New Drugs Unleash Immune System to Attack Tumors
Lung, Skin, Kidney Tumors Shrink in Early-Stage Trials
Immune Drugs: How They Work continued...
The PD-1 blocker also appears to have fewer side effects and greater anti-tumor activity than Yervoy, a different type of immune-system drug approved last year for the treatment of melanoma, says Antoni Ribas, MD. Ribas, a melanoma specialist at the University of California, Los Angeles, wrote an editorial accompanying the study in the New England Journal of Medicine.
The lung cancer results have doctors most -- albeit still cautiously -- enthused.
"This level of response in patients with advanced lung cancer, which is typically not responsive to immune-based therapies, was unexpected and notable," Brahmer says.
If the early results pan out, "this will be a game-changer for the treatment of lung cancer," says Louis Weiner, MD, director of Lombardi Comprehensive Cancer Center in Washington, D.C.
The study "really validates the importance of manipulating the immune response to eliminate cancer cells," he tells WebMD.
Although there have been some successes with immune-based therapies for melanoma and kidney cancer, this is the first time that lung cancer patients have been helped, says Weiner.
Immune Therapy Field Expanding
The anti-PD-L1 therapy was tested in about 200 patients. Tumors shrank in five of 49 (10%) non-small-cell lung cancer patients, nine of 52 (17%) melanoma patients, and two of 17 (12%) kidney cancer patients.
Nine percent of patients developed serious side effects, but none died from the treatment.
It's rare for such early-stage studies to be published in a major medical journal. Asked why she thought this research merited publication, Brahmer says, "Taken together, the studies show this pathway is important in cancer. We were able to block it in two different ways and get consistent results."
The researchers are now working to find molecular indicators that may help predict which patients are likely to be helped by the treatment and which will not.
Weiner says that the field of immunotherapy is expanding. Other companies are also developing PD-1 inhibitors. A number of companies are also working on cancer vaccines that retrain the immune system to attack tumors.
If the new drugs work and prove safe in later-stage studies, the hope is that combining them together, or with other anti-cancer agents, will further boost their effectiveness, Brahmer says.