Rigel Pharmaceuticals Inc. (NASDAQ: RIGL) announced the publication of final data from its Phase 1/2 ARROW study evaluating pralsetinib for metastatic RET fusion-positive non-small cell lung cancer in the Journal of Clinical Oncology. The data includes an additional 42 months of follow-up from previously published results.

The study showed a 70% overall response rate among 259 patients with measurable disease, including 7% complete responses and 63% partial responses. Treatment-naive patients achieved a 78% response rate, while patients who received prior platinum-based chemotherapy had a 63% response rate.

Median overall survival was 44.3 months in the overall patient population, with treatment-naive patients reaching 50.1 months and prior-platinum patients achieving 39.7 months. The median treatment duration was 15.0 months.

The study reported regional differences in outcomes, with U.S. patients showing longer median overall survival at 62.4 months compared to 44.5 months in Asia and 29.6 months in Europe. Median progression-free survival was 13.1 months overall, with U.S. patients achieving 25.9 months versus 12.6 months in Asia and 12.8 months in Europe.

Among 15 patients with measurable central nervous system metastases at baseline, the intracranial response rate was 53%. In 11 response-evaluable patients with CNS metastases, the CNS response rate was 73%.

Three treatment-related deaths occurred in treatment-naive patients in Asia, including two cases of pneumonia and one case each of interstitial lung disease and rhabdomyolysis. The study reported no new safety signals and no hypersensitivity reactions in patients receiving prior immunotherapies.

Pralsetinib, marketed as GAVRETO, is approved by the FDA for treating metastatic RET fusion-positive NSCLC and advanced or metastatic RET fusion-positive thyroid cancer in specific patient populations.