0001193125-25-270230 | 10-Q | XBRL Viewer

As discussed in Note 1, on December 2, 2024, we completed the sale of the Facility and certain other manufacturing assets related thereto, including the assignment of our existing manufacturing and supply obligations, to Gannet BioChem, an affiliate of Ampersand, via the APA, for consideration of $64.7 million in cash, net of transaction costs, and an equity interest in Gannet BioChem.

We own 20.0 million common units of Gannet BioChem at $1.00 per unit, representing 100% of the common units outstanding at both closing of the sale of the Facility and at September 30, 2025, and Ampersand owns 81.5 million preferred units at $1.00 per unit, representing 100% of the preferred units outstanding at closing and 99.7% of the preferred units outstanding as of September 30, 2025. Gannet BioChem has reserved 11.3 million appreciation rights for issuance to its officers, employees, directors and consultants, which may only be settled upon a “company sale” as defined by Gannet BioChem’s equity plan and convert to common units in determining their distribution, less the “base value”, which is equal to the fair value of the common units as determined by Gannet BioChem’s board of directors. As of September 30, 2025, Gannet BioChem has issued 8.2 million stock appreciation rights, which have a $1.00 base value.

In the event of a distribution, to the extent available, the preferred unitholders have priority rights to a cumulative preferred dividend at a certain annual rate of return and a return of their investment before any distributions to common unitholders. After such priority distribution to the preferred unitholders, to the extent available, common unitholders are to receive a distribution of both a cumulative dividend at the same rate as the preferred unitholders’ dividend and a return of their

investment, which, for our common units, is equal to $20.0 million (or $1.00 per unit). Any distributions in excess of both of these distributions, if available, are distributed to preferred and common unitholders pro rata.

We have significant influence, but do not control, Gannet BioChem through our noncontrolling representation on Gannet BioChem’s board of directors and our equity interests in Gannet BioChem. Accordingly, we do not consolidate Gannet BioChem and account for our investment in Gannet BioChem using the equity method of accounting. At closing of the sale of the Facility, we estimated the fair value of our equity investment in Gannet BioChem to be $12.2 million, which reflected Ampersand’s liquidation preferences described above. We record our share of Gannet BioChem’s gains and losses under the HLBV basis, which reflects Ampersand’s liquidation preferences as described above. The HLBV method is a balance sheet approach that calculates the change in the hypothetical amount we and Ampersand would be entitled to receive if Gannet BioChem were liquidated at book value, adjusted for any contributions made and distributions received during the period, as well as basis differences between the initial fair value of our investment in Gannet BioChem and our claim on the net assets of Gannet BioChem. Our loss from our investment in Gannet BioChem for the three and nine months ended September 30, 2025 is as follows (in thousands):


	Three Months Ended September 30, 2025			Nine Months Ended September 30, 2025
Claim on net assets of Gannet BioChem - beginning of period	$	5,371		$	12,218
Claim on net assets of Gannet BioChem - end of period		4,837			4,837
Change in claim on net assets of Gannet BioChem	$	(534	)	$	(7,381	)

Gannet BioChem is considered a related party to Nektar. Concurrently with the closing of the transaction, we entered into certain ancillary agreements with Gannet BioChem, including supply agreements for rezpegaldesleukin and NKTR-255, and certain services agreements.

Supply Agreements

Under the terms of the supply agreements, Gannet BioChem has agreed to manufacture and supply the PEG reagents for use in clinical trials of these drug candidates at prices defined within the agreements. There are no minimum purchase commitments and Nektar can terminate the agreement for convenience upon prior written notice. For the three and nine months ended September 30, 2025, we did not make any purchases from Gannet BioChem.

Services Agreements

Pursuant to a transition services agreement and full-time employee equivalent agreement, Nektar is performing certain transition services for the benefit of Gannet BioChem, primarily related to information technology and accounting, and Gannet BioChem is performing certain transition services for the benefit of Nektar, primarily to support research and development activities. The terms of these agreements are no more than two years, subject to certain termination provisions. For the three and nine months ended September 30, 2025, we recorded $0.4 million and $1.2 million, respectively, as research and development expense for services provided by Gannet BioChem to us in our Condensed Consolidated Statements of Operations. For the three and nine months ended September 30, 2025, we recorded $0.2 million and $1.1 million as other income in our Condensed Consolidated Statements of Operations for services provided by us to Gannet BioChem.

As of September 30, 2025, we recorded a net receivable of $0.2 million from Gannet BioChem and a payable of $0.3 million to Gannet BioChem, consisting of amounts billable under the services agreements. We report the net receivable and payable in other current asset and accrued expenses, respectively, in our Condensed Consolidated Balance Sheets.

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)
$ in Thousands

Sep. 30, 2025

Dec. 31, 2024

Current assets:

Cash and cash equivalents

$ 41,032

$ 44,252

^[1]

Short-term investments

229,176

210,974

^[1]

Other current assets (including $177 and $0 as of September 30, 2025 and December 31, 2024, respectively, from a related party)

11,149

6,066

^[1]

Total current assets

281,357

261,292

^[1]

Long-term investments

13,869

^[1]

Property and equipment, net

2,826

3,411

^[1]

Operating lease right-of-use assets

7,171

8,413

^[1]

Equity method investment in Gannet BioChem

4,837

12,218

^[1]

Other assets

5,156

4,647

^[1]

Total assets

301,347

303,850

^[1]

Current liabilities:

Accounts payable

15,563

11,560

^[1]

Accrued expenses (including $316 and $3,403 as of September 30, 2025 and December 31, 2024, respectively, to a related party)

28,594

29,972

^[1]

Operating lease liabilities, current portion

22,183

19,868

^[1]

Total current liabilities

66,340

61,400

^[1]

Operating lease liabilities, less current portion

69,732

82,696

^[1]

75,164

91,776

^[1]

Other long-term liabilities

5,025

7,241

^[1]

Total liabilities

216,261

243,113

^[1]

Commitments and contingencies

Stockholders' equity:

Preferred stock, $0.0001 par value; 10,000,000 shares authorized; no shares designated or outstanding at September 30, 2025 or December 31, 2024, respectively

^[1]

Common stock, $0.0001 par value; 390,000,000 shares and 300,000,000 shares authorized at September 30, 2025 and December 31, 2024; 19,652,513 shares and 12,937,308 shares issued at September 30, 2025 and December 31, 2024, respectively; 19,652,513 shares and 12,385,001 shares outstanding at September 30, 2025 and December 31, 2024, respectively

^[1]

Capital in excess of par value

3,809,235

3,659,885

^[1]

Treasury stock, at cost; 0 shares and 552,307 shares as of September 30, 2025 and December 31, 2024, respectively

(3,000)

^[1]

Accumulated other comprehensive income (loss)

^[1]

Accumulated deficit

(3,724,207)

(3,596,210)

^[1]

Total stockholders' equity

85,086

60,737

^[1]

Total liabilities and stockholders' equity

$ 301,347

$ 303,850

^[1]

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

Restructuring and Impairment - Restructuring Reserve Rollforward (Details) - Contract Termination and Other Costs - Restructuring Plan - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	$ 8,304	$ 8,693	$ 9,078	$ 9,662	$ 5,589	$ 5,542
Expense recognized during the period	140	447	169	46	4,960	975
Payments during the period	(836)	(836)	(554)	(886)	(887)	(928)
Restructuring reserve, ending balance	$ 7,608	$ 8,304	$ 8,693	$ 8,822	$ 9,662	$ 5,589

- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References + Details

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)
$ in Thousands

9 Months Ended

12 Months Ended

Sep. 30, 2025

USD ($)

$ / shares

Dec. 31, 2024

USD ($)

$ / shares

Other current assets | $

$ 11,149

$ 6,066

^[1]

Accrued expenses (including $316 and $3,403 as of September 30, 2025 and December 31, 2024, respectively, to a related party) | $

$ 28,594

$ 29,972

^[1]

Preferred stock, par value (in dollars per share) | $ / shares

$ 0.0001

Preferred stock, shares authorized (in shares)

10,000,000

Preferred stock, shares designated (in shares)

Preferred stock, shares outstanding (in shares)

Common stock, par value (in dollars per share) | $ / shares

$ 0.0001

Common stock, shares authorized (in shares)

390,000,000

300,000,000

Common stock shares, issued (in shares)

19,652,513

12,937,308

Common stock, shares outstanding (in shares)

19,652,513

12,385,001

Treasury Stock, Common, Shares

552,307

Reverse stock split

one-for-fifteen reverse stock split

Stockholders' Equity Note, Stock Split, Conversion Ratio

0.066667

Related Party

Other current assets | $

$ 177

$ 0

Accrued expenses (including $316 and $3,403 as of September 30, 2025 and December 31, 2024, respectively, to a related party) | $

$ 316

$ 3,403

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

Equity Method Investment (Tables)

9 Months Ended

Sep. 30, 2025

Equity Method Investments and Joint Ventures [Abstract]

Schedule Of Equity Method Investments

Our loss from our investment in Gannet BioChem for the three and nine months ended September 30, 2025 is as follows (in thousands):


	Three Months Ended September 30, 2025			Nine Months Ended September 30, 2025
Claim on net assets of Gannet BioChem - beginning of period	$	5,371		$	12,218
Claim on net assets of Gannet BioChem - end of period		4,837			4,837
Change in claim on net assets of Gannet BioChem	$	(534	)	$	(7,381	)

Cash and Investments in Marketable Securities - Portfolio of Cash and Investments in Marketable Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	$ 219,902
Gross Unrealized Gains	50
Gross Unrealized Losses	(26)
Fair Value	219,926	$ 229,253
Cash	11,350	9,822
Total cash and investments in marketable securities	270,208	269,095
Corporate notes and bonds \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	70,569
Gross Unrealized Gains	24
Gross Unrealized Losses	(10)
Fair Value	70,583	109,711
Corporate commercial paper \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	149,333
Gross Unrealized Gains	26
Gross Unrealized Losses	(16)
Fair Value	149,343	119,542
Money market funds \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable securities	24,717	15,993
Certificates of deposit \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable securities	$ 14,215	$ 14,027

Subsequent Event - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Thousands

1 Months Ended

3 Months Ended

9 Months Ended

Oct. 31, 2025

Sep. 30, 2025

Sep. 30, 2024

Subsequent Event [Line Items]

Commissions

$ 1,150

$ 0

At-the-Market Offering

Subsequent Event [Line Items]

Net proceeds from issuance of common stock

$ 34,489

$ 0

Commissions

$ 1,276

At-the-Market Offering | Common Stock

Subsequent Event [Line Items]

Sale and issuance of shares

^[1]

600,198

Net proceeds from issuance of common stock

$ 34,300

Offering per share price

$ 59.24

Subsequent Event | At-the-Market Offering | Common Stock

Subsequent Event [Line Items]

Sale and issuance of shares

673,725

Net proceeds from issuance of common stock

$ 38,300

Shares remained available for grant

Commissions

$ 1,200

Offering per share price

$ 58.55

[1]	All share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

Equity Method Investment - Schedule of equity method investment (Details) - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2025

Sep. 30, 2024

^[1]

Sep. 30, 2025

Sep. 30, 2024

^[1]

Schedule of Equity Method Investments [Line Items]

Change in claim on net assets of Gannet BioChem

$ (534)

$ 0

$ (7,381)

$ 0

Gannet BioChem

Schedule of Equity Method Investments [Line Items]

Claim on net assets of Gannet BioChem - beginning of period

5,371

12,218

Claim on net assets of Gannet BioChem - end of period

4,837

Change in claim on net assets of Gannet BioChem

$ (534)

$ (7,381)

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

- Definition

Amount of income (loss) for proportionate share of equity method investee's income (loss).

