April 17 (UPI) -- Combining the immunotherapy drug pembrolizumab with chemotherapy doubled survival in patients with some forms of lung cancer compared with chemo alone, according to an international Phase III clinical trial.
Researchers found the promising results for participants whose lung cancer does not begin in the squamous cells -- the surface lung cell layer -- and who also lack certain genetic mutations.
The findings were presented Monday at the American Association for Cancer Research Annual Meeting 2018 in Chicago and published in the New England Journal of Medicine.
Lung cancer is the leading cause of cancer death in the United States with an estimated 156,000 deaths each year, according to the American Cancer Society.
The mortality rate in non-small cell lung cancer is high because, in most cases, the cancer has already spread at the time of diagnosis. Small cell lung cancer is less common than non-small cell lung cancer, which affects up to 85 percent of all lung cancer patients, according to the American Cancer Society.
Non-small cell lung cancer occurs mainly smokers, even those who quit, but is also the leading type of lung cancer occurring in non-smokers.
The combination of pembrolizumab, manufactured by Merck and marketed as Keytruda, with chemotherapy has been approved by the Federal Drug Administration to treat these patients, based on a previous phase II trial.
"The data show that treatment with pembrolizumab and chemotherapy together is more effective than chemotherapy alone," Dr. Leena Gandhi, director of the thoracic medical oncology program at Perlmutter Cancer Center at NYU Langone Health and a lead investigator on the previous phase II trial, said in a press release. "Using this combination therapy to treat patients with such an aggressive disease could be an important advance in keeping patients alive and well for longer."
In the study, 616 adults with untreated, metastatic NSNSCLC without EGFR or ALK alterations at 118 international sites were randomly recruited for the trial between February 2016 and March 2017.
A total of 405 patients were treated with both pembrolizumab and platinum plus pemetrexed, and 202 received platinum plus pemetrexed with a saline placebo. The median age of participants was the mid-60s.
With the combo, the risk of death was reduced by 51 percent compared with chemo alone after a followup of 10.5 months. Participants treated with the combination therapy also had 48 percent reduction in progression or death.
Among both groups, the risk of severe side effects was similar -- 67.2 percent in the combination and 65.8 percent with just chemo. However, the risk of acute kidney injury risk with the combination treatment was higher at 5.2 percent, compared to chemo at 0.5 percent. Nausea, anemia and fatigue were the most common side effects experienced by participants.
"Although some non-small cell lung cancer patients have increased benefit of targeted therapy or immunotherapy instead of chemotherapy, for some groups of patients with NSNSCLC, chemotherapy has been the standard treatment for more than 30 years," Gandhi said. "But for patients with NSNSLC without EGFR or ALK alterations, this study may suggest a new standard of care."