Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2016	Oct. 27, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q3
Trading Symbol	NKTR
Entity Registrant Name	NEKTAR THERAPEUTICS
Entity Central Index Key	0000906709
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		152,835,294

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 63,295	$ 55,570
Short-term investments	190,216	253,374
Accounts receivable, net	14,249	19,947
Inventory	10,754	11,346
Other current assets	4,008	9,814
Total current assets	282,522	350,051
Property, plant and equipment, net	65,553	71,336
Goodwill	76,501	76,501
Other assets	519	754
Total assets	425,095	498,642
Current liabilities:
Accounts payable	7,118	2,363
Accrued compensation	15,733	5,998
Accrued clinical trial expenses	10,946	8,220
Other accrued expenses	6,761	4,156
Interest payable	4,198	4,198
Capital lease obligations, current portion	2,370	4,756
Liability related to refundable upfront payment	12,500	0
Deferred revenue, current portion	14,101	21,428
Other current liabilities	2,578	10,127
Total current liabilities	76,305	61,246
Senior secured notes, net	243,004	241,699
Capital lease obligations, less current portion	2,143	1,073
Liability related to the sale of future royalties, net	108,893	116,029
Deferred revenue, less current portion	57,088	62,426
Other long-term liabilities	5,515	9,740
Total liabilities	492,948	492,213
Commitments and contingencies
Stockholders’ equity (deficit):
Preferred stock, $0.0001 par value; 10,000 shares authorized; no shares designated, issued or outstanding at September 30, 2016 or December 31, 2015	0	0
Common stock, $0.0001 par value; 300,000 shares authorized; 137,796 shares and 135,289 shares issued and outstanding at September 30, 2016 and December 31, 2015, respectively	13	13
Capital in excess of par value	1,912,907	1,876,072
Accumulated other comprehensive loss	(1,962)	(2,170)
Accumulated deficit	(1,978,811)	(1,867,486)
Total stockholders’ equity (deficit)	(67,853)	6,429
Total liabilities and stockholders’ equity (deficit)	$ 425,095	$ 498,642

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares designated	0	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	137,796,000	135,289,000
Common stock, shares outstanding	137,796,000	135,289,000

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue:
Product sales	$ 14,698	$ 7,240	$ 41,664	$ 26,182
Royalty revenue	5,573	187	13,150	1,057
Non-cash royalty revenue related to sale of future royalties	7,692	6,050	22,341	14,752
License, collaboration and other revenue	8,373	46,475	50,829	149,423
Total revenue	36,336	59,952	127,984	191,414
Operating costs and expenses:
Cost of goods sold	7,033	6,760	23,611	25,738
Research and development	51,951	43,229	153,569	135,652
General and administrative	10,253	9,544	31,515	30,031
Total operating costs and expenses	69,237	59,533	208,695	191,421
Income (loss) from operations	(32,901)	419	(80,711)	(7)
Non-operating income (expense):
Interest expense	(5,614)	(4,202)	(16,918)	(12,491)
Non-cash interest expense on liability related to sale of future royalties	(4,902)	(5,226)	(14,929)	(15,428)
Interest income and other income (expense), net	332	898	1,666	1,355
Total non-operating expense, net	(10,184)	(8,530)	(30,181)	(26,564)
Loss before provision for income taxes	(43,085)	(8,111)	(110,892)	(26,571)
Provision for income taxes	139	92	433	469
Net loss	$ (43,224)	$ (8,203)	$ (111,325)	$ (27,040)
Basic and diluted net loss per share	$ (0.32)	$ (0.06)	$ (0.82)	$ (0.21)
Weighted average shares outstanding used in computing net loss per share	137,094	132,631	136,415	131,882

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement Of Income And Comprehensive Income [Abstract]
Comprehensive loss	$ (43,167)	$ (8,526)	$ (111,117)	$ (27,294)

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net loss	$ (111,325)	$ (27,040)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Non-cash royalty revenue related to sale of future royalties	(22,341)	(14,752)
Non-cash interest expense on liability related to sale of future royalties	14,929	15,428
Stock-based compensation	18,793	14,499
Depreciation and amortization	11,502	9,109
Other non-cash transactions	(2,190)	(1,448)
Changes in operating assets and liabilities:
Accounts receivable, net	5,698	641
Inventory	592	2,600
Other assets	6,041	3,843
Accounts payable	4,799	(525)
Accrued compensation	9,735	7,056
Accrued clinical trial expenses	2,726	3,394
Other accrued expenses	2,386	949
Interest payable	0	(3,750)
Liability related to refundable upfront payment	12,500	0
Deferred revenue	(12,665)	(11,832)
Other liabilities	(5,793)	3,854
Net cash (used in) provided by operating activities	(64,613)	2,026
Cash flows from investing activities:
Purchases of investments	(142,972)	(202,870)
Maturities of investments	201,449	155,683
Sales of investments	4,969	23,778
Release of restricted cash	0	25,000
Purchases of property, plant and equipment	(3,741)	(8,722)
Net cash provided by (used in) investing activities	59,705	(7,131)
Cash flows from financing activities:
Payment of capital lease obligations	(5,376)	(3,798)
Proceeds from shares issued under equity compensation plans	18,041	15,516
Net cash provided by financing activities	12,665	11,718
Effect of exchange rates on cash and cash equivalents	(32)	(159)
Net increase in cash and cash equivalents	7,725	6,454
Cash and cash equivalents at beginning of period	55,570	12,365
Cash and cash equivalents at end of period	63,295	18,819
Supplemental disclosure of cash flow information:
Cash paid for interest	15,513	16,095
Supplemental schedule of non-cash investing and financing activities:
Accrued debt issuance costs	$ 0	$ 8,503

