Neeraj Agarwal: Hello, my name is Dr. Neeraj Agarwal. I'm a professor of medicine and director of Genitourinary Oncology Program at the Huntsman Cancer Institute at the University of Utah in Salt Lake City. I'm so pleased to welcome Dr. Nobuaki Matsubara, a medical oncologist at the National Cancer Center Hospital in Japan. Welcome, Nobuaki.

Nobuaki Matsubara: Thank you very much, Agarwal. So I'm happy to join UroToday.

Neeraj Agarwal: Yeah. Thank you for taking the time. And first of all, I'd like to congratulate you for presenting your data in the ASCO 2025 meeting on the health-related quality of life, as reported by the patients from the TALAPRO-2 Phase III trial. Could you tell us more about your data and the results?

Nobuaki Matsubara: Yes, thank you very much, Agarwal. So we have already reported and published our first analysis of the PRO data from TALAPRO-2. Today, so in this ASCO, I reported a final PRO result. So at the time of the final OS result. So in this report, we can confirm the PRO still remained compared to the enzalutamide monotherapy. So there is no significant deterioration on the PRO data.

Neeraj Agarwal: So even though patients were receiving one additional drug, talazoparib. So patients on enzalutamide plus talazoparib were on two medications. On the other side, patients were receiving enzalutamide plus placebo. So they were on one medication. And still there was no detrimental effect on the quality of life as reported by the patients. That is quite meaningful to our patients when their outcomes were improving.

We saw significantly improved radiographic progression-free survival benefit. We saw significant overall survival benefit in all-comer mCRPC patient population, and in those patients with newly diagnosed mCRPC who had homologous recombination repair mutations. So while they were experiencing improved PFS and rPFS, or OS, there was no detriment in the quality of life. Is that correct? How did you measure quality of life?

Nobuaki Matsubara: Yes. So we use the quality of life measurement—EORTC QLQ-C30, QLQ-PR25, and BPI-SF short form—for the bone pain. So all of the actual measurements are compared between the experimental treatment arm and the enzalutamide arm. But we can't observe any detrimental deterioration on the combination arm. It is a very clinically meaningful result because combination arm showed a higher rate of anemia or neutropenia. But from the patient perspective, patient-reported perspective, there is no significant difference between the PRO measurement. It's very meaningful.

Neeraj Agarwal: Yeah. That's a good point. So patients were experiencing expected side effects of treatment. Talazoparib is associated with anemia compared to other PARP inhibitors. More anemia, less gastrointestinal toxicity—adverse events, if you will. And we know PARP inhibitors have similar toxicity profile, but some have more of anemia. Some have more of GI toxicities.

But in this case, despite the fact, as you just mentioned, patients are experiencing anemia, but it was not being reflected in how they felt their quality of life is or was on the trial. And I agree with you these results are quite meaningful because what ultimately matters is how our patients are feeling on a given treatment, not what we are looking or what we are observing, but how they are feeling and how they are reporting.

And by the way, I would like to bring to the attention of our audience is that all the tools which were used for measuring quality of life are validated tools. They are used in pretty much all mCRPC trials, and they are widely acknowledged as acceptable tools. They may not be perfect, but they are one of the most acceptable tools for measuring quality of life for our patients. Is that correct?

Nobuaki Matsubara: Yeah, that's correct.

Neeraj Agarwal: Yeah. Any other comment you'd like to make?

Nobuaki Matsubara: Yes, so I reported cohort 1 of the TALAPRO-2 trial. Cohort 1 means non-selected or all-comer population regardless of HRR mutant status. So our friend is also present in this year's ASCO cohort 2 PRO final result. So this data also confirmed no deterioration on the PRO result in the cohort 2 HRR-mutant population.

So his data and my data are very consistent, so it means adding the talazoparib never deteriorated patient-reported outcome strongly.

Neeraj Agarwal: So thank you for bringing up both cohorts. So cohort 1 was an all-comer mCRPC population with newly diagnosed mCRPC. And cohort 2 included only those patients with newly diagnosed mCRPC who had HRR mutations. And what you are telling us that talazoparib with enzalutamide improved radiographic progression-free overall survival without adversely affecting the quality of life of our patients in both cohorts. Well, thank you very much for joining us, for taking the time. And congratulations again.

Nobuaki Matsubara: Thank you very much, Dr. Agarwal.