+ References + Details

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) $ in Thousands	9 Months Ended
	Sep. 30, 2025 USD ($)
2025 Secondary Public Offering
Underwriting discounts	$ 6,900
At-the-Market Offering
Commissions	$ 1,066

Organization and Summary of Significant Accounting Policies - Additional Information (Detail)
$ / shares in Units, $ in Thousands

1 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

Jul. 02, 2025

USD ($)

$ / shares

Jun. 08, 2025

Jun. 06, 2025

Dec. 02, 2024

USD ($)

Oct. 31, 2025

USD ($)

$ / shares

Sep. 30, 2025

USD ($)

$ / shares

Sep. 30, 2024

USD ($)

Sep. 30, 2025

USD ($)

$ / shares

Sep. 30, 2024

USD ($)

Dec. 31, 2024

USD ($)

Organization And Summary Of Significant Accounting Policies [Line Items]

Cash and investments in marketable securities

$ 270,208

$ 269,095

Aggregate maximum public offering amount

300,000

Accounts receivable, credit loss expense (reversal)

$ 0

Reverse stock split, ratio

0.07

0.066667

Reverse stock split

Reverse Stock Split Amendment, to effect a reverse stock split of Nektar’s Common Stock at a ratio of one-for-fifteen, effective June 8, 2025.

one-for-fifteen reverse stock split

Asset Purchase Agreement | Asset Acquisition By Ampersand Capital Partners

Organization And Summary Of Significant Accounting Policies [Line Items]

Proceeds from sale of assets

$ 64,700

Ownership interest received

20.00%

Sales Agreement

Organization And Summary Of Significant Accounting Policies [Line Items]

Aggregate maximum public offering amount

$ 75,000

Percentage of gross sale of common stock sold through sales agents commission rate

3.00%

At-the-Market Offering

Organization And Summary Of Significant Accounting Policies [Line Items]

Net proceeds from issuance of common stock

$ 34,489

$ 0

Common Stock

Organization And Summary Of Significant Accounting Policies [Line Items]

Reverse stock split, ratio

0.07

Common Stock | 2025 Offering

Organization And Summary Of Significant Accounting Policies [Line Items]

Sale and issuance of shares | shares

4,893,618

Offering per share price | $ / shares

$ 23.5

Net proceeds from issuance of common stock

$ 107,200

Common Stock | At-the-Market Offering

Organization And Summary Of Significant Accounting Policies [Line Items]

Sale and issuance of shares | shares

^[1]

600,198

Offering per share price | $ / shares

$ 59.24

Net proceeds from issuance of common stock

$ 34,300

Common Stock | At-the-Market Offering | Subsequent Event

Organization And Summary Of Significant Accounting Policies [Line Items]

Sale and issuance of shares | shares

673,725

Offering per share price | $ / shares

$ 58.55

Net proceeds from issuance of common stock

$ 38,300

[1]	All share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

License and Collaboration Agreements

9 Months Ended

Sep. 30, 2025

License And Collaboration Agreements [Abstract]

License and Collaboration Agreements

Note 7 — 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 milestone payments, reimbursements for research and development activities and (before the sale of the Facility) payments for the manufacture and supply of our PEG reagents. We generally include our costs of performing these services in research and development expense, except for costs for product sales to our collaboration partners which we include in cost of goods sold. We analyze our agreements to determine whether we should account for the agreements within the scope of ASC 808 Collaborative Arrangements, and, if so, we analyze whether we should account for any elements under ASC 606 Revenue from Contracts with Customers.

Biolojic Design, Ltd. (Biolojic): NKTR-0165

In 2021, we entered into a research collaboration and license option agreement with Biolojic to discover and develop agonistic antibodies that activate a novel and previously un-drugged target for the treatment of autoimmune diseases. In 2023, we exercised an option to gain an exclusive license to specified agonistic antibodies and other materials that were developed pursuant to this arrangement in all fields of use (other than in the field of oncology). As a result of exercising the option to gain an exclusive license, we may be required to pay up to $18.0 million based on the achievement of certain development milestones, including the first milestone of $3.0 million payable upon the acceptance of the first investigational new drug application, and up to $35.0 million based on the achievement of certain regulatory approval milestones. Each milestone is payable only once, regardless of the number of indications for which we develop the licensed product. We record a liability when a milestone payment becomes probable. As of September 30, 2025, no milestones have been achieved or are considered probable, and no liability has been recorded.

Bristol-Myers Squibb Company (BMS): Bempegaldesleukin, also referred to as NKTR-214

Effective April 3, 2018, we entered into a Strategic Collaboration Agreement (the BMS Collaboration Agreement) and a Share Purchase Agreement with BMS. Pursuant to the BMS Collaboration Agreement, we and BMS jointly developed

bempegaldesleukin in combination with BMS’ Opdivo®. The parties shared the internal and external development costs for bempegaldesleukin in combination regimens based on each party’s relative ownership interest in the compounds included in the regimens.

Upon the effective date of the BMS Collaboration Agreement in April 2018, BMS paid us a non-refundable upfront cash payment of $1.0 billion and purchased 552,307 shares of our common stock pursuant to the Share Purchase Agreement for total additional cash consideration of $850.0 million. In 2020, we received additional non-refundable milestone payments of $50.0 million.

In April 2022, we announced that BMS and we decided to discontinue all development of bempegaldesleukin in combination with Opdivo®. On September 6, 2023, BMS and we terminated the BMS Collaboration Agreement, and pursuant to the surviving provisions of the BMS Collaboration Agreement, the cost sharing provisions continued to remain in effect as BMS and we have wound down the bempegaldesleukin program. On February 12, 2024, we repurchased the 552,307 shares previously sold to BMS for total cash consideration of $3.0 million.

We determined that the BMS Collaboration Agreement falls within the scope of ASC 808. Based on the cost sharing provisions described above, we recognize the net reimbursement to (from) BMS as an increase (decrease) to the applicable expense. For the three months ended September 30, 2025 and 2024, such amounts are immaterial and are included in research and development expense.

Eli Lilly and Company (Lilly): Rezpegaldesleukin (previously referred to as NKTR-358)

On July 23, 2017, we entered into a worldwide license agreement (the Lilly Agreement) with Lilly to co-develop rezpegaldesleukin, a novel immunological drug candidate that we invented, pursuant to which we received an initial payment of $150.0 million and were eligible for up to $250.0 million in additional development and regulatory milestones. On April 23, 2023, we received from Lilly a notice of at-will termination of the Lilly Agreement. We regained full rights to rezpegaldesleukin from Lilly, and the Lilly Agreement subsequently terminated. Following the return of our rights to develop rezpegaldesleukin, we bear all costs of development.

Other

We have other collaboration agreements that have resulted in commercialized products for our collaborations partners. Under these agreements, we are entitled to receive royalties based on net sales of these products as well as sales milestones. As discussed in Note 3, we have sold our rights to receive royalties from these other collaboration agreements. Our non-cash royalty revenue, which totaled $11.5 million and $33.1 million for the three and nine months ended September 30, 2025, respectively and $15.7 million and $48.0 million for the three and nine months ended September 30, 2024, respectively, represents revenue for granting licenses which we had satisfied in prior periods.

We have a collaboration agreement with UCB for dapirolizumab pegol, under which we are entitled to a total of up to $40.0 million of regulatory approval milestones, as well as royalties in the low single digits based on net sales of commercialized products, if any. UCB is developing dapirolizumab pegol, a PEGylated antibody fragment, with Biogen, Inc. for the treatment of systemic lupus erythematosus. However, given the current phase of development of this product and the uncertainty in clinical development, we have excluded these milestones from the transaction price for this agreement.

We have not sold our rights to receive these milestones or royalties from dapirolizumab pegol under the APA for the sale of the Facility, and the assignment of the supply agreements to Gannet BioChem does not alter the potential milestones and potential royalties payable by UCB to us pursuant to the collaboration agreement for dapirolizumab pegol nor the non-cash royalties payable under our collaboration agreement for CIMZIA®.

Commitments and Contingencies

9 Months Ended

Sep. 30, 2025

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 each reporting date 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 for that period and on our cash flows and liquidity.

On August 7, 2023, we filed a complaint in the United States District Court for the Northern District of California (the Court) against Eli Lilly and Company (Lilly) alleging, among other claims, breach of contract and breach of implied covenant of good faith and fair dealing (the Complaint), in connection with our collaboration with Lilly. Following the denial of its motion to dismiss the Complaint entirely, Lilly filed an answer that included counterclaims against us alleging breach of specified confidentiality provisions and defamation. On September 19, 2025, Lilly filed a motion to voluntarily dismiss its counterclaims with prejudice, which the Court granted on October 7, 2025. Lilly has filed a motion for summary judgment, and the court has not yet issued a decision on this motion, as well as other pre-trial motions filed by both parties that remain pending before the Court. Following the shutdown of the federal government, on October 14, 2025, the Court postponed the previously calendared October 27, 2025 starting date of the jury trial, and scheduled a status conference for the parties on December 11, 2025, following which we expect to learn additional details concerning the new starting date of the jury trial.

After previously authorizing good and service tax (GST) refunds of approximately $3.3 million for the period of July 2017 to September 2019, the Indian GST authorities issued a show cause notice in October 2023 seeking to recover this refund, plus penalties and interest, for which we have subsequently received a demand in September 2025 seeking payment to Indian GST authorities. We have not paid the demand in view of an appeal we filed with the Indian authorities, and believe the basis for both the show cause notice and demand is without merit. We believe a loss is not probable and therefore have not accrued a liability as of September 30, 2025.

We have recorded no liability for any litigation matters in our Condensed Consolidated Balance Sheets at either September 30, 2025 or December 31, 2024.

Indemnifications in Connection with Commercial Agreements

As part of our collaboration agreements with our partners related to the license, development, manufacture and supply of our proprietary 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 commencing 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. For example, we made certain intellectual property representations in connection with our RPI and HCR transactions, however, the time limitation we have to indemnify RPI with respect to any breach of these intellectual property-based representations and warranties has passed. In the event it is determined that we breached certain of the representations and warranties or covenants made by us in any such agreements or certain express indemnification provisions are applicable, we could incur substantial indemnification liabilities depending on the timing, nature, and amount of any such claims.

To date, we have not incurred any costs to defend lawsuits or settle claims related to these indemnification obligations, nor any breaches of representations or warranties or covenants. Because the aggregate amount of any potential indemnification obligation is not a stated amount, we cannot reasonably estimate the overall maximum amount of any such obligations.

