A large-scale clinical trial has shown that a vaccine combined with the immune-boosting drug Interleukin-2 can improve both response rate and progression-free survival in patients with advanced melanoma, the most lethal type of skin cancer.
Therapeutic cancer vaccines, unlike typical vaccines that prevent infections, are meant to jump-start the immune system to help it battle existing tumors. This is the first vaccine study for melanoma — in fact, one of the first for any type of cancer — to show a clinical benefit.
The study findings, which were published in the June 2 New England Journal of Medicine, potentially represent a significant step forward for the treatment of not only melanoma, but other cancers as well, according to study co-investigator Howard Kaufman, MD, director of the Rush University Cancer Center.
"This trial is an early example of success with a cancer vaccine," Kaufman says. "If we can use the body's own defense system to attack tumor cells, we provide a mechanism for ridding the body of cancer without destroying healthy tissue."
The Results Are in — and They’re Promising
Rush investigators participated in the phase III trial, which compared the effectiveness of Interleukin-2 alone versus a combination of Interleukin-2 and a peptide vaccine, which is a small portion of protein that is present on the surface of the melanoma cancer cells. Interleukin-2 is already FDA-approved to treat both metastatic melanoma and kidney cancer.
The peptide vaccine works by stimulating the patient's T-cells, which are known for controlling immune responses, to secrete enzymes that seek out and destroy the cancer cell's membrane. Interleuken-2 enhances the vaccine's effectiveness by stimulating the production of lymphocytes, a type of white blood cell that circulates throughout the body. More circulating lymphocytes means there are more cells available to do the job the vaccine has educated them to do.
The potent vaccine and Interleuken-2 combination yielded a more positive response than the drug alone. About 16 percent of study participants saw tumors shrink by 50 percent or more, compared to 6 percent given Interleukin-2 alone. Those in the combination group also had slightly longer progression-free survival rates of 2.2 months compared to 1.6 months, which means those participants had more time in which the tumor did not grow. They also lived an average of nearly seven months longer than those only given Interleukin-2.
Researchers will use these study results as a jumping-off point: The next step is to improve the vaccine's effectiveness by combining it with other immune-stimulatory agents, such as adjuvants, other cytokines and antibodies, that further activate the body's immune cells.
Kaufman says the vaccine, if eventually approved by the FDA, would be relatively inexpensive because it is based on a protein that's present in most melanoma cancers, whereas other vaccines have had to be created for each individual patient and could not, therefore, be produced en masse.
More Information at Your Fingertips ...
- Read this story from a past issue of Discover Rush Online about nilotnib, a promising targeted therapy for metastatic melanoma.
- Learn about how using tanning beds increases a person’s risk of melanoma on the Rush News Blog.
- In these videos, Howard Kaufman, MD, director of the Rush University Cancer Center, discusses how to detect skin cancer, what to look for, how skin cancer is treated, and what you can do to reduce your risk of getting skin cancer.
- Looking for a doctor? Call toll free: (888) 352-RUSH (7874).
- Stay in touch with Rush with the Rush News Blog, Rush InPerson, Facebook, Twitter and YouTube.
Please note: All physicians featured in Discover Rush Online are on the medical faculty of Rush University Medical Center. Some of the physicians featured are in private practice and, as independent practitioners, are not agents or employees of Rush University Medical Center.
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