Exelixis Announces Update on Patent Litigation Trial Appeal with MSN Laboratories
Exelixis, Inc. (Nasdaq: EXEL) today announced that in the lawsuit Exelixis, Inc. (Exelixis) vs. MSN Laboratories Private Limited et al. (MSN), Civil Action No. 22-00228 (Consolidated), the U.S. Court of Appeals for the Federal Circuit (Appeal No. 25-1236) has affirmed a key portion of the 2024 judgment of the U.S. District Court for the District of Delaware in Exelixis’ favor. The appellate court upheld the District Court's decision that three patents covering the crystalline malate salt of cabozantinib (No. 11,091,439 [crystalline salt]; 11,091,440 [pharmaceutical compositions]; and 11,098,015 [methods of treatment]) are not invalid. Concurrently, the appellate court dismissed the appeal regarding the validity dispute over one of Exelixis’ patents covering low-impurity cabozantinib formulations (U.S. Patent No. 11,298,349), ruling the matter moot.
The Federal Circuit’s decision upholds the validity of the ’439, ’440 and ’015 crystalline salt patents, preserving market exclusivity of Exelixis’ cabozantinib (marketed under the brand name CABOMETYX). While the appellate court issued a procedural ruling dismissing the ’349 formulation patent appeal as moot, this decision does not impact the broader strength or integrity of the cabozantinib patent estate.
Exelixis will continue to pursue all necessary legal actions to defend its intellectual property portfolio, which is essential to safeguarding the scientific innovation that drives the company’s mission to help cancer patients recover stronger and live longer.
Given today’s decision, the earliest that MSN may be permitted to commercially launch its proposed generic product in the U.S. is January 15, 2030, subject to any additional appeals or regulatory exclusivity. MSN’s ability to commercially launch would depend on the outcome of litigation involving another low-impurity formulation patent (U.S. Pat. No. 12,128,039) that expires in February 2032, with a trial scheduled to begin in November 2026.
About Exelixis
Exelixis is a globally ambitious oncology company innovating next-generation medicines and regimens at the forefront of cancer care. Powered by drug discovery and development excellence, we are rapidly evolving our product portfolio to target an expanding range of tumor types and indications with our clinically differentiated pipeline of small molecules and biotherapeutics. This comprehensive approach harnesses decades of robust investment in our science and partnerships to advance our pipeline of franchise molecules, including our novel oral kinase inhibitor zanzalintinib, and to extend the impact of our flagship commercial product, CABOMETYX (cabozantinib). Exelixis is driven by a bold scientific pursuit to create transformational treatments that give more patients hope for the future. For information about the company and its mission to help cancer patients recover stronger and live longer, visit www.exelixis.com, follow @ExelixisInc on X (Twitter), like Exelixis, Inc. on Facebook and follow Exelixis on LinkedIn.

