitted but not earlier than an entity’s adoption date of Topic 606. The Company is currently evaluating the potential impact that the adoption of ASU 2018-07 may have on the Company’s financial position and results of operations. In July 2018, the FASB issued ASU 2018-09, Codification Improvements “ (ASC 2018-09”). The amendments in ASU 2018-09 affect a wide variety of Topics in the FASB Codification and apply to all reporting entities within the scope of the affected accounting guidance. The Company has evaluated Compensation—Stock Compensation—Income Taxes , are the only provisions that currently apply to the Company. The amendments in Compensation—Stock Compensation—Income Taxes , clarify that an entity should recognize excess tax benefits related to stock compensation transactions in the period in which the amount of the deduction is determined. The amendments in In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework- Changes to the Disclosure Requirement for Fair Value Measurement (“ASU 2018-13”) which amends the disclosure requirements for fair value measurements. The amendments in ASU 2018-13 are effective for fiscal years beginning after December 15, 2019, with early adoption permitted. The Company is currently evaluating the potential impact that the adoption of ASU 2018-13 may have on the Company’s financial position and results of operations. In August 2018, the FASB issued ASU No. 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract (a consensus of the FASB Emerging Issues Task Force) (“ASU 2018-15)” which provides additional guidance on the accounting for costs of implementation activities performed in a cloud computing arrangement that is a service contract. The amendments in ASU 2018-15 are effective for fiscal years beginning after December 15, 2019, with early adoption permitted. The Company is currently evaluating the potential impact that the adoption of ASU 2018-15 may have on the Company’s financial position and results of operations.

Nature of Business (Tables)

Nature of Business (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Standards Update 2016-18
Table Text Blocks
Schedule of adjusted Statements of Consolidated Cash Flows from previously reported amount	Nine Months Ended September 30, 2017 As previously reported Adjustments As adjusted Cash flows from Operating Activities: Net decrease (increase) in restricted cash related to lease obligations $ 1,190 $ (1,190) $ — Net cash flows used in operating activities (90,349) (1,190) (91,539) Net change in cash, cash equivalents, and restricted cash 108,636 (1,190) 107,446 Cash, cash equivalents, and restricted cash, beginning of period 54,004 8,247 62,251 Cash, cash equivalents, and restricted cash, end of period $ 162,640 $ 7,057 $ 169,697

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Table Text Blocks
Schedule of potentially dilutive securities that have been excluded from computation of diluted weighted average shares outstanding	The following potentially dilutive securities have been excluded from the computation of diluted weighted average shares outstanding as their effect would be anti-dilutive (in thousands): Nine Months Ended September 30, 2018 2017 Options to purchase common stock Shares subject to repurchase Restricted stock units 3,238 2,205 Shares subject to issuance under Employee Stock Purchase Plan 59 74 Note hedge warrants 20,250 20,250 2022 Notes 20,250 20,250

Collaboration, License, Co-Pr_2

Collaboration, License, Co-Promotion and Other Commercial Agreements (Tables)	9 Months Ended
	Sep. 30, 2018
Table Text Blocks
Schedule of revenue attributable to transactions from collaboration and license arrangements	The following table provides amounts included in the Company’s condensed consolidated statements of operations as collaborative arrangements revenue and sale of API attributable to transactions from these arrangements (in thousands): Collaborative Arrangements Revenue Three Months Ended Nine Months Ended September 30, September 30, Collaborative Arrangements Revenue 2018 2017 2018 2017 Linaclotide Agreements: Allergan (North America) $ $ $ $ Allergan (Europe and other) AstraZeneca (China, Hong Kong and Macau) — — — 208 Co-Promotion and Other Agreements: Exact Sciences (Cologuard) (1) — — Allergan (VIBERZI) Other Total collaborative arrangements revenue $ $ $ $ Sale of API Linaclotide Agreements: Astellas (Japan) $ $ $ $ Other (2) — — Total sale of API $ $ $ $ (1) In August 2016, the Company terminated the Exact Sciences Co-Promotion Agreement for Cologuard. Under the terms of the agreement, the Company continued to receive royalty payments through July 2017. (2) During the three months ended September 30, 2018, the Company recorded approximately $0.8 million in revenue related to the sale of API to Allergan.
Allergan
Table Text Blocks
Schedule of revenue attributable to transactions from collaboration and license arrangements	The Company recognized collaborative arrangements revenue from the Allergan collaboration agreement for North America during the three and nine months ended September 30, 2018 and 2017 as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Collaborative arrangements revenue related to sales of LINZESS in the U.S. $ 52,261 $ 73,905 $ 182,675 $ 179,664 Royalty revenue 463 452 1,458 1,386 Other (1) — 1,677 — 1,677 Total collaborative arrangements revenue $ 52,724 $ 76,034 $ 184,133 $ 182,727 (1)
Schedule of amount recorded by the Company for share of net loss related to collaborative arrangement	The following table presents the amounts recorded by the Company for commercial efforts related to LINZESS in the U.S. in the three and nine months ended September 30, 2018 and 2017 (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Collaborative arrangements revenue related to sales of LINZESS in the U.S. (1)(2) $ 52,261 $ 73,905 $ 182,675 $ 179,664 Selling, general and administrative costs incurred by the Company (1) (10,915) (10,457) (33,556) (34,062) The Company’s share of net profit $ 41,346 $ 63,448 $ 149,119 $ 145,602 (1) Includes only collaborative arrangement revenue or selling, general and administrative costs attributable to the cost-sharing arrangement with Allergan for the three and nine months ended September 30, 2018 and 2017. (2) Certain of the unfavorable adjustments to the Company’s share of the LINZESS net profits were reduced or eliminated during the nine months ended September 30, 2017 in connection with the co-promotion activities under the Company’s agreement with Allergan to co-promote VIBERZI in the U.S., as described below in Agreement with Allergan for VIBERZI .

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Table Text Blocks
Schedule of assets and liabilities measured at fair value on a recurring basis	The following tables present the assets and liabilities the Company has measured at fair value on a recurring basis (in thousands): Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Other Significant Active Markets for Observable Unobservable Identical Assets Inputs Inputs September 30, 2018 (Level 1) (Level 2) (Level 3) Assets: Cash and cash equivalents: Money market funds $ 116,037 $ 116,037 $ — $ — Repurchase agreements 30,000 30,000 — — Available-for-sale securities: U.S. Treasury securities 6,740 6,740 — — U.S. government-sponsored securities 13,096 — 13,096 — Convertible Note Hedges 142,774 — — 142,774 Total assets measured at fair value $ 308,647 $ 152,777 $ 13,096 $ 142,774 Liabilities: Note Hedge Warrants $ 122,778 $ — $ — $ 122,778 Contingent Consideration 74 — — 74 Total liabilities measured at fair value $ 122,852 $ — $ — $ 122,852 Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Other Significant Active Markets for Observable Unobservable Identical Assets Inputs Inputs December 31, 2017 (Level 1) (Level 2) (Level 3) Assets: Cash and cash equivalents: Money market funds $ $ $ — $ — U.S. Treasury securities — — Repurchase agreements — — Available-for-sale securities: U.S. Treasury securities — — U.S. government-sponsored securities — — Convertible Note Hedges 108,188 — — 108,188 Total assets measured at fair value $ $ $ $ Liabilities: Note Hedge Warrants $ 92,188 $ — $ — $ 92,188 Contingent Consideration 31,258 — — 31,258 Total liabilities measured at fair value $ 123,446 $ — $ — $ 123,446
Schedule of assumptions used in fair market valuations	Nine Months Ended Year Ended September 30, December 31, 2018 2017 Convertible Note Hedge Convertible Note Hedge Note Hedges Warrants Note Hedges Warrants Risk-free interest rate (1) 2.9 % 2.9 % 2.1 % 2.2 % Time to maturity 3.7 4.4 4.5 5.0 Stock price (2) $ 18.46 $ 18.46 $ 14.99 $ 14.99 Strike price (3) $ 16.58 $ 21.50 $ 16.58 $ 21.50 Common stock volatility (4) 40.7 % 41.6 % 44.1 % 44.1 % Dividend yield — % — % — % — % (1) Based on U.S. Treasury yield curve, with terms commensurate with the terms of the Convertible Note Hedges and the Note Hedge Warrants. (2) The closing price of the Company’s Class A common stock on the last trading day of the quarter ended September 30, 2018 and December 31, 2017, respectively. (3) As per the respective agreements for the Convertible Note Hedges and Note Hedge Warrants. (4) Selected volatility based on historical volatility of the Company’s Class A common stock.
Schedule of the change in Level 3 convertible note derivatives	The following table reflects the change in the Company’s Level 3 convertible note derivatives from December 31, 2017 through September 30, 2018 (in thousands): Convertible Note Hedge Note Hedges Warrants Balance at December 31, 2017 $ 108,188 $ (92,188) Change in fair value, recorded as a component of gain (loss) on derivatives 34,586 (30,590) Balance at September 30, 2018 $ 142,774 $ (122,778)
Schedule of changes in contingent consideration payable	The following table reflects the change in the Company’s Level 3 contingent consideration payable from December 31, 2017 through September 30, 2018 (in thousands): Contingent Consideration Fair Value at December 31, 2017 31,258 Changes in fair value (31,045) Payments/transfers to accrued expenses and other current liabilities (139) Fair value at September 30, 2018 $ 74