Organization and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Summary of Significant Accounting Policies	Note 1 — Organization and Summary of Significant Accounting Policies Organization We are a biopharmaceutical company headquartered in San Francisco, California and incorporated in Delaware. We are developing a pipeline of drug candidates that utilize our PEGylation and advanced polymer conjugate technology platforms, which are designed to enable the development of new molecular entities that target known mechanisms of action. Our current proprietary pipeline is comprised of drug candidates across a number of therapeutic areas including oncology, pain, anti-infectives, and immunology. Our research and development activities have required significant ongoing investment to date and are expected to continue to require significant investment. As a result, we expect to continue to incur substantial losses and negative cash flows from operations in the future. We have financed our operations primarily through cash generated from licensing, collaboration and manufacturing agreements and financing transactions. At September 30, 2016, we had approximately $253.5 million in cash and investments in marketable securities. Also, as of September 30, 2016, we had $254.5 million in debt, including $250.0 million in principal of senior secured notes and $4.5 million of capital lease obligations, of which $2.4 million is current. Basis of Presentation and Principles of Consolidation Our consolidated financial statements include the financial position, results of operations and cash flows of our wholly-owned subsidiaries: Nektar Therapeutics (India) Private Limited (Nektar India) and Nektar Therapeutics UK Limited. All intercompany accounts and transactions have been eliminated in consolidation. We prepared our Condensed Consolidated Financial Statements following the requirements of the Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. generally accepted accounting principles (GAAP) for annual periods can be condensed or omitted. In the opinion of management, these financial statements include all normal and recurring adjustments that we consider necessary for the fair presentation of our financial position and operating results. Our Condensed Consolidated Financial Statements are denominated in U.S. dollars. Accordingly, changes in exchange rates between the applicable foreign currency and the U.S. dollar will affect the translation of each foreign subsidiary’s financial results into U.S. dollars for purposes of reporting our consolidated financial results. Translation gains and losses are included in accumulated other comprehensive loss in the stockholders’ equity section of the Condensed Consolidated Balance Sheets. To date, such cumulative currency translation adjustments have not been significant to our consolidated financial position. Our comprehensive loss consists of our net loss plus our foreign currency translation gains and losses and unrealized holding gains and losses on available-for-sale securities, neither of which were significant during the three and nine months ended September 30, 2016 and 2015. In addition, there were no significant reclassifications out of accumulated other comprehensive loss to the statements of operations during the three and nine months ended September 30, 2016 and 2015. The accompanying Condensed Consolidated Financial Statements are unaudited. The Condensed Consolidated Balance Sheet data as of December 31, 2015 was derived from the audited consolidated financial statements which are included in our Annual Report on Form 10-K for the year ended December 31, 2015 filed with the SEC on February 29, 2016. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the consolidated financial statements and the accompanying notes to those financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2015. Revenue, expenses, assets, and liabilities can vary during each quarter of the year. The results and trends in these interim Condensed Consolidated Financial Statements are not necessarily indicative of the results to be expected for the full year or any other periods. Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Accounting estimates and assumptions are inherently uncertain. Actual results could differ materially from those estimates and assumptions. Our estimates include those related to estimated selling prices of deliverables in collaboration agreements, estimated periods of performance, the net realizable value of inventory, the impairment of investments, the impairment of goodwill and long-lived assets, contingencies, accrued clinical trial expenses, estimated non-cash royalty revenue and interest expense from our liability related to our sale of future royalties, stock-based compensation, and ongoing litigation, among other estimates. We base our estimates on historical experience and on other assumptions that management believes are reasonable under the circumstances. These estimates form the basis for making judgments about the carrying values of assets and liabilities when these values are not readily apparent from other sources. As appropriate, estimates are assessed each period and updated to reflect current information and any changes in estimates will generally be reflected in the period first identified. Reclassifications Certain items previously reported in specific financial statement captions have been reclassified to conform to the current period presentation, including as a result of the adoption of new accounting guidance related to debt issuance costs described below. Such reclassifications do not materially impact previously reported revenue, operating income (loss), net income (loss), total assets, liabilities or stockholders’ equity (deficit). Segment Information We operate in one business segment which focuses on applying our technology platforms to improve the performance of established and novel drug candidates. We operate in one segment because our business offerings have similar economics and other characteristics, including the nature of products and manufacturing processes, types of customers, distribution methods and regulatory environment. We are comprehensively managed as one business segment by our Chief Executive Officer and his management team. Significant Concentrations Our customers are primarily pharmaceutical and biotechnology companies that are located in the U.S. and Europe. Our accounts receivable balance contains billed and unbilled trade receivables from product sales, milestones, other contingent payments and royalties, as well as time and materials based billings from collaborative research and development agreements. When appropriate, we provide for an allowance for doubtful accounts by reserving for specifically identified doubtful accounts. We generally do not require collateral from our customers. We perform a regular review of our customers’ payment histories and associated credit risk. We have not experienced significant credit losses from our accounts receivable and our allowance for doubtful accounts was not significant at either September 30, 2016 or December 31, 2015. We are dependent on our suppliers and contract manufacturers to provide raw materials, drugs and devices of appropriate quality and reliability and to meet applicable contract and regulatory requirements. In certain cases, we rely on single sources of supply of one or more critical materials. Consequently, in the event that supplies are delayed or interrupted for any reason, our ability to develop and produce our drug candidates or our ability to meet our supply obligations could be significantly impaired, which could have a material adverse effect on our business, financial condition and results of operations. Revenue Recognition Our revenue is derived from our arrangements with pharmaceutical and biotechnology collaboration partners and may result from one or more of the following: upfront and license fees, payments for contract research and development, milestone and other contingent payments, manufacturing and supply payments, and royalties. Our performance obligations under our collaborations may include licensing our intellectual property, manufacturing and supply obligations, and research and development obligations. In order to account for the multiple-element arrangements, we identify the deliverables included within the arrangement and evaluate which deliverables represent separate units of accounting. Analyzing the arrangement to identify deliverables requires the use of judgment, and each deliverable may be an obligation to deliver goods or services, a right or license to use an asset, or another performance obligation. Revenue is recognized separately for each identified unit of accounting when the basic revenue recognition criteria are met: there is persuasive evidence that an arrangement exists, delivery has occurred, the price is fixed or determinable, and collection is reasonably assured. At the inception of each new multiple-element arrangement or the material modification of an existing multiple-element arrangement, we allocate all consideration received under multiple-element arrangements to all units of accounting based on the relative selling price method, generally based on our best estimate of selling price (ESP). The objective of ESP is to determine the price at which we would transact a sale if the product or service was sold on a stand-alone basis. We determine ESP for the elements in our collaboration arrangements by considering multiple factors including, but not limited to, technical complexity of the performance obligation and similarity of elements to those performed under previous arrangements. Since we apply significant judgment in arriving at the ESPs, any material change in our estimates would significantly affect the allocation of the total consideration to the different elements of a multiple element arrangement. Product sales Product sales are primarily derived from fixed price and cost-plus manufacturing and supply agreements with our collaboration partners. We have not experienced any significant returns from our customers. Royalty revenue Generally, we are entitled to royalties from our collaboration partners based on the net sales of their approved drugs that are marketed and sold in one or more countries where we hold royalty rights. We recognize royalty revenue when the cash is received or when the royalty amount to be received is estimable and collection is reasonably assured. With respect to the non-cash royalties related to sale of future royalties described in Note 4, revenue is recognized when estimable, otherwise, revenue is recognized during the period in which the related royalty report is received, which generally occurs in the quarter after the applicable product sales are made. License, collaboration and other revenue The amount of upfront fees and other payments received by us in license and collaboration arrangements that are allocated to continuing performance obligations, such as manufacturing and supply obligations, are deferred and generally recognized ratably over our expected performance period under each respective arrangement. We make our best estimate of the period over which we expect to fulfill our performance obligations, which may include technology transfer assistance, research activities, clinical development activities, and manufacturing activities from research and development through the commercialization of the product. Given the uncertainties of these collaboration arrangements, significant judgment is required to determine the duration of the performance period and this estimate is periodically re-evaluated. Contingent consideration received from the achievement of a substantive milestone is recognized in its entirety in the period in which the milestone is achieved, which we believe is consistent with the substance of our performance under our various license and collaboration agreements. A milestone is defined as an event (i) that can only be achieved based in whole or in part either on the entity’s performance or on the occurrence of a specific outcome resulting from the entity’s performance, (ii) for which there is substantive uncertainty at the date the arrangement is entered into that the event will be achieved, and (iii) that would result in additional payments being due to the entity. A milestone is substantive if the consideration earned from the achievement of the milestone is consistent with our performance required to achieve the milestone or the increase in value to the collaboration resulting from our performance, relates solely to our past performance, and is reasonable relative to all of the other deliverables and payments within the arrangement. Our license and collaboration agreements with our partners provide for payments to us upon the achievement of development milestones, such as the completion of clinical trials or regulatory submissions, approvals by regulatory authorities, and commercial launches of drugs. Given the challenges inherent in developing and obtaining regulatory approval for drug products and in achieving commercial launches, there was substantial uncertainty whether any such milestones would be achieved at the time of execution of these licensing and collaboration agreements. In addition, we evaluated whether the development milestones met the remaining criteria to be considered substantive. As a result of our analysis, we consider our remaining development milestones under all of our license and collaboration agreements to be substantive and, accordingly, we expect to recognize as revenue future payments received from each milestone only if and as such milestone is achieved. Our license and collaboration agreements with certain partners also provide for contingent payments to us based solely upon the performance of the respective partner. For such contingent amounts, we expect to recognize the payments as revenue when earned under the applicable contract, which is generally upon completion of performance by the respective partner, provided that collection is reasonably assured. Our license and collaboration agreements with our partners also provide for payments to us upon the achievement of specified sales volumes of approved drugs. We consider these payments to be similar to royalty payments and we will recognize such sales-based payments upon achievement of such sales volumes, provided that collection is reasonably assured. Research and Development Expense Research and development costs are expensed as incurred and include salaries, benefits and other operating costs such as outside services, supplies and allocated overhead costs. We perform research and development for our proprietary drug candidates and technology development and for certain third parties under collaboration agreements. For our proprietary drug candidates and our internal technology development programs, we invest our own funds without reimbursement from a third party. We record accruals for the estimated costs of our clinical trial activities performed by third parties. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows to our vendors. Payments under the contracts depend on factors such as the achievement of certain events, successful enrollment of patients, and completion of certain clinical trial activities. We generally accrue costs associated with the start-up and reporting phases of the clinical trials ratably over the estimated duration of the start-up and reporting phases. We generally accrue costs associated with the treatment phase of clinical trials based on the total estimated cost of the treatment phase on a per patient basis and we expense the per patient cost ratably over the estimated patient treatment period based on patient enrollment in the trials. In specific circumstances, such as for certain time-based costs, we recognize clinical trial expenses using a methodology that we consider to be more reflective of the timing of costs incurred. Advance payments for goods or services that will be used or rendered for future research and development activities are capitalized as prepaid expenses and recognized as expense as the related goods are delivered or the related services are performed. We base our estimates on the best information available at the time. However, additional information may become available to us which may allow us to make a more accurate estimate in future periods. In this event, we may be required to record adjustments to research and development expenses in future periods when the actual level of activity becomes more certain. Such increases or decreases in cost are generally considered to be changes in estimates and will be reflected in research and development expenses in the period identified. Long-Lived Assets We assess the impairment of long-lived assets, primarily property, plant and equipment and goodwill, whenever events or changes in business circumstances indicate that the carrying amounts of the assets may not be fully recoverable. When such events occur, we determine whether there has been an impairment in value by comparing the carrying value of the asset with its fair value, as measured by the anticipated undiscounted net cash flows associated with the asset. In the case of goodwill impairment, we perform an impairment test at least annually, on October 1 of each year, and market capitalization is generally used as the measure of fair value. If an impairment in value exists, the asset is written down to its estimated fair value. Income Taxes For the three and nine months ended September 30, 2016 and 2015, we recorded an income tax provision for our Nektar India operations at an effective tax rate of approximately 35%. The U.S. federal deferred tax assets generated from our net operating losses have been fully reserved, as we believe it is not more likely than not that the benefit will be realized. Adoption of New Accounting Principle In April 2015, the Financial Accounting Standards Board (FASB) issued guidance to simplify the presentation of debt issuance costs by requiring debt issuance costs to be presented as a deduction from the corresponding debt liability. This guidance is effective for our interim and annual periods beginning January 1, 2016. Upon adoption, the new guidance must be applied retrospectively to all periods presented. Accordingly, as of January 1, 2016, we reclassified $0.4 million and $3.0 million of capitalized debt issuance costs to senior secured notes, net, and liability related to the sale of future royalties, net, respectively, from our other assets balance. This reclassification has also been applied retrospectively to these balances in our Condensed Consolidated Balance Sheet as of December 31, 2015. Recent Accounting Pronouncements In May 2014, the FASB issued guidance codified in Accounting Standards Codification (ASC) 606, Revenue Recognition — Revenue from Contracts with Customers, which amends the guidance in former ASC 605, Revenue Recognition, and is effective for public companies for fiscal years beginning after December 15, 2017. Entities have the option of using either a full retrospective or a modified retrospective approach to adopt this new guidance. We are currently evaluating the impact of the provisions of ASC 606. In March 2016, the FASB issued guidance to simplify several aspects of employee share-based payment accounting, including income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. This guidance will become effective for us beginning in the first quarter of 2017. Early adoption is permitted. We are currently evaluating the impact of the adoption of this standard. In February 2016, the FASB issued guidance to amend a number of aspects of lease accounting, including requiring lessees to recognize almost all leases with a term greater than one year as a right-of-use asset and corresponding liability, measured at the present value of the lease payments. The guidance will become effective for us beginning in the first quarter of 2019 and is required to be adopted using a modified retrospective approach. Early adoption is permitted. We are currently evaluating the impact of the adoption of this standard.

Cash and Investments in Marketable Securities

9 Months Ended

Sep. 30, 2016

Fair Value Disclosures [Abstract]

Cash and Investments in Marketable Securities

Note 2 — Cash and Investments in Marketable Securities

Cash and investments in marketable securities, including cash equivalents, are as follows (in thousands):

	Estimated Fair Value at
	September 30, 2016		December 31, 2015
Cash and cash equivalents	$	63,295	$	55,570
Short-term investments		190,216		253,374
Total cash and investments in marketable securities	$	253,511	$	308,944

We invest in liquid, high quality debt securities. Our investments in debt securities are subject to interest rate risk. To minimize the exposure due to an adverse shift in interest rates, we invest in securities with maturities of two years or less and maintain a weighted average maturity of one year or less. As of September 30, 2016 and December 31, 2015, all of our investments had maturities of one year or less.

Gross unrealized gains and losses were not significant at either September 30, 2016 or December 31, 2015. During the three and nine months ended September 30, 2016, we sold available-for-sale securities totaling $5.0 million and gross realized gains and losses on those sales were not significant. During the three and nine months ended September 30, 2015, we sold available-for-sale securities totaling $18.6 million and $23.8 million, respectively, and gross realized gains and losses on those sales were not significant. The cost of securities sold is based on the specific identification method.

Under the terms of our 7.75% senior secured notes due October 2020, we are required to maintain a minimum cash and investments in marketable securities balance of $60.0 million during the term of the notes.

