Neeraj Agarwal: Hi. My name is Dr. Neeraj Agarwal. I'm a professor of Medicine and director of the Genitourinary Oncology Program at the Huntsman Cancer Institute, University of Utah. Today, I'm very pleased to welcome Dr. Zeynep Ozay, also from Huntsman Cancer Institute, who is presenting her data on comparative effectiveness of PLUVICTO or lutetium-177 versus cabazitaxel in patients with metastatic castration-resistant prostate cancer.

So, Zeynep, first of all, congratulations on your presentation. And thank you for being here.

Zeynep Ozay: Thank you so much, Dr. Agarwal. It's an honor to be here.

Neeraj Agarwal: So tell me, what kind of database did you use? To begin with. And then we can talk about the number of patients and then findings. So what was this database you used for your analysis?

Zeynep Ozay: So in our study, we used the nationwide Flatiron database. This database collects data from over 200 cancer centers in the US. And in our database, we had over 24,000 patients with prostate cancer. And in our analysis, we included 1,445 patients with mCRPC, who had progression on ARPI and docetaxel.

Neeraj Agarwal: It's a large number of patients. That's the size of a phase III trial. So you have more than 1,400 patients, who either received cabazitaxel or PLUVICTO, is that correct?

Zeynep Ozay: Yes, that's right.

Neeraj Agarwal: Yeah. And what did you find?

Zeynep Ozay: So yeah, in our study, as I said, we included more than 1,400 patients with metastatic castration-resistant prostate cancer. And these patients had progression on ARPIs and docetaxel. And then in our study, over 200 patients were treated with lutetium, and over 1,200 patients were treated with cabazitaxel.

Our endpoints were real-world time to next therapy, or TTNT, and real-world overall survival. And we did this comprehensive propensity score matching to balance differences between these two groups. And our study has shown that patients treated with lutetium had significantly better outcomes compared to patients treated with cabazitaxel.

Specifically, median real-world TTNT was 8.3 months with lutetium and 4.7 months with cabazitaxel. Regarding overall survival data, we saw that patients who were treated with lutetium had an overall survival of 10.3 months, compared to patients who were treated with cabazitaxel. Those patients had an overall survival of 8.8 months. And all of these differences were statistically significant.

Neeraj Agarwal: So just for our viewers' recollection, out of this 1,400 patients, about 200 had lutetium therapy, and 1,200 of these patients had cabazitaxel chemotherapy. And progression-free survival was almost doubled. And by the way, progression-free survival in the Flatiron database is indirectly assessed by time to next therapy.

So just to make it clear, that you are looking for time to next therapy. And it was eight months for lutetium and four months for cabazitaxel. And even overall survival, it looks like lutetium seems to be doing better with a 10-month overall survival, which is about eight-month overall survival with cabazitaxel. Why is it possible that there could be a selection bias, which was not measured by the excellent statisticians you're working with?

Zeynep Ozay: Yeah, that's possible. First of all, this was a retrospective study. We used real-world data. And there was a lot of missingness in our database. For example, we did not assess PSMA PET-CT results. We didn't have PSA response rates. We didn't compare PSA responses. There could be a selection bias in our study. And the other potential biases--

Neeraj Agarwal: Unknown biases.

Zeynep Ozay: --unknown biases with real-world database.

Neeraj Agarwal: Absolutely. I still think these data inform or help our practice. We have the TheraP trial reported from Australia, great investigators, showing that responses and progression-free survival were better with lutetium. I think it's nice to see the results being validated in real-world data sets.

Zeynep Ozay: I agree. The TheraP trial included patients with mCRPC, who had progression on ARPIs and docetaxel, similar to our study. But they included patients with PSMA-positive disease—that's different between our study. But as you mentioned, the TheraP study showed better PSA response and better progression-free survival with lutetium. But overall survival did not seem to fit--

Neeraj Agarwal: Yeah, it was covered--

Zeynep Ozay: Yeah.

Neeraj Agarwal: --for overall survival. That's great. Well, congratulations again. I'm so glad you could make time to come here and join us today.

Zeynep Ozay: Thank you so much, Dr. Agarwal, for having me.