Immunotherapy drug Keytruda Tops Chemo in Lung Cancer Study

Credit: wsj.com

Researches have stopped a study of Keytruda (pembrolizumab) the immunotherapy drug that former president Jimmy Carter says helped stop the progression of his advanced melanoma, because the medication is so effective that they want to offer it to all the patients in the trial. The study, named KEYNOTE-024, tested Keytruda against a standard platinum-based chemotherapy in 305 lung cancer patients who had not yet been treated for their disease. Merck, the company that makes the drug, says it helped slow the spread of the patients’ tumors and helped them live longer overall.

The study was stopped on the recommendation of an independent committee, which has not yet shared details about the results. However, Dr. Pasl Janne, a lung cancer specialist at Harvard Medical School and Dana-Farber Cancer Institute, said in a statement to NBC News that he suspects the data was “significant enough that this will be a practice-changing finding.” Dr. Roger Perimutter, president of Merck Research Laboratories, added that the company looks forward to “sharing these data with the medical community and with regularity authorities around the world.”

Immunotherapy differs from standard chemotherapy in that it mobilizes the body’s own T-cells to fight cancer cells. Normally, T-cells fight cancer in part through the action of genes called anti-programmed-death-receptor-1 (PD -1) and PD-L1. But when cancer cells take control of the PD-1 pathway, they can “hide” from T-cells, preventing them from doing their job. Keytruda works by targeting the abnormal PD-1/PD-L1 proteins, thus allowing the immune system to function as it should. About 25 percent of lung cancers are associated with the PD-1/L1 abnormality, according to Dr. Natalie Azar, a contributor to NBC News.

Keytruda is generally less toxic than standard chemotherapy, but it can have serious side effects. The major risk is that it can cause the immune system to attack healthy organs and tissues, particularly the lung, colon, liver, kidneys, endocrine system and brain.

Keytruda is currently approved only as second-line treatment for patients with metastatic non-small cell lung cancer whose disease has advanced after other treatments have been tried.  However, based on the results of the study, Merck plans to ask the Food and Drug Administration to make the drug available to patients who have not been treated yet.