Our portfolio of cash and investments in marketable securities includes (in thousands):

			Estimated Fair Value at
	Fair Value Hierarchy Level		September 30, 2016		December 31, 2015
Corporate notes and bonds		2	$	74,564	$	181,969
Corporate commercial paper		2		95,924		61,150
Obligations of U.S. government agencies		2		16,798		7,325
Available-for-sale investments				187,286		250,444
Money market funds		1		62,092		53,728
Certificate of deposit	N/A			2,930		2,930
Cash	N/A			1,203		1,842
Total cash and investments in marketable securities			$	253,511	$	308,944

Level 1 —	Quoted prices in active markets for identical assets or liabilities.
Level 2 —	Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
Level 3 —	Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

All of our investments are categorized as Level 1 or Level 2, as explained in the table above. We use a market approach to value our Level 2 investments. The disclosed fair value related to our investments is based primarily on the reported fair values in our period-end brokerage statements, which are based on market prices from a variety of industry standard data providers and generally represent quoted prices for similar assets in active markets or have been derived from observable market data. We independently validate these fair values using available market quotes and other information. During the three and nine months ended September 30, 2016 and 2015, there were no transfers between Level 1 and Level 2 of the fair value hierarchy.

Additionally, as of September 30, 2016, based on a discounted cash flow analysis using Level 3 inputs including financial discount rates, we believe the $250.0 million in principal amount of our 7.75% senior secured notes due October 2020 is consistent with its fair value.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Inventory

9 Months Ended

Sep. 30, 2016

Inventory Disclosure [Abstract]

Inventory

Note 3 — Inventory

Inventory consists of the following (in thousands):

	September 30, 2016		December 31, 2015
Raw materials	$	2,386	$	3,236
Work-in-process		6,695		6,087
Finished goods		1,673		2,023
Total inventory	$	10,754	$	11,346

Inventory is generally manufactured upon receipt of firm purchase orders from our collaboration partners. Inventory includes direct materials, direct labor, and manufacturing overhead and cost is determined on a first-in, first-out basis. Inventory is valued at the lower of cost or market and defective or excess inventory is written down to net realizable value based on historical experience or projected usage.

Liability Related to the Sale of Future Royalties	9 Months Ended
Liability Related to the Sale of Future Royalties	Sep. 30, 2016
Liability Related To Sale Of Potential Future Royalties [Abstract]
Liability Related to Sale of Future Royalties	Note 4 — Liability Related to Sale of Future Royalties On February 24, 2012, we entered into a Purchase and Sale Agreement (the Purchase and Sale Agreement) with RPI Finance Trust (RPI), an affiliate of Royalty Pharma, pursuant to which we sold, and RPI purchased, our right to receive royalty payments (the Royalty Entitlement) arising from the worldwide net sales, from and after January 1, 2012, of (a) CIMZIA^®, under our license, manufacturing and supply agreement with UCB Pharma (UCB), and (b) MIRCERA^®, under our license, manufacturing and supply agreement with F. Hoffmann-La Roche Ltd and Hoffmann-La Roche Inc. (together referred to as Roche). We received aggregate cash proceeds of $124.0 million for the Royalty Entitlement. As part of this sale, we incurred approximately $4.4 million in transaction costs, which will be amortized to interest expense over the estimated life of the Purchase and Sale Agreement. Although we sold all of our rights to receive royalties from the CIMZIA^®and MIRCERA^® products, as a result of our ongoing manufacturing and supply obligations related to the generation of these royalties, we will continue to account for these royalties as revenue. We recorded the $124.0 million in proceeds from this transaction as a liability (Royalty Obligation) that will be amortized using the interest method over the estimated life of the Purchase and Sale Agreement as royalties from the CIMZIA^® and MIRCERA^® products are remitted directly to RPI. During the nine months ended September 30, 2016 and 2015, we recognized $22.3 million and $14.8 million, respectively, in non-cash royalties from net sales of CIMZIA^® and MIRCERA^® and we recorded $14.9 million and $15.4 million, respectively, of related non-cash interest expense. Since its inception, our estimate of the total interest expense on the Royalty Obligation resulted in an effective annual interest rate of approximately 17%. We periodically assess the estimated royalty payments to RPI from UCB and Roche and to the extent such payments are greater or less than our initial estimates, or the timing of such payments is materially different than our original estimates, we will prospectively adjust the amortization of the Royalty Obligation. Pursuant to the Purchase and Sale Agreement, in March 2014 and March 2013, we were required to pay RPI $7.0 million and $3.0 million, respectively, as a result of worldwide net sales of MIRCERA^® for the 12 month periods ended December 31, 2013 and 2012 not reaching certain minimum thresholds. The Purchase and Sale Agreement does not include any other potential payments related to minimum net sales thresholds and, therefore, we do not expect to make any further payments to RPI related to this agreement. In addition, the Purchase and Sale Agreement grants RPI the right to receive certain reports and other information relating to the Royalty Entitlement and contains other representations and warranties, covenants and indemnification obligations that are customary for a transaction of this nature. To our knowledge, we are currently in compliance with these provisions of the Purchase and Sale Agreement; however, if we were to breach our obligations, we could be required to pay damages to RPI that are not limited to the purchase price we received in the sale transaction.

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2016
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 5 — Commitments and Contingencies Legal Matters From time to time, we are involved in lawsuits, arbitrations, claims, investigations and proceedings, consisting of intellectual property, commercial, employment and other matters, which arise in the ordinary course of business. We make provisions for liabilities when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Such provisions are reviewed at least quarterly and adjusted to reflect the impact of settlement negotiations, judicial and administrative rulings, advice of legal counsel, and other information and events pertaining to a particular case. Litigation is inherently unpredictable. If any unfavorable ruling were to occur in any specific period, there exists the possibility of a material adverse impact on the results of our operations of that period and on our cash flows and liquidity. On August 14, 2015, Enzon, Inc. filed a breach of contract complaint in the Supreme Court of the State of New York (Court) claiming damages of $1.5 million plus interest for unpaid licensing fees through the date of the complaint. Enzon alleged that we failed to pay a post-patent expiration immunity fee related to one of the licenses. Following a hearing held on December 21, 2015, the Court granted Nektar’s motion to dismiss the Enzon complaint. Enzon filed an appeal to the Court’s dismissal decision. On October 25, 2016 the Supreme Court of the State of New York, Appellate Division, reversed the earlier decision by the Court granting Nektar’s motion to dismiss the Enzon complaint. As a result, the case has been remanded to the Court for further proceedings. Indemnifications in Connection with Commercial Agreements As part of our collaboration agreements with our partners related to the license, development, manufacture and supply of drugs based on our proprietary technologies and drug candidates, we generally agree to defend, indemnify and hold harmless our partners from and against third party liabilities arising out of the agreement, including product liability (with respect to our activities) and infringement of intellectual property to the extent the intellectual property is developed by us and licensed to our partners. The term of these indemnification obligations is generally perpetual any time after execution of the agreement. There is generally no limitation on the potential amount of future payments we could be required to make under these indemnification obligations. From time to time we enter into other strategic agreements such as divestitures and financing transactions pursuant to which we are required to make representations and warranties and undertake to perform or comply with certain covenants. In the event it is determined that we breached certain of the representations and warranties or covenants made by us in any such agreements, we could incur substantial indemnification liabilities depending on the timing, nature, and amount of any such claims. To date, we have not incurred costs to defend lawsuits or settle claims related to these indemnification obligations. Because the aggregate amount of any potential indemnification obligation is not a stated amount, the overall maximum amount of any such obligations cannot be reasonably estimated. No liabilities have been recorded for these obligations in our Condensed Consolidated Balance Sheets at either September 30, 2016 or December 31, 2015.

License and Collaboration Agreements

9 Months Ended

Sep. 30, 2016

Organization Consolidation And Presentation Of Financial Statements [Abstract]

License and Collaboration Agreements

Note 6 — License and Collaboration Agreements

We have entered into various collaboration agreements including license agreements and collaborative research, development and commercialization agreements with various pharmaceutical and biotechnology companies. Under these collaboration arrangements, we are entitled to receive license fees, upfront payments, milestone and other contingent payments, royalties, sales milestones, and payments for the manufacture and supply of our proprietary PEGylation materials and/or reimbursement for research and development activities. All of our collaboration agreements are generally cancelable by our partners without significant financial penalty. Our costs of performing these services are generally included in research and development expense, except that costs for product sales to our collaboration partners are included in cost of goods sold.

In accordance with our collaboration agreements, we recognized license, collaboration and other revenue as follows (in thousands):

		Three months ended September 30,				Nine months ended September 30,
Partner	Drug or Drug Candidate	2016		2015		2016		2015
AstraZeneca AB	MOVANTIK^TM and MOVANTIK^TM fixed-dose combination program	$	3,000	$	40,000	$	31,000	$	130,000
Roche	PEGASYS^® and MIRCERA^®		1,929		3,212		5,771		9,619
Amgen, Inc.	Neulasta^®		1,250		1,250		3,750		3,750
Daiichi Sankyo Europe GmbH	ONZEALD^TM (NKTR-102)		216		—		3,474		—
Bayer Healthcare LLC	BAY41-6551 (Amikacin Inhale)		357		357		1,072		1,562
Baxalta Incorporated	ADYNOVATE^TM		336		409		648		607
Other			1,285		1,247		5,114		3,885
License, collaboration and other revenue		$	8,373	$	46,475	$	50,829	$	149,423

As of September 30, 2016, our collaboration agreements with partners included potential future payments for development milestones totaling approximately $147.0 million, including amounts from our agreements with Daiichi, Bayer, Baxalta and Ophthotech described below. In addition, under our collaboration agreements we are entitled to receive contingent development payments and contingent sales milestones and royalty payments, including those related to MOVANTIK^TM and the MOVANTIK^TM fixed-dose combination drug development programs, as described below.

There have been no material changes to our collaboration agreements in the nine months ended September 30, 2016, except as described below.

Bristol-Myers Squibb: NKTR-214

On September 21, 2016, we entered into a Clinical Trial Collaboration Agreement (BMS Agreement) with Bristol-Myers Squibb Company, a Delaware corporation (BMS), pursuant to which we and BMS will collaborate to conduct Phase 1/2 clinical trials evaluating our IL-2-based CD122-biased agonist, known as NKTR-214, and BMS’ human monoclonal antibody that binds PD-1, known as Opdivo (nivolumab), as a potential combination treatment regimen in five tumor types and seven potential indications, and such other clinical trials evaluating the combined therapy as may be mutually agreed upon by the parties (each, a “Combination Therapy Trial”).

