On July 24, 2025, USPTO Acting Director Coke Morgan Stewart discretionarily denied two of Amgen's inter partes review (IPR) petitions challenging Bristol Myers Squibb's patents related to the blockbuster cancer immunotherapy Opdivo (nivolumab) and Yervoy (ipilimumab). The decision represents a notable shift in Patent Trial and Appeal Board (PTAB) policy that could significantly impact biosimilar development strategies.
Patent Challenge Details
Stewart denied IPR2025-00601 and IPR2025-00602, which challenged BMS's U.S. Patent Nos. 9,856,320 and 10,174,113 respectively. However, a third petition, IPR2025-00603 challenging U.S. Patent No. 11,332,529, was referred to the Board for merit review rather than being discretionarily denied.
The patents at issue relate to methods of treating cancer with a combination of an anti-PD-1 antibody and an anti-CTLA-4 antibody. Amgen is currently developing ABP 206, a biosimilar version of Opdivo.
Settled Expectations as New Denial Grounds
In an unprecedented move, the Acting Director cited "strong settled expectations of the Patent Owner" as the primary basis for denial, specifically noting that the challenged patents had been in force for six and seven years respectively. This reasoning marked a departure from previous discretionary denial decisions in biosimilar-related IPRs.
"The IPRs were denied based on a totality of the arguments presented in the case, but pointed specifically to the 'strong settled expectations of the Patent Owner' in the '320 and '113 patents given they had been in force for six and seven years respectively," Stewart stated in the decision.
In contrast, the Director found that the 2022-issued patent in IPR2025-00603 "did not have the same strongly settled expectations given it had only been in force for three years."
Unusual Procedural Context
Unlike many previous discretionary denials, these patents are not subject to parallel litigation between the parties, as Amgen has not yet filed an abbreviated Biologics License Application (aBLA) for ABP 206 and no BPCIA litigation has been initiated. The Acting Director acknowledged this fact weighed against discretionary denial but still concluded denial was appropriate.
Policy Implications for Biosimilar Development
The decision could create significant challenges for biosimilar manufacturers in timing their IPR filings. As noted in the analysis, "This could mean that IPRs may become less useful for biosimilar manufacturers if the patents they are challenging have not been issued very recently."
Amgen had argued that denying IPRs based on potential BPCIA proceedings would create a chilling effect: "PO's argument would preclude all biosimilar manufacturers from ever filing an IPR as all biosimilar products developed to date have faced the potential for BPCIA litigation."
The company emphasized the efficiency benefits of IPRs compared to BPCIA proceedings, noting that "a Final Written Decision in this IPR would be issued by October of 2026—likely years earlier than any resolution via the BPCIA procedures," which typically take 2.5-3.5 years for district court decisions.
Market Context
The stakes are substantial, with Bristol Myers Squibb reporting U.S. sales of $5.35 billion for Opdivo in 2024. Amgen also raised policy arguments about biosimilars providing "the public to potentially access less expensive treatment options for treatment, and IPRs play a critical role in the process."
Regulatory Framework Changes
The decisions follow the Acting Director's rescission of previous guidance from former Director Vidal and implementation of new guidance in March 2025, including an "Interim Process for PTAB Workload Management" that specifically lists "settled expectations of the parties, such as the length of time the claims have been in force" as a consideration factor.
The Director's decision to deny institution is not appealable, adding finality to this policy shift that may reshape how biosimilar companies approach patent challenges in the pharmaceutical industry.