Available-for-Sale Securities (

Available-for-Sale Securities (Tables)	9 Months Ended
	Sep. 30, 2018
Table Text Blocks
Schedule of summary of available-for-sale securities	The following tables summarize the available-for-sale securities held at September 30, 2018 and December 31, 2017 (in thousands): Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value September 30, 2018 U.S. Treasury securities $ 6,744 $ — $ (4) $ 6,740 U.S. government-sponsored securities 13,101 — (5) 13,096 Total $ 19,845 $ — $ (9) $ 19,836 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value December 31, 2017 U.S. Treasury securities $ 64,378 $ — $ (35) $ 64,343 U.S. government-sponsored securities 31,384 — (47) 31,337 Total $ 95,762 $ — $ (82) $ 95,680

Inventory (Tables)

Inventory (Tables)	9 Months Ended
	Sep. 30, 2018
Table Text Blocks
Schedule of Inventory	Inventory consisted of the following (in thousands): September 30, 2018 December 31, 2017 Finished Goods $ 76 $ 735 $ 76 $ 735

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2018
Table Text Blocks
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, 2018 December 31, 2017 Salaries $ 1,750 $ Accrued vacation 3,835 Accrued incentive compensation 12,342 Other employee benefits 2,602 Professional fees 2,681 Accrued interest 2,761 Workforce reduction charges 7,853 — Other 11,134 $ 44,958 $

Notes Payable (Tables)

Notes Payable (Tables)	9 Months Ended
	Sep. 30, 2018
Table Text Blocks
Schedule of redemption price as percentage of outstanding principal balance	Redemption Payment Dates Percentage From and including March 15, 2018 to and including March 14, 2019 108.00 % From and including March 15, 2019 to and including March 14, 2020 105.50 % From and including March 15, 2020 to and including March 14, 2021 102.75 % From and including March 15, 2021 and thereafter 100.00 %
Schedule of outstanding Convertible Note	The Company’s outstanding Convertible Note balances as of September 30, 2018 and December 31, 2017 consisted of the following (in thousands): September 30, 2018 December 31, 2017 Liability component: Principal $ 335,699 $ 335,699 Less: unamortized debt discount (69,080) (80,530) Less: unamortized debt issuance costs (5,264) (5,976) Net carrying amount $ 261,355 $ 249,193 Equity component $ 114,199 $ 114,199
Schedule of interest expense related to Convertible Notes	The following table sets forth total interest expense recognized related to the 2022 Notes during the three and nine months ended September 30, 2018 and 2017 (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Contractual interest expense $ 1,889 $ 1,888 $ 5,665 $ 5,665 Amortization of debt issuance costs 249 206 712 590 Amortization of debt discount 3,900 3,574 11,450 10,492 Total interest expense $ 6,038 $ 5,668 $ 17,827 $ 16,747

Employee Stock Benefit Plans (T

Employee Stock Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2018
Table Text Blocks
Share-based compensation expense reflected in the condensed consolidated statements of operations	The following table summarizes share-based compensation expense reflected in the condensed consolidated statements of operations for the three and nine months ended September 30, 2018 and 2017 (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Research and development $ $ $ $ Selling, general and administrative Restructuring expenses — — $ $ $ $
Summary of stock option activity	Weighted- Average Number of Shares Fair Value (in thousands) Outstanding at December 31, 2017 21,086 $ 12.90 Granted 3,168 14.93 Exercised (2,430) 10.32 Cancelled (964) 14.93 Outstanding at September 30, 2018 20,860 $ 13.42
Schedule of weighted-average assumptions used to estimate the fair value of the stock options using the Black-Scholes option-pricing model	Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Expected volatility 44.1 % 45.2 % 43.6 % 46.0 % Expected term (in years) 6.0 6.0 Risk-free interest rate 2.8 % % 2.7 % % Expected dividend yield — % — % — % — %
Summary of RSU activity	Weighted- Average Number Grant Date of Shares Fair Value Unvested as of December 31, 2017 2,277 $ 15.08 Granted 2,017 $ 15.64 Vested (594) $ 15.07 Forfeited (462) $ 15.14 Unvested as of September 30, 2018 3,238 $ 15.42

Workforce Reduction (Tables)

Workforce Reduction (Tables)	9 Months Ended
	Sep. 30, 2018
Table Text Blocks
Schedule of charges made to the reduction in field-based workforce	The following table summarizes the accrued liabilities activity recorded in connection with the reduction in workforce for the nine months ended September 30, 2018 (in thousands): Amounts Accrued at Charges Amount Paid Adjustments September 30, 2018 Employee severance, benefits and related costs January 2018 Reduction $ 2,228 $ (2,184) $ (13) $ 31 June 2018 Reduction 3,877 (1,727) 14 2,164 August 2018 Reduction 5,212 (553) 11 4,670 Total $ 11,317 $ (4,464) $ 12 $ 6,865 Contract related costs August 2018 Reduction $ 988 $ — $ — $ 988 Total $ 988 $ — $ — $ 988

Nature of Business - Business S

Nature of Business - Business Separation (Details)	May 04, 2018company
Overview
Number of independent publicly traded companies resulting from authorized separation	2

Nature of Business - Co-promoti

Nature of Business - Co-promotion Agreements (Details)	9 Months Ended
	Sep. 30, 2018
Collaborative arrangement, co-promotion agreements | Allergan
Collaboration agreements
Treatment of ulcerative	2 years

Nature of Business - Notes Paya

Nature of Business - Notes Payable (Details) - Notes Payable - USD ($) $ in Millions	Jan. 05, 2017	Sep. 30, 2018	Sep. 23, 2016	Jan. 31, 2013
Notes Payable
Net proceed received	$ 11.2
Fees and expenses	$ 3.7
8.375% Notes due 2026
Notes Payable
Aggregate principal amount of notes issued			$ 150
Annual interest rate of notes (as a percent)		8.375%	8.375%
11% PhaRMA Notes
Notes Payable
Aggregate principal amount of notes issued				$ 175
Annual interest rate of notes (as a percent)	11.00%			11.00%
Debt redeemed	$ 135.1