We will act as the sponsor of each Combination Therapy Trial. Under the BMS Agreement, BMS will be responsible for 50% of all out-of-pocket costs reasonably incurred in connection with third party contract research organizations, laboratories, clinical sites and institutional review boards. Each party will otherwise be responsible for its own internal costs, including internal personnel costs, incurred in connection with each Combination Therapy Trial. Nektar and BMS will use commercially reasonable efforts to manufacture and supply NKTR-214 and Opdivo (nivolumab), respectively, for each Combination Therapy Trial with each party bearing its own costs related thereto. The parties will form a joint development committee to oversee clinical trial design, regulatory strategy, and other activities necessary to conduct and support the Combination Therapy Trials.

Ownership of, and global commercial rights to, NKTR-214 remain solely with us under the BMS Agreement. If we wish to license the right to commercialize NKTR-214 in one of certain major market territories prior to September 30, 2018 (Exclusivity Expiration Date), we must first negotiate with BMS, for a period of three months (Negotiation Period), to grant an exclusive license to develop and commercialize NKTR-214 in any of these major market territories. If we do not reach an agreement with BMS for an exclusive license within the Negotiation Period, we will be free to license any right to NKTR-214 to other parties in any territory worldwide except that in the event that we receive a license offer from a third party during a period of 90 calendar days after the end of the Negotiation Period, we will provide BMS ten business days to match the terms of such third-party offer. After the Exclusivity Expiration Date, we are free to license NKTR-214 without any further obligation to BMS. Each party grants to the other party a non-exclusive, worldwide (subject to certain exceptions in the case of the license granted by BMS), non-transferable and royalty-free research and development license to such licensing party’s patent rights, technology and regulatory documentation to use its compound solely to the extent necessary to discharge its obligations under the BMS Agreement with respect to the conduct of the Combination Therapy Trials.

Daiichi Sankyo Europe GmbH: ONZEALD^TM (etirinotecan pegol), also referred to as NKTR-102

Effective May 30, 2016, we entered into a collaboration and license agreement with Daiichi Sankyo Europe GmbH, a German limited liability company (Daiichi), under which we granted Daiichi exclusive commercialization rights in the European Economic Area, Switzerland, and Turkey (collectively, the European Territory) to our proprietary product candidate ONZEALD™ (etirinotecan pegol), which is also known as NKTR-102, a long-acting topoisomerase I inhibitor in clinical development for the treatment of adult patients with advanced breast cancer who have brain metastases (BCBM). Nektar retains all rights to ONZEALD™ in all countries outside the European Territory including the United States.

Under the terms of the agreement and in consideration for the exclusive commercialization rights in the European Territory, Daiichi paid us a $20.0 million up-front payment in August 2016 and we will be eligible to receive up to an aggregate of $60.0 million in regulatory and commercial milestones, including a $10.0 million payment upon the first commercial sale of ONZEALD™ following conditional marketing approval by the European Commission (EC), a $25.0 million payment upon the first commercial sale following final marketing authorization approval of ONZEALD™ by the EC, and a $25.0 million sales milestone upon Daiichi’s first achievement of a certain specified annual net sales target. We are also eligible to receive a 20% royalty on net sales of ONZEALD™ by Daiichi in all countries in the European Territory except for net sales in Turkey where Nektar is eligible to receive a 15% royalty. The parties will enter into a supply agreement whereby we will be responsible for supplying Daiichi with its requirements for ONZEALD™ on a fully burdened reimbursed cost basis. Daiichi will be responsible for all commercialization activities for ONZEALD™ in the European Territory and will bear all associated costs. In addition, we are responsible for funding and conducting a Phase 3 confirmatory trial in patients with BCBM which we call the ATTAIN study.

Daiichi may terminate the agreement in the event that the EC does not grant conditional marketing approval for ONZEALD™ based on existing clinical data for ONZEALD™ or the conditional marketing approval for ONZEALD™ is not granted prior to a pre-specified future date (Daiichi Pre-Conditional Approval Termination). We may terminate the Agreement in the event that the EC requires changes in the ATTAIN study that materially increase the costs of such trial and Daiichi elects not to reimburse us for such incremental costs (Nektar Pre-Conditional Approval Termination). In the event of a Daiichi Pre-Conditional Approval Termination or a Nektar Pre-Conditional Approval Termination, we would be obligated to pay Daiichi a $12.5 million termination payment. Following conditional marketing approval of ONZEALD™ by the EC, we would no longer have such termination payment obligation. Each party has certain other termination rights based on the safety or efficacy findings including the outcome of the ATTAIN study and any material uncured breaches of the Agreement. The $12.5 million contingent termination payment from us to Daiichi is recorded in our liability related to refundable upfront payment balance in our Condensed Consolidated Balance Sheet at September 30, 2016.

We identified our grant of the exclusive license to Daiichi on May 30, 2016 and our ongoing clinical and regulatory development service obligations as the significant, non-contingent deliverables under the agreement and determined that each represents a separate unit of accounting. We made our best estimate of the selling price for the license grant based on a discounted cash flow analysis of projected ONZEALD™ sales and estimated the selling price for the development services based on our experience with the costs of similar clinical studies and regulatory activities. Based on these estimates, we allocated the $7.5 million non-refundable portion of the $20.0 million upfront payment from Daiichi to these items based on their relative selling prices. As a result, we recognized $3.5 million of revenue in the nine months ended September 30, 2016 from this arrangement, primarily related to the delivery of the license. As of September 30, 2016, we have deferred revenue of approximately $4.0 million related to our development service obligations under this agreement, which we expect to recognize through May 2021, the estimated end of our development obligations. If and when the remaining $12.5 million portion of the upfront payment becomes non-refundable, we expect to allocate this amount between the license and development service obligation consistent with the estimated selling prices of these deliverables. The license related amount will be recognized immediately and the development service related amount will be recorded as deferred revenue and recognized ratably over the remaining obligation period.

We determined that the milestones noted above payable to us by Daiichi upon the first commercial sale of ONZEALD™ following conditional marketing approval and following final marketing authorization approval of ONZEALD™ by the EC are substantive milestones that will be recognized if and when achieved. In addition, we determined that the sales milestone due to us upon Daiichi’s first achievement of a certain specified annual net sales target should be considered a contingent payment and will be recognized if and when achieved.

AstraZeneca AB: MOVANTIK^TM (naloxegol oxalate), previously referred to as naloxegol and NKTR-118, and MOVANTIK^TM fixed-dose combination program, previously referred to as NKTR-119

We are a party to an agreement with AstraZeneca AB (AstraZeneca) under which we granted AstraZeneca a worldwide, exclusive license under our patents and other intellectual property to develop, market, and sell MOVANTIK^TM and MOVANTIK^TM fixed-dose combination program. AstraZeneca is responsible for all research, development and commercialization and is responsible for all drug development and commercialization decisions for MOVANTIK^TM and the MOVANTIK^TM fixed-dose combination program. AstraZeneca paid us an upfront payment of $125.0 million, which we received in the fourth quarter of 2009 and which was fully recognized as of December 31, 2010. In addition, we have received the payments described further below based on development events related to MOVANTIK^TM completed solely by AstraZeneca. We are entitled to receive up to $75.0 million of commercial launch contingent payments related to the MOVANTIK^TM fixed-dose combination program, based on development events to be pursued and completed solely by AstraZeneca. In addition, we are entitled to significant and escalating double-digit royalty payments and sales milestone payments based on annual worldwide net sales of MOVANTIK^TM and MOVANTIK^TM fixed-dose combination products.

On September 16, 2014, the United States Food and Drug Administration (FDA) approved MOVANTIK^TM for the treatment of opioid-induced constipation (OIC) in adult patients with chronic, non-cancer pain. On December 9, 2014, AstraZeneca announced that MOVENTIG^® (the naloxegol brand name in the European Union or EU) had been granted Marketing Authorisation by the European Commission (EC) for the treatment of opioid-induced constipation (OIC) in adult patients who have had an inadequate response to laxative(s). In March 2015, AstraZeneca announced that MOVANTIK™ launched in the United States which resulted in our receipt of a $100.0 million non-refundable commercial launch payment on March 31, 2015, which was recognized as revenue in March 2015. In March 2015, we agreed to pay AstraZeneca a total of $10.0 million to fund U.S. television advertising in consideration for certain additional commercial information rights. We recorded this $10.0 million obligation as a liability, made the initial $5.0 million payment to AstraZeneca in July 2015, and the remaining $5.0 million payment in July 2016. We determined that this $10.0 million obligation should be recorded as a reduction of revenue, which we recorded in the three months ended March 31, 2015. In August 2015, we received and recognized as revenue an additional $40.0 million non-refundable payment triggered by the first commercial sale of MOVENTIG^® in Germany.

On March 1, 2016, AstraZeneca announced that it had entered into an agreement with ProStrakan Group plc (ProStrakan), a subsidiary of Kyowa Hakko Kirin Co. Ltd., granting ProStrakan exclusive marketing rights to MOVENTIG^® in the EU, Iceland, Liechtenstein, Norway and Switzerland. Under the terms of AstraZeneca’s agreement with ProStrakan, ProStrakan made a $70.0 million upfront payment to AstraZeneca and will make additional payments based on achieving market access milestones, tiered net sales royalties, as well as sales milestones. Under our license agreement with AstraZeneca, AstraZeneca and we will share the upfront payment, market access milestones, royalties and sales milestones from ProStrakan with AstraZeneca receiving 60% and Nektar receiving 40%. This payment sharing arrangement is in lieu of other royalties payable by AstraZeneca to us and a portion of the sales milestones as described below. Our 40% share of royalty payments made by ProStrakan to AstraZeneca will be financially equivalent to us receiving high single-digit to low double-digit royalties dependent on the level of ProStrakan’s net sales. ProStrakan’s MOVENTIG^® net sales will be included for purposes of achieving the annual global sales milestones payable to us by AstraZeneca and will also be included for purposes of determining the applicable ex-U.S. royalty rate, from the tier schedule in our AstraZeneca license agreement, that will be applied to ex-U.S. sales outside of the ProStrakan territory. The global sales milestones under our license agreement with AstraZeneca will be reduced in relation to the amount of ProStrakan MOVENTIG^® net sales that contribute to any given annual sales milestone target. As a result, we were entitled to receive 40% (or $28.0 million) of the $70.0 million payment received by AstraZeneca from ProStrakan in March 2016, recognized this amount as revenue in March 2016 and received this $28.0 million in April 2016. In the three months ended September 30, 2016, we recognized $3.0 million related to our share of an additional sublicense milestone payment made by ProStrakan to AstraZeneca in September 2016. As of September 30, 2016, we do not have deferred revenue related to our agreement with AstraZeneca.

