A man with metastatic melanoma, who was predicted to live four months, has lived for three years and is still in remission, following an experimental treatment for the deadly skin cancer, a new study reports.
The findings suggest giving melanoma patients an extra dose of their own tumor-fighting cells may be a way to combat the disease. However, the treatment is far from being considered a cure — the other 10 patients in the study showed either a short-term benefit or none at all.
The treatment involves extracting from a patient the immune system cells that can fight cancer, making billions of copies of them in a lab, then transferring them back into the patient.
A 57-year old man experienced complete disease remission, the researchers said. Another four patients experienced a stall in the progression of their disease. All of the patients had previously not responded to traditional treatments.
Of the patients who had their melanoma stall, all eventually saw their disease progress again within 12 to 19 weeks of the therapy, the researchers said.
The differences in the patients' responses likely had to do with how long the cancer-fighting cells, known as cytotoxic T-cells, last in the body. The longer they stick around, the better. In fact, in the patient who remains in remission today, the T cells persisted for 18 months, while in other patients, they persisted for less than a month, Yee said.
The researchers are now looking for ways to manipulate these cells so that they persist longer in the body, for more patients. It may also be possible to boost the patients' responses with drugs or vaccines, said study researcher Dr. Cassian Yee, of the Fred Hutchinson Cancer Research Center in Seattle.
The study, which will be published online this week in the journal Proceedings of the National Academy of Sciences, is not the first to report cancer remission in a melanoma patient following treatment with tumor-fighting cells. A small number of remission cases have been previously reported. However, those cases tended to involve the use of more toxic treatment regimens.
Melanoma is the most deadly form of skin cancer. People with metastatic melanoma, whose cancer has spread to other organs, typically live about eight months, and those included in the study were expected to live four months or less, Yee said.
The researchers screened the patients' blood to identify T-cells that attack and kill melanoma cells. These cells exist naturally in melanoma cancer patients, but in very low amounts.
To further increase the number of T-cells in the body after the treatment, all patients received high doses of the chemotherapy drug cyclophosphamide prior to their T-cell infusion, and were also given growth factors, which promote cell growth.
Eight patients were given low doses of growth factors, and three patients were given high doses. While the low doses were well-tolerated, the high doses were found to be toxic, and the therapy for these patients had to be interrupted.
"I think it's incredible," Dr. Michele Green, a dermatologist at Lenox Hill Hospital in New York City, said of the findings. "It’s the most optimistic news on melanoma I've seen in a really long time," Green said.
The fact that even one patient had remission of this usually terminal disease shows tremendous promise, Green said.
Unlike chemotherapy, which aims at killing all rapidly dividing cells, the T- cells specifically target the cancer, Green said.
However, this therapy still has kinks that need working out, and a treatment for melanoma or other cancer types may be years away, Green said.
Pass it on:Increasing the supply of a patient's own tumor-fighting cells may help treat melanoma.