Nature of Business - Revenue Re

Nature of Business - Revenue Recognition - Cumulative Adjustment (Details) $ in Millions	Dec. 31, 2017USD ($)
Accounting Standards Update 2014-09
Revenue Recognition
Cumulative effect of adoption of accounting standard	$ 0

Nature of Business - Revenue _2

Nature of Business - Revenue Recognition - Practical Expedients (Details)	9 Months Ended
	Sep. 30, 2018
Practical expedients
Practical Expedient, Incremental Cost	true
Practical Expedient, Use of Transaction Price	true
Practical Expedient, Nonrestatement of Modified Contract	true

Nature of Business - Statements

Nature of Business - Statements of Consolidated Cash Flows from Previously Reported Amounts (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
New Accounting Pronouncements
Net cash flows used in operating activities	$ (80,155)	$ (91,539)
Net change in cash, cash equivalents, and restricted cash	16,446	107,446
Cash, cash equivalents and restricted cash, beginning of period	132,792	62,251
Cash, cash equivalents and restricted cash, end of period	$ 149,238	169,697
As previously reported
New Accounting Pronouncements
Net decrease (increase) in restricted cash related to lease obligations		1,190
Net cash flows used in operating activities		(90,349)
Net change in cash, cash equivalents, and restricted cash		108,636
Cash, cash equivalents and restricted cash, beginning of period		54,004
Cash, cash equivalents and restricted cash, end of period		162,640
Adjustments | Accounting Standards Update 2016-18
New Accounting Pronouncements
Net decrease (increase) in restricted cash related to lease obligations		(1,190)
Net cash flows used in operating activities		(1,190)
Net change in cash, cash equivalents, and restricted cash		(1,190)
Cash, cash equivalents and restricted cash, beginning of period		8,247
Cash, cash equivalents and restricted cash, end of period		$ 7,057

Net Loss Per Share - Notes Paya

Net Loss Per Share - Notes Payable (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Jun. 30, 2015
Convertible Senior Notes | 2.25% Convertible Senior Notes due in 2022
Notes Payable
Aggregate principal amount of notes issued	$ 335,699	$ 335,699	$ 335,700

Net Loss Per Share - Note Hedge

Net Loss Per Share - Note Hedge Warrants (Details)	Sep. 30, 2018shares
Note hedge warrants
Note Hedge Warrants
Shares into which warrants may be converted (in shares)	20,249,665

Net Loss Per Share - Potentiall

Net Loss Per Share - Potentially Dilutive Securities (Details) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	64,754	64,192
Options to purchase common stock
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	20,860	21,320
Shares subject to repurchase
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	97	93
Restricted stock units
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	3,238	2,205
Shares subject to issuance under Employee Stock Purchase Plan
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	59	74
Note hedge warrants
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	20,250	20,250
Convertible debt securities
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	20,250	20,250

Goodwill and Intangible Assets

Goodwill and Intangible Assets - General Information (Details) - USD ($) $ in Thousands	Jun. 02, 2016	Dec. 31, 2017
Lesinurad transaction
Business Combinations
Payment for acquisition of Lesinurad license	$ 100,000
Contingent consideration	$ 67,885
Licensing agreement | AstraZeneca
Business Combinations
Royalty percentage per agreement	single digits
Milestone payment made		$ 15,000
Licensing agreement | Post-marketing Activities
Business Combinations
Period for reimbursement amount of development activities (in years)	10 years
Licensing agreement | Post-marketing Activities | Maximum
Business Combinations
Reimbursement obligation	$ 100,000

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Lesinurad License Agreement Termination - Reduced Projected Revenue and Net Cash Flow Assumptions (Details) - USD ($) $ in Thousands	Aug. 02, 2018	Sep. 30, 2018	Sep. 30, 2018
Goodwill and Intangible Assets
Impairment of intangible assets		$ 151,794	$ 151,794
Developed Technology
Goodwill and Intangible Assets
Impairment of intangible assets		$ 151,800
Licensing agreement | AstraZeneca
Goodwill and Intangible Assets
Effective period from notice	180 days

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Intangible Asset and Goodwill Impairment (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)
Impairment of Long-Lived Assets
Impairment of goodwill	$ 0

Collaboration, License, Co-Pr_3

Collaboration, License, Co-Promotion and Other Commercial Agreements - Summary (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Revenue	$ 65,686	$ 86,825	$ 215,947	$ 204,068
Collaborative arrangements
Revenues:
Revenue	54,194	76,652	188,487	187,156
Active pharmaceutical ingredient
Revenues:
Revenue	10,257	9,491	24,494	15,476
Collaborative arrangement, other agreements | Collaborative arrangements
Revenues:
Revenue	465	78	1,273	81
Allergan | Active pharmaceutical ingredient
Revenues:
Revenue	756		756
Allergan | Collaborative arrangement, collaboration and license agreements | North America | Collaborative arrangements
Revenues:
Revenue	52,724	76,034	184,133	182,727
Allergan | Collaborative arrangement, collaboration and license agreements | Europe and Other | Collaborative arrangements
Revenues:
Revenue	255	131	831	349
Allergan | Collaborative arrangement, co-promotion agreements | Collaborative arrangements
Revenues:
Revenue	750	301	2,250	1,247
AstraZeneca | Collaborative arrangement | China, Hong Kong, and Macau | Collaborative arrangements
Revenues:
Revenue		0		208
Exact Sciences | Collaborative arrangement, co-promotion agreements | Collaborative arrangements
Revenues:
Revenue		108		2,544
Astellas Pharma Inc. | Japan | Active pharmaceutical ingredient
Revenues:
Revenue	$ 9,501	$ 9,491	$ 23,738	$ 15,476

Collaboration, License, Co-Pr_4

Collaboration, License, Co-Promotion and Other Commercial Agreements - Accounts Receivable (Details) - Collaborative arrangements and active pharmaceutical ingredient $ in Millions	Sep. 30, 2018USD ($)
Accounts receivable, net
Accounts receivable, net and related party accounts receivable, net, net of related party accounts payable	$ 64.7
Accounts payable from related party	$ 6.6

Collaboration, License, Co-Pr_5

Collaboration, License, Co-Promotion and Other Commercial Agreements - North America - General Information (Details) - North America - Collaborative arrangement $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)itempayment	Sep. 30, 2017USD ($)
Sales milestones
Collaboration, License and Co-Promotion Agreements
Sales-related milestone if certain conditions are met	$ 100		$ 100
Allergan
Collaboration, License and Co-Promotion Agreements
Equity investment in the entity's capital stock			25
Net cost sharing offset or incremental expense related to research and development expense	2.5	$ 0.5	2.5	$ 0.5
Cost sharing amount, reduction to research and development	5.8		$ 5.8
Remaining commercial-period performance obligations | item			3
Allergan | Development milestones
Collaboration, License and Co-Promotion Agreements
Cumulative license fees and development milestone payments received	$ 205		$ 205
Number of milestone payments received | payment			6
Allergan | Sales milestones
Collaboration, License and Co-Promotion Agreements
Percentage of net profit from commercialization (as a percent)			50.00%
Percentage of net loss from commercialization (as a percent)			50.00%

