Pralsetinib in RET fusion-positive non-small cell lung cancer: update from the ARROW trial

RET fusions are present in 1%-2% of non-small cell lung cancer. The multinational phase 1-2 ARROW trial evaluates the highly potent, oral, selective RET inhibitor pralsetinib in diverse advanced RET fusion-positive malignancies. An update of ARROW results in NSCLC showed that pralsetinib resulted in ORR 72% (95% CI 60-82) in treatment-naïve patients and 59% (50-67) in patients with prior platinum-based chemotherapy. Median duration of response was not reached and 22.3 months in these two groups. Tumor shrinkage was observed in all treatment-naïve patients and in 97% of patients with prior platinum-based chemotherapy; median progression-free survival was 13.0 and 16.5 months, respectively. Among the 10 patients with measurable intracranial metastases (all previously treated) 7 had intracranial response. Seven percent of patients discontinued due to TRAEs.