AnaptysBio Halts Phase 2 Ulcerative Colitis Trial; Lyell Immunopharma Secures CAR-T Rights

AnaptysBio's Phase 2 trial of rosnilimab for moderate-to-severe ulcerative colitis failed to meet its primary (mean change in modified Mayo Score at Week 12) and key secondary endpoints (clinical response and remission); the global trial will be discontinued1 2 3 5 8.

Rosnilimab was safe and well tolerated in the trial, showing approximately 90% pathogenic T cell depletion, but this did not translate into clinical efficacy for ulcerative colitis1 2 3.

Discontinuing the trial will save AnaptysBio at least $10 million, and the company expects to end 2025 with about $300 million in cash, including a $75 million milestone payment from GSK tied to Jemperli sales1 2 3.

AnaptysBio plans to advance rosnilimab into rheumatoid arthritis, targeting an update in H1 2026, and is progressing other pipeline assets including ANB033 for celiac disease; the company reiterated its intention to separate biopharma operations from its royalty assets by the end of 20261 3 6.

Lyell Immunopharma has announced a licensing deal for global rights to a next-generation CAR-T product candidate in development for metastatic colorectal cancer, known as LYL2734.

LYL273 has shown promising early results with a 67% overall response rate and 83% disease control rate at the highest tested dose in metastatic colorectal cancer patients, alongside a manageable safety profile4.