The results of a phase 3 clinical trial published Wednesday in the New England Journal of Medicine showed that the treatment, which uses a superconcentrated boost of the person's own immune cells, was more effective than the leading existing treatment at putting patients into remission.“These are immune cells that are found in the tumor, trying to kill the tumor, but obviously not doing a good enough job because the tumor is growing,” said Dr. Patrick Hwu, the president and CEO of the Moffitt Cancer Center in Tampa, Florida.In addition to the infusion of the billions of TILs, patients are also given interleukin-2, which is a growth factor that supports the new cells and helps them proliferate, he said.TIL therapy isn't commercially available yet, although the Moffitt Cancer Center is one of several research institutions that have been working with Iovance Biotherapeutics, a California-based biotech company that’s on track to apply for Food and Drug Administration approval for its TIL therapy product.Improvements in melanoma treatments Melanoma is the most dangerous form of skin cancer, and for decades, metastatic melanoma — which means cancer that has has spread to other parts of the body — was considered a death sentence."