In general, other than as described above and in this paragraph, AstraZeneca has full responsibility for all research, development and commercialization costs under our license agreement. As part of its approval of MOVANTIK^TM, the FDA required AstraZeneca to perform a post-marketing, observational epidemiological study comparing MOVANTIK^TM to other treatments of OIC in patients with chronic, non-cancer pain. As a result, the royalty rate payable to us from net sales of MOVANTIK^TM in the U.S. by AstraZeneca will be reduced by up to two percentage points to fund 33% of the external costs incurred by AstraZeneca to fund such post approval study once it is initiated, subject to a $35.0 million aggregate cap. Any costs incurred by AstraZeneca can only be recovered by the reduction of the royalty paid to us. In no case can amounts be recovered by the reduction of a contingent payment due from AstraZeneca to us or through a payment from us to AstraZeneca.

Baxalta Incorporated: Hemophilia

We are a party to an exclusive research, development, license and manufacturing and supply agreement with Baxalta Incorporated (Baxalta) entered into in September 2005 to develop products designed to improve therapies for Hemophilia A patients using our PEGylation technology. Under the terms of the agreement, we are entitled to research and development funding and are responsible for supplying Baxalta with its requirements for our proprietary materials. Baxalta is responsible for all clinical development, regulatory, and commercialization expenses.

This Hemophilia A program includes ADYNOVATE^TM, which was approved by the FDA in November 2015 for use in adults and adolescents, aged 12 years and older, who have Hemophilia A, and is now marketed in the U.S. As a result of the FDA’s approval, we achieved and recognized a $10.0 million development milestone in November 2015, which was received in January 2016. In addition, under the terms of this agreement, we are entitled to a $10.0 million development milestone due upon marketing authorization in the EU, as well as sales milestones upon achievement of annual sales targets and royalties based on annual worldwide net sales of products resulting from this agreement. As of September 30, 2016, we do not have deferred revenue related to this agreement.

Roche: PEGASYS^® and MIRCERA^®

In February 2012, we entered into a toll-manufacturing agreement with Roche under which we will manufacture the proprietary PEGylation material used by Roche to produce MIRCERA^®. Roche entered into the toll-manufacturing agreement with the objective of establishing us as a secondary back-up supply source on a non-exclusive basis. Under the terms of our toll-manufacturing agreement, Roche paid us an upfront payment of $5.0 million and an additional $22.0 million in performance-based milestone payments upon our achievement of certain manufacturing readiness, validation and production milestones, including the delivery of specified quantities of PEGylation materials, all of which were completed as of January 2013. Roche will also pay us additional consideration for any future orders of the PEGylation materials for MIRCERA^® beyond the initial quantities manufactured through January 2013. Roche has the right to terminate the toll-manufacturing agreement due to an uncured material default by us. In addition, in August 2013, we agreed to deliver additional quantities of PEGylation materials used by Roche to produce PEGASYS^® and MIRCERA^®, all of which were delivered in the last quarter of 2013, for total consideration of $18.6 million. As of September 30, 2016, we have deferred revenue of approximately $1.9 million related to this agreement, which we expect to recognize through December 2016, the estimated end of our obligations under this agreement.

In February 1997, we entered into a license, manufacturing and supply agreement with Roche, under which we granted Roche a worldwide, exclusive license to certain intellectual property related to our proprietary PEGylation materials used in the manufacture and commercialization of PEGASYS^®. Our performance obligations under this PEGASYS^® agreement ended on December 31, 2015.

Amgen, Inc.: Neulasta®

In October 2010, we amended and restated an existing supply and license agreement by entering into a supply, dedicated suite and manufacturing guarantee agreement (the amended and restated agreement) and a license agreement with Amgen Inc. and Amgen Manufacturing, Limited (together referred to as Amgen). Under the terms of the amended and restated agreement, we received a $50.0 million payment in the fourth quarter of 2010 in return for our guaranteeing the supply of certain quantities of our proprietary PEGylation materials to Amgen. As of September 30, 2016, we have deferred revenue of approximately $20.4 million related to this agreement, which we expect to recognize through October 2020, the estimated end of our obligations under this agreement.

Bayer Healthcare LLC: BAY41-6551 (Amikacin Inhale)

In August 2007, we entered into a co-development, license and co-promotion agreement with Bayer Healthcare LLC (Bayer) to develop a specially-formulated inhaled Amikacin. We are responsible for development and manufacturing and supply of our proprietary nebulizer device included in the Amikacin product. In April 2013, Bayer initiated a Phase 3 clinical trial in the treatment of intubated and mechanically ventilated patients with Gram-negative pneumonia. As of September 30, 2016, we have received an upfront payment of $40.0 million (which was paid to us in 2007) and milestone payments totaling $30.0 million (the last of which was paid to us in 2013). In addition, in June 2013, we made a $10.0 million payment to Bayer for the reimbursement of some of its costs of the Phase 3 clinical trial.

We are entitled to receive a total of up to an additional $50.0 million of development milestones upon achievement of certain development objectives, as well as sales milestones upon achievement of annual sales targets and royalties based on annual worldwide net sales of Amikacin Inhale. As of September 30, 2016, we have deferred revenue of approximately $18.2 million related to this agreement, which we expect to recognize through June 2029, the estimated end of our obligations under this agreement.

Ophthotech Corporation: Fovista^®

We are a party to an agreement with Ophthotech Corporation (Ophthotech), dated September 30, 2006, under which Ophthotech received a worldwide, exclusive license to certain of our proprietary PEGylation technology to develop, manufacture and sell Fovista®. Under the terms of our agreement, we are the exclusive supplier of all of Ophthotech’s clinical and commercial requirements for our proprietary PEGylation reagent used in Fovista^®, which is currently in Phase 3 clinical development. On May 19, 2014, Ophthotech entered into a Licensing and Commercialization Agreement with Novartis Pharma AG for Fovista^®. Under our agreement with Ophthotech, in June 2014, we received a $19.8 million payment in connection with this licensing agreement. As of September 30, 2016, we have deferred revenue of approximately $17.2 million related to this agreement, which we expect to recognize through March 2029, the estimated end of our obligations under our agreement with Ophthotech.

In addition, we are entitled to up to $9.5 million in additional payments based upon Ophthotech’s potential achievement of certain regulatory and sales milestones, including a $2.5 million milestone due upon acceptance for review of a regulatory approval application in the U.S. or EU. We are also entitled to royalties on net sales of Fovista^® that vary based on sales levels, if commercialized.

Other

In addition, as of September 30, 2016, we have a number of collaboration agreements, including with our collaboration partner UCB, under which we are entitled to up to a total of $45.5 million of development milestones upon achievement of certain development objectives, as well as sales milestones upon achievement of annual sales targets and royalties based on net sales of commercialized products, if any. However, given the current phase of development of the potential products under these collaboration agreements, we cannot estimate the probability or timing of achieving these milestones. As of September 30, 2016, we have deferred revenue of approximately $9.4 million related to these other collaboration agreements, which we expect to recognize through 2020, the estimated end of our obligations under those agreements.

Stock-Based Compensation

9 Months Ended

Sep. 30, 2016

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation

Note 7 — Stock-Based Compensation

Total stock-based compensation expense was recognized in our Condensed Consolidated Statements of Operations as follows (in thousands):

	Three months ended September 30,				Nine months ended September 30,
	2016		2015		2016		2015
Cost of goods sold	$	396	$	274	$	1,186	$	837
Research and development		3,181		2,208		9,505		6,755
General and administrative		2,589		2,280		8,102		6,907
Total stock-based compensation	$	6,166	$	4,762	$	18,793	$	14,499

During the three months ended September 30, 2016 and 2015, we granted options to purchase 657,960 and 483,300 shares, respectively, at a weighted average grant-date fair value of $8.06 per share and $5.86 per share, respectively. During the three months ended September 30, 2016 and 2015, we granted 56,000 and 120,000 restricted stock unit awards (RSUs), respectively.

During the nine months ended September 30, 2016 and 2015, we granted options to purchase 1,447,250 and 962,310 shares, respectively, at a weighted average grant-date fair value of $7.42 per share and $6.10 per share, respectively. During the nine months ended September 30, 2016 and 2015, we granted 58,000 and 120,000 RSUs, respectively.

As a result of stock issuances under our equity compensation plans, during the three months ended September 30, 2016 and 2015, we issued 1,193,764 and 1,031,573 shares of our common stock, respectively, and during the nine months ended September 30, 2016 and 2015, we issued 2,507,701 and 2,000,823 shares of our common stock, respectively.

- Definition

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

+ References + Details

Net Loss Per Share	9 Months Ended
Net Loss Per Share	Sep. 30, 2016
Earnings Per Share [Abstract]
Net Loss Per Share	Note 8 — Net Loss Per Share Basic net loss per share is calculated based on the weighted-average number of common shares outstanding during the periods presented. For all periods presented in the accompanying Condensed Consolidated Statements of Operations, the net loss available to common stockholders is equal to the reported net loss. Basic and diluted net loss per share are the same due to our historical net losses and the requirement to exclude potentially dilutive securities which would have an anti-dilutive effect on net loss per share. During the three and nine months ended September 30, 2016 and 2015, potentially dilutive securities consisted of common shares underlying outstanding stock options and RSUs. During the three months ended September 30, 2016 and 2015, there were weighted average outstanding stock options and RSUs of 19.1 million and 20.6 million shares, respectively, and during the nine months ended September 30, 2016 and 2015, there were weighted average outstanding stock options and RSUs of 19.4 million and 21.3 million shares, respectively.

Subsequent Event	9 Months Ended
Subsequent Event	Sep. 30, 2016
Subsequent Events [Abstract]
Subsequent Event	Note 9 — Subsequent Event On October 24, 2016, we completed the issuance and sale of 14,950,000 shares of our common stock, including 1,950,000 shares issued upon the full exercise by the underwriters of an option granted by us to the underwriters, in an underwritten public offering with total proceeds of approximately $189.7 million after deducting the underwriting commissions and discounts of approximately $12.1 million. In addition, we incurred approximately $0.6 million in legal and accounting fees, filing fees, and other costs in connection with this offering.

