Eli Lilly presents data from LIBRETTO-001 clinical trial
Eli Lilly presented data from the LIBRETTO-001 clinical trial intended to support the registration of oral selpercatinib1 monotherapy, also known as LOXO-292, for the treatment of RET-altered thyroid cancers. RET-altered thyroid cancers are comprised of two different populations, RET-mutant medullary thyroid cancer and RET fusion-positive thyroid cancers. In the RET-mutant MTC registration dataset consisting of the first 55 enrolled patients with prior cabozantinib and/or vandetanib2, selpercatinib treatment resulted in a 56% objective response rate. This population was heavily pretreated, and ORR was similar regardless of prior multikinase inhibitor therapy. As of the data cut-off date of June 17, 2019, median duration of response was not reached and median progression-free survival was not reached. Selpercatinib therapy also resulted in robust biochemical response rates for serum tumor markers calcitonin and carcinoembryonic antigen. In a safety analysis of all 531 patients enrolled to LIBRETTO-001, selpercatinib was well-tolerated, with only nine patients discontinuing therapy due to treatment-related adverse events. Investigators also presented the results of selpercatinib in RET-mutant MTC patients who have received neither cabozantinib nor vandetanib. In this analysis of 76 patients, selpercatinib treatment resulted in a 59% ORR. Median DOR and PFS were not reached in this treatment-naive population, as the vast majority of patients remain in response or progression-free. Investigators also presented the results of selpercatinib in heavily pretreated RET fusion-positive thyroid cancer patients. In this analysis of 26 patients, selpercatinib treatment resulted in a 62% ORR. Median DOR and PFS were not reached in this population, as the vast majority of patients remain in response or progression-free.