Collaboration, License, Co-Pr_6

Collaboration, License, Co-Promotion and Other Commercial Agreements - North America - Change in Accounting Estimate (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Change in accounting estimate
Revenue	$ 65,686	$ 86,825	$ 215,947	$ 204,068
Collaborative arrangements
Change in accounting estimate
Revenue	54,194	76,652	188,487	187,156
Collaborative arrangements | Collaborative arrangement, collaboration and license agreements | Allergan | North America
Change in accounting estimate
Revenue	52,724	76,034	184,133	182,727
Collaborative arrangements, LINZESS | Collaborative arrangement, collaboration and license agreements | Allergan | North America
Change in accounting estimate
Revenue	52,261	$ 73,905	$ 182,675	$ 179,664
Sales Returns and Allowances | Collaborative arrangements, LINZESS | Collaborative arrangement, collaboration and license agreements | Allergan | North America
Change in accounting estimate
Revenue	(29,700)
Sales Returns and Allowances | Allergan
Change in accounting estimate
Revenue	$ (59,300)

Collaboration, License, Co-Pr_7

Collaboration, License, Co-Promotion and Other Commercial Agreements - North America - Collaborative Arrangements Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Revenue	$ 65,686	$ 86,825	$ 215,947	$ 204,068
Collaborative arrangements
Revenues:
Revenue	54,194	76,652	188,487	187,156
Allergan | Collaborative arrangement, collaboration and license agreements | North America | Collaborative arrangements
Revenues:
Revenue	52,724	76,034	184,133	182,727
Allergan | Collaborative arrangement, collaboration and license agreements | North America | Collaborative arrangements, LINZESS
Revenues:
Revenue	52,261	73,905	182,675	179,664
Allergan | Collaborative arrangement, collaboration and license agreements | North America | Royalty
Revenues:
Revenue	$ 463	452	$ 1,458	1,386
Allergan | Collaborative arrangement, collaboration and license agreements | North America | Other
Revenues:
Revenue		$ 1,677		$ 1,677

Collaboration, License, Co-Pr_8

Collaboration, License, Co-Promotion and Other Commercial Agreements - North America - Commercial Efforts (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Collaboration, License and Co-Promotion Agreements
Revenue	$ 65,686	$ 86,825	$ 215,947	$ 204,068
Collaborative arrangements
Collaboration, License and Co-Promotion Agreements
Revenue	54,194	76,652	188,487	187,156
Collaborative arrangements | Allergan | North America | Collaborative arrangement, collaboration and license agreements
Collaboration, License and Co-Promotion Agreements
Revenue	52,724	76,034	184,133	182,727
Collaborative arrangements, LINZESS | Allergan | North America | Collaborative arrangement, collaboration and license agreements
Collaboration, License and Co-Promotion Agreements
Revenue	52,261	73,905	182,675	179,664
Collaborative arrangements, LINZESS | Allergan | U.S. | Collaborative arrangement, collaboration and license agreements
Collaboration, License and Co-Promotion Agreements
Revenue	52,261	73,905	182,675	179,664
Selling, general and administrative costs incurred by the Company	(10,915)	(10,457)	(33,556)	(34,062)
The Company's share of net profit (loss)	$ 41,346	$ 63,448	$ 149,119	$ 145,602

Collaboration, License, Co-Pr_9

Collaboration, License, Co-Promotion and Other Commercial Agreements - North America - Royalty Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Revenue	$ 65,686	$ 86,825	$ 215,947	$ 204,068
Collaborative arrangements
Revenues:
Revenue	54,194	76,652	188,487	187,156
Collaborative arrangements | Collaborative arrangement, collaboration and license agreements | North America | Allergan
Revenues:
Revenue	52,724	76,034	184,133	182,727
Royalty | Collaborative arrangement, collaboration and license agreements | North America | Allergan
Revenues:
Revenue	463	452	1,458	1,386
Royalty | Collaborative arrangement, collaboration and license agreements | Canada and Mexico | Allergan
Revenues:
Revenue	$ 500	$ 500	$ 1,500	$ 1,400

Collaboration, License, Co-P_10

Collaboration, License, Co-Promotion and Other Commercial Agreements - European and Other Territories (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Oct. 31, 2015	Sep. 30, 2012
Collaboration, License and Co-Promotion Agreements
Revenue	$ 65,686	$ 86,825	$ 215,947	$ 204,068
Allergan | Licensing agreement
Collaboration, License and Co-Promotion Agreements
Royalty percentage, five years following the first commercial sale			upper-single digits
Annual royalty			5 years
Royalty percentage, thereafter			low-double digits
Royalty percentage, expanded territory			lower-single digits
Allergan | Europe | Licensing agreement
Collaboration, License and Co-Promotion Agreements
Remaining milestone payment due upon the amendment to the license agreement					$ 42,500
Collaborative arrangements
Collaboration, License and Co-Promotion Agreements
Revenue	54,194	76,652	$ 188,487	187,156
Collaborative arrangements | Allergan | Europe | Licensing agreement
Collaboration, License and Co-Promotion Agreements
Revenue remaining performance obligation						$ 0
Royalty | Allergan | Europe | Licensing agreement
Collaboration, License and Co-Promotion Agreements
Revenue	$ 200	$ 300	$ 800	$ 300

Collaboration, License, Co-P_11

Collaboration, License, Co-Promotion and Other Commercial Agreements - Japan (Details) $ in Thousands	1 Months Ended				3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2016USD ($)	Feb. 29, 2016USD ($)	Nov. 30, 2014USD ($)	Nov. 30, 2009USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)payment
Collaboration, License and Co-Promotion Agreements
Revenue					$ 65,686	$ 86,825	$ 215,947	$ 204,068
Deferred revenue					13,521		13,521
Active pharmaceutical ingredient
Collaboration, License and Co-Promotion Agreements
Revenue					10,257	9,491	24,494	15,476
Astellas Pharma Inc. | Japan
Collaboration, License and Co-Promotion Agreements
Up-front fee received				$ 30,000
Astellas Pharma Inc. | Japan | Active pharmaceutical ingredient
Collaboration, License and Co-Promotion Agreements
Revenue					9,501	$ 9,491	23,738	$ 15,476
Deferred revenue					$ 13,500		$ 13,500
Revenue remaining performance obligation	$ 0								$ 0
Astellas Pharma Inc. | Japan | Additional development milestones
Collaboration, License and Co-Promotion Agreements
Number of milestone payments | payment									3
Total milestone payments to be received									$ 45,000
Astellas Pharma Inc. | Japan | Phase 3 milestones
Collaboration, License and Co-Promotion Agreements
Milestone payment to be received by company upon milestone achievement			$ 15,000
Astellas Pharma Inc. | Japan | Japanese NDA equivalent filing milestone
Collaboration, License and Co-Promotion Agreements
Milestone payment to be received by company upon milestone achievement		$ 15,000
Astellas Pharma Inc. | Japan | Approval of Japanese NDA equivalent filing milestone
Collaboration, License and Co-Promotion Agreements
Milestone payment to be received by company upon milestone achievement	$ 15,000

