Bristol-Myers Squibb Company / Five Prime Therapeutics

Advanced Solid Tumors (CSF-1R + PD-1 combo)

Disease Overview

The six tumor types studied (NSCLC, melanoma, head and neck, pancreatic, colorectal, malignant glioma) collectively account for hundreds of thousands of US diagnoses annually. The combination hypothesis was that CSF-1R blockade would deplete or repolarize tumor-associated macrophages (TAMs), converting immunologically 'cold' tumors—particularly pancreatic and colorectal—into PD-1-responsive ones.

Competitive Landscape

At the November 2014 announcement, the macrophage/myeloid-targeted I-O space was crowded but undifferentiated: Daiichi Sankyo/Plexxikon's pexidartinib (later Turalio, approved 2019 for tenosynovial giant cell tumor) was the most clinically advanced CSF-1R inhibitor, while Roche's emactuzumab (RG7155) and Novartis's MCS110 (anti-CSF-1) competed in solid tumors. The BMS-Five Prime Phase 1a/1b clinical collaboration—a $30M one-time payment with BMS funding study costs—was a low-risk option, but BMS doubled down in October 2015 with a $1.74B expanded license ($350M upfront, up to $1.05B oncology milestones per product, double-digit royalties), per FierceBiotech and GEN. The franchise unraveled in February 2020 when the Phase 2 cabiralizumab+Opdivo±chemo trial in advanced pancreatic cancer (NCT03336216, ~160 patients) missed PFS, with BMS announcing 'no near-term plans for additional sponsored development'. BMS nonetheless acquired Five Prime in March 2021 for $1.9B, primarily for bemarituzumab (anti-FGFR2b) in gastric cancer, not cabiralizumab.