New Approaches for Advanced Melanomaby Sunni Hosemann
Dr. Elizabeth Grimm (l) and Dr. Patrick Hwu discuss new avenues in melanoma research.
When a melanoma is found early and properly removed, the outlook is excellent. In fact, patients with early-stage melanoma can have survival rates as high as 95%. But for patients with melanoma that has metastasized, the disease is more deadly: the survival rate for patients with metastatic melanomas involving a major organ is no more than 6%—evidence that today’s clinicians have a challenge in finding ways to better manage advanced forms of the disease.
Currently, only two FDA-approved drugs exist for the treatment of metastatic melanoma: dacarbazine and interleukin (IL)-2. Dacarbazine is a conventional cytotoxic chemotherapy agent. According to Kevin Kim, M.D., an assistant professor in the Department of Melanoma Medical Oncology at The University of Texas M. D. Anderson Cancer Center, the rate of response to dacarbazine in metastatic melanoma is only about 10%, and it rarely produces a durable response. And although combination regimens that include dacarbazine have been investigated, none have improved survival more than dacarbazine alone.
On the other hand, IL-2, which works by stimulating killer T-cells to attack melanoma, produces a response in 15% to 20% of patients; in 7% to 8% of patients, the response is durable.
“We can essentially cure some patients with advanced disease using IL-2, but only a small minority of patients have this remarkable response. We want to know why,” said Patrick Hwu, M.D., professor and chair of the Department of Melanoma Medical Oncology. Knowing ahead of treatment who is likely to respond to IL-2 would spare the majority of patients with advanced melanoma from undergoing a treatment that can be toxic and must be delivered in the ICU. “Beyond that,” said Dr. Hwu, “if we can understand how it’s working, perhaps we can convert non-responders into responders.”
Clearly, other treatments are also needed for those who are unlikely to respond to either of these two agents, both of which are toxic and costly. To that end, investigators are pursuing several promising avenues.