Efficacy and safety of pralsetinib in patients with advanced RET fusion-positive non-small cell lung cancer

BackgroundPralsetinib is a potent, selective RET inhibitor targeting oncogenic RET alterations. As part of the global, phase 1/2 ARROW trial (NCT03037385), the efficacy and safety of pralsetinib in Chinese patients with advanced RET fusion-positive non-small cell lung cancer (NSCLC) were evaluated. MethodsAdult patients with advanced, RET fusion-positive NSCLC with or without prior platinum-based chemotherapy were enrolled into two cohorts receiving 400-mg once-daily oral pralsetinib. Primary end points were objective response rates assessed by blinded independent central review and safety. ResultsOf 68 patients enrolled, 37 had received prior platinum-based chemotherapy (48.6% with >= 3 prior systemic regimens) and 31 were treatment-naive. As of March 4, 2022 (data cutoff), of the patients with measurable lesions at baseline, a confirmed objective response was observed in 22 (66.7%; 95% confidence interval [CI], 48.2-82.0) of 33 pretreated patients, including 1 (3.0%) complete response and 21 (63.6%) partial responses; and in 25 (83.3%; 95% CI, 65.3-94.4) of 30 treatment-naive patients, including two (6.7%) complete responses and 23 (76.7%) partial responses. Median progression-free survival was 11.7 months (95% CI, 8.7-not estimable) in pretreated patients and 12.7 months (95% CI, 8.9-not estimable) in treatment-naive patients. The most common grade 3/4 treatment-related adverse events in 68 patients were anemia (35.3%) and decreased neutrophil count (33.8%). Eight (11.8%) patients discontinued pralsetinib because of treatment-related adverse events. ConclusionPralsetinib showed robust and durable clinical activity with a well-tolerated safety profile in Chinese patients with RET fusion-positive NSCLC.Clinical trial registration: NCT03037385.