Data from FDA Approval Summary: Pralsetinib for the Treatment of Lung and Thyroid Cancers With <i>RET</i> Gene Mutations or Fusions

The FDA granted accelerated approval for pralsetinib on September 4, 2020 for non–small cell lung cancer (NSCLC) and December 1, 2020 for thyroid cancer, for: (i) adult patients with metastatic RET fusion–positive NSCLC, (ii) adult and pediatric patients ≥12 years of age with advanced or metastatic RET-mutant medullary thyroid cancer who require systemic therapy, and (iii) adult and pediatric patients ≥12 years of age with advanced or metastatic RET fusion–positive thyroid cancer who require systemic therapy and who are radioactive iodine refractory (if radioactive iodine is appropriate). Approval was based on the results of a multicenter, open-label, multi-cohort clinical trial (ARROW, NCT03037385), demonstrating substantial overall response rates (ORR) and durable responses in patients with RET-altered tumors. ORRs within the approved patient populations ranged from 57% [95% confidence interval (CI), 46–68] in patients with RET fusion–positive NSCLC previously treated with platinum chemotherapy to 89% (95% CI, 52–100) in patients with RET fusion–positive thyroid cancer, with response duration of at least 6 months in most responders. The product label includes warnings and precautions for pneumonitis, hypertension, hepatotoxicity, hemorrhagic events, tumor lysis syndrome, risk of impaired wound healing, and embryo-fetal toxicity. This article summarizes the major considerations during FDA review leading to the approval of pralsetinib.