WASHINGTON -
Keytruda has a unique action, enlisting the body’s immune response against the lethal cancer. Normally, cancerous tumors disarm the immune system. But Keytruda inhibits the action of one of the proteins tumors use to block immune response.
Known generically as , the drug reportedly is safe with few side effects. Conventional chemotherapy drugs target fast-growing cancer cells and can cause disabling side effects.
The FDA gave speedy approval to Keytruda after a large, phase one safety trial.
In a study involving 173 patients, distant tumors from the original cancer shrank in about a quarter of cases. The positive effect lasted up to eight-and-a-half months.
But Keytruda is very expensive. Merck has set the price of the drug at more than $12,000 per month. A year’s worth of treatment with Keytruda adds up to around $150,000.