Collaboration, License, Co-P_12

Collaboration, License, Co-Promotion and Other Commercial Agreements - China, Hong Kong and Macau (Details) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Aug. 31, 2014USD ($)	Oct. 31, 2012USD ($)	Sep. 30, 2018USD ($)item	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)item	Sep. 30, 2017USD ($)
Collaboration, License and Co-Promotion Agreements
Revenue			$ 65,686	$ 86,825	$ 215,947	$ 204,068
Collaborative arrangements
Collaboration, License and Co-Promotion Agreements
Revenue			$ 54,194	76,652	$ 188,487	187,156
AstraZeneca | Collaborative arrangement | China, Hong Kong, and Macau
Collaboration, License and Co-Promotion Agreements
Prior notice period to terminate the agreement		180 days
Up-front fee received		$ 25,000
Additional budget for activities supporting the development of linaclotide	$ 14,000
Total amount of non-contingent arrangement consideration		34,000
Amount of arrangement consideration for clinical trial material supply services and research, development and regulatory activities		$ 9,000
Percentage of costs of clinical trial material supply services and research, development and regulatory activities allocated		55.00%
Arrangement Consideration allocated to the License Deliverable		$ 29,700
Arrangement Consideration allocated to the R&D Services		1,800
Arrangement Consideration allocated to the JDC services		100
Arrangement Consideration allocated to the clinical trial material supply services		300
Arrangement Consideration allocated to Co-Promotion Deliverable		2,100
Net cost sharing offset or incremental expense related to research and development expense				200		200
Number of performance obligations, total | item			6		6
Number of performance obligations, fulfilled | item			2		2
Number of performance obligations, ongoing | item			4		4
AstraZeneca | Collaborative arrangement | China, Hong Kong, and Macau | Collaborative arrangements
Collaboration, License and Co-Promotion Agreements
Revenue				$ 0		$ 208
Allocable to the performance obligations on a relative standalone selling price basis	$ 34,000
AstraZeneca | Collaborative arrangement | China, Hong Kong, and Macau | Commercialization milestone
Collaboration, License and Co-Promotion Agreements
Milestone payment to be received by company upon milestone achievement		$ 125,000
Percentage of net profit from commercialization (as a percent)		55.00%
Percentage of net loss from commercialization (as a percent)		55.00%

Collaboration, License, Co-P_13

Collaboration, License, Co-Promotion and Other Commercial Agreements - Co-Promotion Agreements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Collaboration, License and Co-Promotion Agreements
Revenue	$ 65,686	$ 86,825	$ 215,947	$ 204,068
Collaborative arrangements
Collaboration, License and Co-Promotion Agreements
Revenue	54,194	76,652	188,487	187,156
Exact Sciences | Collaborative arrangement, co-promotion agreements | Collaborative arrangements
Collaboration, License and Co-Promotion Agreements
Revenue		108		2,544
Allergan | Collaborative arrangement, co-promotion agreements
Collaboration, License and Co-Promotion Agreements
Milestone payment to be received by company upon milestone achievement			7,500
Collaborative arrangement compensated amount			$ 3,000
Treatment of ulcerative			2 years
Allergan | Collaborative arrangement, co-promotion agreements | Collaborative arrangements
Collaboration, License and Co-Promotion Agreements
Revenue	$ 750	301	$ 2,250	1,247
Net profit share adjustment		2,400		5,200
Collaborative arrangement compensated amount		$ 300		$ 1,200
Sales milestones | Allergan | Collaborative arrangement, co-promotion agreements
Collaboration, License and Co-Promotion Agreements
Milestone payment to be received by company upon milestone achievement			$ 3,000

Collaboration, License, Co-P_14

Collaboration, License, Co-Promotion and Other Commercial Agreements - Other Collaborations and License Agreements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Collaboration, License and Co-Promotion Agreements
Research and development	$ 46,794	$ 37,065	$ 122,231	$ 108,111
Collaborative arrangement, other agreements
Collaboration, License and Co-Promotion Agreements
Research and development			5,000	$ 0
Collaborative arrangement, other agreements, agreement one | Development milestones
Collaboration, License and Co-Promotion Agreements
Contingent milestone payable			7,500
Collaborative arrangement, other agreements, agreement one | Regulatory milestones
Collaboration, License and Co-Promotion Agreements
Contingent milestone payable			18,000
Milestone payment made			$ 0

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - General Information (Details)	Sep. 30, 2018
Fair Value of Financial Instruments
Threshold percentage of collateralized value (as a percent)	102.00%

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Assets:
Available-for-sale securities	$ 19,836	$ 95,680
Liabilities:
Derivative liability, type	us-gaap:WarrantMember	us-gaap:WarrantMember
U.S. Treasury securities
Assets:
Available-for-sale securities	$ 6,740	$ 64,343
U.S. government-sponsored securities
Assets:
Available-for-sale securities	13,096	31,337
Recurring basis
Assets:
Convertible note hedges	142,774	108,188
Total assets measured at fair value	308,647	330,169
Liabilities:
Note hedge warrants	122,778	92,188
Contingent consideration	74	31,258
Total liabilities measured at fair value	122,852	123,446
Recurring basis | U.S. Treasury securities
Assets:
Available-for-sale securities	6,740	64,343
Recurring basis | U.S. government-sponsored securities
Assets:
Available-for-sale securities	13,096	31,336
Recurring basis | Money market funds
Assets:
Cash and cash equivalents	116,037	44,311
Recurring basis | U.S. Treasury securities
Assets:
Cash and cash equivalents		11,991
Recurring basis | Repurchase agreements
Assets:
Cash and cash equivalents	30,000	70,000
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Total assets measured at fair value	152,777	190,645
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury securities
Assets:
Available-for-sale securities	6,740	64,343
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Assets:
Cash and cash equivalents	116,037	44,311
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury securities
Assets:
Cash and cash equivalents		11,991
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Repurchase agreements
Assets:
Cash and cash equivalents	30,000	70,000
Recurring basis | Significant Other Observable Inputs (Level 2)
Assets:
Total assets measured at fair value	13,096	31,336
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. government-sponsored securities
Assets:
Available-for-sale securities	13,096	31,336
Recurring basis | Significant Unobservable Inputs (Level 3)
Assets:
Convertible note hedges	142,774	108,188
Total assets measured at fair value	142,774	108,188
Liabilities:
Note hedge warrants	122,778	92,188
Contingent consideration	74	31,258
Total liabilities measured at fair value	$ 122,852	$ 123,446

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Transfers Between Fair Value Measurement Levels (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Fair value transfers
Fair value transfer between measurement levels	$ 0	$ 0	$ 0	$ 0

Fair Value of Financial Instr_6

Fair Value of Financial Instruments - Assumptions - Convertible Note Hedges (Details)		Sep. 30, 2018Y$ / shares	Dec. 31, 2017Y$ / shares
Fair Value of Financial Instruments
Derivative asset, valuation technique		us-gaap:ValuationTechniqueOptionPricingModelMember	us-gaap:ValuationTechniqueOptionPricingModelMember
Measurement Input, Risk Free Interest Rate
Fair Value of Financial Instruments
Derivative asset, measurement input	[1]	0.029	0.021
Measurement Input, Expected Term
Fair Value of Financial Instruments
Derivative asset, measurement input | Y		3.7	4.5
Measurement Input, Share Price
Fair Value of Financial Instruments
Derivative asset, measurement input	[2]	18.46	14.99
Measurement Input, Exercise Price
Fair Value of Financial Instruments
Derivative asset, measurement input	[3]	16.58	16.58
Measurement Input, Price Volatility
Fair Value of Financial Instruments
Derivative asset, measurement input	[4]	0.407	0.441
Measurement Input, Expected Dividend Rate
Fair Value of Financial Instruments
Derivative asset, measurement input		0	0
[1]	Based on U.S. Treasury yield curve, with terms commensurate with the terms of the Convertible Note Hedges and the Note Hedge Warrants.
[2]	The closing price of the Company’s Class A common stock on the last trading day of the quarter ended September 30, 2018 and December 31, 2017, respectively.
[3]	As per the respective agreements for the Convertible Note Hedges and Note Hedge Warrants.
[4]	Selected volatility based on historical volatility of the Company’s Class A common stock.

