Eli Lilly and Company has announced the opening of the LIBRETTO-531 clinical trial [NCT04211337] for selpercatinib, also known as LOXO-292, for treatment-naïve RET-mutant medullary thyroid cancer (MTC) patients. This is the second Phase 3 trial to open for selpercatinib, a highly selective and potent, oral investigational new medicine in clinical development for the treatment of patients with cancers that harbor abnormalities in the rearranged during transfection (RET) kinase. Enrolled trial participants will be randomized to receive either selpercatinib or physician's choice of cabozantinib or vandetanib as initial treatment of their advanced or metastatic RET-mutant MTC.

"Approximately 60 percent of people with medullary thyroid cancer have an activating RET point mutation, yet the current therapeutic options are not ideal for many patients," said Lori Wirth, MD, medical director of the Center for Head and Neck Cancer, Massachusetts General Hospital Cancer Center. "This Phase 3 trial of selpercatinib in patients with advanced or metastatic RET-mutant MTC seeks to confirm a new standard of care that we hope will provide a more effective treatment option for this patient population."

"While medullary thyroid cancer is rare, the occurrence of RET mutations in MTC is high," said Gary Bloom, executive director for ThyCa: Thyroid Cancer Survivors' Association, Inc. "For that reason, we are very excited about the opening of this Phase 3 trial because it shows promise for patients with advanced and metastatic RET-mutant MTC. Due to new treatment options, it is imperative that MTC patients discuss with their medical doctors if and when they should undergo genomic testing of their tumors. This will ensure that people with RET tissue mutations have access to potential treatments and clinical trials such as this one for selpercatinib."