Lilly’s Retevmo outperforms in trials for RET fusion-positive NSCLC and RET-mutant MTC

Eli Lilly (Lilly) has disclosed the results from two pivotal Phase 3 studies, LIBRETTO-431 and LIBRETTO-531, evaluating the efficacy of Retevmo in treating patients with specific types of advanced or metastatic cancers. These revelations were spotlighted during the ESMO Congress 2023 and simultaneously found a place in the esteemed New England Journal of Medicine.

Key Outcomes of LIBRETTO-431 and LIBRETTO-531

Dr. David Hyman, Chief Medical Officer at Lilly, acknowledged the significant insights from these studies. He emphasized, “These results from LIBRETTO-431 and LIBRETTO-531 are striking and provide critical evidence supporting the importance of optimizing initial therapy for patients with RET-driven cancers.”

Lilly reveals LIBRETTO-431 & LIBRETTO-531 Phase 3 study results for Retevmo. Photo courtesy of Momoneymoproblemz/Wikimedia Commons.

A Deeper Look into LIBRETTO-431 for NSCLC

LIBRETTO-431 focused on evaluating Retevmo for patients with advanced or metastatic RET fusion-positive NSCLC. LIBRETTO-431’s primary investigator, Dr. Caicun Zhou, advocated the potential of Retevmo, asserting, “These data provide clear evidence that Retevmo offers highly meaningful clinical impact for patients diagnosed with RET fusion-positive NSCLC.”

The trial revealed that patients on Retevmo experienced a median progression-free survival (PFS) of 24.8 months compared to 11.2 months in the control arm. Retevmo also demonstrated superior PFS with an increase of more than 13 months in median PFS. Other detailed results from the study further emphasize Retevmo’s potential as an effective treatment option.

Insights from LIBRETTO-531 on RET-Mutant MTC

LIBRETTO-531 centered on the evaluation of Retevmo versus multikinase inhibitors (MKIs) in patients with advanced or metastatic RET-mutant medullary thyroid cancer (MTC). At a median follow-up of around 12 months, the study showcased that the median PFS in the Retevmo arm had not been reached, making it a promising option for MTC treatment. Treatment with Retevmo also resulted in a significant improvement in various other measured metrics.

In both studies, Retevmo’s safety profile remained generally consistent with previous data. These results not only cement the drug’s potential but also pave the way for more comprehensive treatment strategies for patients with RET-driven cancers.