TAMPA — Several developments in the treatment of advanced melanoma announced in recent days extend life and represent important progress against the most deadly form of skin cancer. But they are still not the cure scientists and patients are hoping for.
When melanoma has spread beyond the skin, life expectancy usually is less than a year. This week, results were released on the clinical trials of two new drugs that extend survival — one gives patients an additional six months, the other more than 11 months, on average.
And last week, another study found that combining an investigational melanoma peptide vaccine with interleukin-2 extended survival by almost six months. The University of South Florida was among the test sites for that investigation.
All three studies were reported in the New England Journal of Medicine.
The American Cancer Society estimates that 68,720 new cases of melanoma will be diagnosed this year and about 8,700 Americans will die from the disease. Adding a few more months of life may not sound impressive to people unaffected by the disease. But for patients and families, it's huge, as it is for medical researchers.
"Those three approaches give better response rates than anything we have ever used," said Dr. Douglas Reintgen, professor of surgery and director of cancer initiatives at USF Health in Tampa.
"It's a stepping-stone for investigators and patients to see that hope is not lost in Stage 4 melanoma. Progress is being made."
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He noted that the FDA has approved only two drugs for treatment of Stage 4 melanoma, both of which are highly toxic and have limited benefit.
Until now, melanoma vaccine research has failed to produce a useful therapy. "This is the first vaccine that has shown some effectiveness," said Reintgen, who served as principal investigator at USF on the melanoma vaccine study conducted on 185 patients at 21 centers nationwide.
This is quite different from the vaccines against infectious disease we all get from infancy. The purpose is not to prevent melanoma from occurring in the first place, but to boost the body's ability to fight existing tumors.
In the study, which involved 10 patients at USF, participants were given either high-dose interleukin-2 and an experimental vaccine or interleukin-2 alone. Interleukin-2, currently the gold-standard treatment, boosts the immune system so it can recognize and kill melanoma cells. The vaccine "teaches'' the immune system to recognize a substance on melanoma cells and launch an even stronger attack against the cancer. It adds little toxicity to the interleukin-2 therapy, other than redness and swelling at the injection site.
Sixteen percent of patients nationwide who received the combination therapy responded to treatment, meaning their tumors shrank by more than half; only 6 percent of patients in the group that received just interleukin-2 had a similar response.
Interferon, given to most patients diagnosed with early-stage disease, comes with severe flulike symptoms, often leaving patients bed-bound during the monthlong course of treatment. Interleukin-2 can cause life-threatening bleeding in the lungs and brain and must be administered in the critical care unit of a hospital.
Reintgen expects to see FDA approval for the vaccine in a year or so. One of the two new drugs, vemurafenib, which targets a gene mutation found in about half of patients, is expected to be approved later this year. The other new drug, ipilimumab, which also stimulates the immune system, was FDA-approved in March.
Irene Maher can be reached at email@example.com.