Pfizer’s decision to cut its early-stage cancer asset was due to “strategic business reasons” and not driven by safety or efficacy concerns.
Pfizer has pulled the plug on an early-stage PD-L1 program as it looks to refine its cancer strategy after a series of encouraging readouts and high-value deals in recent months.
The asset, dubbed PF-08046037, was being evaluated in a Phase 1 study, which combined the drug with sasanlimab, another investigational cancer therapy. Pfizer was testing the doublet against a variety of advanced or metastatic cancers, including non-small cell lung cancer, pancreatic ductal adenocarcinoma, and head and neck squamous cell carcinoma. The pharma launched the trial in July 2025 and enrolled eight patients.
The decision to discontinue the study was driven by “strategic business reasons,” according to an update on the U.S. clinical trials database. Pfizer emphasized that the termination was not driven by safety and efficacy issues. The pharma has no other active studies for PF-08046037, according to its website.
PF-08046037 is a monoclonal antibody designed to seek out immune cells expressing the PD-L1 marker, according to a primer on Pfizer’s website. After binding PD-L1, the asset is taken into the cell where it releases its payload, an agonist of the TLR7 protein. Activating TLR7 then kicks off a signaling cascade that helps drive the body’s anti-tumor response.
“Currently, no further studies evaluating PF‑08046037 are planned, however this doesn’t have wider implications towards future research in immune-stimulating ADCs,” a Pfizer spokesperson told BioSpace on Friday.
The last few months have been good for Pfizer’s cancer arm. In February, the pharma reported that an investigational regimen combining its antibody-drug conjugate (ADC) Padcev with Merck’s mega-blockbuster PD-1 drug Keytruda elicited a 47% reduction in the risk of disease progression or death as compared with standard of care in patients with muscle-invasive bladder cancer.
Analysts reacted optimistically to these findings, with Truist Securities in a Feb. 28 note writing that the doublet “rewrites the standard of care” in this indication.
A few weeks later, Pfizer’s atirmociclib, which could potentially succeed the breast cancer drug Ibrance, significantly improved progression-free survival in a Phase 2 study—an effect that stayed consistent even when patients were stratified according to performance status, menopausal status and prior treatment.
Pfizer has been investing heavily into its cancer portfolio. In May 2025, for instance, the pharma fronted $1.25 billion to partner with China’s 3SBio, gaining access to the biotech’s PD-1/VEGF bispecific antibody SSGJ-707—and entering a closely watched frontier in cancer therapeutics. This agreement also put Pfizer on the hook for $4.8 billion.
In January, Pfizer put up to $865 million on the line in a multi-year licensing deal with Cartography Biosciences, leveraging the biotech’s proprietary engine for cancer targets.
