AcceleRET Lung: A phase 3 study of first-line pralsetinib in patients with RET fusion–positive advanced/metastatic NSCLC.

TPS9159 Background: RET gene fusions have been identified as oncogenic drivers in multiple tumor types, including 1–2% of non-small cell lung cancer (NSCLC). Pralsetinib is a potent, selective RET inhibitor, approved in the US and EU for the treatment of metastatic RET fusion–positive NSCLC based on the phase 1/2 ARROW study (NCT03037385). In the ARROW study (data cutoff: Nov 6, 2020), patients who initiated 400 mg once daily (QD) of pralsetinib after platinum-based chemotherapy achieved an overall response rate (ORR) of 62%, per independent central review. In the treatment-naïve group, the ORR was 79%. Most treatment-related adverse events were grade 1–2 across the entire safety population treated at 400 mg QD (n=471). AcceleRET Lung, an international, open-label, randomized, phase 3 study (NCT04222972), will evaluate the efficacy and safety of pralsetinib versus standard of care (SOC) for first-line treatment of advanced/metastatic RET fusion–positive NSCLC. Abstracts for this study were previously submitted to the European Lung Cancer Congress 2020, the American Society of Clinical Oncology 2020 annual meeting, and 2020 World Conference on Lung Cancer. Methods: Approximately 226 patients with metastatic RET fusion–positive NSCLC will be randomized 1:1 to oral pralsetinib (400 mg QD) or SOC (non-squamous histology: platinum/pemetrexed ± pembrolizumab followed by maintenance pemetrexed ± pembrolizumab [at investigator’s discretion]; squamous histology: platinum/gemcitabine or platinum + pembrolizumab + paclitaxel/nab-paclitaxel followed by maintenance pembrolizumab). Stratification factors include intended use of pembrolizumab, history of brain metastases, and Eastern Cooperative Oncology Group Performance Status. Key eligibility criteria include no prior systemic treatment for advanced/metastatic NSCLC; RET fusion–positive tumor by local or central assessment; no additional actionable oncogenic drivers; no prior selective RET inhibitor; measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. Patients with central nervous system metastases were permitted if asymptomatic and on a stable dose of corticosteroids. Cross-over to receive pralsetinib upon disease progression will be permitted for patients randomized to SOC. The primary endpoint is progression-free survival (blinded independent central review; RECIST v1.1). Secondary endpoints include ORR, overall survival, duration of response, disease control rate, clinical benefit rate, time to intracranial progression, intracranial ORR, safety/tolerability and quality of life evaluations. Identification of potential biomarkers of antineoplastic activity and resistance was an exploratory endpoint. Recruitment has begun with sites (active or planned) in North America, Central America, Europe and Asia. Clinical trial information: NCT04222972.