Segment Reporting - Summary of Significant Expense Categories and Consolidated Net Loss (Details) - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2025

Sep. 30, 2024

Sep. 30, 2025

Sep. 30, 2024

Segment Reporting Information [Line Items]

Revenue

$ 11,790

$ 24,124

^[1]

$ 33,425

$ 69,252

^[1]

Operating costs and expenses:

Cost of goods sold

4,435

^[1]

22,709

^[1]

Clinical development, contract manufacturing and other third party costs

15,850

24,321

52,871

59,077

Employee costs

10,888

9,544

33,782

29,915

Facilities costs

3,052

3,779

9,378

12,417

Other operating costs

10,297

11,013

37,881

33,442

Other segment expenses

3,375

5,377

11,950

31,238

Total operating costs and expenses

43,462

58,469

^[1]

145,862

188,798

^[1]

Loss from operations

(31,672)

(34,345)

^[1]

(112,437)

(119,546)

^[1]

Non-operating income (expense):

Non-cash interest expense on liabilities related to the sales of future royalties

(6,047)

(6,020)

^[1]

(16,415)

(17,959)

^[1]

Interest income

2,819

3,437

^[1]

7,662

11,558

^[1]

Other income (expense), net

(121)

(120)

^[1]

405

(255)

^[1]

Total non-operating income (expense), net

(3,349)

(2,703)

^[1]

(8,348)

(6,656)

^[1]

Loss before provision (benefit) for income taxes and equity method investment

(35,021)

(37,048)

^[1]

(120,785)

(126,202)

^[1]

Provision (benefit) for income taxes

(33)

^[1]

(169)

^[1]

Loss before equity method investment

(34,988)

(37,057)

^[1]

(120,616)

(126,222)

^[1]

Loss from equity method investment

(534)

^[1]

(7,381)

^[1]

Net loss

(35,522)

(37,057)

^[1]

(127,997)

(126,222)

^[1]

Rezpegaldesleukin (cytokine Treg stimulant)

Operating costs and expenses:

Clinical development, contract manufacturing and other third party costs

11,155

15,684

37,888

36,667

NKTR-255 (IL-15 receptor agonist)

Operating costs and expenses:

Clinical development, contract manufacturing and other third party costs

1,413

5,108

5,034

12,790

NKTR-0165 (tumor necrosis factor receptor type II agonist)

Operating costs and expenses:

Clinical development, contract manufacturing and other third party costs

3,119

3,900

8,931

7,751

Discovery Research and Other Programs

Operating costs and expenses:

Clinical development, contract manufacturing and other third party costs

$ 163

$ (371)

$ 1,018

$ 1,869

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

Restructuring and Impairment - Sublease Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Restructuring Cost and Reserve [Line Items]
Total impairment of right-of-use assets and property, plant and equipment	$ 0	$ 8,329
Property, Plant and Equipment
Restructuring Cost and Reserve [Line Items]
Total impairment of right-of-use assets and property, plant and equipment		1,042
Operating Lease Right-of-Use Assets
Restructuring Cost and Reserve [Line Items]
Total impairment of right-of-use assets and property, plant and equipment		7,287
Reported Value Measurement
Restructuring Cost and Reserve [Line Items]
Property, plant and equipment and operating lease right-of-use assets		14,403
Reported Value Measurement \| Property, Plant and Equipment
Restructuring Cost and Reserve [Line Items]
Property, plant and equipment and operating lease right-of-use assets		1,897
Reported Value Measurement \| Operating Lease Right-of-Use Assets
Restructuring Cost and Reserve [Line Items]
Property, plant and equipment and operating lease right-of-use assets		12,506
Estimate of Fair Value Measurement \| Fair Value, Level 3
Restructuring Cost and Reserve [Line Items]
Property, plant and equipment and operating lease right-of-use assets		(6,074)
Estimate of Fair Value Measurement \| Property, Plant and Equipment \| Fair Value, Level 3
Restructuring Cost and Reserve [Line Items]
Property, plant and equipment and operating lease right-of-use assets		(855)
Estimate of Fair Value Measurement \| Operating Lease Right-of-Use Assets \| Fair Value, Level 3
Restructuring Cost and Reserve [Line Items]
Property, plant and equipment and operating lease right-of-use assets		$ (5,219)

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

Condensed Consolidated Financial Statement Details - Schedule of Other Current Assets (Details) - USD ($)
$ in Thousands

Sep. 30, 2025

Dec. 31, 2024

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Other current assets

$ 11,149

$ 6,066

^[1]

Prepaid research and development expenses

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Other current assets

7,500

1,947

Interest and other non-trade receivables

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Other current assets

1,289

1,609

Other prepaid expenses

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Other current assets

$ 2,360

$ 2,510

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

Commitments and Contingencies - Additional Information (Details) - USD ($)	Sep. 30, 2025	Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Repayment due of GST refunds	$ 3,300,000
Liability for litigation	$ 0	$ 0

Cash and Investments in Marketable Securities - Additional Information (Detail) $ in Thousands	Sep. 30, 2025 USD ($) Investments
Fair Value Disclosures [Abstract]
Number of investments in unrealized loss positions \| Investments	29
Investments in continuous unrealized loss positions for 12 months or longer \| $	$ 0

Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2025

Share-Based Payment Arrangement [Abstract]

Schedule of Stock-Based Compensation Expense

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


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Cost of goods sold	$	—	$	516	$	—	$	1,673
Research and development		1,630		2,010		4,268		6,337
General and administrative		1,442		2,865		6,188		8,799
Total stock-based compensation	$	3,072	$	5,391	$	10,456	$	16,809

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 3,072	$ 5,391	$ 10,456	$ 16,809
Cost of goods sold
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	0	516	0	1,673
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	1,630	2,010	4,268	6,337
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 1,442	$ 2,865	$ 6,188	$ 8,799

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2025

Sep. 30, 2024

Sep. 30, 2025

Sep. 30, 2024

Statement of Comprehensive Income [Abstract]

Net loss

$ (35,522)

$ (37,057)

^[1]

$ (127,997)

$ (126,222)

^[1]

Other comprehensive income (loss):

Net unrealized gain (loss) on available-for-sale securities

877

(11)

312

Net foreign currency translation gain (loss)

(28)

(37)

Other comprehensive income (loss)

849

(5)

275

Comprehensive loss

$ (35,452)

$ (36,208)

$ (128,002)

$ (125,947)

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

- Definition

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

+ References + Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1B

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482739/220-10-55-15

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1A

+ Details

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical) $ in Thousands	3 Months Ended
	Sep. 30, 2025 USD ($)
Secondary Offering
Underwriting discounts, commissions and offering costs	$ 7,840
At-the-Market Offering
Underwriting discounts, commissions and offering costs	$ 1,276

Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2025

Equity [Abstract]

Summary of Reverse Stock Split, Shares Reserved for Issuance Under Employee Stock Plans

As a result of the Reverse Stock Split, shares reserved for issuance under our employee stock plans are as follows:


	September 30, 2025		December 31, 2024
Stock options outstanding		2,185,410		2,203,927
Weighted average exercise price	$	79.11	$	83.73
RSUs outstanding		41,894		101,524
Shares available for future grant under the 2017 Performance Incentive Plan		921,896		551,727
Shares available for issuance under the employee stock purchase plan		46,650		47,383
Total shares reserved for issuance under our employee stock plans		3,195,850		2,904,561

Organization and Summary of Significant Accounting Policies - Weighted Average Outstanding Stock Options (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Stock Options, RSUs And PSUs
Organization And Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities (in shares)	2,202,024	1,726,765	2,256,665	1,761,960

Stock-Based Compensation

9 Months Ended

Sep. 30, 2025

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

Note 9 — Stock-Based Compensation

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


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Cost of goods sold	$	—	$	516	$	—	$	1,673
Research and development		1,630		2,010		4,268		6,337
General and administrative		1,442		2,865		6,188		8,799
Total stock-based compensation	$	3,072	$	5,391	$	10,456	$	16,809

Condensed Consolidated Financial Statement Details

9 Months Ended

Sep. 30, 2025

Inventory Disclosure [Abstract]

Condensed Consolidated Financial Statement Details

Note 3 — Condensed Consolidated Financial Statement Details

Other Current Assets

Other current assets consist of the following (in thousands):


	September 30, 2025		December 31, 2024
Prepaid research and development expenses	$	7,500	$	1,947
Interest and other non-trade receivables		1,289		1,609
Other prepaid expenses		2,360		2,510
Total other current assets	$	11,149	$	6,066

Accrued Expenses

Accrued expenses consist of the following (in thousands):


	September 30, 2025		December 31, 2024
Accrued compensation	$	8,606	$	2,832
Accrued research and development expenses		12,084		14,453
Accrued contract termination costs		3,149		2,767
Other accrued expenses		4,755		9,920
Total accrued expenses	$	28,594	$	29,972

Liabilities Related to the Sales of Future Royalties

In 2012 and 2020, we sold to RPI Finance Trust (RPI) and entities managed by Healthcare Royalty Management, LLC (HCR), respectively, our rights to receive royalties under our license and manufacturing agreements with certain pharmaceutical partners under the 2012 Purchase and Sale Agreement and the 2020 Purchase and Sale Agreement, respectively. We account for these transactions as debt and recognize non-cash royalty revenue and non-cash interest expense to amortize the proceeds over the lives of the respective arrangements. We periodically update our prospective non-cash interest rate based on our estimates of future royalties. As of September 30, 2025, our imputed interest rate for the arrangement with HCR was 28%.

The original 2020 Purchase and Sale Agreement was to expire -- and wherein the right to receive royalties would revert to us -- if HCR received aggregate royalties of $210.0 million on or prior to December 31, 2025 (the 2025 Threshold), or, if the 2025 Threshold was not achieved by December 31, 2025, when HCR received aggregate royalties of $240.0 million. On March 4, 2024, Nektar and HCR amended the original 2020 Purchase and Sale Agreement (the Amendment), pursuant to which the parties agreed to remove our reversionary rights in the royalties in exchange for a $15.0 million payment from HCR. Accordingly, HCR will receive all future royalties of the products, and none of these royalties will return to Nektar. We accounted for the Amendment as a modification of the existing arrangement and therefore recorded the $15.0 million proceeds as an increase to the liability.

The following is a reconciliation of the changes in our liabilities related to the sales of future royalties for the nine months ended September 30, 2025 (in thousands):


	Nine Months Ended September 30, 2025
	2012 Purchase and Sale Agreement			2020 Purchase and Sale Agreement			Total
Liabilities related to the sales of future royalties, net – beginning balance	$	7,197		$	84,579		$	91,776
Non-cash royalty revenue		(5,619	)		(27,506	)		(33,125	)
Non-cash interest expense		1,983			14,432			16,415
Amortization of transaction costs		—			98			98
Liabilities related to the sales of future royalties, net – ending balance	$	3,561		$	71,603		$	75,164

Organization and Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

excluded shares underlying the weighted average outstanding stock options, restricted stock units (RSUs) and performance stock units (PSUs), as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Potentially dilutive securities		2,202,024		1,726,765		2,256,665		1,761,960

Equity Method Investment - Additional Information (Details) - USD ($)
$ / shares in Units, shares in Millions

3 Months Ended

9 Months Ended

Dec. 02, 2024

Sep. 30, 2025

Sep. 30, 2024

^[1]

Sep. 30, 2025

Sep. 30, 2024

^[1]

Schedule of Equity Method Investments [Line Items]

Equity method investment dividends or distributions

$ 20,000,000

Equity method investment dividends or distributions per unit

$ 1

Research and development expenses

$ 27,252,000

$ 35,031,000

87,618,000

$ 92,163,000

Other income

$ (121,000)

$ (120,000)

$ 405,000

$ (255,000)

Huntsville Manufacturing Facility

Schedule of Equity Method Investments [Line Items]

Common unit, price per unit

$ 1

Percentage of the common units outstanding

100.00%

Huntsville Manufacturing Facility | Stock Appreciation Rights (SARs)

Schedule of Equity Method Investments [Line Items]

Shares issued

8.2

Shares reserved for issuance

11.3

Gannet BioChem

Schedule of Equity Method Investments [Line Items]

Fair value of investment

$ 12,200,000

Minimum purchase commitments

$ 0

Purchases made

$ 0

Gannet BioChem | Huntsville Manufacturing Facility

Schedule of Equity Method Investments [Line Items]

Common units owned

20.0

Services Agreements | Gannet BioChem

Schedule of Equity Method Investments [Line Items]

Agreement term

2 years

Research and development expenses

400,000

$ 1,200,000

Other income

200,000

1,100,000

Net accounts receivable

200,000

Net payable

$ 300,000

Asset Acquisition By Ampersand Capital Partners | Huntsville Manufacturing Facility

