Federal health officials on Friday expanded approval of an innovative Merck drug to treat patients with an advanced form of the most common lung cancer.
The Food and Drug Administration approved Keytruda for advanced non-small cell lung cancer patients who have seen their tumors spread after taking other therapies.
Keytruda is part of a promising new class of drugs called immunotherapies, which harness the body's immune system to help fight cancer.
Immunotherapies, also called immuno-oncology drugs, have brought the first significant advances in patient survival - though generally not cures - in many years for some cancer types, particularly lung cancer and melanoma.