Drugmaker Merck & Co. says it will advance a new cancer drug into bigger patient tests, after promising findings in an early study against a very aggressive, common type of breast cancer.
Merck says its Keytruda (KEE'truh-duh) shrank tumors in one-third of patients, all of whom had triple-negative breast cancer that had spread. Most had worsened after multiple rounds of chemotherapy and other treatments.
The drug is in a hot new class of medicines, mostly still experimental, called immuno-oncology drugs. They harness the body's immune system to fight cancer.
Merck, based in Whitehouse Station, New Jersey, says it will start mid-stage patient tests of Keytruda in the first half of 2015. It's received accelerated approval for advanced melanoma and is being tested against five other cancer types besides breast cancer.