Compared to patients treated only with chemotherapy, the combination of an immunotherapy drug and chemotherapy almost doubled the survival time for some lung cancer patients, according to a study published in The New England Journal of Medicine.
The study results only apply to patients whose lung cancer does not start in the surface lung cell layer, or squamous cells, and who also do not have certain genetic mutations. "Non-small cell lung cancer is actually the leading cause of cancer death in the world even though it's not the most common cancer," lead study investigator Leena Gandhi, MD, told CNN.
The reason non-small cell lung cancer is the leading cause of cancer death is because the existing chemotherapy drugs provide only limited survival benefits for patients, Dr. Gandhi said. "A matter of months, not years," she said.
For patients who have already been treated with chemotherapy, immunotherapy, which uses the body's immune system to fight off tumors, is known to improve these patients' survival rates. In leading this study, Dr. Gandhi aimed to determine whether using immunotherapy earlier in treatment, combined with chemotherapy, would do more for patients.
The study, which tested treatment effectiveness and side effects, included 616 patients at 118 medical facilities across the world. One group of 400 patients received standard chemotherapy and the immunotherapy drug pembrolizumab, while a smaller group of patients received chemotherapy.
Combining standard chemotherapy with pembrolizumab was "superior in terms of response — keeping people alive without progression of their cancer — and improving the overall survival of patients with metastatic lung cancer compared to chemotherapy alone," Dr. Gandhi said. "And the differences were not small."
For patients who received the combined therapy, the chance of death or progression of their cancer was reduced by 48 percent compared to the patients who only received chemotherapy.
For non-squamous non-small cell lung cancer patients, median survival with chemotherapy alone is approximately 11 or 12 months, said Jorge Gomez, MD, volunteer spokesperson for the American Lung Association and medical oncologist and director of thoracic oncology at New York City-based Mount Sinai Hospital, who was not involved in the study.
But the median survival among the study participants who received both immunotherapy and chemo has yet to be reached. "It's already been 21 months," Dr. Gomez said. "The differences are big enough now that you know it's going to be a very big number and it's important to get this information to people so they can start using this regimen."
Dr. Gomez thinks the survival rate could be as high as double chemotherapy alone, "which would be very impressive," he said. "I only treat lung cancer and I've been doing that for about 20 years. These drugs are very, very interesting. Now, not everybody benefits unfortunately, but some of the people who benefit seem to benefit in a way we've never seen."