Fair Value of Financial Instr_7

Fair Value of Financial Instruments - Assumptions - Note Hedge Warrants (Details)		Sep. 30, 2018Y$ / shares	Dec. 31, 2017Y$ / shares
Fair Value of Financial Instruments
Derivative liability, valuation technique		us-gaap:ValuationTechniqueOptionPricingModelMember	us-gaap:ValuationTechniqueOptionPricingModelMember
Measurement Input, Risk Free Interest Rate
Fair Value of Financial Instruments
Derivative liability, measurement input	[1]	0.029	0.022
Measurement Input, Expected Term
Fair Value of Financial Instruments
Derivative liability, measurement input | Y		4.4	5
Measurement Input, Share Price
Fair Value of Financial Instruments
Derivative liability, measurement input	[2]	18.46	14.99
Measurement Input, Exercise Price
Fair Value of Financial Instruments
Derivative liability, measurement input	[3]	21.50	21.50
Measurement Input, Price Volatility
Fair Value of Financial Instruments
Derivative liability, measurement input	[4]	0.416	0.441
Measurement Input, Expected Dividend Rate
Fair Value of Financial Instruments
Derivative liability, measurement input		0	0
[1]	Based on U.S. Treasury yield curve, with terms commensurate with the terms of the Convertible Note Hedges and the Note Hedge Warrants.
[2]	The closing price of the Company’s Class A common stock on the last trading day of the quarter ended September 30, 2018 and December 31, 2017, respectively.
[3]	As per the respective agreements for the Convertible Note Hedges and Note Hedge Warrants.
[4]	Selected volatility based on historical volatility of the Company’s Class A common stock.

Fair Value of Financial Instr_8

Fair Value of Financial Instruments - Change in Level 3 - Convertible Note Hedges (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Change in Level 3 Assets
Balance at beginning of period	$ 108,188
Change in fair value, recorded as a component of gain (loss) on derivatives	34,586
Balance at end of period	$ 142,774

Fair Value of Financial Instr_9

Fair Value of Financial Instruments - Change in Level 3 - Note Hedge Warrants (Details) - Warrants $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Change in Level 3 Liabilities
Balance at beginning of period	$ (92,188)
Change in fair value, recorded as a component of gain (loss) on derivatives	(30,590)
Balance at end of period	$ (122,778)

Fair Value of Financial Inst_10

Fair Value of Financial Instruments - Contingent Consideration - Liability Recorded (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jun. 02, 2016
Contingent Consideration
Non-cash change in fair value of contingent consideration	$ (33,519)	$ (628)	$ (31,045)	$ 7,919
Lesinurad transaction
Contingent Consideration
Estimated fair value of contingent acquisition consideration payable	100		$ 100		$ 67,900
Non-cash change in fair value of contingent consideration	$ 33,500

Fair Value of Financial Inst_11

Fair Value of Financial Instruments - Change in Level 3 - Contingent Consideration (Details) - Business Combination, Contingent Consideration, Liability $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Change in Level 3 Liabilities
Balance at beginning of period	$ 31,258
Change in fair value	(31,045)
Payments/transfers to accrued expenses and other current liabilities	(139)
Balance at end of period	$ 74

Fair Value of Financial Inst_12

Fair Value of Financial Instruments - Notes Payable (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 23, 2016	Jun. 30, 2015
Notes Payable | 8.375% Notes due 2026
Fair value disclosures
Annual interest rate of notes (as a percent)	8.375%		8.375%
Aggregate principal amount of notes issued in private placement			$ 150,000
Notes Payable | 8.375% Notes due 2026 | Significant Unobservable Inputs (Level 3)
Fair value disclosures
Aggregate principal amount of notes issued in private placement			$ 150,000
Estimated fair value	$ 151,900	$ 152,500
Convertible Senior Notes | 2.25% Convertible Senior Notes due in 2022
Fair value disclosures
Annual interest rate of notes (as a percent)	2.25%			2.25%
Aggregate principal amount of notes issued in private placement	$ 335,699	335,699		$ 335,700
Convertible Senior Notes | 2.25% Convertible Senior Notes due in 2022 | Significant Other Observable Inputs (Level 2)
Fair value disclosures
Estimated fair value	$ 433,700	$ 392,800

Fair Value of Financial Inst_13

Fair Value of Financial Instruments - Nonrecurring Fair Value Measurements - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Impairment of Intangible Assets (Excluding Goodwill) [Abstract]
Impairment of finite-lived intangible assets	$ 151,794	$ 151,794

Available-for-Sale Securities -

Available-for-Sale Securities - Tabular Disclosure (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Available-for-Sale Securities
Amortized Cost	$ 19,845	$ 95,762
Gross Unrealized Losses	(9)	(82)
Fair Value	19,836	95,680
U.S. Treasury securities
Available-for-Sale Securities
Amortized Cost	6,744	64,378
Gross Unrealized Losses	(4)	(35)
Fair Value	6,740	64,343
U.S. government-sponsored securities
Available-for-Sale Securities
Amortized Cost	13,101	31,384
Gross Unrealized Losses	(5)	(47)
Fair Value	$ 13,096	$ 31,337

Available-for-Sale Securities_2

Available-for-Sale Securities - Contractual Maturities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Available-for-Sale Securities
Contractual maturities, one year or less	$ 19,836
Fair Value	$ 19,836	$ 95,680

Available-for-Sale Securities_3

Available-for-Sale Securities - Unrealized Loss Position (Details) $ in Millions	Sep. 30, 2018USD ($)security	Dec. 31, 2017USD ($)security
Available-for-Sale Securities
Number of investments classified as available-for-sale securities in an unrealized loss position, twelve months or less	7	29
Number of investments classified as available-for-sale securities in an unrealized loss position, more than twelve months	0	0
Aggregate fair value of securities none of which had been in an unrealized loss position for more than twelve months | $	$ 19.8	$ 95.7

Available-for-Sale Securities_4

Available-for-Sale Securities - Other-than-temporary Impairment (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Available-for-Sale Securities
Other-than-temporary impairments	$ 0

Available-for-Sale Securities_5

Available-for-Sale Securities - Sales (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Available-for-Sale Securities
Sales of available-for-sale securities	$ 0	$ 0	$ 0	$ 0

Inventory - Tabular Disclosure

Inventory - Tabular Disclosure (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Inventory
Finished Goods	$ 76	$ 735
Total	$ 76	$ 735

Inventory - General Information

Inventory - General Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Inventory
Write-down of inventory	$ 0	$ 0	$ 0	$ 0

Inventory - Purchase Commitment

Inventory - Purchase Commitments (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Lesinurad Products
Purchase commitments
Write-down of commercial supply and inventory to net realizable value and loss on non-cancellable purchase commitments	$ 0.6	$ 2.5
Linaclotide Products
Purchase commitments
Write-down of commercial supply and inventory to net realizable value and settlement on non-cancellable purchase commitments	$ 2.5	$ 2.5

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Tabular Disclosure (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accrued Expenses
Salaries	$ 1,750	$ 4,566
Accrued vacation	3,835	4,672
Accrued incentive compensation	12,342	13,403
Other employee benefits	2,602	1,305
Professional fees	2,681	1,261
Accrued interest	2,761	873
Workforce reduction charges	7,853
Other	11,134	12,157
Total accrued expenses and other current liabilities	$ 44,958	$ 38,237

Accrued Expenses and Other Cu_4

Accrued Expenses and Other Current Liabilities - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Accrued Expenses
Other accrued expenses	$ 11,134	$ 11,134	$ 12,157
Activities associated with the Company’s intent to separate into two independent publicly traded companies	2,100	2,100
Linaclotide Products
Accrued Expenses
Accrual for non-cancellable purchase commitments	2,500	2,500	3,400
Write-down of commercial supply and inventory to net realizable value and settlement on non-cancellable purchase commitments	2,500	2,500
Lesinurad Products
Accrued Expenses
Write-down of excess non-cancellable sample purchase commitments	$ 1,400	$ 1,400
Commercial and Sample Supply Commitments
Accrued Expenses
Accrual for non-cancellable purchase commitments			1,300
Other accrued expenses, finished goods inventory			$ 200