Organization and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization	Organization We are a biopharmaceutical company headquartered in San Francisco, California and incorporated in Delaware. We are developing a pipeline of drug candidates that utilize our PEGylation and advanced polymer conjugate technology platforms, which are designed to enable the development of new molecular entities that target known mechanisms of action. Our current proprietary pipeline is comprised of drug candidates across a number of therapeutic areas including oncology, pain, anti-infectives, and immunology. Our research and development activities have required significant ongoing investment to date and are expected to continue to require significant investment. As a result, we expect to continue to incur substantial losses and negative cash flows from operations in the future. We have financed our operations primarily through cash generated from licensing, collaboration and manufacturing agreements and financing transactions. At September 30, 2016, we had approximately $253.5 million in cash and investments in marketable securities. Also, as of September 30, 2016, we had $254.5 million in debt, including $250.0 million in principal of senior secured notes and $4.5 million of capital lease obligations, of which $2.4 million is current.
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation Our consolidated financial statements include the financial position, results of operations and cash flows of our wholly-owned subsidiaries: Nektar Therapeutics (India) Private Limited (Nektar India) and Nektar Therapeutics UK Limited. All intercompany accounts and transactions have been eliminated in consolidation. We prepared our Condensed Consolidated Financial Statements following the requirements of the Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. generally accepted accounting principles (GAAP) for annual periods can be condensed or omitted. In the opinion of management, these financial statements include all normal and recurring adjustments that we consider necessary for the fair presentation of our financial position and operating results. Our Condensed Consolidated Financial Statements are denominated in U.S. dollars. Accordingly, changes in exchange rates between the applicable foreign currency and the U.S. dollar will affect the translation of each foreign subsidiary’s financial results into U.S. dollars for purposes of reporting our consolidated financial results. Translation gains and losses are included in accumulated other comprehensive loss in the stockholders’ equity section of the Condensed Consolidated Balance Sheets. To date, such cumulative currency translation adjustments have not been significant to our consolidated financial position. Our comprehensive loss consists of our net loss plus our foreign currency translation gains and losses and unrealized holding gains and losses on available-for-sale securities, neither of which were significant during the three and nine months ended September 30, 2016 and 2015. In addition, there were no significant reclassifications out of accumulated other comprehensive loss to the statements of operations during the three and nine months ended September 30, 2016 and 2015. The accompanying Condensed Consolidated Financial Statements are unaudited. The Condensed Consolidated Balance Sheet data as of December 31, 2015 was derived from the audited consolidated financial statements which are included in our Annual Report on Form 10-K for the year ended December 31, 2015 filed with the SEC on February 29, 2016. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the consolidated financial statements and the accompanying notes to those financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2015. Revenue, expenses, assets, and liabilities can vary during each quarter of the year. The results and trends in these interim Condensed Consolidated Financial Statements are not necessarily indicative of the results to be expected for the full year or any other periods.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Accounting estimates and assumptions are inherently uncertain. Actual results could differ materially from those estimates and assumptions. Our estimates include those related to estimated selling prices of deliverables in collaboration agreements, estimated periods of performance, the net realizable value of inventory, the impairment of investments, the impairment of goodwill and long-lived assets, contingencies, accrued clinical trial expenses, estimated non-cash royalty revenue and interest expense from our liability related to our sale of future royalties, stock-based compensation, and ongoing litigation, among other estimates. We base our estimates on historical experience and on other assumptions that management believes are reasonable under the circumstances. These estimates form the basis for making judgments about the carrying values of assets and liabilities when these values are not readily apparent from other sources. As appropriate, estimates are assessed each period and updated to reflect current information and any changes in estimates will generally be reflected in the period first identified.
Reclassifications	Reclassifications Certain items previously reported in specific financial statement captions have been reclassified to conform to the current period presentation, including as a result of the adoption of new accounting guidance related to debt issuance costs described below. Such reclassifications do not materially impact previously reported revenue, operating income (loss), net income (loss), total assets, liabilities or stockholders’ equity (deficit).
Segment Information	Segment Information We operate in one business segment which focuses on applying our technology platforms to improve the performance of established and novel drug candidates. We operate in one segment because our business offerings have similar economics and other characteristics, including the nature of products and manufacturing processes, types of customers, distribution methods and regulatory environment. We are comprehensively managed as one business segment by our Chief Executive Officer and his management team.
Significant Concentrations	Significant Concentrations Our customers are primarily pharmaceutical and biotechnology companies that are located in the U.S. and Europe. Our accounts receivable balance contains billed and unbilled trade receivables from product sales, milestones, other contingent payments and royalties, as well as time and materials based billings from collaborative research and development agreements. When appropriate, we provide for an allowance for doubtful accounts by reserving for specifically identified doubtful accounts. We generally do not require collateral from our customers. We perform a regular review of our customers’ payment histories and associated credit risk. We have not experienced significant credit losses from our accounts receivable and our allowance for doubtful accounts was not significant at either September 30, 2016 or December 31, 2015. We are dependent on our suppliers and contract manufacturers to provide raw materials, drugs and devices of appropriate quality and reliability and to meet applicable contract and regulatory requirements. In certain cases, we rely on single sources of supply of one or more critical materials. Consequently, in the event that supplies are delayed or interrupted for any reason, our ability to develop and produce our drug candidates or our ability to meet our supply obligations could be significantly impaired, which could have a material adverse effect on our business, financial condition and results of operations.
Revenue Recognition	Revenue Recognition Our revenue is derived from our arrangements with pharmaceutical and biotechnology collaboration partners and may result from one or more of the following: upfront and license fees, payments for contract research and development, milestone and other contingent payments, manufacturing and supply payments, and royalties. Our performance obligations under our collaborations may include licensing our intellectual property, manufacturing and supply obligations, and research and development obligations. In order to account for the multiple-element arrangements, we identify the deliverables included within the arrangement and evaluate which deliverables represent separate units of accounting. Analyzing the arrangement to identify deliverables requires the use of judgment, and each deliverable may be an obligation to deliver goods or services, a right or license to use an asset, or another performance obligation. Revenue is recognized separately for each identified unit of accounting when the basic revenue recognition criteria are met: there is persuasive evidence that an arrangement exists, delivery has occurred, the price is fixed or determinable, and collection is reasonably assured. At the inception of each new multiple-element arrangement or the material modification of an existing multiple-element arrangement, we allocate all consideration received under multiple-element arrangements to all units of accounting based on the relative selling price method, generally based on our best estimate of selling price (ESP). The objective of ESP is to determine the price at which we would transact a sale if the product or service was sold on a stand-alone basis. We determine ESP for the elements in our collaboration arrangements by considering multiple factors including, but not limited to, technical complexity of the performance obligation and similarity of elements to those performed under previous arrangements. Since we apply significant judgment in arriving at the ESPs, any material change in our estimates would significantly affect the allocation of the total consideration to the different elements of a multiple element arrangement. Product sales Product sales are primarily derived from fixed price and cost-plus manufacturing and supply agreements with our collaboration partners. We have not experienced any significant returns from our customers. Royalty revenue Generally, we are entitled to royalties from our collaboration partners based on the net sales of their approved drugs that are marketed and sold in one or more countries where we hold royalty rights. We recognize royalty revenue when the cash is received or when the royalty amount to be received is estimable and collection is reasonably assured. With respect to the non-cash royalties related to sale of future royalties described in Note 4, revenue is recognized when estimable, otherwise, revenue is recognized during the period in which the related royalty report is received, which generally occurs in the quarter after the applicable product sales are made. License, collaboration and other revenue The amount of upfront fees and other payments received by us in license and collaboration arrangements that are allocated to continuing performance obligations, such as manufacturing and supply obligations, are deferred and generally recognized ratably over our expected performance period under each respective arrangement. We make our best estimate of the period over which we expect to fulfill our performance obligations, which may include technology transfer assistance, research activities, clinical development activities, and manufacturing activities from research and development through the commercialization of the product. Given the uncertainties of these collaboration arrangements, significant judgment is required to determine the duration of the performance period and this estimate is periodically re-evaluated. Contingent consideration received from the achievement of a substantive milestone is recognized in its entirety in the period in which the milestone is achieved, which we believe is consistent with the substance of our performance under our various license and collaboration agreements. A milestone is defined as an event (i) that can only be achieved based in whole or in part either on the entity’s performance or on the occurrence of a specific outcome resulting from the entity’s performance, (ii) for which there is substantive uncertainty at the date the arrangement is entered into that the event will be achieved, and (iii) that would result in additional payments being due to the entity. A milestone is substantive if the consideration earned from the achievement of the milestone is consistent with our performance required to achieve the milestone or the increase in value to the collaboration resulting from our performance, relates solely to our past performance, and is reasonable relative to all of the other deliverables and payments within the arrangement. Our license and collaboration agreements with our partners provide for payments to us upon the achievement of development milestones, such as the completion of clinical trials or regulatory submissions, approvals by regulatory authorities, and commercial launches of drugs. Given the challenges inherent in developing and obtaining regulatory approval for drug products and in achieving commercial launches, there was substantial uncertainty whether any such milestones would be achieved at the time of execution of these licensing and collaboration agreements. In addition, we evaluated whether the development milestones met the remaining criteria to be considered substantive. As a result of our analysis, we consider our remaining development milestones under all of our license and collaboration agreements to be substantive and, accordingly, we expect to recognize as revenue future payments received from each milestone only if and as such milestone is achieved. Our license and collaboration agreements with certain partners also provide for contingent payments to us based solely upon the performance of the respective partner. For such contingent amounts, we expect to recognize the payments as revenue when earned under the applicable contract, which is generally upon completion of performance by the respective partner, provided that collection is reasonably assured. Our license and collaboration agreements with our partners also provide for payments to us upon the achievement of specified sales volumes of approved drugs. We consider these payments to be similar to royalty payments and we will recognize such sales-based payments upon achievement of such sales volumes, provided that collection is reasonably assured.
Research and Development Expense	Research and Development Expense Research and development costs are expensed as incurred and include salaries, benefits and other operating costs such as outside services, supplies and allocated overhead costs. We perform research and development for our proprietary drug candidates and technology development and for certain third parties under collaboration agreements. For our proprietary drug candidates and our internal technology development programs, we invest our own funds without reimbursement from a third party. We record accruals for the estimated costs of our clinical trial activities performed by third parties. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows to our vendors. Payments under the contracts depend on factors such as the achievement of certain events, successful enrollment of patients, and completion of certain clinical trial activities. We generally accrue costs associated with the start-up and reporting phases of the clinical trials ratably over the estimated duration of the start-up and reporting phases. We generally accrue costs associated with the treatment phase of clinical trials based on the total estimated cost of the treatment phase on a per patient basis and we expense the per patient cost ratably over the estimated patient treatment period based on patient enrollment in the trials. In specific circumstances, such as for certain time-based costs, we recognize clinical trial expenses using a methodology that we consider to be more reflective of the timing of costs incurred. Advance payments for goods or services that will be used or rendered for future research and development activities are capitalized as prepaid expenses and recognized as expense as the related goods are delivered or the related services are performed. We base our estimates on the best information available at the time. However, additional information may become available to us which may allow us to make a more accurate estimate in future periods. In this event, we may be required to record adjustments to research and development expenses in future periods when the actual level of activity becomes more certain. Such increases or decreases in cost are generally considered to be changes in estimates and will be reflected in research and development expenses in the period identified.
Long-Lived Assets	Long-Lived Assets We assess the impairment of long-lived assets, primarily property, plant and equipment and goodwill, whenever events or changes in business circumstances indicate that the carrying amounts of the assets may not be fully recoverable. When such events occur, we determine whether there has been an impairment in value by comparing the carrying value of the asset with its fair value, as measured by the anticipated undiscounted net cash flows associated with the asset. In the case of goodwill impairment, we perform an impairment test at least annually, on October 1 of each year, and market capitalization is generally used as the measure of fair value. If an impairment in value exists, the asset is written down to its estimated fair value.
Income Taxes	Income Taxes For the three and nine months ended September 30, 2016 and 2015, we recorded an income tax provision for our Nektar India operations at an effective tax rate of approximately 35%. The U.S. federal deferred tax assets generated from our net operating losses have been fully reserved, as we believe it is not more likely than not that the benefit will be realized.
Adoption of New Accounting Principle	Adoption of New Accounting Principle In April 2015, the Financial Accounting Standards Board (FASB) issued guidance to simplify the presentation of debt issuance costs by requiring debt issuance costs to be presented as a deduction from the corresponding debt liability. This guidance is effective for our interim and annual periods beginning January 1, 2016. Upon adoption, the new guidance must be applied retrospectively to all periods presented. Accordingly, as of January 1, 2016, we reclassified $0.4 million and $3.0 million of capitalized debt issuance costs to senior secured notes, net, and liability related to the sale of future royalties, net, respectively, from our other assets balance. This reclassification has also been applied retrospectively to these balances in our Condensed Consolidated Balance Sheet as of December 31, 2015.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the FASB issued guidance codified in Accounting Standards Codification (ASC) 606, Revenue Recognition — Revenue from Contracts with Customers, which amends the guidance in former ASC 605, Revenue Recognition, and is effective for public companies for fiscal years beginning after December 15, 2017. Entities have the option of using either a full retrospective or a modified retrospective approach to adopt this new guidance. We are currently evaluating the impact of the provisions of ASC 606. In March 2016, the FASB issued guidance to simplify several aspects of employee share-based payment accounting, including income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. This guidance will become effective for us beginning in the first quarter of 2017. Early adoption is permitted. We are currently evaluating the impact of the adoption of this standard. In February 2016, the FASB issued guidance to amend a number of aspects of lease accounting, including requiring lessees to recognize almost all leases with a term greater than one year as a right-of-use asset and corresponding liability, measured at the present value of the lease payments. The guidance will become effective for us beginning in the first quarter of 2019 and is required to be adopted using a modified retrospective approach. Early adoption is permitted. We are currently evaluating the impact of the adoption of this standard.
Liability Related to Sale of Future Royalties	We periodically assess the estimated royalty payments to RPI from UCB and Roche and to the extent such payments are greater or less than our initial estimates, or the timing of such payments is materially different than our original estimates, we will prospectively adjust the amortization of the Royalty Obligation.

