Eli Lilly ends Rigel (RIGL) RIPK1 licensing deal, no future milestones

(Moderate)

(Neutral)

Form Type

8-K

Rhea-AI Filing Summary

Rigel Pharmaceuticals reports that Eli Lilly and Company has elected to terminate their License and Collaboration Agreement covering ocadusertib (previously R552) and other RIPK1 inhibitors. Lilly’s termination is in its entirety and becomes effective June 15, 2026.

The agreement, signed on February 18, 2021, had granted Lilly an exclusive worldwide license to develop and commercialize RIPK1 inhibitors for non-CNS and CNS diseases, with potential milestone payments and royalties to Rigel. After termination, Lilly’s rights to the licensed compounds will cease, subject to transition provisions, and Rigel expects to regain full rights to these programs.

Rigel is evaluating the impact of the termination and, following this step and the earlier end of the CNS disease program effective in November 2025, does not expect to receive future milestones or royalties under the agreement.

Positive

None.

Negative

Eli Lilly’s full termination of the RIPK1 License and Collaboration Agreement eliminates Rigel’s opportunity for future milestones and royalties from this partnership, removing a potential non-dilutive revenue stream tied to ocadusertib and related compounds.

Insights

Lilly’s exit ends Rigel’s RIPK1 partnership and future deal-based revenue from this agreement.

The collaboration with Eli Lilly gave Rigel an exclusive-license partner for ocadusertib and other RIPK1 inhibitors in CNS and non-CNS diseases, with potential milestones and royalties. Lilly’s decision to terminate the agreement in its entirety removes that partnered development path.

Rigel now expects no future milestones or royalties from this agreement, after the earlier CNS program termination effective in November 2025. Regaining full rights gives Rigel strategic control over the RIPK1 assets, but the filing does not outline any alternative plans or partners.

8-K Event Classification

Item 1.02 — Termination of a Material Definitive Agreement

1 item

Item 1.02 Termination of a Material Definitive Agreement Business

A significant contract was terminated, which may affect business operations or revenue.

Key Figures

Notice of termination date: April 16, 2026 Termination effective date: June 15, 2026 Agreement signing date: February 18, 2021 +1 more

4 metrics

Notice of termination date April 16, 2026 Date Rigel received Lilly’s written termination notice

Termination effective date June 15, 2026 Date the License and Collaboration Agreement will terminate

Agreement signing date February 18, 2021 Original date of the License and Collaboration Agreement

CNS program termination effective November 2025 Effective date of prior termination of CNS disease program under the Agreement

Key Terms

License and Collaboration Agreement, ocadusertib, RIPK1 inhibitor, non-central nervous system, +2 more

6 terms

License and Collaboration Agreement financial

"Lilly’s election to terminate that certain License and Collaboration Agreement, dated February 18, 2021"

A license and collaboration agreement is a contract where one party gives another the legal right to use intellectual property (like a drug formula, technology or brand) and both parties agree to work together to develop, make or sell the resulting product. For investors it matters because the deal spells out who pays, who controls development, how future sales and profits are split, and how risks and costs are shared—so it directly affects a company’s potential revenue, expenses and value, like a partnership for building and selling a new product.

ocadusertib technical

"an exclusive worldwide license to develop and commercialize ocadusertib (previously R552), an investigational, potent and selective RIPK1 inhibitor"

RIPK1 inhibitor technical

"an investigational, potent and selective receptor interacting serine/threonine protein kinase 1 (“RIPK1”) inhibitor"

non-central nervous system medical

"for the treatment of non-central nervous system (“non-CNS”) diseases, and additional RIPK1 inhibitors for the treatment of central nervous system (“CNS”) diseases"

milestone payments financial

"The Agreement also provided for collaboration between the parties on development activities, as well as potential milestone payments and royalties to Rigel."

Milestone payments are predetermined sums a company agrees to pay or receive when specific development, regulatory, or commercial goals are reached in a partnership or license deal. Think of them like progress bonuses: they turn uncertain future outcomes into conditional cash events, so investors track them as potential sources of revenue, value inflection points, and risk—payments only arrive if the agreed milestones are actually achieved.

royalties financial

"the Company does not expect to receive future milestones or royalties under the Agreement."

