On 17 May 2024, Regeneron filed a second complaint against Celltrion in the US District Court for the Northern District of West Virginia asserting infringement of 25 US patents relating to aflibercept (including method of treatment, formulation and manufacturing claims). Regeneron’s first complaint against Celltrion was filed in November 2023, alleging infringement of 38 patents, including the 25 patents asserted in the second complaint.
Both complaints relate to Celltrion’s aBLA filed with the FDA on 29 June 2023 for CT-P42, biosimilar to Regeneron’s Eylea® (aflibercept). The first complaint was filed after Regeneron had provided Celltrion with its list of patents as part of the BPCIA patent dance procedure and the second complaint was filed after the parties completed that procedure and agreed on the patents to be litigated.
The second Celltrion Complaint is the seventh US proceeding brought by Regeneron in relation to aflibercept biosimilars, the others being against Amgen, Mylan, Celltrion (1st action), Samsung Bioepis (2 actions) and Formycon. All proceedings remain pending.