New cancer drug gets FDA approval

Merck to call the drug Keytruda

The Food and Drug Administration on Thursday approved the first of an eagerly awaited new class of cancer drugs that unleash the body’s immune system to fight tumors.

The drug, which Merck will sell under the name Keytruda, was approved for patients with advanced melanoma who have exhausted other therapies.

Cancer researchers have been almost giddy in the past couple of years about the potential of drugs like Keytruda, which seem to solve a century-old mystery of how cancerous cells manage to evade the body’s immune system.

The answer is that tumors activate brakes on the immune system, preventing it from attacking them. Keytruda is the first drug approved that inhibits the action of one of those brakes, a protein known as PD-1, or programmed death receptor 1.

“This is really opening up a whole new avenue of effective therapies previously not available,” said Dr. Louis M. Weiner, director of the Georgetown Lombardi Comprehensive Cancer Center in Washington and a spokesman for the American Association for Cancer Research.

This general approach might work for many types of cancer, although so far the main successes in clinical trials have come against the deadly skin cancer melanoma, lung cancer and kidney cancer.

Merck said Thursday that the drug, known generically as pembrolizumab, would cost about $12,500 a month or about $150,000 a year.

Merck said the price was in line with that of other cancer drugs, although it seemed to be a bit higher than some. Many doctors have complained about the rapidly escalating prices of cancer drugs, which they said could put treatments out of reach for some patients.

The drugmaker has won a race to market in the United States against Bristol-Myers Squibb, Roche and AstraZeneca, which are in advanced stages of testing drugs that block the action of PD-1. Bristol’s drug, nivolumab, being developed with Ono Pharmaceutical, was approved two months ago in Japan, also as a treatment for advanced melanoma.

Keytruda was approved based on a trial involving 173 participants who all received the drug, with no control group. Tumors shrank in about 24 percent of patients, the FDA said, with the effect lasting at least 1.4 to 8.5 months and continuing beyond this period in most patients.

Merck will now have to conduct two controlled clinical trials to verify that the drug can prolong lives and delay the progression of disease.