Organization and Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization We are a research-based biopharmaceutical company headquartered in San Francisco, California and incorporated in Delaware. We (individually or with a partner) are developing a pipeline of drug candidates that utilize our advanced polymer conjugate technology platforms, which are designed to enable the development of new molecular entities that target known mechanisms of action. Our research and development pipeline of new investigational drugs includes investigational treatments in the field of immunotherapy. 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.
Results of Clinical Trial Programs and the Restructuring Plans	Results of Clinical Trial Programs and the Restructuring Plans In March and April 2022, we announced that our registrational trials of bempegaldesleukin in combination with Opdivo® in metastatic melanoma, renal cell carcinoma and locally advanced or metastatic urothelial cancer under our Strategic Collaboration Agreement with Bristol-Myers Squibb Company (BMS) did not meet their primary endpoints. Based on these results, in April 2022, we announced our decisions to discontinue all development of bempegaldesleukin in combination with checkpoint inhibitors, including these trials, our registrational trial in adjuvant melanoma under our BMS Collaboration Agreement, and our Phase 2/3 study of bempegaldesleukin in combination with Keytruda® in squamous cell cancer of the head and neck under our Co-Development Agreement with SFJ Pharmaceuticals. See Note 5 for additional information regarding our BMS Collaboration Agreement and Co-Development Agreement with SFJ Pharmaceuticals. Pursuant to the Strategic Collaboration Agreement, we and BMS continue our efforts to wind down the bempegaldesleukin program. In April 2022, we also announced new strategic reorganization and cost restructuring plans (together, the 2022 Restructuring Plan), pursuant to which we we completed an approximately 70% reduction of our workforce during 2022 and sold our research facility in India in December 2022. On February 23, 2023, we announced the topline data from the Phase 2 study of rezpegaldesleukin in adult patients with systemic lupus erythematosus (SLE) (Phase 2 Lupus Study) under our collaboration agreement with Eli Lilly and Company (Lilly). Lilly notified us that it does not intend to advance rezpegaldesleukin into Phase 3 development for SLE. On April 27, 2023, we announced that we would be regaining the full rights to rezpegaldesleukin from Lilly. Based on the positive results from a Phase 1b study in which rezpegaldesleukin reduced atopic dermatitis symptoms, we plan to initiate a Phase 2b study of rezpegaldesleukin in patients with moderate-to-severe atopic dermatitis in 2023. We will also explore other auto-immune indications for the development of rezpegaldesleukin. Pursuant to plans approved by our Board of Directors (the Board) on March 29, 2023, we announced on April 17, 2023, a new strategic reprioritization and cost restructuring plan (the 2023 Restructuring Plan). Under the 2023 Restructuring Plan, we are reducing our San Francisco-based workforce by approximately 60%, which is expected to be substantially completed by June 2023. We have incurred and expect to incur significant costs resulting from the 2022 and 2023 Restructuring Plans. See Note 6 for additional information on the effect on our Condensed Consolidated Financial Statements.
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation Our Condensed Consolidated Financial Statements include the financial position, results of operations and cash flows of Nektar Therapeutics and our wholly-owned subsidiaries. We have eliminated all intercompany accounts and transactions 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, we may condense or omit certain footnotes or other financial information that are normally required by U.S. generally accepted accounting principles (GAAP) for annual periods. 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. We include translation gains and losses in accumulated other comprehensive loss in the stockholders’ equity section of our 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 gains and losses on available-for-sale securities. There were no significant reclassifications out of accumulated other comprehensive loss to the statements of operations during the three months ended March 31, 2023 and 2022. The accompanying Condensed Consolidated Financial Statements are unaudited. The Condensed Consolidated Balance Sheet data as of December 31, 2022 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, 2022 filed with the SEC on February 28, 2023. 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. 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 period.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles (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. As appropriate, we assess estimates each period, update them to reflect current information, and generally reflect any changes in estimates in the period first identified.