Notes Payable - 8.375% Notes du

Notes Payable - 8.375% Notes due 2026 - General Information (Details) - 8.375% Notes due 2026 - Notes Payable - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 23, 2016
Notes Payable
Aggregate principal amount of notes issued		$ 150
Annual interest rate of notes (as a percent)	8.375%	8.375%
Debt issuance costs capitalized		$ 0.5
Percentage of net sales to determine quarterly payments (as a percent)	7.50%
Amount of principal expected to be paid within twelve months	$ 39.2

Notes Payable - 8.375% Notes _2

Notes Payable - 8.375% Notes due 2026 - Redemption Percentage (Details) - 8.375% Notes due 2026 - Notes Payable	9 Months Ended
	Sep. 30, 2018
From and including March 15, 2018 to and including March 14, 2019
Notes Payable
Payment start date	Mar. 15, 2018
Payment end date	Mar. 14, 2019
Redemption Percentage	108.00%
From and including March 15, 2019 to and including March 14, 2020
Notes Payable
Payment start date	Mar. 15, 2019
Payment end date	Mar. 14, 2020
Redemption Percentage	105.50%
From and including March 15, 2020 to and including March 14, 2021
Notes Payable
Payment start date	Mar. 15, 2020
Payment end date	Mar. 14, 2021
Redemption Percentage	102.75%
From and including March 15, 2021 and thereafter
Notes Payable
Payment start date	Mar. 15, 2021
Redemption Percentage	100.00%

Notes Payable - 2.25% Convertib

Notes Payable - 2.25% Convertible Senior Notes due 2022 - General Information (Details)	1 Months Ended	9 Months Ended
	Jun. 30, 2015USD ($)D$ / sharesshares	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Notes Payable
Net proceed received			$ 146,250,000
Payments for convertible note hedges	$ 21,100,000
2.25% Convertible Senior Notes due in 2022 | Convertible Senior Notes
Notes Payable
Aggregate principal amount of notes issued	335,700,000	$ 335,699,000		$ 335,699,000
Net proceed received	324,000,000
Fees and expenses	$ 11,700,000
Annual interest rate of notes (as a percent)	2.25%	2.25%
Initial conversion rate, number of shares to be issued per $1000 of principal amount (in shares)	60.3209
Principal amount used for debt instrument conversion ratio	$ 1,000
Initial conversion price (in dollars per share) | $ / shares	$ 16.58
Shares issuable upon conversion of debt (in shares) | shares	20,249,665
Number of trading days | D	20
Consecutive trading days | D	30
Minimum percentage of stock price	130.00%
Number of business days immediately after any five consecutive trading day period during the measurement period | D	5
Number of consecutive trading days before five business days during the measurement period | D	5
Percentage of the trading price to the product of the sale price of the entity's common stock and the conversion rate	98.00%
Repurchase price, as percentage of principal amount, if company undergoes change of control	100.00%
Percentage of aggregate principal amount payable, in case of event of default	25.00%
Debt issuance costs capitalized		$ 5,264,000		$ 5,976,000
Maximum period of the sole remedy for event failures in the Indenture		180 days
Amortization period	7 years

Notes Payable - 2.25% Convert_2

Notes Payable - 2.25% Convertible Senior Notes due 2022 - Balances (Details) - 2.25% Convertible Senior Notes due in 2022 - Convertible Senior Notes - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Jun. 30, 2015
Liability component:
Aggregate principal amount of notes issued	$ 335,699	$ 335,699	$ 335,700
Less: unamortized debt discount	(69,080)	(80,530)
Less: unamortized debt issuance costs	(5,264)	(5,976)
Net carrying amount	261,355	249,193
Equity component	$ 114,199	$ 114,199

Notes Payable - 2.25% Convert_3

Notes Payable - 2.25% Convertible Senior Notes due 2022 - Additional Information (Details) - 2.25% Convertible Senior Notes due in 2022 - Convertible Senior Notes - USD ($) $ in Millions	1 Months Ended
	Jun. 30, 2015	Sep. 30, 2018
Notes Payable
Debt issuance costs incurred	$ 11.7
Debt issuance costs allocated to equity components	4
Debt issuance costs allocated to liability components	$ 7.7
Debt instrument term	7 years
Effective interest rate on liability components		9.34%

Notes Payable - 2.25% Convert_4

Notes Payable - 2.25% Convertible Senior Notes due 2022 - Total Interest Expense (Details) - 2.25% Convertible Senior Notes due in 2022 - Convertible Senior Notes - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest Expense
Contractual interest expense	$ 1,889	$ 1,888	$ 5,665	$ 5,665
Amortization of debt issuance costs	249	206	712	590
Amortization of debt discount	3,900	3,574	11,450	10,492
Total interest expense	$ 6,038	$ 5,668	$ 17,827	$ 16,747

Notes Payable - Convertible Not

Notes Payable - Convertible Note Hedge and Warrant Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	9 Months Ended
	Jun. 30, 2015	Sep. 30, 2018	Dec. 31, 2017
Notes Payable
Long-term asset		$ 142,774	$ 108,188
Long-term liability		$ 122,778	$ 92,188
Net derivative issuance cost	$ 21,100
Convertible Note Hedge
Notes Payable
Shares issuable upon conversion of debt (in shares)		20,249,665
Initial conversion price (in dollars per share)		$ 16.58
Long-term asset	91,900
Note Hedge Warrant Derivatives
Notes Payable
Shares into which warrants may be converted (in shares)		20,249,665
Trading day period		150 days
Long-term liability	$ 70,800
Note hedge warrants
Notes Payable
Shares into which warrants may be converted (in shares)		20,249,665
Warrants strike price (in dollars per share)		$ 21.50

Notes Payable - Pharma Notes (D

Notes Payable - Pharma Notes (Details) - USD ($) $ in Thousands	Jan. 05, 2017	Sep. 30, 2017	Jan. 31, 2013
Notes Payable
Loss on extinguishment of debt		$ 2,009
Notes Payable | 11% PhaRMA Notes
Notes Payable
Annual interest rate of notes (as a percent)	11.00%		11.00%
Aggregate principal amount of notes issued in private placement			$ 175,000
Loss on extinguishment of debt	$ 2,000

Commitments and Contingencies -

Commitments and Contingencies - Capital Leases (Details) - Vehicles	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2018
Lease Commitments
Capital lease, term	12 months
Weighted average interest rate on the outstanding capital lease obligations (as a percent)		2.60%

Commitments and Contingencies_2

Commitments and Contingencies - Operating Leases (Details) - Operating Leases, Vehicles, 2018 Vehicle Leases $ in Millions	Sep. 30, 2018USD ($)
Lease Commitments
Operating lease, term	12 months
Option to extend lease term	1 month
Letters of credit securing operating lease obligations	$ 1.3
Weighted average interest rate on the outstanding capital lease obligations (as a percent)	3.30%

Employee Stock Benefit Plans -

Employee Stock Benefit Plans - Share-based Compensation Reflected in the Consolidated Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Employee Stock Benefit Plans
Share-based compensation expense	$ 13,025	$ 8,697	$ 32,819	$ 25,116
Research and development
Employee Stock Benefit Plans
Share-based compensation expense	3,823	3,246	10,945	9,439
Selling, general and administrative
Employee Stock Benefit Plans
Share-based compensation expense	7,643	$ 5,451	19,708	$ 15,677
Restructuring
Employee Stock Benefit Plans
Share-based compensation expense	$ 1,559		$ 2,166

