Rigel Pharmaceuticals Regains Rights to Ocadusertib as Eli Lilly Ends Collaboration

On April 16, 2026, Rigel Pharmaceuticals, Inc. Received formal written notice from Eli Lilly and Company of its decision to terminate the License and Collaboration Agreement between the two companies. The agreement, originally signed on February 18, 2021, granted Lilly an exclusive worldwide license to develop and commercialize ocadusertib, an investigational RIPK1 inhibitor being studied for non-central nervous system indications.

The termination becomes effective June 15, 2026, at which point Rigel will regain full global rights to ocadusertib and additional RIPK1 inhibitors covered under the agreement. Though, as part of the termination, Rigel will not be eligible to receive any future milestone payments or royalties that would have been payable upon successful development and commercialization of the licensed compounds by Lilly.

Rikald, the RIPK1 inhibitor platform developed by Rigel, has been a focus of the company’s efforts in inflammatory and autoimmune diseases. Ocadusertib, in particular, has advanced through preclinical and early clinical development as a potential treatment for conditions such as ulcerative colitis and other immune-mediated disorders. With the return of rights, Rigel now has full autonomy to determine the future development path, partnership strategy, or potential out-licensing of these assets.

The decision by Eli Lilly to end the collaboration reflects a strategic reassessment of its external innovation pipeline. While the specific rationale behind the termination was not disclosed in the public filing, such moves are common in the pharmaceutical industry as companies periodically evaluate the clinical progress, market potential, and strategic fit of partnered assets.

For Rigel, the termination represents both a challenge and an opportunity. The loss of anticipated financial support from Lilly removes a significant non-dilutive funding source for the ocadusertib program. However, regaining control allows Rigel to pursue alternative partnerships, seek modern investment, or advance the program independently based on its own corporate priorities and scientific assessment.

As of the date of the notice, Rigel has not announced any immediate plans for ocadusertib but has indicated that it will evaluate all options to maximize the value of its RIPK1 inhibitor portfolio. The company continues to focus on its broader pipeline, including other kinase inhibitors and immunomodulatory programs in various stages of development.

Investors and analysts will be watching closely for Rigel’s next steps regarding ocadusertib, particularly whether the company seeks a new collaboration partner or advances the asset through internal development. The return of rights opens the door for Rigel to restructure the economic terms of any future partnership to better reflect the asset’s current stage, and potential.

This development underscores the dynamic nature of biopharmaceutical collaborations, where agreements can be terminated based on evolving strategic priorities, even after several years of joint effort. For Rigel, the focus now shifts to leveraging its regained independence to drive the future of its RIPK1 inhibitor programs.

Key Takeaways

• Eli Lilly terminated its 2021 License and Collaboration Agreement with Rigel Pharmaceuticals on April 16, 2026, effective June 15, 2026.
• Rigel will regain full global rights to ocadusertib and other RIPK1 inhibitors but will not receive future milestone payments or royalties from Lilly.
• The termination allows Rigel to independently determine the future development, partnering, or commercialization strategy for these assets.
• Ocadusertib is an investigational RIPK1 inhibitor being studied for non-central nervous system autoimmune and inflammatory conditions.
• Rigel has not disclosed immediate plans for ocadusertib but will evaluate options to maximize the value of its returned rights.

Frequently Asked Questions

What is ocadusertib?

Ocadusertib is an investigational small-molecule inhibitor of RIPK1 (Receptor-Interacting Serine-Threonine Kinase 1), a protein involved in regulating inflammation and cell death. It is being developed for the treatment of inflammatory and autoimmune diseases, particularly those affecting the gastrointestinal system, such as ulcerative colitis.

Why did Eli Lilly terminate the agreement with Rigel?

The specific reasons for the termination were not disclosed in the public SEC filing or press releases. However, pharmaceutical companies routinely review and adjust their external collaborations based on clinical progress, shifting therapeutic priorities, portfolio management, and assessments of commercial potential.

What happens to Rigel now that it has regained rights to ocadusertib?

Rigel now has full authority over the ocadusertib program and may choose to pursue a new partnership, seek additional funding, advance the asset through internal development, or explore other strategic options. The company has stated it will evaluate all possibilities to maximize the value of its RIPK1 inhibitor portfolio.

Will Rigel receive any further payments from Eli Lilly related to this agreement?

No. As part of the termination, Rigel will not be eligible to receive any future milestone payments or royalties that would have been triggered by development, regulatory approval, or commercial sales of ocadusertib or other licensed compounds by Lilly.

When does the termination become effective?

The termination of the License and Collaboration Agreement between Rigel Pharmaceuticals and Eli Lilly becomes effective on June 15, 2026, following the notice received on April 16, 2026.