Merck, Eisai's Keytruda-Lenvima combo pads historic approval with lifesaving data win

Merck and Eisai aim to turn a conditional approval for their Keytruda-Lenvima combo in endometrial cancer into a full one with life-extension clinical win. (Merck)

Last September, Merck & Co. and Eisai’s Keytruda and Lenvima combo nabbed its first approvals for certain endometrial cancers under a brand-new collaboration among regulatory agencies in three countries. Now, the companies believe they have new data to turn the conditional nod into a full one.

The Keytruda-Lenvima combo triggered more responses, extended the time patients lived without their tumors growing and, most importantly, cut the risk of death compared with chemotherapy in previously treated women with endometrial cancer, Merck and Eisai said Wednesday.

The positive results from the phase 3 Keynote-775 trial were observed in the mismatch repair proficient (pMMR) subgroup as well as the entire study population, which also includes patients with the microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) biomarkers. The combo is currently approved in endometrial cancer that’s not MSI-H or dMMR.

RELATED: ESMO: Merck, Eisai detail Keytruda-Lenvima combo results after triple endometrial cancer OK

Last year, drug regulators from the U.S., Canada and Australia simultaneously greenlighted the Keytruda-Lenvima pair. It was the first nod under Project Orbis, a collaborative program that allows concurrent reviews by three agencies to shorten cancer drugs’ path to market.

At the time, all three go-aheads were doled out under the respective regulators’ conditional approval pathway based on tumor shrinkage and response duration data from the single-arm Keynote-146 study. In the U.S., full approval is contingent upon confirmatory data. Enter Keynote-775.

Merck and Eisai said an independent data monitoring committee has judged the improvements in the study as statistically significant and clinically meaningful. Detailed results will be presented at an upcoming medical meeting.

RELATED: Merck, Eisai further complicate kidney cancer race with Keytruda-Lenvima win

Since the endometrial cancer nod, Keytruda and Lenvima have shown they can also work as a combo in kidney cancer. In the pivotal Keynote-581 trial, the pair topped Pfizer’s Sutent in newly diagnosed renal cell carcinoma. Industry watchers will be eager to compare the specific data—which remain under wraps—with those posted by combinations between Keytruda and Pfizer’s Inlyta; Bristol Myers Squibb’s Opdivo and Exelixis’ Cabometyx; and Bristol’s duo immuno-oncology regimen that comprises Opdivo and Yervoy.

The two companies are also exploring the Keytruda-Lenvima cocktail in previously untreated patients with endometrial carcinoma with the phase 3 LEAP-001 trial. They recently saw positive signs for the combo in ovarian and colorectal cancers as well.