Pralsetinib

Pralsetinib, similar to the previously approved selpercatinib, is a kinase inhibitor with enhanced specificity for RET tyrosine kinase receptors (RTKs) over other RTK classes. Enhanced RET (Rearranged during transfection) oncogene expression is a hallmark of many cancers, including non-small cell lung cancer. Although multikinase inhibitors, including cabozantinib, ponatinib, sorafenib, sunitinib, and vandetanib, have shown efficacy in RET-driven cancers, their lack of specificity is generally associated with substantial toxicity. Pralsetinib (BLU-667) and selpercatinib (LOXO-292) represent the first generation of specific RET RTK inhibitors for the treatment of RET-driven cancers.

Although a phase 1/2 trial of pralsetinib termed ARROW (NCT03037385) is still ongoing, pralsetinib was granted accelerated FDA approval on September 4, 2020, for the treatment of metastatic RET-fusion positive non-small cell lung cancer. It is currently marketed under the brand name GAVRETO™ by Blueprint Medicines.

Pralsetinib is indicated for the treatment of metastatic non-small cell lung cancer (NSCLC) in adult patients who are confirmed to possess a rearranged during transfection (RET) gene fusion, as determined by an FDA approved test. It is also indicated in adult and pediatric patients 12 years of age and older for the treatment of advanced or metastatic RET fusion-positive thyroid cancer who require systemic therapy and for whom radioactive iodine is not appropriate. The indication for advanced or metastatic RET fusion-positive thyroid cancer was approved under accelerated approval based on the overall response rate and duration of response, and continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials.