The combination of radiation therapy and two immunotherapies may be optimal for treating metastatic melanoma, according to research published online March 9 in Nature.
A multidisciplinary team from the University of Pennsylvania found in a phase I trial that the combination of radiation therapy and ipilimumab (an antibody that targets CLTA-4) was safe and shrank tumors in 18% of 22 metastatic melanoma patients. Meanwhile, a concurrent study on mice suggested that an antibody that targets PD-L1 or its partner PD-1 is an ideal third treatment to improve response and immunity, according to the group.
The PD-L1 pathway was found in many of the patients whose cancer had progressed despite the treatment. Antibodies that block the PD-L1 pathway, which cancer cells use to hide from the immune system, include pembrolizumab or nivolumab.
The group is now working to start clinical trials of the three-treatment combination in other tumors such as pancreatic, lung, and breast.