Schedule of Equity Method Investments [Line Items]

Preferred units owned by a related party

81.5

Preferred unit, price per unit owned by related party

$ 1

Percentage of the preferred units owned by related party outstanding

100.00%

Percentage of preferred units outstanding

99.70%

Asset Acquisition By Ampersand Capital Partners | Huntsville Manufacturing Facility | Stock Appreciation Rights (SARs)

Schedule of Equity Method Investments [Line Items]

Share issued base value

$ 1

Asset Acquisition By Ampersand Capital Partners | Asset Purchase Agreement | Huntsville Manufacturing Facility

Schedule of Equity Method Investments [Line Items]

Consideration in cash, net of transaction costs

$ 64,700,000

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

Cash and Investments in Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2025

Fair Value Disclosures [Abstract]

Schedule of 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, 2025		December 31, 2024
Cash and cash equivalents	$	41,032	$	44,252
Short-term investments		229,176		210,974
Long-term investments		—		13,869
Total cash and investments in marketable securities	$	270,208	$	269,095

Schedule of Portfolio of Cash and Investments in Marketable Securities

Our portfolio of cash and investments in marketable securities consists of the following (in thousands):


		September 30, 2025									December 31, 2024
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Fair Value
Corporate notes and bonds	2	$	70,569	$	24	$	(10	)	$	70,583	$	109,711
Corporate commercial paper	2		149,333		26		(16	)		149,343		119,542
Available-for-sale investments		$	219,902	$	50	$	(26	)	$	219,926	$	229,253
Money market funds	1									24,717		15,993
Certificates of deposit	2									14,215		14,027
Cash	N/A									11,350		9,822
Total cash and investments in marketable securities									$	270,208	$	269,095

License and Collaboration Agreements - Additional Information (Details)

1 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

Feb. 12, 2024

USD ($)

Jul. 23, 2017

USD ($)

Apr. 30, 2018

USD ($)

Sep. 30, 2025

USD ($)

Milestones

Sep. 30, 2024

USD ($)

^[1]

Sep. 30, 2025

USD ($)

Milestones

Sep. 30, 2024

USD ($)

^[1]

Dec. 31, 2023

USD ($)

Dec. 31, 2020

USD ($)

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Revenue

$ 11,790,000

$ 24,124,000

$ 33,425,000

$ 69,252,000

Non-cash royalty revenue related to the sales of future royalties

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Revenue

11,490,000

$ 15,731,000

33,125,000

$ 48,029,000

Bristol Myers Squibb Company | Purchase Agreement

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Shares issued (in shares) | shares

552,307

Sale of stock consideration received

$ 850,000,000

Other Partner

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Potential future additional payments for development milestones

$ 40,000,000

Nektar-358 | Maximum | Eli Lilly And Company

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Potential future additional development and regulatory milestones (up to)

$ 250,000,000

Nektar 0165 | Biolojic Design Company [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Payable For Newdrug Investigle Milestone

$ 3,000,000

Number of Milestone | Milestones

Nektar 0165 | Maximum | Biolojic Design Company [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Potential future additional payments for development milestones

35,000,000

Payment For Development Milestones

$ 18,000,000

Bristol Myers Squibb Collaboration Agreement

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Sale of stock shares repurchased | shares

552,307

Sale of stock repurchased cash consideration

$ 3,000,000

Nektar's | Nektar-358

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Received upfront and milestone payment

$ 150,000,000

Nektar's | Bristol Myers Squibb Collaboration Agreement | Nektar 214

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Upfront and milestone payments received from license agreements

$ 1,000,000,000

Nektar's | Bristol Myers Squibb Collaboration Agreement | Nektar 214 | Milestone One

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Potential future additional payments for development milestones

$ 50,000,000

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

Restructuring and Impairment (Tables)

9 Months Ended

Sep. 30, 2025

Restructuring and Related Activities [Abstract]

Schedule of Restructuring and Impairment

In connection with our 2022 and 2023 Restructuring Plans, restructuring and impairment includes the following (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Impairment of right-of-use assets and property, plant and equipment	$	—	$	—	$	—	$	8,329
Contract termination and other restructuring costs		140		46		756		5,981
Restructuring and impairment	$	140	$	46	$	756	$	14,310

The following is a reconciliation of the impairment charges we recorded for the three and nine months ended September 30, 2024, including the net book values of the sublease assets before the impairment and the fair values of the sublease assets (in thousands):


	Nine Months Ended September 30, 2024
	Property, Plant and Equipment			Operating Lease Right-of-Use Assets			Total
Net book value of impaired facilities before write-off	$	1,897		$	12,506		$	14,403
Less: Fair value of impaired facilities — Level 3 of Fair Value Hierarchy		(855	)		(5,219	)		(6,074	)
Total impairment of right-of-use assets and property, plant and equipment	$	1,042		$	7,287		$	8,329

The following are reconciliations of the contract termination and other costs for three and nine months ended September 30, 2025 and 2024 (in thousands):


	For the Nine Months Ended September 30,
	2025			2024
Liability balances as of December 31, 2024 and 2023, respectively	$	9,078		$	5,542
Expense recognized during the period		169			975
Payments during the period		(554	)		(928	)
Liability balances as of March 31, 2025 and 2024, respectively	$	8,693		$	5,589
Expense recognized during the period		447			4,960
Payments during the period		(836	)		(887	)
Liability balances as of June 30, 2025 and 2024, respectively	$	8,304		$	9,662
Expense recognized during the period		140			46
Payments during the period		(836	)		(886	)
Liability balances as of September 30, 2025 and 2024, respectively	$	7,608		$	8,822

Segment Reporting

9 Months Ended

Sep. 30, 2025

Segment Reporting [Abstract]

Segment Reporting

Note 10 — Segment Reporting

We operate in one business segment which focuses on applying our expertise to develop novel drug candidates. 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, who is our chief operating decision maker (CODM).

The CODM assesses the performance of the Company and decides how to allocate resources based upon net loss that is also reported within the Condensed Consolidated Statements of Operations. The measure of segment assets that is reviewed by the CODM is reported within the Condensed Consolidated Balance Sheet as total assets.

The following is a summary of the significant expense categories and consolidated net loss details provided to the CODM (in thousands):


	Three Months Ended September 30,						Nine Months Ended September 30,
	2025			2024			2025			2024
Revenue:	$	11,790		$	24,124		$	33,425		$	69,252
Operating costs and expenses:
Cost of goods sold		—			4,435			—			22,709
Clinical development, contract manufacturing and other third party costs
Rezpegaldesleukin (IL-2 receptor agonist/regulatory T cell agent)		11,155			15,684			37,888			36,667
NKTR-0165 (tumor necrosis factor receptor type II agonist)		3,119			3,900			8,931			7,751
NKTR-255 (IL-15 receptor agonist)		1,413			5,108			5,034			12,790
Discovery research and other programs		163			(371	)		1,018			1,869
Total clinical development, contract manufacturing and other third party costs		15,850			24,321			52,871			59,077
Employee costs (a)(b)		10,888			9,544			33,782			29,915
Facilities costs (a)		3,052			3,779			9,378			12,417
Other operating costs (a)(c)		10,297			11,013			37,881			33,442
Other segment expenses		3,375			5,377			11,950			31,238
Total operating costs and expenses		43,462			58,469			145,862			188,798
Loss from operations		(31,672	)		(34,345	)		(112,437	)		(119,546	)
Non-operating income (expense):
Non-cash interest expense on liability related to sale of future royalties		(6,047	)		(6,020	)		(16,415	)		(17,959	)
Interest income		2,819			3,437			7,662			11,558
Other income (expense), net		(121	)		(120	)		405			(255	)
Total non-operating income (expense), net		(3,349	)		(2,703	)		(8,348	)		(6,656	)
Loss before provision (benefit) for income taxes and equity method investment		(35,021	)		(37,048	)		(120,785	)		(126,202	)
Provision (benefit) for income taxes		(33	)		9			(169	)		20
Loss before equity method investment		(34,988	)		(37,057	)		(120,616	)		(126,222	)
Loss from equity method investment		(534	)		—			(7,381	)		—
Net loss	$	(35,522	)	$	(37,057	)	$	(127,997	)	$	(126,222	)

Other segment expense items included within net loss include the following (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Impairment of right-of-use assets and property, plant and equipment	$	-	$	-	$	-	$	8,329
Contract termination costs		140		46		756		5,981
Stock-based compensation (a)		3,072		4,875		10,456		15,136
Depreciation and amortization expense (a)		163		456		738		1,792
Total other segment expenses	$	3,375	$	5,377	$	11,950	$	31,238

Employee costs, facilities costs, other operating costs, stock-based compensation expense and depreciation and amortization expense include amounts reported in research and development expense and general and administrative expense in our Condensed Consolidated Statements of Operations. Such amounts reported in cost of goods sold in our Condensed Consolidated Statements of Operations are included in cost of goods sold in the summary of significant segment expenses.

Includes compensation and benefits for our employees and costs for our contractors and temporary workers.

Includes legal and patent expenses, information technology infrastructure and other costs, professional accounting, insurance, travel and entertainment and other third party services and expenses.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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-Topic 280
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+ Details

Segment Reporting - Additional Information (Details)	9 Months Ended
Segment Reporting - Additional Information (Details)	Sep. 30, 2025 Segment
Segment Reporting [Abstract]
Number of operating business segment	1
Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration]	srt:ChiefExecutiveOfficerMember
Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description	The CODM assesses the performance of the Company and decides how to allocate resources based upon net loss that is also reported within the Condensed Consolidated Statements of Operations. The measure of segment assets that is reviewed by the CODM is reported within the Condensed Consolidated Balance Sheet as total assets.

Pay vs Performance Disclosure - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2025

Sep. 30, 2024

Sep. 30, 2025

Sep. 30, 2024

Pay vs Performance Disclosure

Net Income (Loss)

$ (35,522)

$ (37,057)

^[1]

$ (127,997)

$ (126,222)

^[1]

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

Organization and Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization

Nektar Therapeutics (Nektar, we) is a clinical stage, research-based drug discovery biopharmaceutical company headquartered in San Francisco, California and incorporated in Delaware, focused on discovering and developing innovative medicines in the field of immunotherapy. Within this growing field, we direct our efforts toward creating new immunomodulatory agents that selectively induce, amplify, attenuate or prevent immune responses in order to achieve desired therapeutic outcomes. Our pipeline of clinical-stage and preclinical-stage immunomodulatory agents targets the treatment of autoimmune diseases (e.g. rezpegaldesleukin and NKTR-0165, respectively) and cancer (e.g. NKTR-255).

We are conducting Phase 2b trials of rezpegaldesleukin in patients with moderate-to-severe atopic dermatitis which we initiated in October 2023 (the Phase 2b REZOLVE-AD trial) and in patients with severe-to-very severe alopecia areata which we initiated in March 2024 (the Phase 2b REZOLVE-AA trial). On February 24, 2025, we announced that we had entered into a collaboration agreement with TrialNet to evaluate rezpegaldesleukin in patients with new onset stage 3 type 1 diabetes mellitus in a Phase 2 study. TrialNet will conduct the study with funding from the National Institutes of Health, primarily through the Special Statutory Funding Program for Type 1 Diabetes through the National Institute of Diabetes and Digestive and Kidney Diseases. Nektar will supply rezpegaldesleukin for the study and will retain all rights to the rezpegaldesleukin program under the collaboration.

On June 24, 2025, we announced data from the 16-week induction period of the ongoing Phase 2b REZOLVE-AD trial being conducted in 393 patients.

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. As of September 30, 2025, we had approximately $270.2 million in cash and investments in marketable securities.

