Merck and Eisai have decided to discontinue the Phase III LEAP-003 trial of Keytruda (pembrolizumab) in combination with Lenvima (lenvatinib) to treat unresectable or metastatic melanoma in adult patients.

The placebo-controlled, randomised Phase III trial was designed for assessing Merck‘s anti-PD-1 therapy Keytruda and Eisai’s Lenvima against Keytruda alone for the first-line treatment of adult patients.

The decision to discontinue the clinical trial is based on an independent data monitoring committee (DMC) recommendation.

The independent DMC reviewed the data obtained from a planned interim analysis and determined that the combination of Keytruda and Lenvima did not show an improvement in overall survival (OS), which was one of the two primary endpoints of the trial.

The participants treated with Keytruda along with Lenvima had statistically significant improvement in progression-free survival (PFS), the trial’s other primary endpoint, compared to Keytruda plus placebo treated group, according to an earlier interim analysis.

Merck and Eisai are advising the trial investigators to inform the study participants regarding the treatment.

The companies have also reported data from another late-stage trial, the Phase III LEAP-017 trial, of Keytruda in combination with Lenvima in unresectable and metastatic colorectal cancer patients.

The findings showed that the trial did not meet its primary endpoint of OS.

A trend toward improvement in OS was observed with Keytruda plus Lenvima compared to regorafenib or TAS-102 (trifluridine and tipiracil hydrochloride) in the final pre-specified OS analysis.

The safety profile of Keytruda in combination with Lenvima in LEAP-003 and LEAP-017 trials was found to be in line with the previously reported data.

Eisai Oncology clinical development senior vice president Corina Dutcus said: “With the LEAP-003 and LEAP-017 trials, we set out to help improve outcomes for patients with two difficult-to-treat advanced cancers, melanoma, and colorectal cancer.

“While these results are different from our initial expectation, insights from both studies will help contribute to our understanding of Keytruda plus Lenvima.

“We remain confident in Lenvima as a pillar of Eisai’s oncology portfolio and will continue to evaluate its potential in ongoing trials within the LEAP programme.”