FAIRLESS HILLS, PA. (AP) — U.S. regulators have approved the first medicine for patients with the most common type of lung cancer whose tumors have a genetic mutation long considered untreatable with drugs. The Food and Drug Administration on Friday said it’s approved Amgen’s drug Lumakras for non-small cell lung cancer patients with the mutation whose cancer worsened after initial treatment with different drugs. This is the first targeted therapy for tumors with a so-called KRAS mutation, which affects cell growth and division, and is found in many cancer types.