Merck received FDA approval of Keytruda, the first in a new class of immunotherapy drugs aimed at a target called PD-1, earlier this month in advanced melanoma. Data at ESMO show it may have promise in gastric, bladder, lung and other cancers, as well.
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Keytruda, also known as pembrolizumab, produced a 31 percent overall response rate in a small study in advanced gastric cancer, Merck said. The drug was tested in patients whose cancer tested positive for a marker called PD-L1. Twelve people out of 39 responded to the drug, and 11 of those 12 remain on therapy.
"Although gastric cancer is a relatively small market, there is significant unmet need," BMO Capital Markets analyst Alex Arfaei wrote in a research note Monday. Gastric cancer, he said, is the fifth-most common cancer in the world and the third-leading cause of cancer death.
The company also presented data Monday in bladder cancer, the ninth-most commonly diagnosed cancer worldwide, according to ESMO. There are more than 380,000 new cases and 150,000 deaths each year.
"No major progress has been made for more than a decade," Maria De Santis, an oncologist with Kaiser Franz Josef Hospital in Vienna, said in an ESMO statement.
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Merck's Keytruda produced a 24 percent response rate in a trial in an advanced form of the disease presented this weekend, and the company said it plans to start a late-stage trial in the indication this year. The conference also highlighted a drug from Roche, MPDL3280A, which showed a 43 percent response rate in a recent study.
Merck also had data on Keytruda in lung and head and neck cancers, which John Boris, an analyst with SunTrust Robinson Humphrey, described as "competitive" and "encouraging."