In PhIII data, Eli Lilly’s Retevmo meets primary endpoint of improving progression-free survival

Eli Lilly’s Retevmo to treat advanced or metastatic rearranged during transfection (RET)-mutant medullary thyroid cancer (MTC) showed promising results at improving progression-free survival compared to multikinase inhibitors, in topline data the company released Tuesday.

The LIBRETTO-531 trial met its primary endpoint, showing a statistically significant and clinically meaningful improvement in progression-free survival, Eli Lilly said in a press release. The randomized Phase III study sought to compare Retevmo to the multikinase inhibitors cabozantinib or vandetanib.

The trial enrolled 291 patients with progressive, advanced kinase inhibitor naïve RET–mutant MTC.

The full results of the study will be presented at an upcoming medical meeting and will be submitted to a peer reviewed journal, Lilly said. It also said it plans to discuss the results with health officials.

The FDA granted the drug traditional approval last September for patients with locally advanced or metastatic non-small cell lung cancer with a RET gene fusion after first being granted accelerated approval in 2020.

The drug also won accelerated approval in 2022 to treat adult patients with locally advanced or metastatic solid tumors with a RET gene fusion that have progressed on or following prior systemic treatment or who have no satisfactory alternative treatment options.

Adverse events reported in the study were generally consistent with those reported in previous studies of Retevmo, Lilly said.

David Hyman

David Hyman, chief medical officer at Loxo@Lilly, said in the release that the topline results underscore the importance of selectivity in targeting RET-driven cancers and that Lilly suggests Retevmo should be the “preferred first-line treatment” for people with this type of cancer.

“Taken together with the recent positive Retevmo Phase 3 LIBRETTO-431 announcement in lung cancer, these results underscore the importance of timely and broad-based genomic testing to ensure patients who could potentially benefit receive targeted therapies. We look forward to sharing detailed data with the oncology community,” Hyman said.

fda