Amgen Shows Strong Results for Melanoma Treatment, but Is It Enough?
Biotechnological firm Amgen has announced strong results for its new treatment of melanoma, the deadliest form of skin cancer. For the first time, the use of a virus to kill cancer has succeeded in a late-stage clinical trial. However, many experts in the field say that the news may not be something about which people should cheer.
The trial used a pioneering treatment, called talimogene laherparepvec or TVEC, according to the New York Times. The virus is the herpes simplex 1 virus, the same form that causes cold sores. The virus has been modified to reproduce only in cancer cells, not in healthy ones, and contains a gene called GM-CSF that stimulates the immune system. When the virus is inserted into a melanoma tumor, it replicates, causing the cancerous cell to burst. That, in turn, releases the virus and the GM-CSF gene, which triggers an immune response.
The late-stage trial took place over six months and involved 400 patients. The treatment shrank the tumors completely or partially in 16 percent of patients. In patients who simply received an injection of the GM-CSF gene, that occurred in only two percent of patients. It seems that the virus may help people live longer, but that difference is not yet statistically significant, Forbes reports. However, Amgen says that may change later this year.
The study is considered a success in the fight against melanoma. In a statement, Amgen says that melanoma is responsible for just five percent of skin cancer cases, but 75 percent of skin cancer deaths. Still, Dr. Antoni Ribas, who specializes in melanoma at the University of California, Los Angeles, says that there may not be reason to cheer yet. He claims that TVEC may not be that successful as a drug for a number of reasons.
First, only one-third of people with the aggressive cancer have a tumor on or near their skin in a location where it can be injected. Most patients have had the tumor spread to hard-to-reach places like the liver and the brain.
In addition, there have been many new advances against melanoma in recent years, with two new promising drugs approved in 2011. The landscape, he says, has shifted in a way that raises the expectations for treatment.