As we continue our research and development activities, we will need additional cash to fund our operations. Accordingly, we may enter into new collaboration agreements or other similar transactions, and we may also seek financing transactions, which may include dilutive equity-based financings, such as an offering of our common stock. There can be no assurance that any additional collaboration agreements or financings will be available to us on commercially reasonable terms. We believe we have sufficient cash and investments in marketable securities to fund operations through at least the next twelve months from the date of the filing of these financial statements.

We filed a shelf registration statement on Form S-3 and a related prospectus (the Shelf Registration Statement) that was declared effective by the Securities and Exchange Commission (the SEC) on April 1, 2025. Pursuant to the Shelf Registration Statement, we may offer and sell common stock, preferred stock, debt securities, warrants and or units having an aggregate public offering price of up to $300.0 million. In connection with the filing of the Shelf Registration Statement, we also entered into an equity distribution agreement (the ATM Sales Agreement) with Piper Sandler & Co. and BTIG, LLC, relating to the sale of our common stock having an aggregate offering price of up to $75.0 million (the ATM Shares). The sales of the ATM Shares will be made by any method permitted that is deemed to be an “at-the-market” equity offering as defined in Rule 415(a)(4) promulgated under the Securities Act, including sales made directly on or through Nasdaq or on any other existing trading market for our common stock. We have agreed to pay Piper Sandler & Co. and BTIG, LLC a commission equal to 3.0% of the gross sales price of all common stock sold through them as sales agents.

On July 2, 2025, pursuant to the Shelf Registration Statement, we completed the sale and issuance of 4,893,618 shares of our common stock in an underwritten public offering (the 2025 Offering) at a price of $23.50 per share. The net proceeds to the Company from the 2025 Offering totaled approximately $107.2 million, after deducting underwriting discounts and commissions and offering costs. See Note 6 for additional information.

During the three months ended September 30, 2025, we issued 600,198 shares of our common stock under the ATM Sales Agreement at a weighted average price of $59.24 per share for net proceeds of $34.3 million after deducting related commissions and offering costs. In October 2025, we issued an additional 673,725 shares of our common stock under the ATM Sales Agreement at a weighted average price of $58.55 for net proceeds of $38.3 million after deducting related commissions. No ATM shares remain available for issuance under the ATM Sales Agreement.

Sale of Manufacturing Facility

On December 2, 2024, we completed the sale of our manufacturing facility located in Huntsville, Alabama (the Facility) and certain other manufacturing assets related thereto, including the assignment of our existing manufacturing and supply obligations, to Gannet BioChem, an affiliate of Ampersand Management LLC d/b/a Ampersand Capital Partners (Ampersand), via an Asset Purchase Agreement (the APA), for consideration of $64.7 million in cash, net of transaction costs, and an approximate 20% equity ownership at the time of close in Gannet BioChem. See Note 4 for additional information. As a result of the sale of the Facility, we no longer recognize product sales or cost of goods sold.

Basis of Presentation and Principles of Consolidation

We have prepared our Condensed Consolidated Financial Statements pursuant to U.S. generally accepted accounting principles (U.S. GAAP) and the rules and regulations of the 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. 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 include the financial position, results of operations and cash flows of our wholly-owned subsidiaries. In determining whether we are the primary beneficiary of a variable interest entity, we consider whether we have both the power to direct activities of the entity that most significantly impact the entity’s economic performance and the obligation to absorb losses of, or the right to receive benefits from, the entity that could potentially be significant to that entity. We do not have any interests in any variable interest entities of which we are the primary beneficiary. We have eliminated all intercompany accounts and transactions in consolidation.

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.

Our comprehensive loss consists of our net loss plus our foreign currency translation gains and losses (to the extent recognized in other comprehensive income (loss)) and unrealized gains and losses on available-for-sale securities. There were no significant reclassifications out of accumulated other comprehensive income (loss) to the statements of operations during the three and nine months ended September 30, 2025 and 2024. We include translation gains and losses in accumulated other comprehensive income (loss) in the stockholders’ equity section of our Condensed Consolidated Balance Sheets. However, if we have concluded that we have substantially liquidated the entity, such as for our subsidiary in India, we recognize subsequent translation gains and losses in other income (expense) in our Condensed Consolidated Statements of Operations.

The accompanying Condensed Consolidated Financial Statements are unaudited. The Condensed Consolidated Balance Sheet data as of December 31, 2024 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, 2024 filed with the SEC on March 14, 2025. 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. 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.

Related Parties

Transactions between related parties are considered to be related party transactions even though they may not be given accounting recognition. Accounting Standards Codification (ASC) 850, Related Party Disclosures (ASC 850) requires that transactions with related parties that would make a difference in decision making shall be disclosed so that users of the financial statements can evaluate their significance. See Note 4 regarding our related party transactions with Gannet BioChem.

Significant Concentrations

Our customers are primarily pharmaceutical and biotechnology companies with whom we have multi-year arrangements. Before the sale of the Facility, our accounts receivable balance primarily contained trade receivables from product sales. We have not recorded provisions for credit losses for the three and nine months ended September 30, 2025 and 2024. Accounts receivable at September 30, 2025 and December 31, 2024 are immaterial due to the sale of the Facility in December 2024.

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, our suppliers and contract manufacturers may rely on single sources of supply of one or more critical materials. As a result of the sale of the Facility, we are dependent on Gannet BioChem for the supply of the polyethylene glycol reagents (PEG reagents) used in the manufacture of rezpegaldesleukin and NKTR-255. 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.

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.

Reverse Stock Split

On June 6, 2025, we filed a Certificate of Amendment to the Certificate of Incorporation, or the Reverse Stock Split Amendment, to effect a reverse stock split of Nektar’s Common Stock at a ratio of one-for-fifteen, effective June 8, 2025. No fractional shares of common stock were issued as a result of the Reverse Stock Split. All share and per share figures in these financial statements have been adjusted to give retrospective effect to the Reverse Stock Split. See Note 6 for additional information.

Treasury Stock

We record treasury stock activities under the cost method. Treasury stock is included in authorized and issued shares but excluded from outstanding shares. The re-issuance of treasury stock is accounted for on a first-in, first-out basis and any differences between the cost of treasury stock and the re-issuance proceeds are charged or credited to additional paid-in capital. In connection with the 2025 Offering, we re-issued all shares held in treasury stock. See Note 6 for additional information.

Restructuring

In April 2022 and April 2023, we announced certain restructuring plans (the 2022 Restructuring Plan and the 2023 Restructuring Plan, respectively), pursuant to which we terminated significant portions of our workforce and decided to sublease all of our leased premises in San Francisco, California, including our office space on Third St. (Third St. Facility) and our office and laboratory space on Mission Bay Blvd. South (Mission Bay Facility).

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 contract termination costs incurred when we cancel the contract in accordance with its terms, or for costs to be incurred over the remaining contract term without economic benefit to us at the cease-use date.

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 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.

Income Taxes

On July 4, 2025, the budget reconciliation bill H.R. 1, known as the One Big Beautiful Bill (OBBB), was signed into law. The OBBB contains several changes to corporate taxation including modifications to capitalization of research and development expenses, limitations on deductions for interest expense and accelerated fixed asset depreciation. We are in the process of evaluating the OBBB’s impact on our financial statements.

Equity Method Investment

Our investment in Gannet BioChem is considered a variable interest entity for which we are not the primary beneficiary. We use the equity method of accounting to account for our investment in Gannet BioChem, which is an entity that we do not control, but have the ability to exert significant influence. Judgments regarding the level of influence over the equity method investment include consideration of key factors such as our ownership interest, representation on the board of directors or participation in policy-making decisions.

Under the equity method of accounting, our investment in Gannet BioChem is initially recorded at fair value. The carrying value of the investment is subsequently adjusted based on our share of the net income or loss of the entity which we present as gain or loss from equity method investment in our Condensed Consolidated Statements of Operations. We record our share of the equity method investment’s results of operations on a three-month lag basis.

Due to Ampersand’s right to receive a cumulative preferred dividend at a certain annual rate of return and return of capital before any distributions are made to us as further disclosed in Note 4, we record our gain or loss on our investment in Gannet BioChem under the hypothetical liquidation at book value (HLBV) method.

The HLBV method is a balance sheet approach that calculates the change in the hypothetical amount Ampersand and we would be entitled to receive if Gannet BioChem were liquidated at book value at the end of each period, adjusted for any contributions made and distributions received during the period, as well as basis differences between the initial fair value of our investment in Gannet BioChem and our claim on the net assets of Gannet BioChem. Our maximum exposure to loss in Gannet BioChem is limited to the carrying value of our investment.

We evaluate our equity method investment at the end of each reporting period to determine whether events or changes in business circumstances indicate that the carrying value of the investment may not be recoverable. This evaluation consists of several qualitative and quantitative factors that may include recent financial results, projected financial results and operating trends of the investees and other publicly available information that may affect the value of our investment.

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, including the pre-funded warrant, as further disclosed in Note 4, during the periods presented. Shares of common stock into which the pre-funded warrant may be exercised are considered outstanding for the purposes of computing basic net loss per share because the shares may be issued for little or no consideration, are fully vested and are exercisable after the original issuance date. For the three and nine months ended September 30, 2025 and 2024, 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. We excluded shares underlying the weighted average outstanding stock options, restricted stock units (RSUs) and performance stock units (PSUs), as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Potentially dilutive securities		2,202,024		1,726,765		2,256,665		1,761,960

Recent Accounting Pronouncements

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which will require incremental income tax disclosures on an annual basis for all public entities. The amendments require that public business entities disclose specific categories in the rate reconciliation and provide additional information for reconciling items meeting a quantitative threshold. The amendments also require disclosure of income taxes paid to be disaggregated by jurisdiction, and disclosure of income tax expense disaggregated by federal, state, and foreign. ASU 2023-09 is effective for annual reporting beginning with the fiscal year ending December 31, 2025. We are currently evaluating the incremental disclosures that will be required in our consolidated financial statements.

In November 2024, the FASB issued ASU No. 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, an accounting standard update that requires the Company to disclose more detailed information about the types of expenses (including employee compensation, depreciation, and amortization) included in each relevant income statement expense caption. In January 2025, the FASB issued ASU 2025-01, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date, to clarify the effective date of ASU 2024-03. The ASU is effective for fiscal years beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. We are currently evaluating the incremental disclosures that will be required in our consolidated financial statements.

Condensed Consolidated Financial Statement Details - Schedule of Liability Related to Sale of Potential Future Royalties (Details) - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2025

Sep. 30, 2024

^[1]

Sep. 30, 2025

Sep. 30, 2024

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

$ 91,776

Non-cash royalty revenue

(33,125)

$ (48,029)

Non-cash interest expense

$ 6,047

$ 6,020

16,415

$ 17,959

^[1]

Amortization of transaction costs

75,164

2012 Purchase and Sale Agreement

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

7,197

Non-cash royalty revenue

(5,619)

Non-cash interest expense

1,983

Amortization of transaction costs

3,561

2020 Purchase and Sale Agreement

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

84,579

Non-cash royalty revenue

(27,506)

Non-cash interest expense

14,432

Amortization of transaction costs

$ 71,603

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

Organization and Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2025

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

On June 24, 2025, we announced data from the 16-week induction period of the ongoing Phase 2b REZOLVE-AD trial being conducted in 393 patients.

On July 2, 2025, pursuant to the Shelf Registration Statement, we completed the sale and issuance of 4,893,618 shares of our common stock in an underwritten public offering (the 2025 Offering) at a price of $23.50 per share. The net proceeds to the Company from the 2025 Offering totaled approximately $107.2 million, after deducting underwriting discounts and commissions and offering costs. See Note 6 for additional information.

