Adding radiation to immunotherapy has been shown to result in therapeutic synergy, according to Allison Campbell, MD, PhD, and colleagues from Yale School of Medicine and Salk Institute. 

The abscopal effect occurs when high dose radiation is given to those on immunotherapy, so that tumors not targeted by the radiation can shrink.

They explored whether adding high dose radiation to a single site of disease would reinvigorate an immune response in patients who have progressed on anti-PD-1 therapy.

Patients had at least two measurable sites of diseases. After patients progressed on immunotherapy, they were given high dose radiation in 3 or 5 fractions.

Responses occurred outside the radiation field. All responses were abscopal, Campbell said. 

Ten percent of patients had a partial response that lasted over one year. A partial response with stable disease was seen in 57% of patients.

Video Source: EurekAlert
Video Content: American Society for Radiation Oncology