Significant Concentrations	Significant ConcentrationsOur customers are primarily pharmaceutical companies that are located in the U.S. and Europe and with whom we have multi-year arrangements. Our accounts receivable balance contains billed and unbilled trade receivables from product sales, milestones (to the extent that they have been achieved and are due from the counterparty), and other contingent payments, as well as reimbursable costs from collaborative research and development agreements. We are dependent on our suppliers and contract manufacturers to provide raw materials and drugs 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, our ability to supply comparator drugs for our clinical trials, 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. For our available-for-sale securities, we have significant concentrations of issuers in the banking and financial services industries. While our investment policy requires that we only invest in highly-rated securities and limit our exposure to any single issuer, various factors may materially affect the financial condition of issuers. Additionally, pursuant to our investment policy, we may sell securities before maturity if the issuer’s credit rating has been downgraded below our minimum credit rating requirements, which may result in a loss on the sale. Accordingly, if various factors result in downgrades below our minimum credit rating requirements and if we decide to sell these securities, we may experience losses on such sales.
Restructuring	Restructuring We recognize restructuring charges related to reorganization plans that have been committed to by management when liabilities have been incurred. In connection with these activities, we record restructuring charges at fair value for: •contractual or other employee termination benefits provided that the obligations result from services already rendered based on rights that vest or accumulated when the payment of benefits becomes probable and the amount can be reasonably estimated, •one-time employee termination benefits on the communication date from management to the employees provided that management has committed to a plan of termination, the plan identifies the employees and their expected termination dates, the details of termination benefits are complete, and it is unlikely that changes to the plan will be made or the plan will be withdrawn, •contract termination costs when we cancel the contract in accordance with its terms, and •costs to be incurred over the remaining contract term without economic benefit to us at the cease-use date. For one-time employee terminations benefits, we recognize the liability in full on the communication date when future services are not required or amortize the liability ratably over the service period, if required. The fair value of termination benefits reflects our estimates of expected utilization of certain Company-funded post-employment benefits. See Note 6 for additional information on the severance expense that we recognized for employees terminated in connection with our reductions-in-force.
Impairment of Goodwill	Impairment of Goodwill Goodwill is assessed for impairment on an annual basis and whenever events and circumstances indicate that it may be impaired. Factors that may indicate potential impairment and trigger an impairment test include, but are not limited to, current economic, market and geopolitical conditions, including a significant, sustained decline in our stock price and market capitalization compared to the net book value; an adverse change in legal factors, business climate or operational performance of the business; or significant changes in the ability of the reporting unit to generate positive cash flows for our strategic business objectives. If the carrying value of the reporting unit, including goodwill, exceeds the reporting unit’s fair value, we will recognize a goodwill impairment loss, and we will write down goodwill such that the carrying value of the reporting unit equals its fair value, provided that we cannot reduce goodwill below zero. See Note 6 for additional information regarding the impairment charges we recorded in connection with our goodwill.
Long-Lived Asset Impairment	Long-Lived Asset Impairment We assess the impairment of long-lived assets whenever events or changes in business circumstances indicate that the carrying amounts of the assets may not be fully recoverable. In the case of property, plant and equipment and right-of-use assets for our leases, we determine whether there has been an impairment by comparing the carrying value of the asset to the anticipated undiscounted net cash flows associated with the asset. If such cash flows are less than the carrying value, we write down the asset to its fair value, which may be measured as anticipated net cash flows associated with the asset, discounted at a rate that we believe a market participant would utilize to reflect the risks associated with the cash flows, such as credit risk. See Note 6 for additional information regarding the impairment charges we recorded in connection with our leased facilities and certain property and equipment.
Net Loss per Share	Net Loss per Share For all periods presented in the Condensed Consolidated Statements of Operations, the net loss available to common stockholders is equal to the reported net loss. We calculate basic net loss per share based on the weighted-average number of common shares outstanding during the periods presented. For the three months ended March 31, 2023 and 2022, basic and diluted net loss per share are the same due to our net losses and the requirement to exclude potentially dilutive securities which would have an antidilutive effect on net loss per share.
Inventory	We value inventory at the lower of cost or net realizable value, and we write down defective or excess inventory to net realizable value based on historical experience or projected usage. We expense inventory related to our research and development activities as manufactured by us or when purchased.