Sale of Manufacturing Facility

Basis of Presentation and Principles of Consolidation

Use of Estimates

Related Parties

Significant Concentrations

Reverse Stock Split

Treasury Stock

Restructuring

Long-Lived Asset Impairment

Income Taxes

Equity Method Investment

Net Loss per Share


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Potentially dilutive securities		2,202,024		1,726,765		2,256,665		1,761,960

Recent Accounting Pronouncements

Condensed Consolidated Financial Statement Details - Narrative (Details) - 2020 Purchase and Sale Agreement $ in Millions			9 Months Ended
	Mar. 04, 2024 USD ($)	Dec. 16, 2020 USD ($)	Sep. 30, 2025 USD ($)
Goodwill [Line Items]
Royalties liability discount rate			0.28
Payment of transaction related to purchase and sale agreement		$ 210.0
Payment of transaction related to purchase and sale agreement if threshold is not achieved		$ 240.0
Amount exchanged to remove cap on royalties	$ 15.0
Proceeds from sale of royalty rights			$ 15.0

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 350
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-Name Accounting Standards Codification
-Section 55
-Paragraph 24
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-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1A

+ Details

Restructuring and Impairment - Summary of Restructuring Plans, Restructuring and Impairment (Details) - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2025

Sep. 30, 2024

Sep. 30, 2025

Sep. 30, 2024

Restructuring Cost and Reserve [Line Items]

Impairment of right-of-use assets and property and equipment

$ 0

$ 8,329

Restructuring and impairment

$ 140

$ 46

^[1]

756

14,310

^[1]

2022 and 2023 Restructuring Plans

Restructuring Cost and Reserve [Line Items]

Impairment of right-of-use assets and property and equipment

8,329

Contract termination and other restructuring costs

140

756

5,981

Restructuring and impairment

$ 140

$ 46

$ 756

$ 14,310

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

Condensed Consolidated Financial Statement Details - Schedule of Accrued Expenses (Details) - USD ($)
$ in Thousands

Sep. 30, 2025

Dec. 31, 2024

Inventory Disclosure [Abstract]

Accrued compensation

$ 8,606

$ 2,832

Accrued research and development expenses

12,084

14,453

Accrued contract termination costs

3,149

2,767

Other accrued expenses

4,755

9,920

Total accrued expenses

$ 28,594

$ 29,972

^[1]

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

Stockholders' Equity - Summary of Reverse Stock Split, Shares Reserved for Issuance Under Employee Stock Plans (Details) - $ / shares	Sep. 30, 2025	Dec. 31, 2024
Class of Stock [Line Items]
Total shares reserved for issuance under our employee stock plans	3,195,850	2,904,561
Employee Stock Option
Class of Stock [Line Items]
Stock options outstanding	2,185,410	2,203,927
Weighted average exercise price	$ 79.11	$ 83.73
Restricted Stock Units (RSUs) [Member]
Class of Stock [Line Items]
RSUs outstanding	41,894	101,524
2017 Performance Incentive Plan
Class of Stock [Line Items]
Total shares reserved for issuance under our employee stock plans	921,896	551,727
Employee Stock Purchase Plan
Class of Stock [Line Items]
Total shares reserved for issuance under our employee stock plans	46,650	47,383

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Segment Reporting - Schedule of Other Segment Expense Items Included within Net Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Impairment of right-of-use assets and property and equipment			$ 0	$ 8,329
Stock-based compensation	$ 3,072	$ 5,391	10,456	16,809
Depreciation and amortization expense			836	4,059
Total other segment expenses	3,375	5,377	11,950	31,238
Other Segment
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Impairment of right-of-use assets and property and equipment	0	0	0	8,329
Contract termination costs	140	46	756	5,981
Stock-based compensation	3,072	4,875	10,456	15,136
Depreciation and amortization expense	163	456	738	1,792
Total other segment expenses	$ 3,375	$ 5,377	$ 11,950	$ 31,238

Restructuring and Impairment - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Jun. 30, 2024	Sep. 30, 2025	Dec. 31, 2024
Restructuring Cost and Reserve [Line Items]
Impairment charges	$ 0	$ 8,300,000	$ 0
Measurement Input, Market Participant Subtenant Borrowing Rate
Restructuring Cost and Reserve [Line Items]
Operating lease, measurement input		6.20%
Third St. Facility
Restructuring Cost and Reserve [Line Items]
Impairment charges		$ 4,400,000
Mission Bay Facility
Restructuring Cost and Reserve [Line Items]
Impairment charges		$ 3,900,000
Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Contract termination and other costs included in accrued expenses	$ 3,100,000		$ 3,100,000	$ 2,800,000

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

Restructuring and Impairment

9 Months Ended

Sep. 30, 2025

Restructuring and Related Activities [Abstract]

Restructuring and Impairment

Note 8 — Restructuring and Impairment

In connection with our 2022 and 2023 Restructuring Plans, restructuring and impairment includes the following (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Impairment of right-of-use assets and property, plant and equipment	$	—	$	—	$	—	$	8,329
Contract termination and other restructuring costs		140		46		756		5,981
Restructuring and impairment	$	140	$	46	$	756	$	14,310

Impairment of Long-Lived Assets

As a result of our 2022 and 2023 Restructuring Plans, we decided to seek a sublease for all of our leased spaces in the Third St. Facility and the Mission Bay Facility. Accordingly, we evaluate each space for impairment at each reporting date, as facts and circumstances change. The significant assumptions in our impairment analysis relate to sublease income, including the length of time to enter into a sublease, sublease rental payments, free rent periods, tenant improvement allowances and broker commissions. When available, we use sublease negotiations or agreements, but in the absence of such information, we develop our own subjective estimates based on current real estate trends and market conditions. Accordingly, our estimates are subject to significant risk, and the terms of sublease agreements, if any, and the resulting amount and timing of sublease income, if ever realized, may be materially different than our estimates.

As part of our evaluation of each sublease space, we separately compare the estimated undiscounted sublease income, as described above, for each sublease to the net book value of the related long-term assets, which include right-of-use assets and certain property, plant and equipment, primarily for leasehold improvements (collectively, sublease assets). If such sublease income exceeds the net book value of the sublease assets, we do not record an impairment charge. Otherwise, we record an impairment charge by reducing the net book value of the sublease assets to their estimated fair value, which we determined by discounting the estimated sublease income using the estimated borrowing rate of a market participant subtenant.

During the three months ended June 30, 2024, as the life sciences and office lease markets continued to deteriorate, we recorded non-cash impairment charges totaling $8.3 million, consisting of $3.9 million for our office and laboratory leased space in the Mission Bay Facility and $4.4 million for our office lease space in the Third St. Facility.

For these impairment charges, we developed our estimates of sublease income based on market participant assumptions as described above, and we discounted the sublease income using the estimated borrowing rate of a market participant subtenant, which we estimated to be 6.2% for the three months ended June 30, 2024. We recorded no impairment charges for three and nine months ended September 30, 2025, nor for the three months ended September 30, 2024.


	Nine Months Ended September 30, 2024
	Property, Plant and Equipment			Operating Lease Right-of-Use Assets			Total
Net book value of impaired facilities before write-off	$	1,897		$	12,506		$	14,403
Less: Fair value of impaired facilities — Level 3 of Fair Value Hierarchy		(855	)		(5,219	)		(6,074	)
Total impairment of right-of-use assets and property, plant and equipment	$	1,042		$	7,287		$	8,329

Contract Termination and Other Costs

We have incurred significant contract termination costs in connection with our Restructuring Plans. Because we continue to adjust the liability based on updates to our assumptions at each reporting date, we continue to recognize expense as our estimates change until settlement.

The following are reconciliations of the contract termination and other costs for three and nine months ended September 30, 2025 and 2024 (in thousands):


	For the Nine Months Ended September 30,
	2025			2024
Liability balances as of December 31, 2024 and 2023, respectively	$	9,078		$	5,542
Expense recognized during the period		169			975
Payments during the period		(554	)		(928	)
Liability balances as of March 31, 2025 and 2024, respectively	$	8,693		$	5,589
Expense recognized during the period		447			4,960
Payments during the period		(836	)		(887	)
Liability balances as of June 30, 2025 and 2024, respectively	$	8,304		$	9,662
Expense recognized during the period		140			46
Payments during the period		(836	)		(886	)
Liability balances as of September 30, 2025 and 2024, respectively	$	7,608		$	8,822

As of September 30, 2025 and December 31, 2024, we report $3.1 million and $2.8 million, respectively, within accrued expenses and the remaining amounts within other long-term liabilities on our Condensed Consolidated Balance Sheets.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2025

USD ($)

Sep. 30, 2024

USD ($)

Sep. 30, 2025

USD ($)

Sep. 30, 2024

USD ($)

Research and development

$ 27,252

$ 35,031

^[1]

$ 87,618

$ 92,163

^[1]

Other income (expense), net

(121)

$ (120)

^[1]

$ 405

$ (255)

^[1]

Reverse stock split, ratio

0.07

Reverse stock split

one-for-fifteen reverse stock split

Related Party

Research and development

421

$ 0

$ 1,242

$ 0

Other income (expense), net

$ 190

$ 0

$ 1,051

$ 0

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

Segment Reporting (Tables)

9 Months Ended

Sep. 30, 2025

Segment Reporting [Abstract]

Summary of Significant Expense Categories and Consolidated Net Loss

The following is a summary of the significant expense categories and consolidated net loss details provided to the CODM (in thousands):


	Three Months Ended September 30,						Nine Months Ended September 30,
	2025			2024			2025			2024
Revenue:	$	11,790		$	24,124		$	33,425		$	69,252
Operating costs and expenses:
Cost of goods sold		—			4,435			—			22,709
Clinical development, contract manufacturing and other third party costs
Rezpegaldesleukin (IL-2 receptor agonist/regulatory T cell agent)		11,155			15,684			37,888			36,667
NKTR-0165 (tumor necrosis factor receptor type II agonist)		3,119			3,900			8,931			7,751
NKTR-255 (IL-15 receptor agonist)		1,413			5,108			5,034			12,790
Discovery research and other programs		163			(371	)		1,018			1,869
Total clinical development, contract manufacturing and other third party costs		15,850			24,321			52,871			59,077
Employee costs (a)(b)		10,888			9,544			33,782			29,915
Facilities costs (a)		3,052			3,779			9,378			12,417
Other operating costs (a)(c)		10,297			11,013			37,881			33,442
Other segment expenses		3,375			5,377			11,950			31,238
Total operating costs and expenses		43,462			58,469			145,862			188,798
Loss from operations		(31,672	)		(34,345	)		(112,437	)		(119,546	)
Non-operating income (expense):
Non-cash interest expense on liability related to sale of future royalties		(6,047	)		(6,020	)		(16,415	)		(17,959	)
Interest income		2,819			3,437			7,662			11,558
Other income (expense), net		(121	)		(120	)		405			(255	)
Total non-operating income (expense), net		(3,349	)		(2,703	)		(8,348	)		(6,656	)
Loss before provision (benefit) for income taxes and equity method investment		(35,021	)		(37,048	)		(120,785	)		(126,202	)
Provision (benefit) for income taxes		(33	)		9			(169	)		20
Loss before equity method investment		(34,988	)		(37,057	)		(120,616	)		(126,222	)
Loss from equity method investment		(534	)		—			(7,381	)		—
Net loss	$	(35,522	)	$	(37,057	)	$	(127,997	)	$	(126,222	)

Schedule of Other Segment Expense Items Included within Net Loss

Other segment expense items included within net loss include the following (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Impairment of right-of-use assets and property, plant and equipment	$	-	$	-	$	-	$	8,329
Contract termination costs		140		46		756		5,981
Stock-based compensation (a)		3,072		4,875		10,456		15,136
Depreciation and amortization expense (a)		163		456		738		1,792
Total other segment expenses	$	3,375	$	5,377	$	11,950	$	31,238

Includes compensation and benefits for our employees and costs for our contractors and temporary workers.

