Dr. Sartor: The next presentation I'm going to give is the PRESTO trial, and this is presented at ESMO 2022 by Rahul Aggarwal.
It is a Phase III open-label study of androgen, what's called annihilation, if you will, in those with high-risk, biochemically relapsed prostate cancer. These are individuals who had a radical prostatectomy and a short PSA doubling time, and we know that these individuals are at risk for metastatic disease, and the short doubling time definition here was less than or equal to nine months. And, of course, they had to have no evidence of metastases on conventional imaging. There was randomization, one to one to one, to get one year of therapy with ADT, or ADT plus apalutamide, or ADT plus apalutamide plus abiraterone. Patients were stratified for PSA double time of less than three months versus 3 to 9 and for follow-up.
So, what was looked at here was the prolongation about chemical relapse. In other words, the time till the PSA went up and the time till the testosterone would recover. I think, importantly, and we didn't really know this very well before, that the time to testosterone recovery is pretty much the same, whether or not you're using ADT alone, ADT plus apalutamide, ADT plus apalutamide plus abiraterone. So, not a lot of differences in the time to testosterone recovery. In fact, there's no significant differences. Now, it turns out that there is a longer period of time for the PSA to relapse if you have either the apalutamide or the apalutamide plus the abiraterone added. And it turns out that this is going to be right around 20 months for ADT alone and up to around 26 months if you're using either apalutamide or the combination therapies. It's actually 25 to 26. But there wasn't really a difference between apalutamide ADT versus ADT plus apalutamide plus abiraterone.
I was perhaps a little bit disappointed that we didn't get more. I was hoping to get maybe 40, 50% prolongation in the time to relapse, and that did not occur. The difference between 20, 25, 20, 26 is not a dramatic difference, and there was more toxicity when you added in the apalutamides and the apalutamides plus abiraterones. In particular, there was more hypertension and there were a few more patients who ended up stopping therapy as a consequence of the hormones that were used.
So, all in all, even though androgen annihilation sounds like a really good idea, and here was studied with a one-month interval, I don't think that these are dramatic practice-changing type results. Yes, there was a prolongation in the time period between ADT and ADT plus the apalutamide or apalutamide plus abiraterone, but it wasn't dramatic. It was really a prolongation of kind of five to six months for a year of treatment, which I did not think was that impressive myself. But who knows, maybe I'm not like everybody else. So, with that, that's a summary of the PRESTO trial and my interpretation of the results as presented by Rahul Aggarwal at ESMO 2022.