On 1 October 2025, the US Patent Trial and Appeal Board (PTAB) issued its decision in the inter partes review (IPR), filed by Amgen in February 2025 and instituted in July 2025, challenging the validity of BMS’ US patent US11332529 (‘529) relating to methods of treating colorectal cancer using nivolumab (Opdivo®) and ipilimumab (Yervoy®).
On 18 August 2025, BMS had filed a statutory disclaimer of all 18 claims of ‘529. However, in April 2025 it had amended the claims of its pending application US18/787,822 (a continuation of ‘529) to include a new claim 43 that was patentably indistinct from disclaimed claim 1 of the ’529 patent. BMS sought denial of the ‘529 patent without an adverse judgment. Amgen successfully argued that an adverse judgment should be issued.
The Board characterised BMS’ actions as employing a “whac-a-mole strategy” and concluded that BMS unfairly sought to avoid Amgen’s challenge through a statutory disclaimer only to pursue patentably indistinct claims in the ’822 continuation application. It rejected BMS’ attempt to exit “one door of the agency, only to walk back in another door to resurrect the same claims in an ex parte proceeding”.
The Board’s decision notes that BMS had indicated its intention to assert the ’529 patent against Amgen, presumably in relation to Amgen’s nivolumab biosimilar under development.
Xbrane/Intas also has a nivolumab biosimilar under development. Earlier in 2025, Sandoz suspended the Phase 3 trial of its nivolumab biosimilar. In April 2025, Sandoz and Shanghai Henlius Biotech announced a global collaboration agreement for an ipilimumab biosimilar.