Pralsetinib RET Inhibitor Shrinks Diverse Tumors (46% ORR, 11-mo DoR)

Pralsetinib is a tyrosine kinase inhibitor designed to target cancer-driving RET fusions and mutations. In the Phase 2 ARROW basket trial (n = 29; 11 histologies, NCT03037385), adults with pre-treated, RET fusion-positive solid tumors, had an ORR was 46% with 3 complete responses (2 pancreatic, 1 CUP), median DoR 11.1 mo, PFS 7.0 mo, and OS 10.3 mo. 66% of patients experienced Grade ≥3 treatment-related events, mostly reversible neutropenia, transaminase elevations and anemia, with 1 case of serious hypertension. All adverse events were manageable.