June 19, 2008 -- Melanoma researchers may have saved a patient's life with an experimental immune system treatment that used the patient's own cells.
That patient was a 52-year-old man with recurrent melanoma that had spread to a lung and to a groin lymph node. After getting the experimental treatment, his melanoma disappeared and didn't come back during the next two years.
Since then, "we're in touch with him indirectly through his doctor," researcher Cassian Yee, MD, tells WebMD. "As far as I know, he's still doing well without any symptoms."
But the treatment isn't ready for widespread use yet, and it's not a cure, says Yee, who works at Seattle's Fred Hutchinson Cancer Research Center.
"This is just a small step," Yee says. "There are many other immunotherapy treatments that we're not doing, that other people are doing, that probably deserve more attention."
Still, Yee's team has shown that its basic idea for fighting melanoma might work.
Experimental Melanoma Treatment
Yee and colleagues hunted for special immune system cells called CD4+ T cells in a blood sample provided by the melanoma patient. Specifically, the scientists looked for CD4+ T-cells that targeted the man's melanoma.
The researchers isolated those cells and cloned them in their lab over several months, and then infused 5 billion of the cloned CD4+ T-cells back into the patient.
"What we and others have thought might be important is that we need to give patients more of these cancer-fighting T cells which may be present in low frequency in most people," Yee says. "You can do that either by giving them a vaccine or, in our case, we took the cells out and grew them and gave them back to him."
That may sound simple, but it's complex work.
"It's taken us many years to get to this point," Yee says. "Hopefully, we'll eventually streamline the process a bit, but it's not something most labs do."
No side effects were seen. Details of the melanoma patient's case appear in The New England Journal of Medicine.
But Yee points out that his team has tried the same T cell approach on eight other patients, none of whom has had the same success.
"There are some responses in the other patients, but not nearly as good as this one individual," Yee says. "I cannot tell you right now why that's the case."
"We are hoping to expand this study, but because it's very expensive and it takes several months to grow the T cells, only a very, very small number of patients would be eligible for the trial," Yee says. "We have far more requests than we can handle and so we are primarily interested in seeing what the next step might be in improving therapy."
An editorial published with the report calls the melanoma patient's case "remarkable" but cautions that "this type of approach will not always work" because cancers try many different tactics to defeat the immune system.
T-cell therapy is "promising," but there are "many other examples of effective cancer immunotherapy," writes editorialist Louis M. Weiner, MD, director of Georgetown University's Lombardi Comprehensive Cancer Center.
Does the melanoma patient's recovery "represent a mirage, an oasis, or an early sighting of the destination? Time will tell, but I suspect that if the destination is not yet at hand, it is in sight," Weiner writes.