On 24 July 2025, the Patent Trial and Appeal Board (PTAB) instituted an inter partes review (IPR), filed by Amgen in February 2025, challenging the validity of a BMS US patent (US11332529) relating to methods of treating colorectal cancer using nivolumab (Opdivo®) and ipilimumab (Yervoy®).
However, PTAB denied two further IPR petitions filed by Amgen at the same time in relation to patents for nivolumab/ipilimumab (US9856320 for treating cancer generally and US10174113 for treating melanoma) on the basis that the patents had been in force for 6 and 7 years respectively, creating strong settled expectations in patent protection for the patent owner. PTAB held that similar expectations did not arise in relation to the instituted IPR as the subject patent had been in force for only 3 years.
Since Amgen’s IPR petitions were filed, the Opdivo®/Yervoy® combination has been approved for colorectal cancer in the US (April 2025) and Australia (June 2025), and for hepatocellular carcinoma in the EU (March 2025), US (April 2025), Japan (June 2025) and Korea (July 2025).
At least Amgen, Sandoz and Xbrane/Intas have nivolumab biosimilars under development. Zydus received regulatory approval for its nivolumab biosimilar from India’s CDSCO in July 2024. In April 2025, Sandoz and Shanghai Henlius Biotech announced a global collaboration agreement for an ipilimumab biosimilar.