On May 07, 2020, in an unsealed opinion, Delaware court found Kyprolis® patents valid in a Hatch-Waxman litigation challenged by Cipla.
Plaintiff (Onyx Therapeutics Inc) sued Defendants (Apotex, Aurobindo, Breckenridge, Cipla, Dr. Reddy’s, Fresenius Kabi, Innopharma, MSN, Qilu Pharma and Sagent) as they sought to bring to market generic versions of Plaintiffs’ Kyprolis ® (Carfilzomib), a drug indicated for the treatments for relapsed multiple myeloma. Carfilzomib is a novel epoxyketone-based irreversible proteasome inhibitor. All of the defendants other than Cipla entered into consent judgments with Onyx and thus cases were dismissed. Cipla stipulated that its proposed ANDA product infringes Onyx’s U.S. Patent Nos. 7,417,042 and 8,207,125 (Compound Patents) expiring on Jul. 20, 2026 & Apr. 14, 2025 respectively as well as Onyx’s U.S. Patent No. 7,737,112 (Formulation Patent) expiring on Dec. 07, 2027. Cipla, however, contends that the Asserted claims are invalid. In May 2019, the Court held a five-day bench trial.
Onyx asserted claims 23 and 24 (specific compound or its salt) of the ’042 Patent. Onyx asserted claims 1 (specific compound) and 25 (composition with cyclodextrin) of the ’125 patent. Onyx also asserted claims 31 (composition with SBECD and 10 mM citric acid adjusted to pH 3.5) and 32 (composition with SBECD in lyophilized form) of the ’112 Patent.
1. Compound patents:
Cipla sought to invalidate the asserted claims of the Compound Patents as obvious in view of YU-101 (lead compound under development by Proteolix) disclosed in the US 6,831,099 Patent. The addition of a morpholine ring to the N-terminus of YU-101 made it more soluble & thus new compound Carfilzomib was produced. It was known in the art that morpholino acts as a solubilizing substituent.