Federal Circuit Upholds Cabozantinib Crystalline Salt Patents, Preserving Exelixis Market Exclusivity to 2030
核心洞察
The U.S. Court of Appeals for the Federal Circuit affirmed the validity of three Exelixis patents covering the crystalline malate salt of cabozantinib, upholding a key portion of the 2024 Delaware District Court judgment.
The appellate court dismissed as moot the appeal concerning a low-impurity cabozantinib formulation patent (U.S. Patent No. 11,298,349), without affecting the broader cabozantinib patent estate.
The ruling preserves market exclusivity for CABOMETYX, with the earliest possible U.S. commercial launch of MSN's proposed generic product now set for January 15, 2030.
The U.S. Court of Appeals for the Federal Circuit has affirmed a key portion of the 2024 judgment of the U.S. District Court for the District of Delaware in favor of Exelixis, Inc., upholding the validity of three patents covering the crystalline malate salt of cabozantinib. The decision, announced by Exelixis on August 31, 2026, preserves market exclusivity for the company's cancer drug marketed under the brand name CABOMETYX.
The appellate court, ruling in Exelixis, Inc. v. MSN Laboratories (搜索) Private Limited et al. (Civil Action No. 22-00228, Consolidated; Appeal No. 25-1236), upheld the District Court's determination that the three patents — No. 11,091,439 (crystalline salt), 11,091,440 (pharmaceutical compositions), and 11,098,015 (methods of treatment) — are not invalid. Concurrently, the Federal Circuit dismissed the appeal regarding the validity dispute over U.S. Patent No. 11,298,349, which covers low-impurity cabozantinib formulations, ruling the matter moot.
Implications for Market Exclusivity
The Federal Circuit's decision upholds the validity of the '439, '440 and '015 crystalline salt patents, preserving the market exclusivity of Exelixis' cabozantinib. While the appellate court issued a procedural ruling dismissing the '349 formulation patent appeal as moot, Exelixis stated that this decision does not impact the broader strength or integrity of the cabozantinib patent estate.
Given the decision, the earliest that MSN Laboratories (搜索) may be permitted to commercially launch its proposed generic product in the United States is January 15, 2030, subject to any additional appeals or regulatory exclusivity.
Ongoing Litigation
MSN's ability to commercially launch its generic product would also depend on the outcome of litigation involving another low-impurity formulation patent, U.S. Patent No. 12,128,039, which expires in February 2032. A trial in that matter is scheduled to begin in November 2026.
Company Position
Exelixis indicated that it will continue to pursue all necessary legal actions to defend its intellectual property portfolio, which the company described as essential to safeguarding the scientific innovation that drives its mission to help cancer patients recover stronger and live longer.