Radiosurgery Plus Immunotherapy in Patients With Brain Metastases From Melanoma
Posted: Wednesday, August 8, 2018
Pairing immunotherapy with radiosurgery in patients with brain metastases associated with melanoma may be advantageous, according to research recently published in the Journal of Neuro-Oncology. The study, conducted by Tyler Robin, MD, PhD, of the University of Colorado Cancer Center, and colleagues, analyzed the survival outcomes of patients receiving treatment from immune checkpoint inhibitors in addition to Gamma Knife radiosurgery. In addition, new brain metastases developed at a median of 3.1 months with anti–CTLA-4 immunotherapies compared with a median that was not reached with anti–PD-1 immunotherapies.
“Big studies have shown a dramatic increase in survival for melanoma patients with brain metastases, and our study hints at one possible reason why: There may be an underlying synergy between these therapies,” shared Dr. Robin, referring to combination immunotherapy and radiosurgery, in a press release from Colorado Cancer Blogs.
The researchers retrospectively analyzed the outcomes of the combination therapy in 38 patients with melanoma brain metastases. All patients began treatment with immune checkpoint inhibitors within 8 weeks of undergoing Gamma Knife radiosurgery sometime between 2012 and 2017. At a median follow-up of 31.6 months, the median progression-free survival was 3.4 months. The median overall survival was not reached due to the large percentage of patients still living when the study results were analyzed.
In the study population, 25 patients received anti–CTLA-4 immunotherapy and 13 received anti–PD-1 with or without anti–CTLA-4 immunotherapy. Overall, the latter group experienced significantly improved results, including comparative progression-free survival of 20.3 months versus 2.4 months. The study also analyzed the safety of combining immune checkpoint inhibitors and radiosurgery treatments. A total of six patients developed adverse reactions during the study, all of which were considered central nervous system toxicities of at least a grade 2.