Payments made to the owner of an asset or intellectual property each time that asset is used or a product is sold, often calculated as a percentage of sales or a set amount per unit. Royalties matter to investors because they create predictable, ongoing income streams and affect a company’s cash flow and valuation—like a landlord collecting rent or an author getting a steady cut whenever a book is sold.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Understanding 8-K Material Events →

Accepted by SEC EDGAR 04/21/2026 - 04:18 PM

FAQ

What agreement did Eli Lilly terminate with Rigel Pharmaceuticals (RIGL)?

Eli Lilly terminated its License and Collaboration Agreement with Rigel, originally signed on February 18, 2021. The deal covered ocadusertib (R552) and other RIPK1 inhibitors for CNS and non-CNS diseases, including development collaboration, milestones, and royalties for Rigel.

When does Eli Lilly’s termination of the Rigel RIPK1 agreement take effect?

The termination becomes effective June 15, 2026. Rigel received Lilly’s written notice of termination on April 16, 2026, and the agreement will end in accordance with its terms after that effective date, subject to any transition provisions between the parties.

What happens to Rigel’s rights to ocadusertib and RIPK1 programs after termination?

After termination, Lilly’s rights to the licensed compounds cease, subject to transition provisions. Rigel expects to regain full rights to ocadusertib and the related RIPK1 programs, giving the company control over future development and potential partnering decisions for these assets.

Will Rigel Pharmaceuticals (RIGL) still receive milestones or royalties from Eli Lilly?

Rigel does not expect to receive future milestones or royalties under the agreement. This reflects both the full termination effective June 15, 2026 and the earlier termination of the CNS disease program that took effect in November 2025 under the same collaboration.

What was covered by the Rigel–Eli Lilly RIPK1 License and Collaboration Agreement?

The agreement granted Lilly an exclusive worldwide license to develop and commercialize ocadusertib and additional RIPK1 inhibitors. It applied to non-central nervous system diseases and central nervous system diseases, and included development collaboration plus potential milestone payments and royalties to Rigel.

How is Rigel responding to the termination of its agreement with Eli Lilly?

Rigel states that it is currently evaluating the impact of Lilly’s termination. The company also notes that, once the agreement ends, it expects to regain full rights to the licensed RIPK1 compounds and related programs previously covered by the collaboration.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): April 16, 2026

RIGEL PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

Delaware

(State or other jurisdiction of incorporation)


0-29889			94-3248524
(Commission File No.)			(IRS Employer Identification No.)

611 Gateway Boulevard Suite 900
South San Francisco, CA			94080
(Address of principal executive offices)			(Zip Code)

Registrant’s telephone number, including area code: (650) 624-1100

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Title of Each Class

Trading

Symbol(s)

Name of Each Exchange on Which

Registered

Common Stock, par value $0.001 per share

RIGL

The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 1.02. Termination of a Material Definitive Agreement.

On April 16, 2026, Rigel Pharmaceuticals, Inc. (“Rigel”) received written notice from Eli Lilly and Company (“Lilly”) of Lilly’s election to terminate that certain License and Collaboration Agreement, dated February 18, 2021 (the “Agreement”), between Rigel and Lilly.

Pursuant to the terms of the Agreement, Lilly has elected to terminate the Agreement in its entirety. The termination will become effective June 15, 2026.

The Agreement granted Lilly an exclusive worldwide license to develop and commercialize ocadusertib (previously R552), an investigational, potent and selective receptor interacting serine/threonine protein kinase 1 (“RIPK1”) inhibitor, for the treatment of non-central nervous system (“non-CNS”) diseases, and additional RIPK1 inhibitors for the treatment of central nervous system (“CNS”) diseases. The Agreement also provided for collaboration between the parties on development activities, as well as potential milestone payments and royalties to Rigel.

Following the effective date of termination, the Agreement will terminate in accordance with its terms, including the cessation of Lilly’s rights to the licensed compounds, subject to any applicable transition provisions. Rigel expects to regain full rights to the licensed compounds and related programs upon termination.

Rigel is currently evaluating the impact of the termination. Following termination of the Agreement, including the prior termination of the CNS disease program under the Agreement, effective in November 2025, the Company does not expect to receive future milestones or royalties under the Agreement.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.


Dated: April 21, 2026	RIGEL PHARMACEUTICALS, INC.

	By:	/s/ Raymond J. Furey
		Raymond J. Furey
		Executive Vice President, General Counsel, Chief Compliance Officer, and Corporate Secretary

Source: View Original Filing on SEC EDGAR

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