Lung Cancer Drug Could Be 'Game-Changer' Roche drug more effective on smokers than non-smokers: study By Evann Gastaldo, Newser Staff Posted Sep 30, 2013 9:43 AM CDT 15 comments Comments (Shutterstock) (Newser) – An experimental drug is actually more effective against lung cancer in patients who smoke than those who never have, Reuters reports. MPDL3280A, a Roche drug, is "great news for lung cancer patients," who are notoriously difficult to treat, researchers say; one oncologist says early-stage trials suggest it is "definitely a game-changer." In 53 patients with non-small cell lung cancer (NSCLC) tumors, 23% saw their tumors get smaller. But 26% of smokers saw their tumors respond, compared to just 10% of those who had never smoked. "Bingo, this is the first targeted agent (drug) that shows more activity in smokers than in non-smokers," says the lead researcher. Why? The drug targets PD-L1, a protein that tumors use to manipulate T-cells in the immune system. The cells go inactive, and the tumors grow. MPDL3280A, an engineered antibody, blocks PD-L1; the T-cells awaken, grow, and multiply as they attack the cancer. The drug worked best on patients with higher levels of PD-L1, Bloomberg reports. Smokers have more genetic mutations in their tumors than non-smokers, and researchers think that's why their immune systems might respond more vigorously. Merck and Bristol-Myers Squibb are working on similar immunotherapy drugs, and Roche is looking into the possibility that its drug could treat other cancers.