Includes legal and patent expenses, information technology infrastructure and other costs, professional accounting, insurance, travel and entertainment and other third party services and expenses.

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($)
$ in Thousands

Total

Secondary Offering

At-the-Market Offering

Common Shares

Secondary Offering

Common Shares

At-the-Market Offering

Treasury Stock

Secondary Offering

Capital in Excess of Par Value

Secondary Offering

^[2]

Capital in Excess of Par Value

At-the-Market Offering

^[2]

Accumulated Other Comprehensive Income/(Loss)

Accumulated Deficit

Beginning balance (in shares) at Dec. 31, 2023

^[1]

12,757,984

Beginning balance at Dec. 31, 2023

$ 130,987

$ 1

^[1]

$ 3,608,155

^[1]

$ 80

$ (3,477,249)

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Shares issued under equity compensation plans (in shares)

^[1]

35,131

Shares issued under equity compensation plans

^[1]

Stock-based compensation

6,000

^[1]

Repurchase of common stock from Bristol-Myers Squibb (in shares)

^[1]

(552,307)

552,307

Repurchase of common stock from Bristol-Myers Squibb

(3,000)

$ (3,000)

Issuance of prefunded warrant

30,000

^[1]

Comprehensive income (loss)

(37,285)

(483)

(36,802)

Ending balance (in shares) at Mar. 31, 2024

^[1]

12,240,808

Ending balance at Mar. 31, 2024

126,705

$ 1

^[1]

$ (3,000)

3,644,158

^[1]

(403)

(3,514,051)

Ending balance (in shares) at Mar. 31, 2024

^[1]

552,307

Beginning balance (in shares) at Dec. 31, 2023

^[1]

12,757,984

Beginning balance at Dec. 31, 2023

130,987

$ 1

^[1]

3,608,155

^[1]

(3,477,249)

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Comprehensive income (loss)

(125,947)

Ending balance (in shares) at Sep. 30, 2024

^[1]

12,296,312

Ending balance at Sep. 30, 2024

48,884

$ 1

^[1]

$ (3,000)

3,654,999

^[1]

355

(3,603,471)

Ending balance (in shares) at Sep. 30, 2024

^[1]

552,307

Beginning balance (in shares) at Mar. 31, 2024

^[1]

12,240,808

Beginning balance at Mar. 31, 2024

126,705

$ 1

^[1]

$ (3,000)

3,644,158

^[1]

(403)

(3,514,051)

Beginning balance (in shares) at Mar. 31, 2024

^[1]

552,307

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Shares issued under equity compensation plans (in shares)

^[1]

29,095

Shares issued under equity compensation plans

^[1]

Stock-based compensation

5,418

^[1]

Comprehensive income (loss)

(52,454)

(91)

(52,363)

Ending balance (in shares) at Jun. 30, 2024

^[1]

12,269,903

Ending balance at Jun. 30, 2024

79,688

$ 1

^[1]

$ (3,000)

3,649,595

^[1]

(494)

(3,566,414)

Ending balance (in shares) at Jun. 30, 2024

^[1]

552,307

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Shares issued under equity compensation plans (in shares)

^[1]

26,409

Shares issued under equity compensation plans

^[1]

Stock-based compensation

5,391

^[1]

Comprehensive income (loss)

(36,208)

849

(37,057)

Ending balance (in shares) at Sep. 30, 2024

^[1]

12,296,312

Ending balance at Sep. 30, 2024

$ 48,884

$ 1

^[1]

$ (3,000)

3,654,999

^[1]

355

(3,603,471)

Ending balance (in shares) at Sep. 30, 2024

^[1]

552,307

Beginning balance (in shares) at Dec. 31, 2024

12,385,001

^[2]

Beginning balance at Dec. 31, 2024

$ 60,737

^[3]

$ 1

^[2]

$ (3,000)

3,659,885

^[2]

(3,596,210)

Beginning balance (in shares) at Dec. 31, 2024

552,307

^[2]

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Shares issued under equity compensation plans (in shares)

^[2]

21,709

Shares issued under equity compensation plans

$ 7

^[2]

Stock-based compensation

3,898

^[2]

Comprehensive income (loss)

(50,904)

(22)

(50,882)

Ending balance (in shares) at Mar. 31, 2025

^[2]

12,406,710

Ending balance at Mar. 31, 2025

$ 13,738

$ 1

^[2]

$ (3,000)

3,663,790

^[2]

(3,647,092)

Ending balance (in shares) at Mar. 31, 2025

^[2]

552,307

Beginning balance (in shares) at Dec. 31, 2024

12,385,001

^[2]

Beginning balance at Dec. 31, 2024

$ 60,737

^[3]

$ 1

^[2]

$ (3,000)

3,659,885

^[2]

(3,596,210)

Beginning balance (in shares) at Dec. 31, 2024

552,307

^[2]

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Comprehensive income (loss)

$ (128,002)

Ending balance (in shares) at Sep. 30, 2025

19,652,513

^[2]

Ending balance at Sep. 30, 2025

$ 85,086

$ 2

^[2]

3,809,235

^[2]

(3,724,207)

Ending balance (in shares) at Sep. 30, 2025

Beginning balance (in shares) at Mar. 31, 2025

^[2]

12,406,710

Beginning balance at Mar. 31, 2025

$ 13,738

$ 1

^[2]

$ (3,000)

3,663,790

^[2]

(3,647,092)

Beginning balance (in shares) at Mar. 31, 2025

^[2]

552,307

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Shares issued under equity compensation plans (in shares)

^[2]

50,542

Shares issued under equity compensation plans

211

^[2]

Stock-based compensation

3,486

^[2]

Comprehensive income (loss)

(41,646)

(53)

(41,593)

Ending balance (in shares) at Jun. 30, 2025

^[2]

12,457,252

Ending balance at Jun. 30, 2025

(24,211)

$ 1

^[2]

$ (3,000)

3,667,487

^[2]

(14)

(3,688,685)

Ending balance (in shares) at Jun. 30, 2025

^[2]

552,307

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Shares issued under equity compensation plans (in shares)

^[2]

34,778

Shares issued under equity compensation plans

236

^[2]

Stock-based compensation

3,072

^[2]

Shares issued under offering, net of underwriting discounts and offering costs (in shares)

^[2]

4,893,618

600,198

(552,307)

Shares issued under offering, net of underwriting discounts and offering costs

$ 107,160

$ 34,279

$ 1

^[2]

$ 3,000

$ 104,159

$ 34,279

Shares issued under prefunded warrant exercise (in shares)

^[2]

1,666,667

Issuance of prefunded warrant

^[2]

Comprehensive income (loss)

$ (35,452)

(35,522)

Ending balance (in shares) at Sep. 30, 2025

19,652,513

^[2]

Ending balance at Sep. 30, 2025

$ 85,086

$ 2

^[2]

$ 3,809,235

^[2]

$ 56

$ (3,724,207)

Ending balance (in shares) at Sep. 30, 2025

[1]	All share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).
[2]	All share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).
[3]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

Stockholders" Equity

9 Months Ended

Sep. 30, 2025

Equity [Abstract]

Stockholders' Equity

Note 6 — Stockholders’ Equity

On June 6, 2025, we filed a Certificate of Amendment to the Certificate of Incorporation, or the Increase in Shares Amendment, to increase the number of authorized shares of the Company’s common stock from 300,000,000 shares to

390,000,000 shares. The increase in authorized shares amendment was previously approved by our stockholders at the Annual Meeting of Stockholders held on May 23, 2025 and became effective upon its filing.

On June 6, 2025, we also filed a Certificate of Amendment to Nektar’s Certificate of Incorporation (the Reverse Stock Split Amendment) to effect a reverse stock split of our common stock at a ratio of one-for-fifteen (the Reverse Stock Split). The Reverse Stock Split Amendment became effective as of 11:59 p.m. Eastern Time on June 8, 2025 (the Effective Time), at which time every fifteen shares of our common stock issued and outstanding immediately prior to the Effective Time were combined into one share of common stock. No fractional shares of our common stock were issued as a result of the Reverse Stock Split. Instead, any fractional shares resulting from the Reverse Stock Split were rounded up at the participant level if such shares of our common stock (including shares subject to issuance upon exercise of the pre-funded warrant) were held directly or rounded down to the nearest whole share of our common stock, if such shares were subject to an award granted under the 2017 Amended and Restated Performance Incentive Plan. Upon effectiveness of the Reverse Stock Split, the number of shares of common stock for which each outstanding option and pre-funded warrant to purchase common stock is exercisable was adjusted, and the exercise price of each outstanding option and pre-funded warrant to purchase common stock was adjusted. The Reverse Stock Split did not change the par value per share or the authorized number of shares of common stock and preferred stock. As a result of the Reverse Stock Split, we have retrospectively recast prior periods for shares of our common stock, including those issued, outstanding and treasury stock, weighted-average shares outstanding and loss per share.

On May 23, 2025, our shareholders approved an amendment to the Amended and Restated 2017 Performance Incentive Plan to increase the aggregate number of shares of common stock authorized for issuance thereunder by 6,000,000 shares, which were subsequently adjusted to 400,000 shares due to the effect of the Reverse Stock Split.

As a result of the Reverse Stock Split, shares reserved for issuance under our employee stock plans are as follows:


	September 30, 2025		December 31, 2024
Stock options outstanding		2,185,410		2,203,927
Weighted average exercise price	$	79.11	$	83.73
RSUs outstanding		41,894		101,524
Shares available for future grant under the 2017 Performance Incentive Plan		921,896		551,727
Shares available for issuance under the employee stock purchase plan		46,650		47,383
Total shares reserved for issuance under our employee stock plans		3,195,850		2,904,561

Prefunded Warrant

In March 2024, we issued a pre-funded warrant to purchase an aggregate of 1,666,667 shares of our common stock to TCG Crossover Fund II, L.P. (TCG) at a price of $18.00 per share for gross proceeds of $30.0 million. Transaction costs were immaterial. The pre-funded warrant had an exercise price of $0.0015 per share and was exercisable at any time after the original issuance date. TCG could not exercise the warrant if TCG, together with its affiliates, would beneficially own more than 9.99% of the number of shares of our common stock outstanding immediately after giving effect to such exercise. TCG could increase or decrease this percentage not in excess of 19.99% by providing at least 61 days prior notice to the Company. On May 28, 2024, we filed with the SEC a registration statement on Form S-3 (file no. 333-279760) registering for resale of up to 1,666,667 shares of our common stock issuable upon exercise of the pre-funded warrant. The registration statement became effective on June 5, 2024.

We classified the pre-funded warrant as a component of permanent equity in our Condensed Consolidated Balance Sheets as it is a freestanding financial instrument that was immediately exercisable, does not embody an obligation for the Company to repurchase its own shares and permits the holder to receive a fixed number of shares of common stock upon exercise. All of the shares underlying the pre-funded warrant have been included in the weighted-average number of shares of common stock used to

calculate net loss per share attributable to common stockholders because the shares may be issued for little or no consideration, are fully vested and are exercisable after the original issuance date of the pre-funded warrant.

On July 1, and July 11, 2025, TCG exercised the pre-funded warrant to purchase 780,000 and 886,667 shares of common stock, respectively. Exercise proceeds are immaterial. As a result of these exercises, no shares remain issuable under the warrant.

