Oncology Pipeline Roundup: Lilly's Retevmo Meets Endpoint, Merck Halts MK-6837, Tango Combo Shows Promise
Eli Lilly's Retevmo met the primary endpoint in a Phase III lung cancer trial, Merck discontinued its TROP2 ADC MK-6837, and a Tango/Revolution combination showed benefit in pancreatic cancer.
Eli Lilly announced positive top-line results from the Phase III LIBRETTO-432 clinical trial of Retevmo (selpercatinib) as adjuvant therapy versus placebo in patients with early-stage (II-IIIA) rearranged during transfection (RET) fusion-positive non-small cell lung cancer (NSCLC). Separately, Merck & Co disclosed it has discontinued its TROP2-directed antibody-drug conjugate (ADC) MK-6837, and early-stage data from Tango and Revolution Medicines showed benefit in advanced pancreatic cancer.
The LIBRETTO-432 study met its primary endpoint, demonstrating a highly statistically-significant and clinically-meaningful improvement in investigator-assessed event-free survival (EFS) compared with placebo. Overall survival results trended in favor of selpercatinib but were immature at the time of the analysis, with few events observed. The overall safety profile of selpercatinib in LIBRETTO-432 was generally consistent with previously reported trials in the selpercatinib development program.
Merck has discontinued MK-6837, an ADC that had been in clinical trials since mid-2024. The company disclosed the decision on its first-quarter call, with the president of Merck Research Laboratories stating: "We have discontinued that." He gave no reason for the discontinuation, but described MK-6837 as "another ADC, which had a unique payload" and cited the "profound impact" of sacituzumab tirumotecan (sac-tmt) as one reason for abandoning the molecule. As of 1 May, the clinicaltrials.gov listing for MK-6837’s phase 1 solid tumour study remained marked "active," having recruited 168 patients, higher than the initial enrolment target of 100, suggesting the decision to discontinue was recent.
In an early-stage clinical trial, patients with advanced pancreatic cancer benefited more from a combination of two targeted drugs — a PRMT5 inhibitor from Tango and Revolution’s pan-RAS inhibitor — than they might from each drug on its own.