Wolfgang, thanks so much for joining us on UroToday.
Wolfgang Fendler: Thank you very much. It's a pleasure to be here.
Zachary Klaassen: So, based on all that work, just give us the genesis and the background for where PPP3 came from.
Wolfgang Fendler: So, PPP3 really is a nomogram, a predictive nomogram of over-survival of outcome of prostate cancer. And this really comes from, is fed by, readouts from PSMA PET, this novel PSMA imaging test in patients with prostate cancer. It basically reads out results from PSMA PET in a standardized fashion, puts these into a small nomogram and the nomogram will then predict three, five, and seven years over-survival. And it can do that in all stages. So, starting from initial stage up to the metastatic advanced stage of prostate cancer.
Zachary Klaassen: That's fantastic. So, the external validation study you guys presented at ASCO this week, just tell us about the study design and some of those key results from that validation.
Wolfgang Fendler: It's really important for us that this nomogram works across the board, across countries, in different scenarios. So, it's really key to validate those findings.
At ASCO, we present another update, another external validation, on 2,000 patients that have been collected internationally from different institutions. We applied the nomogram on those patients that have never seen the nomogram before and we could confirm that there's a significant separation, there's a significant prediction of over-survival outcomes up to seven years, in this external validation cohort.
I think it's important to note that there was a previous external validation already on board with the first publication, which were around three to 4,000 patients, but it's important for us to revalidate and that's what we have done at ASCO.
Zachary Klaassen: That's great. And so what do those validation numbers look like?
Wolfgang Fendler: The initial validation was the C-index. The so-called concordance was 84% on the initial external validation. And on ASCO, we present a secondary validation cohort that has a little bit higher risk so they are at the upper end of the spectrum in terms of over-survival, more advanced disease. So, the C-index here was more than 70% but was not as high as with the initial publication. It's still significant and it's still good to see that it really upholds. It still delivers good prognosis for those patients even with a higher risk index.
Zachary Klaassen: Excellent. Have you guys looked at different PSMA PET agents? Like say, gallium versus other agents available? Have you guys looked at some of that data, as well?
Wolfgang Fendler: Absolutely. It's very important to constantly look into the different types of PET.
Zachary Klaassen: Sure.
Wolfgang Fendler: We've constantly analyzed also in the initial Lancet oncology publication subgroup analysis of gallium versus F18 PET compounds. And we have luckily found that there's no difference between the different types of PETs. So, these PETs are all very, very sensitive. They deliver very similar information. They have some specific detailed differences, but they're not relevant in terms of outcome prediction.
Zachary Klaassen: Right.
Wolfgang Fendler: So, it really works for F18, but also gallium and I suppose all the other PSMA traces, as well.
Zachary Klaassen: That's great. I guess the question is, you have such good data, C-index of 0.84, where do you guys go from here with PPP3?
Wolfgang Fendler: I think now it's important to make it available, to make it usable.
Zachary Klaassen: Sure.
Wolfgang Fendler: That's why we have offered an online tool that can calculate outcomes based on PPP3. By just imputing the results from PSMA PET, it will give an output of over-survival prediction. This can be used in research settings now.
Zachary Klaassen: Sure.
Wolfgang Fendler: We will further explore whether this can be translated into an official clinical application. And we have also simplified the nomogram to a very simple table that you can just print and that you can use in your daily clinical practice. I think it's now important to really include this in the clinic and in clinical discussions, but also to make this available for guidelines to improve management guidance.
Zachary Klaassen: Fantastic. Great conversation. Anything we haven't hit on that you want to discuss? Any take-home messages for our listeners?
Wolfgang Fendler: I think it's very important to note that there are new tools based on PSMA PET for outcome prediction. I think they're very novel, but I think it's now time to use those to implement them in prospective clinical trials and also in the guidelines. And in the end, they have a predictive power that are beyond our current conventional nomograms and they might really help us to improve our clinical care.
Zachary Klaassen: Excellent. Congratulations on the great work and thanks for joining us on UroToday.
Wolfgang Fendler: Thank you very much.