Pan-cancer efficacy of pralsetinib in patients with advanced RET fusion-positive solid tumors

Oncogenic RET fusions occur in diverse cancers. Pralsetinib is a potent, selective inhibitor of RET receptor tyrosine kinase. The ongoing phase 1-2 ARROW trial evaluated pralsetinib efficacy and safety in patients with advanced RET-altered solid tumors. The trial enrolled 29 patients with 12 different RET fusion-positive solid tumor types, excluding NSCLC and thyroid cancer, who had previously received or were not candidates for standard therapies. The overall response rate was 57% (95% CI 35-77). Median duration of response, progression-free survival, and overall survival were 12 months, 7 months, and 14 months, respectively. The most common grade ≥ 3 treatment-related adverse events were neutropenia (31%) and anemia (14%). The authors conclude that these data validate RET as a tissue-agnostic target with sensitivity to RET inhibition, indicating pralsetinib’s potential as a well-tolerated treatment option with rapid, robust, and durable anti-tumor activity in patients with diverse RET fusion-positive solid tumors.