Organization and Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

We are a research-based biopharmaceutical company headquartered in San Francisco, California and incorporated in Delaware. We (individually or with a partner) are developing a pipeline of drug candidates that utilize our advanced polymer conjugate technology platforms, which are designed to enable the development of new molecular entities that target known mechanisms of action. Our research and development pipeline of new investigational drugs includes investigational treatments in the field of immunotherapy.

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.

Results of Clinical Trial Programs and the Restructuring Plans

In March and April 2022, we announced that our registrational trials of bempegaldesleukin in combination with Opdivo® in metastatic melanoma, renal cell carcinoma and locally advanced or metastatic urothelial cancer under our Strategic Collaboration Agreement with Bristol-Myers Squibb Company (BMS) did not meet their primary endpoints. Based on these results, in April 2022, we announced our decisions to discontinue all development of bempegaldesleukin in combination with checkpoint inhibitors, including these trials, our registrational trial in adjuvant melanoma under our BMS Collaboration Agreement, and our Phase 2/3 study of bempegaldesleukin in combination with Keytruda® in squamous cell cancer of the head and neck under our Co-Development Agreement with SFJ Pharmaceuticals. See Note 5 for additional information regarding our BMS Collaboration Agreement and Co-Development Agreement with SFJ Pharmaceuticals. Pursuant to the Strategic Collaboration Agreement, we and BMS continue our efforts to wind down the bempegaldesleukin program.

In April 2022, we also announced new strategic reorganization and cost restructuring plans (together, the 2022 Restructuring Plan), pursuant to which we we completed an approximately 70% reduction of our workforce during 2022 and sold our research facility in India in December 2022.

On February 23, 2023, we announced the topline data from the Phase 2 study of rezpegaldesleukin in adult patients with systemic lupus erythematosus (SLE) (Phase 2 Lupus Study) under our collaboration agreement with Eli Lilly and Company (Lilly). Lilly notified us that it does not intend to advance rezpegaldesleukin into Phase 3 development for SLE. On April 27, 2023, we announced that we would be regaining the full rights to rezpegaldesleukin from Lilly. Based on the positive results from a Phase 1b study in which rezpegaldesleukin reduced atopic dermatitis symptoms, we plan to initiate a Phase 2b study of rezpegaldesleukin in patients with moderate-to-severe atopic dermatitis in 2023. We will also explore other auto-immune indications for the development of rezpegaldesleukin.

Pursuant to plans approved by our Board of Directors (the Board) on March 29, 2023, we announced on April 17, 2023, a new strategic reprioritization and cost restructuring plan (the 2023 Restructuring Plan). Under the 2023 Restructuring Plan, we are reducing our San Francisco-based workforce by approximately 60%, which is expected to be substantially completed by June 2023.

We have incurred and expect to incur significant costs resulting from the 2022 and 2023 Restructuring Plans. See Note 6 for additional information on the effect on our Condensed Consolidated Financial Statements.

Basis of Presentation and Principles of Consolidation

Our Condensed Consolidated Financial Statements include the financial position, results of operations and cash flows of Nektar Therapeutics and our wholly-owned subsidiaries. We have eliminated all intercompany accounts and transactions 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, we may condense or omit certain footnotes or other financial information that are normally required by U.S. generally accepted accounting principles (GAAP) for annual

periods. 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. We include translation gains and losses in accumulated other comprehensive loss in the stockholders’ equity section of our 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 gains and losses on available-for-sale securities. There were no significant reclassifications out of accumulated other comprehensive loss to the statements of operations during the three months ended March 31, 2023 and 2022.

The accompanying Condensed Consolidated Financial Statements are unaudited. The Condensed Consolidated Balance Sheet data as of December 31, 2022 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, 2022 filed with the SEC on February 28, 2023. 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.

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 period.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles (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. As appropriate, we assess estimates each period, update them to reflect current information, and generally reflect any changes in estimates in the period first identified.

