U.S. health regulators approved expanding the use of Merck & Co.'s cancer drug Keytruda to include adding it to chemotherapy to treat lung cancer, broadening the drug's potential market though evidence for the combination's benefit is mixed.
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Keytruda, introduced in 2014, is one of a new wave of cancer drugs designed to work by harnessing the body's own immune system to fight tumors. The U.S. Food and Drug Administration on Wednesday approved combining it with two chemotherapy agents, pemetrexed and carboplatin, to treat patients with an advanced form of lung cancer. Eli Lilly & Co. markets pemetrexed under the brand Alimta, and carboplatin is available generically.
Chemotherapy has been a common first-line treatment for many patients with advanced lung cancer whose tumors don't have certain molecular traits that can be targeted by other drugs.
Keytruda has previously been approved to treat the skin cancer melanoma, head and neck cancer, lymphoma, and lung cancer in patients whose tumors have a high level of a protein called PD-L1. The newly approved use of Keytruda with chemotherapy is for certain lung cancer patients regardless of PD-L1 levels.
Lung cancer is the leading cause of cancer deaths in the U.S., according to the American Cancer Society. The society estimates there will be about 222,500 new cases of lung cancer this year, and 155,870 lung-cancer deaths.
A Merck-funded study of more than 120 patients showed that adding Keytruda to chemotherapy significantly shrank tumors in a higher rate of lung-cancer patients than those receiving chemotherapy alone, 55% versus 29%, according to results published last year in The Lancet. Keytruda also extended the median time from the start of treatment until death or disease progression to 13 months, versus nearly 9 months for chemotherapy alone. Adverse events for patients taking the combination included fatigue and anemia.
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But Keytruda didn't help patients live significantly longer than chemotherapy alone among patients in the study. A year after starting treatment, about 75% of patients receiving Keytruda were alive, versus 72% on chemotherapy alone.
Overall survival -- the time from start of treatment until death from any cause -- is considered the gold-standard measure of efficacy in cancer-drug studies, though the FDA sometimes approves drugs based on other measures of efficacy.
The lack of a significant overall survival benefit could make some doctors cautious about adding Keytruda to chemotherapy for first-line lung-cancer treatment, until more clinical-trial data become available. Also, adding Keytruda comes with a big price tag -- $13,000 a month per patient.
"We need more follow-up and probably larger patient populations to know whether there is indeed a survival advantage," said Matthew Hellmann, a medical oncologist specializing in lung cancer at Memorial Sloan Kettering Cancer Center in New York.
Merck plans to provide updated overall survival data from the study at a medical meeting in June and is running a separate, larger study that will further test whether the Keytruda-chemotherapy combination can improve overall survival, said Roy Baynes, head of clinical development in Merck's research unit.
Keytruda had $1.4 billion in global sales last year. It competes with Bristol-Myers Squibb Co.'s Opdivo and similar immunotherapies from Roche Holding AG and other companies.
While immunotherapies have been shown to be effective in a range of cancers, there are limits. Roche said Wednesday that Tecentriq failed to improve overall survival versus chemotherapy in a clinical trial of patients with bladder cancer. Last year, the FDA approved Tecentriq's use to treat bladder cancer based on an earlier study showing it shrank tumors in some patients.
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(END) Dow Jones Newswires
May 10, 2017 18:52 ET (22:52 GMT)