Merck's Keytruda, on the heels of a first-line kidney cancer win, targets earlier, post-surgery use

Merck & Co.’s Keytruda already bears an FDA nod for use alongside Pfizer’s Inlyta as a first-line treatment for advanced kidney cancer. Now, it has shown it can be used even earlier, following surgery.

Keytruda monotherapy topped placebo at extending the time patients with early renal cell carcinoma lived without their disease coming back after surgical removal of a kidney, Merck said Thursday.

The disease-free survival improvement, shown at an interim analysis of the phase 3 Keynote-564 trial, was statistically significant and clinically meaningful, the company said. And it marked the first time a PD-1 inhibitor showed a benefit in preventing tumor from returning post-surgery in the so-called adjuvant setting for patients with kidney cancer, Roy Baynes, M.D., Ph.D., Merck Research Laboratories’ chief medical officer, said in a statement.

While detailed results haven't yet been shared, Merck said it’ll submit them to regulatory authorities for potential approval. The trial will also continue to see whether adjuvant Keytruda treatment can extend patients’ lives, a key secondary endpoint of the study.

RELATED: Data favor Merck, Eisai's Keytruda-Lenvima as the winner in kidney cancer, but window still open for Bristol Myers: analyst

Keytruda entered the kidney cancer field two years ago with an FDA nod for an Inlyta combo as first-line treatment. A few weeks ago, Merck came up with new data showing Keytruda could be used alongside another tyrosine kinase inhibitor (TKI), its Eisai-partnered Lenvima, in the same setting. That pairing reduced the risk of death by 34% over Pfizer’s standard-of-care Sutent. The win could give Merck another weapon against Bristol Myers Squibb’s Opdivo cocktails with either CTLA4 immunotherapy Yervoy or Exelixis’ TKI Cabometyx.

PD-1/L1 developers are counting on earlier use—both before and after surgery—to drive their drugs’ next phase of growth. In adjuvant kidney cancer alone, Roche is running the IMmotion010 trial for Tecentriq, and AstraZeneca is testing Imfinzi both alone and in a cocktail with its own CTLA4 agent, tremelimumab. Bristol Myers Squibb is comparing Opdivo and the Opdivo-Yervoy combo against placebo in the CheckMate-914 trial.

RELATED: FDA snubs Keytruda in early breast cancer after harsh review as Merck looks to next data analysis

Keytruda currently has one indication in the adjuvant setting, which is for melanoma following complete tumor removal. Merck recently showed the drug's application there helped 65.3% patients in the Keynote-054 trial live without distant metastatic disease after a median 3.5 years of follow-up.

But it also recently suffered a high-profile setback when the FDA rejected an application for Keytruda both before and after surgery in triple-negative breast cancer. The FDA had previously raised concerns that the trial data on Keytruda’s ability to stall cancer recurrence were immature and that the trial design couldn’t distinguish the benefits between the neoadjuvant and adjuvant settings.