Pfizer’s PD-L1 conjugate focus narrows

Pfizer recently began a phase 3 study with its PD-L1-targeting ADC fetrastobart vedotin in relapsed NSCLC – but a planned pivotal trial in first-line head and neck cancer is off, the company disclosed in its third-quarter presentation on Tuesday. A Pfizer spokesperson told ApexOnco this was a “business decision” unrelated to safety concerns. An evolving head and neck field might have spurred Pfizer’s move: Merus’s petosemtamab showed enough in the first line to secure an $8bn buyout from Genmab, while Johnson & Johnson’s Rybrevant recently looking promising in relapsed disease, with a pivotal front-line study in the works. Meanwhile, two Pfizer late-stage cancer readouts, which had been due in 2025, have been delayed: MagnetisMM-5, testing the BCMA-targeting T-cell engager Elrexfio, with or without Darzalex, in double-class exposed multiple myeloma; and Talapro-3, evaluating Talzenna plus Xtandi in first-line castration-sensitive prostate cancer. The spokesperson noted that these are event-driven trials, so couldn't speculate on exact timings, but added the company hopes to report results in the first half of 2026. An FDA decision on the full approval of Braftovi in first-line BRAFm colorectal cancer has also been pushed back to 2026; however, prospects here look good based on data from the Breakwater study.

Pfizer’s third-quarter oncology setbacks

Note: CSPC=castration-sensitive prostate cancer; MM=multiple myeloma. OncologyPipeline & company presentation.