Efficacy of Selpercatinib in RET Fusion-Positive Thyroid Cancers

Vivek Subbiah, MD, discusses the updated results of the LIBRETTO-001 trial, specifically the effect of selpercatinib on RET fusion-positive thyroid tumors.

Vivek Subbiah, MD, a medical oncologist at the University of Texas MD Anderson Cancer Center, discusses the updated results of the LIBRETTO-001 trial (NCT03157128), specifically the effect of selpercatinib (Retevmo) on RET fusion-positive thyroid tumors.

According to Subbiah, of the 55 initial patients who were previously treated with a multikinase inhibitor, the response rate was 69% and the 1-year progression-free survival (PFS) rate was 82%. In 88 patients who were never treated with a multikinase inhibitor, the response rate was 73% and the 1-year PFS rate was 92%. In the 19 patients who were treatment naïve, the response rate was 79% and the 1-year PFS rate was 64%.

Updated results showed that the overall response rate was 79% in patients with previously treated RET fusion-positive thyroid cancer. In the treatment-naïve group, the response rate was 100%, according to Subbiah. Of those responses, 71% were ongoing and 64% remained progression-free. These data supported the approval of selpercatinib capsules for the treatment of thyroid cancer harboring RET alterations.