Cash and Investments in Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2016

Fair Value Disclosures [Abstract]

Cash and Investments in Marketable Securities, Including Cash Equivalents

Cash and investments in marketable securities, including cash equivalents, are as follows (in thousands):

	Estimated Fair Value at
	September 30, 2016		December 31, 2015
Cash and cash equivalents	$	63,295	$	55,570
Short-term investments		190,216		253,374
Total cash and investments in marketable securities	$	253,511	$	308,944

Portfolio of Cash and Investments in Marketable Securities

Our portfolio of cash and investments in marketable securities includes (in thousands):

			Estimated Fair Value at
	Fair Value Hierarchy Level		September 30, 2016		December 31, 2015
Corporate notes and bonds		2	$	74,564	$	181,969
Corporate commercial paper		2		95,924		61,150
Obligations of U.S. government agencies		2		16,798		7,325
Available-for-sale investments				187,286		250,444
Money market funds		1		62,092		53,728
Certificate of deposit	N/A			2,930		2,930
Cash	N/A			1,203		1,842
Total cash and investments in marketable securities			$	253,511	$	308,944

Inventory (Tables)

9 Months Ended

Sep. 30, 2016

Inventory Disclosure [Abstract]

Inventory

Inventory consists of the following (in thousands):

	September 30, 2016		December 31, 2015
Raw materials	$	2,386	$	3,236
Work-in-process		6,695		6,087
Finished goods		1,673		2,023
Total inventory	$	10,754	$	11,346

License and Collaboration Agreements (Tables)

9 Months Ended

Sep. 30, 2016

Organization Consolidation And Presentation Of Financial Statements [Abstract]

License, Collaboration and Other Revenue

In accordance with our collaboration agreements, we recognized license, collaboration and other revenue as follows (in thousands):

		Three months ended September 30,				Nine months ended September 30,
Partner	Drug or Drug Candidate	2016		2015		2016		2015
AstraZeneca AB	MOVANTIK^TM and MOVANTIK^TM fixed-dose combination program	$	3,000	$	40,000	$	31,000	$	130,000
Roche	PEGASYS^® and MIRCERA^®		1,929		3,212		5,771		9,619
Amgen, Inc.	Neulasta^®		1,250		1,250		3,750		3,750
Daiichi Sankyo Europe GmbH	ONZEALD^TM (NKTR-102)		216		—		3,474		—
Bayer Healthcare LLC	BAY41-6551 (Amikacin Inhale)		357		357		1,072		1,562
Baxalta Incorporated	ADYNOVATE^TM		336		409		648		607
Other			1,285		1,247		5,114		3,885
License, collaboration and other revenue		$	8,373	$	46,475	$	50,829	$	149,423

Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2016

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation Expense

Total stock-based compensation expense was recognized in our Condensed Consolidated Statements of Operations as follows (in thousands):

	Three months ended September 30,				Nine months ended September 30,
	2016		2015		2016		2015
Cost of goods sold	$	396	$	274	$	1,186	$	837
Research and development		3,181		2,208		9,505		6,755
General and administrative		2,589		2,280		8,102		6,907
Total stock-based compensation	$	6,166	$	4,762	$	18,793	$	14,499

Organization and Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands		3 Months Ended		9 Months Ended
	Jan. 01, 2016 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015	Sep. 30, 2016 USD ($) Segment	Sep. 30, 2015	Dec. 31, 2015 USD ($)
Organization And Summary Of Significant Accounting Policies [Line Items]
Cash and investments in marketable securities		$ 253,511		$ 253,511		$ 308,944
Senior secured notes		250,000		250,000
Debt and capital lease obligation		254,500		254,500
Capital lease obligations		4,500		4,500
Capital lease obligations, current portion		$ 2,370		$ 2,370		$ 4,756
Number of business segments \| Segment				1
Senior Secured Notes
Organization And Summary Of Significant Accounting Policies [Line Items]
Reclassification of capitalized issuance costs	$ 400
Liability Related To Future Royalties Liability Balances
Organization And Summary Of Significant Accounting Policies [Line Items]
Reclassification of capitalized issuance costs	$ 3,000
India
Organization And Summary Of Significant Accounting Policies [Line Items]
Effective income tax rate – India		35.00%	35.00%	35.00%	35.00%

Cash and Investments in Marketable Securities - Cash and Investments in Marketable Securities, Including Cash Equivalents (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and cash equivalents	$ 63,295	$ 55,570	$ 18,819	$ 12,365
Short-term investments	190,216	253,374
Total cash and investments in marketable securities	$ 253,511	$ 308,944

Cash and Investments in Marketable Securities - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Cash and Investments in Marketable Securities [Line Items]
Maximum maturity term for debt securities investment			Two years or less
Weighted average maturity term for debt securities investment			One year or less
Available-for-sale securities, sold	$ 5,000,000	$ 18,600,000	$ 4,969,000	$ 23,778,000
Level 1 to level 2 transfers	0	0	0	0
Level 2 to level 1 transfers	0	$ 0	0	$ 0
Senior secured notes, principal amount	$ 250,000,000		$ 250,000,000
Senior Notes [Member] \| 7.75% Senior Secured Notes Due October 2020 [Member]
Cash and Investments in Marketable Securities [Line Items]
Senior secured notes, interest rate	7.75%		7.75%
Senior secured notes, maturity date			Oct. 05, 2020
Minimum cash and investments in marketable securities to be maintained	$ 60,000,000		$ 60,000,000
Senior Notes [Member] \| 7.75% Senior Secured Notes Due October 2020 [Member] \| Level 3 [Member]
Cash and Investments in Marketable Securities [Line Items]
Senior secured notes, interest rate	7.75%		7.75%
Senior secured notes, maturity date			Oct. 05, 2020
Senior secured notes, principal amount	$ 250,000,000		$ 250,000,000

Cash and Investments in Marketable Securities - Portfolio of Cash and Investments in Marketable Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	$ 187,286	$ 250,444
Cash, including restricted cash	1,203	1,842
Total cash and investments in marketable securities	253,511	308,944
Corporate Notes and Bonds [Member] \| Fair Value Hierarchy Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	74,564	181,969
Corporate Commercial Paper [Member] \| Fair Value Hierarchy Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	95,924	61,150
Obligations of U.S. government agencies [Member] \| Fair Value Hierarchy Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	16,798	7,325
Money Market Funds [Member] \| Fair Value Hierarchy Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable securities	62,092	53,728
Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable securities	$ 2,930	$ 2,930

Inventory - Inventory (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Inventory Disclosure [Abstract]
Raw materials	$ 2,386	$ 3,236
Work-in-process	6,695	6,087
Finished goods	1,673	2,023
Total inventory	$ 10,754	$ 11,346

Liability Related to the Sale of Future Royalties - Additional Information (Detail) - USD ($) $ in Thousands		1 Months Ended		3 Months Ended		9 Months Ended
	Feb. 24, 2012	Mar. 31, 2014	Mar. 31, 2013	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Liability Related to the Sale of Future Royalties [Line Items]
Non-cash royalty revenue related to sale of future royalties				$ 7,692	$ 6,050	$ 22,341	$ 14,752
Non-cash interest expense on liability related to sale of future royalties				$ 4,902	$ 5,226	$ 14,929	$ 15,428
Annual interest rate						17.00%
Royalty agreement contingent payment description						as a result of worldwide net sales of MIRCERA® for the 12 month periods ended December 31, 2013 and 2012 not reaching certain minimum thresholds.
Purchase and Sale Agreement with RPI [Member]
Liability Related to the Sale of Future Royalties [Line Items]
Proceeds from sale of royalty rights	$ 124,000
Transaction costs related to sale of potential future royalties	$ 4,400
Payment made for milestone not achieved year two		$ 7,000
Payment made for milestone not achieved year one			$ 3,000

