Understanding patient populations in studies of PSMA agents in prostate cancer

In this video, Brian F. Chapin, MD, discusses the importance of understanding patient populations in trials of PSMA agents in prostate cancer. Chapin is an associate professor of urology at the University of Texas MD Anderson Cancer Center in Houston.

Transcription:

Is there anything else you would like to add regarding the FDA approval of flotufolastat F 18 in prostate cancer?

What's really important is you can't compare these tracers to one another, particularly across the trials that exist, but what you can do is have a true understanding of the population at hand. And I think when you look at the studies that have been done of the various PSMA tracers, they're different, and they're different in several contexts. They're different in which patients are being evaluated, whether it be unfavorable intermediate high risk, or very high risk, what proportion of the patients are in each of those studies? I think one of the key things is when we look at things like sensitivity and specificity, sensitivity is very much reliant on the incidence of a disease or the state of the disease. And when we look some of these studies, in some of them, the majority of the patients are conventional imaging negative, and in others, a high proportion of patients are conventional imaging positive but then still went on to the PET scan tracers and on to these subsequent evaluations, and I think it's really critical that we actually know the cohort of patients we're evaluating when we're looking at these because people will, just by instinct, try to compare across studies, but really, the populations are quite different. I think it's critical that we understand that when we're trying to evaluate the use of these tracers. One of the things that the rh PMA potentially has an advantage over some of the other tracers is that there is some decreased urinary excretion of the tracer and so the difficulties that we sometimes run into trying to identify disease at, let's say, the anastomosis after a prostatectomy in the biochemically recurrent setting, if there's high bladder tracer detected, then sometimes it's difficult to identify those lesions. So it's something that I think the company has spoken about quite a bit and I think in the experience that we have and as we go forward is that the various institutions that start using both of these agents or multiple agents are able to look at them, we might have a better idea of what the differences are and where certain tracers may work better than others.

This transcript was edited for clarity.