Significant Concentrations

Significant ConcentrationsOur customers are primarily pharmaceutical companies that are located in the U.S. and Europe and with whom we have multi-year arrangements. Our accounts receivable balance contains billed and unbilled trade receivables from product sales, milestones (to the extent that they have been achieved and are due from the counterparty), and other contingent payments, as well as reimbursable costs from collaborative research and development agreements.

We are dependent on our suppliers and contract manufacturers to provide raw materials and drugs 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, our ability to supply comparator drugs for our clinical trials, 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.

For our available-for-sale securities, we have significant concentrations of issuers in the banking and financial services industries. While our investment policy requires that we only invest in highly-rated securities and limit our exposure to any single issuer, various factors may materially affect the financial condition of issuers. Additionally, pursuant to our investment policy, we may sell securities before maturity if the issuer’s credit rating has been downgraded below our minimum credit rating requirements, which may result in a loss on the sale. Accordingly, if various factors result in downgrades below our minimum credit rating requirements and if we decide to sell these securities, we may experience losses on such sales.

Restructuring

We recognize restructuring charges related to reorganization plans that have been committed to by management when liabilities have been incurred. In connection with these activities, we record restructuring charges at fair value for:

•contractual or other employee termination benefits provided that the obligations result from services already rendered based on rights that vest or accumulated when the payment of benefits becomes probable and the amount can be reasonably estimated,

•one-time employee termination benefits on the communication date from management to the employees provided that management has committed to a plan of termination, the plan identifies the employees and their expected termination dates, the details of termination benefits are complete, and it is unlikely that changes to the plan will be made or the plan will be withdrawn,

•contract termination costs when we cancel the contract in accordance with its terms, and

•costs to be incurred over the remaining contract term without economic benefit to us at the cease-use date.

For one-time employee terminations benefits, we recognize the liability in full on the communication date when future services are not required or amortize the liability ratably over the service period, if required. The fair value of termination benefits reflects our estimates of expected utilization of certain Company-funded post-employment benefits.

See Note 6 for additional information on the severance expense that we recognized for employees terminated in connection with our reductions-in-force.

Impairment of Goodwill

Goodwill is assessed for impairment on an annual basis and whenever events and circumstances indicate that it may be impaired. Factors that may indicate potential impairment and trigger an impairment test include, but are not limited to, current economic, market and geopolitical conditions, including a significant, sustained decline in our stock price and market capitalization compared to the net book value; an adverse change in legal factors, business climate or operational performance of the business; or significant changes in the ability of the reporting unit to generate positive cash flows for our strategic business objectives. If the carrying value of the reporting unit, including goodwill, exceeds the reporting unit’s fair value, we will recognize a goodwill impairment loss, and we will write down goodwill such that the carrying value of the reporting unit equals its fair value, provided that we cannot reduce goodwill below zero.

See Note 6 for additional information regarding the impairment charges we recorded in connection with our goodwill.

Long-Lived Asset Impairment

We assess the impairment of long-lived assets whenever events or changes in business circumstances indicate that the carrying amounts of the assets may not be fully recoverable. In the case of property, plant and equipment and right-of-use assets for our leases, we determine whether there has been an impairment by comparing the carrying value of the asset to the anticipated undiscounted net cash flows associated with the asset. If such cash flows are less than the carrying value, we write down the asset to its fair value, which may be measured as anticipated net cash flows associated with the asset, discounted at a rate that we believe a market participant would utilize to reflect the risks associated with the cash flows, such as credit risk.

See Note 6 for additional information regarding the impairment charges we recorded in connection with our leased facilities and certain property and equipment.

Net Loss per Share

Net Loss per Share For all periods presented in the Condensed Consolidated Statements of Operations, the net loss available to common stockholders is equal to the reported net loss. We calculate basic net loss per share based on the weighted-average number of common shares outstanding during the periods presented. For the three months ended March 31, 2023 and 2022, basic and diluted net loss per share are the same due to our net losses and the requirement to exclude potentially dilutive securities which would have an antidilutive effect on net loss per share.

Inventory

We value inventory at the lower of cost or net realizable value, and we write down defective or excess inventory to net realizable value based on historical experience or projected usage. We expense inventory related to our research and development activities as manufactured by us or when purchased.