Employee Stock Benefit Plans _2

Employee Stock Benefit Plans - Workforce Reduction (Details) $ in Thousands	Aug. 16, 2018employee	Aug. 02, 2018employee	Jun. 27, 2018employee	Jan. 30, 2018employee	Sep. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)
Employee Stock Benefit Plans
Share-based compensation expense					$ 13,025		$ 8,697	$ 32,819	$ 25,116
Restructuring
Employee Stock Benefit Plans
Share-based compensation expense					1,559			2,166
Reduction in Field-based Workforce, January 30, 2018
Workforce Reduction
Number of employees eliminated | employee				60
Reduction in Field-based Workforce, January 30, 2018 | Restructuring | Employee severance, benefits and related costs
Employee Stock Benefit Plans
Share-based compensation expense						$ 200
Reduction in Headquarter-based Workforce, June 27, 2018
Workforce Reduction
Number of employees expected to be eliminated | employee			40
Reduction in Headquarter-based Workforce, June 27, 2018 | Restructuring | Employee severance, benefits and related costs
Employee Stock Benefit Plans
Share-based compensation expense					1,000			$ 1,400
Reduction in Workforce, Termination of Lesinurad License Agreement, August 16, 2018
Workforce Reduction
Number of employees eliminated | employee		100
Number of employees expected to be eliminated | employee	100
Reduction in Workforce, Termination of Lesinurad License Agreement, August 16, 2018 | Restructuring | Employee severance, benefits and related costs
Employee Stock Benefit Plans
Share-based compensation expense					$ 600

Employee Stock Benefit Plans _3

Employee Stock Benefit Plans - Stock Options - Activity (Details) - Options to purchase common stock shares in Thousands	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Number of Shares
Outstanding at the beginning of the period (in shares) | shares	21,086
Granted (in shares) | shares	3,168
Exercised (in shares) | shares	(2,430)
Cancelled (in shares) | shares	(964)
Outstanding at the end of the period (in shares) | shares	20,860
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share) | $ / shares	$ 12.90
Granted (in dollars per share) | $ / shares	14.93
Exercised (in dollars per share) | $ / shares	10.32
Cancelled (in dollars per share) | $ / shares	14.93
Outstanding at the end of the period (in dollars per share) | $ / shares	$ 13.42

Employee Stock Benefit Plans _4

Employee Stock Benefit Plans - Stock Options - Assumptions (Details) - Options to purchase common stock	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Weighted-average assumptions used to estimate the fair value of the stock options using the Black-Scholes option-pricing model
Expected volatility (as a percent)	44.10%	45.20%	43.60%	46.00%
Expected term	6 years	6 years	6 years	6 years
Risk-free interest rate (as a percent)	2.80%	1.90%	2.70%	2.00%
Expected dividend yield (as a percent)	0.00%	0.00%	0.00%	0.00%

Employee Stock Benefit Plans _5

Employee Stock Benefit Plans - Restricted Stock Units - General Information (Details) - Restricted stock units	9 Months Ended
	Sep. 30, 2018shares
Stock Benefit Plans
Right to number of shares of common stock per RSU (in shares)	1
Vesting percentage (as a percent)	25.00%

Employee Stock Benefit Plans _6

Employee Stock Benefit Plans - Restricted Stock Units - Activity (Details) - Restricted stock units	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Number of Shares
Outstanding at the beginning of the period (in shares) | shares	2,277
Granted (in shares) | shares	2,017
Vested (in shares) | shares	(594)
Forfeited (in shares) | shares	(462)
Outstanding at the end of the period (in shares) | shares	3,238
Weighted-Average Grant Date Fair Value
Outstanding at the beginning of the period (in dollars per share) | $ / shares	$ 15.08
Granted (in dollars per share) | $ / shares	15.64
Vested (in dollars per share) | $ / shares	15.07
Forfeited (in dollars per share) | $ / shares	15.14
Outstanding at the end of the period (in dollars per share) | $ / shares	$ 15.42

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2009	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Investor | Allergan
Related Party Transactions
Accounts receivable		$ 55.2		$ 55.2		$ 79
Investor | Allergan | Convertible preferred stock
Related Party Transactions
Shares sold (in shares)	2,083,333
Board of Directors member
Related Party Transactions
Amount of insurance premium paid to the insurance provider		$ 2.9	$ 3	$ 9.2	$ 9
Accounts payable from related party						$ 0

Workforce Reduction - General I

Workforce Reduction - General Information (Details) $ in Thousands	Aug. 16, 2018USD ($)employee	Aug. 02, 2018employee	Jun. 27, 2018USD ($)employee	Jan. 30, 2018employee	Sep. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Sep. 30, 2018USD ($)
Restructuring expenses
Restructuring expenses					$ 10,282		$ 15,096
Reduction in Field-based Workforce, January 30, 2018
Workforce Reduction
Number of employees eliminated | employee				60
Restructuring expenses
Employee severance, benefits and related costs						$ 2,400
Restructuring expenses						$ 2,400
Reduction in Headquarter-based Workforce, June 27, 2018
Workforce Reduction
Number of employees expected to be eliminated | employee			40
Expected cost
Expected cost			$ 5,200
Restructuring expenses
Employee severance, benefits and related costs					2,700
Reduction in Workforce, Termination of Lesinurad License Agreement, August 16, 2018
Workforce Reduction
Number of employees eliminated | employee		100
Number of employees expected to be eliminated | employee	100
Expected cost
Expected cost	$ 7,800
Restructuring expenses
Restructuring expenses					7,600
Reduction in Workforce, Termination of Lesinurad License Agreement, August 16, 2018 | Employee severance, benefits and related costs
Expected cost
Expected cost	5,600
Restructuring expenses
Restructuring expenses					5,400
Reduction in Workforce, Termination of Lesinurad License Agreement, August 16, 2018 | Contract related costs
Expected cost
Expected cost	$ 2,200
Restructuring expenses
Restructuring expenses					$ 2,200

Workforce Reduction - Tabular D

Workforce Reduction - Tabular Disclosure (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended			8 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2018	Sep. 30, 2018
Workforce Reduction
Charges		$ 10,282				$ 15,096
Reduction in Field-based Workforce, January 30, 2018
Workforce Reduction
Charges				$ 2,400
Reduction in Workforce, Termination of Lesinurad License Agreement, August 16, 2018
Workforce Reduction
Charges		7,600
Employee severance, benefits and related costs
Workforce Reduction
Balance at beginning of period	$ 11,317
Amounts paid	(4,464)
Adjustments	12
Balance at end of period	6,865	6,865	$ 6,865		$ 6,865	6,865
Employee severance, benefits and related costs | Reduction in Field-based Workforce, January 30, 2018
Workforce Reduction
Balance at beginning of period					2,228
Amounts paid					(2,184)
Adjustments					(13)
Balance at end of period	31	31	31		31	31
Employee severance, benefits and related costs | Reduction in Headquarter-based Workforce, June 27, 2018
Workforce Reduction
Balance at beginning of period			3,877
Amounts paid			(1,727)
Adjustments			14
Balance at end of period	2,164	2,164	2,164		2,164	2,164
Employee severance, benefits and related costs | Reduction in Workforce, Termination of Lesinurad License Agreement, August 16, 2018
Workforce Reduction
Balance at beginning of period	5,212
Charges		5,400
Amounts paid	(553)
Adjustments	11
Balance at end of period	4,670	4,670	4,670		4,670	4,670
Contract related costs
Workforce Reduction
Balance at beginning of period	988
Balance at end of period	988	988	988		988	988
Contract related costs | Reduction in Workforce, Termination of Lesinurad License Agreement, August 16, 2018
Workforce Reduction
Balance at beginning of period	988
Charges		2,200
Balance at end of period	$ 988	$ 988	$ 988		$ 988	$ 988

Workforce Reduction - Restructu

Workforce Reduction - Restructuring Expenses (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Restructuring expenses
Restructuring expenses	$ 10,282	$ 15,096