Secondary Offering

On July 2, 2025, pursuant to the Shelf Registration Statement, we completed the sale and issuance of 4,893,618 shares of our common stock in an underwritten public offering (the 2025 Offering) at a price of $23.50 per share, which included 638,298 shares sold upon exercise in full by the underwriters of their option to purchase additional shares of common stock in the 2025 Offering. The net proceeds to the Company from the 2025 Offering totaled approximately $107.2 million, after deducting underwriting discounts and commissions and other offering costs. The 2025 Offering was underwritten by Jefferies LLC, pursuant to an underwriting agreement that Nektar and Jefferies LLC had entered into on June 30, 2025.

In connection with the 2025 Offering, we re-issued all 552,307 shares held in treasury stock as of June 30, 2025.

At-The-Market Offering

During the three months ended September 30, 2025, we issued 600,198 shares of our common stock under the ATM Sales Agreement at a weighted average price of $59.24 per share for net proceeds of $34.3 million after deducting related commissions and offering costs. In October 2025, we issued an additional 673,725 shares of our common stock under the ATM Sales Agreement at a weighted average price of $58.55 for net proceeds of $38.3 million after deducting related commissions of approximately $1.2 million. No ATM shares remain available for issuance under the ATM Sales Agreement.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
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-Name Accounting Standards Codification
-Section 50
-Paragraph 8A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-8A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 505
-Name Accounting Standards Codification
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-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478448/946-505-50-6

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
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-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-6

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 14
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-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

+ Details

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)
$ in Thousands

9 Months Ended

Sep. 30, 2025

Sep. 30, 2024

Cash flows from operating activities:

Net loss

$ (127,997)

$ (126,222)

Adjustments to reconcile net loss to net cash used in operating activities:

Non-cash royalty revenue related to the sales of future royalties

(33,125)

(48,029)

Non-cash interest expense on liabilities related to the sales of future royalties

16,415

17,959

^[1]

Loss from equity method investment

7,381

^[1]

Stock-based compensation

10,456

16,809

Depreciation and amortization expense

836

4,059

Impairment of right-of-use assets and property and equipment

8,329

Provision for net realizable value of inventory

Amortization of premiums (discounts), net

(3,626)

(7,711)

Changes in operating assets and liabilities:

Accounts receivable

(841)

Inventory

(808)

Operating leases, net

(9,407)

(7,620)

Other assets

(5,591)

(1,761)

Accounts payable

4,168

(1,023)

Accrued expenses

(3,062)

17,317

Net cash used in operating activities

(143,552)

(129,522)

Cash flows from investing activities:

Purchases of investments

(193,410)

(191,882)

Maturities of investments

192,691

275,247

Purchases of property and equipment

(153)

(1,009)

Payment of transaction costs and working capital adjustment from the sale of the Huntsville manufacturing facility

(697)

Net cash provided by (used in) investing activities

(1,569)

82,356

Cash flows from financing activities:

Proceeds from shares issued under equity compensation plans and other

456

Payments of offering costs associated with issuance of common stock

(1,150)

Proceeds from issuance of pre-funded warrant

30,000

Proceeds from sale of future royalties

15,000

Repurchase of common stock from Bristol-Myers Squibb

(3,000)

Net cash provided by financing activities

141,895

42,035

Effect of foreign exchange rates on cash and cash equivalents

(37)

Net decrease in cash and cash equivalents

(3,220)

(5,168)

Cash and cash equivalents at beginning of period

44,252

35,277

Cash and cash equivalents at end of period

41,032

30,109

2025 Secondary Public Offering

Cash flows from financing activities:

Proceeds from offering, net

108,100

At-the-Market Offering

Cash flows from financing activities:

Proceeds from offering, net

$ 34,489

$ 0

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

Cash and Investments in Marketable Securities - Cash and Investments in Marketable Securities, Including Cash Equivalents (Detail) - USD ($)
$ in Thousands

Sep. 30, 2025

Dec. 31, 2024

Estimated Fair Value at

Cash and cash equivalents

$ 41,032

$ 44,252

^[1]

Short-term investments

229,176

210,974

^[1]

Long-term investments

13,869

^[1]

Total cash and investments in marketable securities

$ 270,208

$ 269,095

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2025

Sep. 30, 2024

^[1]

Sep. 30, 2025

Sep. 30, 2024

^[1]

Revenue:

Total revenue

$ 11,790

$ 24,124

$ 33,425

$ 69,252

Operating costs and expenses:

Cost of goods sold

4,435

22,709

Research and development (including $421 and $0 for the three months ended September 30, 2025 and 2024, respectively, from a related party; and $1,242 and $0 for the nine months ended September 30, 2025 and 2024, respectively, from a related party)

27,252

35,031

87,618

92,163

General and administrative

16,070

18,957

57,488

59,616

Restructuring and impairment

140

756

14,310

Total operating costs and expenses

43,462

58,469

145,862

188,798

Loss from operations

(31,672)

(34,345)

(112,437)

(119,546)

Non-operating income (expense):

Non-cash interest expense on liabilities related to the sales of future royalties

(6,047)

(6,020)

(16,415)

(17,959)

Interest income

2,819

3,437

7,662

11,558

Other income (expense), net (including income of $190 and $0 for the three months ended September 30, 2025 and 2024, respectively, from a related party; and income of $1,051 and $0 for the nine months ended September 30, 2025 and 2024, respectively, from a related party)

(121)

(120)

405

(255)

Total non-operating income (expense), net

(3,349)

(2,703)

(8,348)

(6,656)

Loss before provision (benefit) for income taxes and equity method investment

(35,021)

(37,048)

(120,785)

(126,202)

Provision (benefit) for income taxes

(33)

(169)

Loss before equity method investment

(34,988)

(37,057)

(120,616)

(126,222)

Loss from equity method investment

(534)

(7,381)

Net loss

$ (35,522)

$ (37,057)

$ (127,997)

$ (126,222)

Basic net loss per share (in dollars per share)

$ (1.87)

$ (2.66)

$ (8.14)

$ (9.27)

Diluted net loss per share (in dollars per share)

$ (1.87)

$ (2.66)

$ (8.14)

$ (9.27)

Weighted average shares outstanding used in computing basic net loss per share (in shares)

18,946,559

13,949,851

15,716,396

13,619,270

Weighted average shares outstanding used in computing diluted net loss per share (in shares)

18,946,559

13,949,851

15,716,396

13,619,270

Product sales

Revenue:

Total revenue

$ 0

$ 8,015

$ 0

$ 20,689

Non-cash royalty revenue related to the sales of future royalties

Revenue:

Total revenue

11,490

15,731

33,125

48,029

License, collaboration and other revenue

Revenue:

Total revenue

$ 300

$ 378

$ 300

$ 534

[1]	All share and per share amounts have been retrospectively adjusted to reflect a one-for-fifteen reverse stock split (see Note 6).

Subsequent Events

9 Months Ended

Sep. 30, 2025

Subsequent Events [Abstract]

Subsequent Events

Note 11 — Subsequent Events

In October 2025, we issued an additional 673,725 shares of our common stock under the ATM Sales Agreement at a weighted average price of $58.55 for net proceeds of $38.3 million after deducting related commissions of approximately $1.2 million. No ATM shares remain available for issuance under the ATM Sales Agreement.

Cover Page - shares	9 Months Ended
Cover Page - shares	Sep. 30, 2025	Oct. 31, 2025
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2025
Document Transition Report	false
Entity File Number	0-24006
Entity Registrant Name	NEKTAR THERAPEUTICS
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3134940
Entity Address, Address Line One	455 Mission Bay Boulevard South
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94158
City Area Code	415
Local Phone Number	482-5300
Title of 12(b) Security	Common Stock, $0.0001 par value
Trading Symbol	NKTR
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		20,341,589
Amendment Flag	false
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000906709
Current Fiscal Year End Date	--12-31

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Sep. 30, 2025 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Howard W. Robin, our President and Chief Executive Officer, previously entered into a pre-arranged stock trading plan intended to satisfy the affirmative defense of Rule10b5-1(c) under the Exchange Act on May 22, 2025, which provided for the sale of up to an aggregate 19,998 (on a post-reverse split basis) shares of the Company’s common stock (comprised of previously vested restricted stock units and exercised stock options). The plan terminated on September 9, 2025 upon completion of all transactions thereunder. In the fiscal quarter ended September 30, 2025, no other directors or Section 16 officers of the Company adopted, modified, or terminated a “Rule 10b5-1 trading arrangement” or a “non-Rule 10b5-1 trading arrangement” as each term is defined in Item 408 of Regulation S-K.
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Rule 10b5-1 Arrangement Modified	false
Non-Rule 10b5-1 Arrangement Modified	false
Howard W. Robin [Member]
Trading Arrangements, by Individual
Name	Howard W. Robin
Title	President and Chief Executive Officer, previously
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	May 22, 2025
Rule 10b5-1 Arrangement Terminated	true
Termination Date	September 9, 2025
Arrangement Duration	110 days
Aggregate Available	19,998

Condensed Consolidated Financial Statement Details (Tables)

9 Months Ended

Sep. 30, 2025

Inventory Disclosure [Abstract]

Schedule of Other Current Assets

Other current assets consist of the following (in thousands):


	September 30, 2025		December 31, 2024
Prepaid research and development expenses	$	7,500	$	1,947
Interest and other non-trade receivables		1,289		1,609
Other prepaid expenses		2,360		2,510
Total other current assets	$	11,149	$	6,066

Schedule of Accrued Expenses

Accrued expenses consist of the following (in thousands):


	September 30, 2025		December 31, 2024
Accrued compensation	$	8,606	$	2,832
Accrued research and development expenses		12,084		14,453
Accrued contract termination costs		3,149		2,767
Other accrued expenses		4,755		9,920
Total accrued expenses	$	28,594	$	29,972

Schedule of Liability Related to Sale of Potential Future Royalties

The following is a reconciliation of the changes in our liabilities related to the sales of future royalties for the nine months ended September 30, 2025 (in thousands):


	Nine Months Ended September 30, 2025
	2012 Purchase and Sale Agreement			2020 Purchase and Sale Agreement			Total
Liabilities related to the sales of future royalties, net – beginning balance	$	7,197		$	84,579		$	91,776
Non-cash royalty revenue		(5,619	)		(27,506	)		(33,125	)
Non-cash interest expense		1,983			14,432			16,415
Amortization of transaction costs		—			98			98
Liabilities related to the sales of future royalties, net – ending balance	$	3,561		$	71,603		$	75,164

Cash and Investments in Marketable Securities

9 Months Ended

Sep. 30, 2025

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, 2025		December 31, 2024
Cash and cash equivalents	$	41,032	$	44,252
Short-term investments		229,176		210,974
Long-term investments		—		13,869
Total cash and investments in marketable securities	$	270,208	$	269,095

Our portfolio of cash and investments in marketable securities consists of the following (in thousands):


		September 30, 2025									December 31, 2024
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Fair Value
Corporate notes and bonds	2	$	70,569	$	24	$	(10	)	$	70,583	$	109,711
Corporate commercial paper	2		149,333		26		(16	)		149,343		119,542
Available-for-sale investments		$	219,902	$	50	$	(26	)	$	219,926	$	229,253
Money market funds	1									24,717		15,993
Certificates of deposit	2									14,215		14,027
Cash	N/A									11,350		9,822
Total cash and investments in marketable securities									$	270,208	$	269,095

For the three and nine months ended September 30, 2025 and 2024, there were no transfers between Level 1 and Level 2 of the fair value hierarchy. As of September 30, 2025, we had 29 investments in unrealized loss positions and no investments had been in continuous unrealized loss positions for 12 months or longer. At December 31, 2024, our gross unrealized gains and losses were insignificant.