Dr Wirth on the Full FDA Approval of Selpercatinib for Advanced RET Fusion+ Thyroid Cancer

Lori Wirth, MD, associate professor, medicine, Harvard Medical School; medical director, Center for Head and Neck Cancers; Massachusetts General Hospital, discusses the significance of the June 2024 FDA full approval of selpercatinib (Retevmo) for adult and pediatric patients at least 2 years of age with advanced or metastatic RET fusion–positive thyroid cancer who require systemic therapy and who are radioactive iodine (RAI) refractory, if RAI is appropriate.

Prior to this full approval, selpercatinib had received accelerated approval for the same indication in May 2020. The full approval was supported by data from the phase 1/2 LIBRETTO-001 trial (NCT03157128), where patients who received prior treatment (n = 41) achieved an overall response rate (ORR) of 85% (95% CI, 71%-94%), and those who were naive to systemic therapy (n = 24) experienced an ORR of 96% (95% CI, 79%-100%) when treated with selpercatinib.

Wirth begins by stating that selpercatinib was initially granted accelerated approval by the FDA for patients with RET fusion–positive non-small cell lung cancer, RET-mutated medullary thyroid cancer, RET fusion–positive follicular thyroid cancer, and other RET-driven cancers, based on findings from the 2 LIBRETTO-001 trial. Two subsequent phase 3 confirmatory trials have evaluated the agent in patients with RETfusion–positive medullary thyroid cancer and RET fusion–positive lung cancer, she notes, emphasizing that both studies yielded highly positive results. These results demonstrated that selpercatinib outperformed standard-of-care care therapies for these diseases, Wirth reports.

The full FDA approval of selpercatinib for patients with advanced or metastatic RET fusion–positive thyroid cancer is a significant milestone for patients with RET-driven cancers, as selpercatinib’s high efficacy rates and long-lasting effectiveness, coupled with its excellent safety profile, make it a well-tolerated treatment option, she explains. As a result, this drug will now be widely available to patients in need of therapy, offering a potentially life-changing option for those with thyroid cancer, Wirth concludes.