AcceleRET Lung: A phase III study of first-line pralsetinib in patients (pts) with RET-fusion+ advanced/metastatic non-small cell lung cancer (NSCLC).

TPS9633 Background: RET gene fusions have been identified as oncogenic drivers in multiple tumor types, including 1-2% of NSCLC, but no selective RET inhibitors are approved for use. The investigational RET inhibitor, pralsetinib, potently and selectively targets oncogenic RET alterations, including those that confer resistance to multikinase inhibitors. In the registration-enabling phase 1/2 study (ARROW; NCT03037385), pts with RET-fusion+ NSCLC treated with 400 mg once daily (QD) of pralsetinib (N = 80) after platinum-based chemotherapy achieved an overall response rate (ORR) of 61% (95% CI 50, 72; 2 responses pending confirmation) per independent central review. In addition, a promising ORR of 73% (all centrally confirmed responses) was attained in the treatment naïve cohort (N = 26). Most treatment-related adverse events were grade 1-2 across the entire safety population treated at 400 mg QD (N = 354). AcceleRET Lung, an international, open-label, randomized, phase 3 study, will evaluate the efficacy and safety of pralsetinib versus standard of care (SOC) for first-line treatment of advanced/metastatic RET fusion+ NSCLC (NCT04222972). Methods: Approximately 250 pts with metastatic RET-fusion+ 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; squamous histology: platinum/gemcitabine). Stratification factors include intended use of pembrolizumab, history of brain metastases, and ECOG PS. Key eligibility criteria include no prior systemic treatment for metastatic disease; RET-fusion+ tumor by local or central assessment; no additional actionable oncogenic drivers; no prior selective RET inhibitor; measurable disease per RECIST v1.1. Pts randomized to SOC will be permitted to cross-over to receive pralsetinib upon disease progression. 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. Recruitment has begun with sites (active or planned) in North America, Europe and Asia. Clinical trial information: NCT04222972 .