Both of the recently FDA approved first generation, selective RET inhibitors Selpercatinib (Retevmo) and Pralsetinib (Gavreto) continued to garner attention at this years American Society of Clinical Oncology (ASCO) conference from June 4-8, 2021. Specifically Dr. Vivek Subbiah from MD Anderson published the remarkable intracranial efficacy of Selpercatinib, with 82% (out of 22 patients with measurable intracranial disease) demonstrating overall response rate intracranially, including 23% with complete shrinkage of their brain metastasis and one patient with resolution of leptomeningeal metastasis.
Dr. Alex Drilon from Memorial Sloan Kettering also presented updates on the landmark studies of both drugs, including the latest overall response rate of 85% for Selpercatinib (n=39) and 79% for Pralsetinib (n=68) seen in treatment naïve RET fusion positive NSCLC, and 64% for Selpercatinib (n=105) and 62% for Pralsetinib (n=126) seen in Platinum pre-treated RET fusion positive NSCLC patients. Efficacy was similarly noteworthy and encouraging for RET mutated Medullary thyroid carcinoma patients with an overall response rate of 73% for Selpercatinib (n=88) and 69% for Pralsetinib (n=29) for the treatment naive, and an ORR of 69% for Selpercatinib (n=55) and 73% for Pralsetinib (n=55) for those previously treated with a multikinase inhibitor. (See Table below)
After Selpercatinib gained tissue agnostic FDA approval earlier this year and its “tissue agnostic” efficacy across multiple different types of RET driven cancers was presented at the AACR in April 2021, Pralsetinib’s robust anti-tumor activity in patients with many different types of RET altered solid tumors was also presented at this years ASCO 2021, possibly setting the stage for yet another tissue agnostic FDA approval in the coming months or year.
Blueprint Medicines Presents ARROW Trial Data for GAVRETO® (pralsetinib) Highlighting Durable Clinical Activity in Patients with Metastatic RET Fusion-Positive Non-Small Cell Lung Cancer and Other Advanced Solid Tumors | Blueprint Medicines Corp.