Phase 1 trial of ERAP1 inhibitor GRWD5769 shows tumor shrinkage in six cancer types when combined with cemiplimab (theguardian.com)

• 83 patients with six advanced solid tumor types received GRWD5769 + cemiplimab.
• Tumors shrank in 26 patients; 15 had ≥30% reduction.
• Disease controlled ≥6 months in 18-55% depending on cancer type.
• Oral drug inhibits ERAP1, restoring T-cell recognition of cancer cells.
• Well tolerated; phase 1 trial ongoing with larger study planned.

"A phase 1 trial of the experimental oral drug GRWD5769, an ERAP1 inhibitor, combined with cemiplimab immunotherapy, showed tumor shrinkage in 26 of 83 patients with advanced cervical, bladder, liver, bowel, lung, or head and neck cancers. Tumors reduced by at least 30% in 15 patients. The drug targets cancer cells' ability to hide from the immune system by inhibiting the ERAP1 enzyme. The trial was conducted across the UK, France, Spain, and Australia, and results were presented at ASCO 2026."