Keytruda topped placebo at fending off cancer's return after surgery, an interim analysis of the Keynote-054 trial showed. The details of that spread weren't spelled out, though Merck said Keytruda prolonged recurrence-free survival "significantly longer" than placebo did. "This result demonstrates the meaningful benefit that Keytruda offers for patients with melanoma," Merck SVP Roger Dansey, head of late-stage oncology development, said in a statement. Merck says it's planning to discuss the data with regulatory authorities, and those talks could lead to a filing this year.