At the 2016 American Association for Cancer Research annual meeting today, scientists presented their results of a follow-up study tracking the survival of metastatic melanoma patients who were treated with the immunotherapy drug nivolumab. The drug is currently approved by the U.S. Food and Drug Administration for advanced lung and kidney cancers and advanced melanomas.
Results published in 2014, by a group led by Suzanne Topalian, M.D. professor at the Johns Hopkins Kimmel Cancer Center and associate director for the Bloomberg~Kimmel Institute for Cancer Immunotherapy, showed the first hints that nivolumab could produce lasting, increased survival among patients with metastatic melanoma.
Today’s presentation, also co-authored by Topalian, shows an overall survival rate of 34 percent after four and five years among 107 patients with advanced melanoma who were treated with nivolumab. Typically, the relative five-year survival rate of patients with metastatic melanoma is approximately 16 percent. In other research, long-term survival rates of metastatic melanoma patients who received another type of immunotherapy drug, called ipilimumab, were reported as approximately 21 percent.
Nivolumab aims not to kill cancer cells directly, but to block a pathway that shields tumor cells from immune system components that are potentially able and poised to fight cancer. The pathway includes two proteins called programmed death-1 (PD-1), expressed on the surface of immune cells, and programmed death ligand-1 (PD-L1), expressed on cancer cells. When PD-1 and PD-L1 join together, they form a biochemical shield protecting tumor cells from being destroyed by the immune system.
“This is the longest follow up for any anti-PD-1/PD-L1 trial,” says Topalian. “We’re encouraged by the long-term survival data. Our next steps are to find ways to combine immunotherapy with other treatments to push survival rates even higher, and continue studying the biology of tumors to learn why certain patients with cancer respond to immunotherapy and others do not.”