Medicine Matters oncology

Hi. I'm Hans Hammers. I'm a medical oncologist from UT Southwestern, and I'm here to talk about the Radvax study. I think we've been having some romanticism for a long time with the so-called abscopal effect-- that is, if you radiate a tumor and apply it in the context of immunotherapy, maybe you can see an increased response rate outside of the radiation field.

So Radvax is a small study, but it was designed in a fairly stringent way, that we took, at the time, the most potent immunotherapy there is, i.e. the combination of a CTLA-4 and PD-1 inhibitor - nivolumab and ipilimumab, and combined it with really definitive radiation, stereotactic radiation, 5 times 10 Gy, really designed to almost optimally lead to androgen release, but also potentially stimulate the STING pathway.

Small study, 25 patients, but we think we saw a signal of an increased activity, with a response rate in 56% of patients. The study will be complemented by subsequent future studies, where we will do PD-L1 PET imaging of the whole tumor bulk, and then radiate the coldest tumors, and follow them-- how they may get inflamed, if you will, over the treatment course. So I think it's an interesting finding.

This will be contrasted by the NIVES study, which is in the context of nivolumab monotherapy, where they delivered a lower dose of radiation, which has PD-1 inhibition, and they did not see an increase in response rates. So the questions are, do we need the CTLA-4 component? Do we need a more aggressive radiation approach?

But I think there is enough signal on Radvax to potentially evaluate further. It has limitations. It's a small study-- 25 patients, single-center study really. All patients were recruited at UT Southwestern, but we're excited, and we will move this forward.