Commitments and Contingencies - Additional Information (Detail) - USD ($)	Sep. 30, 2016	Dec. 31, 2015	Aug. 14, 2015
Loss Contingencies [Line Items]
Damage claim for alleged unpaid licenses			$ 1,500,000
Indemnification Obligation [Member]
Loss Contingencies [Line Items]
Indemnification obligations, liabilities	$ 0	$ 0

License and Collaboration Agreements - License, Collaboration and Other Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
License And Collaboration Agreements [Line Items]
License, collaboration and other revenue	$ 8,373	$ 46,475	$ 50,829	$ 149,423
AstraZeneca AB [Member] \| MOVANTIKTM and MOVANTIKTM fixed-dose combination program [Member]
License And Collaboration Agreements [Line Items]
License, collaboration and other revenue	3,000	40,000	31,000	130,000
Roche [Member] \| PEGASYS and MIRCERA [Member]
License And Collaboration Agreements [Line Items]
License, collaboration and other revenue	1,929	3,212	5,771	9,619
Amgen, Inc. [Member] \| Neulasta [Member]
License And Collaboration Agreements [Line Items]
License, collaboration and other revenue	1,250	1,250	3,750	3,750
Daiichi Sankyo Europe GmbH [Member] \| ONZEALDTM (NKTR-102) [Member]
License And Collaboration Agreements [Line Items]
License, collaboration and other revenue	216	0	3,474	0
Bayer Healthcare LLC [Member] \| BAY41-6551 (Amikacin Inhale) [Member]
License And Collaboration Agreements [Line Items]
License, collaboration and other revenue	357	357	1,072	1,562
Baxalta Incorporated [Member] \| ADYNOVATETM [Member]
License And Collaboration Agreements [Line Items]
License, collaboration and other revenue	336	409	648	607
Other [Member]
License And Collaboration Agreements [Line Items]
License, collaboration and other revenue	$ 1,285	$ 1,247	$ 5,114	$ 3,885

License and Collaboration Agreements - Additional Information (Detail) - USD ($)					1 Months Ended									3 Months Ended				9 Months Ended	12 Months Ended
	Sep. 21, 2016	May 30, 2016	Mar. 01, 2016	Sep. 16, 2014	Aug. 31, 2016	Apr. 30, 2016	Mar. 31, 2016	Nov. 30, 2015	Aug. 31, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2013	Feb. 29, 2012	Sep. 30, 2016	Dec. 31, 2013	Dec. 31, 2010	Dec. 31, 2009	Sep. 30, 2016	Dec. 31, 2013	Dec. 31, 2007	Jul. 31, 2016	Dec. 31, 2015	Jul. 31, 2015
Deferred Revenue Arrangement [Line Items]
Potential future additional payments for development milestones																		$ 147,000,000
Liability for refundable upfront payment														$ 12,500,000				$ 12,500,000				$ 0
ONZEALDTM (NKTR-102) [Member] \| Turkey [Member]
Deferred Revenue Arrangement [Line Items]
Percentage of royalty on net sales		15.00%
AstraZeneca-ProStrakan [Member]
Deferred Revenue Arrangement [Line Items]
Percentage of upfront payment, market access milestones, royalties and sales milestones			40.00%
Bristol-Myers Squibb [Member] \| NKTR-214 [Member]
Deferred Revenue Arrangement [Line Items]
Percentage of out-of-pocket costs reimbursed by partner	50.00%
License agreement exclusivity expiration date																		Sep. 30, 2018
License agreement exclusivity negotiation period																		3 months
Daiichi Sankyo Europe GmbH [Member] \| ONZEALDTM (NKTR-102) [Member]
Deferred Revenue Arrangement [Line Items]
Eligible milestone payments receivable upon achievement of regulatory and commercial milestones		$ 60,000,000
Milestone payments to be received upon first commercial sales		10,000,000
Milestone payment to be received upon first commercial sale after final regulatory approval		25,000,000
Milestone payments to be received upon first achievement of annual net sales target		$ 25,000,000
Liability for refundable upfront payment														12,500,000				$ 12,500,000
Daiichi Sankyo Europe GmbH [Member] \| ONZEALDTM (NKTR-102) [Member] \| European Territory Except Turkey [Member]
Deferred Revenue Arrangement [Line Items]
Percentage of royalty on net sales		20.00%
Daiichi Sankyo Europe GmbH [Member] \| ONZEALDTM (NKTR-102) [Member] \| Upfront Payment Arrangement [Member]
Deferred Revenue Arrangement [Line Items]
Received upfront and milestone payments					$ 20,000,000
Non-refundable portion of upfront payment		$ 7,500,000
Revenue recognized from upfront payment																		3,500,000
Deferred revenue														4,000,000				4,000,000
AstraZeneca AB [Member] \| United States [Member]
Deferred Revenue Arrangement [Line Items]
Liability to AZ for DTC advertising payments										$ 10,000,000											$ 5,000,000		$ 5,000,000
Reduction of revenue										(10,000,000)
AstraZeneca AB [Member] \| MOVANTIKTM and MOVANTIKTM fixed-dose combination program [Member] \| Upfront Payment Arrangement [Member]
Deferred Revenue Arrangement [Line Items]
Received upfront and milestone payments																	$ 125,000,000
AstraZeneca AB [Member] \| MOVANTIK Fixed-dose Combination Program [Member]
Deferred Revenue Arrangement [Line Items]
Potential contingent payments based on development events														75,000,000				75,000,000
AstraZeneca AB [Member] \| MOVANTIK [Member]
Deferred Revenue Arrangement [Line Items]
Received upfront and milestone payments										$ 100,000,000
Percentage of post approval study costs to repay				33.00%
Maximum potential reduction in royalties				$ 35,000,000
AstraZeneca AB [Member] \| MOVANTIK [Member] \| United States [Member]
Deferred Revenue Arrangement [Line Items]
Potential reduction in U.S. royalty rate for repayment				2.00%
AstraZeneca AB [Member] \| MOVANTIK [Member] \| European Union [Member]
Deferred Revenue Arrangement [Line Items]
Received upfront and milestone payments									$ 40,000,000
AstraZeneca AB [Member] \| AstraZeneca-ProStrakan [Member]
Deferred Revenue Arrangement [Line Items]
Received upfront and milestone payments						$ 28,000,000								3,000,000
Deferred revenue														0				0
Upfront and milestone payments received by Our collaboration partner under sublicense arrangement			$ 70,000,000
Percentage of upfront milestones royalty and sales milestone payments from sublicense agreement retained by our collaboration partner			60.00%
Contingent payment recognized as revenue							$ 28,000,000
Baxalta Incorporated [Member] \| ADYNOVATETM (Hemophilia) [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue														0				0
Development milestones achieved								$ 10,000,000
Baxalta Incorporated [Member] \| ADYNOVATETM (Hemophilia) [Member] \| European Union [Member]
Deferred Revenue Arrangement [Line Items]
Potential future additional payments for development milestones																		10,000,000
Roche [Member] \| MIRCERA [Member]
Deferred Revenue Arrangement [Line Items]
Consideration received for product delivered in 2013															$ 18,600,000
Roche [Member] \| MIRCERA [Member] \| Performance-based Milestone Payments [Member]
Deferred Revenue Arrangement [Line Items]
Received upfront and milestone payments													$ 22,000,000
Roche [Member] \| MIRCERA [Member] \| Upfront Payment Arrangement [Member]
Deferred Revenue Arrangement [Line Items]
Received upfront and milestone payments													$ 5,000,000
Roche [Member] \| PEGASYS and MIRCERA [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue														1,900,000				1,900,000
Amgen, Inc. [Member]
Deferred Revenue Arrangement [Line Items]
Received upfront and milestone payments																$ 50,000,000
Deferred revenue														20,400,000				20,400,000
Bayer Healthcare LLC [Member]
Deferred Revenue Arrangement [Line Items]
Potential future additional payments for development milestones																		50,000,000
Deferred revenue														18,200,000				18,200,000
Payment made to Bayer for cost of Phase 3 clinical trial												$ 10,000,000
Bayer Healthcare LLC [Member] \| Performance-based Milestone Payments [Member]
Deferred Revenue Arrangement [Line Items]
Received upfront and milestone payments																			$ 30,000,000
Bayer Healthcare LLC [Member] \| Upfront Payment Arrangement [Member]
Deferred Revenue Arrangement [Line Items]
Received upfront and milestone payments																				$ 40,000,000
Ophthotech Corporation [Member] \| Fovista [Member]
Deferred Revenue Arrangement [Line Items]
Potential future additional payments for development milestones																		9,500,000
Received upfront and milestone payments											$ 19,800,000
Deferred revenue														17,200,000				17,200,000
Potential future development milestones upon acceptance for review of regulatory approval														2,500,000				2,500,000
Other [Member]
Deferred Revenue Arrangement [Line Items]
Potential future additional payments for development milestones																		45,500,000
Deferred revenue														$ 9,400,000				$ 9,400,000

Stock-Based Compensation - Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 6,166	$ 4,762	$ 18,793	$ 14,499
Cost of Goods Sold [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	396	274	1,186	837
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	3,181	2,208	9,505	6,755
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 2,589	$ 2,280	$ 8,102	$ 6,907

Stock-Based Compensation - Additional Information (Detail) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock issuances under equity compensation plans	1,193,764	1,031,573	2,507,701	2,000,823
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted options to purchase shares	657,960	483,300	1,447,250	962,310
Weighted average grant-date fair value	$ 8.06	$ 5.86	$ 7.42	$ 6.10
Restricted Stock Units (RSU) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Awards granted	56,000	120,000	58,000	120,000

Net Loss Per Share - Additional Information (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Stock Options and Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average diluted securities excluded from diluted net loss per share	19.1	20.6	19.4	21.3

Subsequent Event - Additional Information (Detail) - Common Stock [Member] - Subsequent Event [Member] $ in Millions	Oct. 24, 2016 USD ($) shares
Subsequent Event [Line Items]
Sale of common stock, Shares \| shares	14,950,000
Proceeds from sale of common stock	$ 189.7
Underwriting commissions and discounts	12.1
Legal, accounting fees, filing fees and other offering expenses	$ 0.6
Underwriters optional shares [Member]
Subsequent Event [Line Items]
Sale of common stock, Shares \| shares	1,950,000