Mark D. Tyson, MD, shares topline results from BOND-003

In this video, Mark D. Tyson, II, MD, MPH, shares key findings from the abstract, “Topline Results: BOND-003 Cohort C- A Phase 3, Single-Arm Study Of Intravesical Cretostimogene Grenadenorepvec For BCG-Unresponsive High-Risk Non-Muscle Invasive Bladder Cancer With Carcinoma In Situ,” which were presented at the Society of Urologic Oncology 25th Annual Meeting in Dallas, Texas. Tyson is a urologic oncologist at Mayo Clinic in Arizona.

Could you describe the background for this trial?

BOND-003 is a registrational phase 3 study evaluating cretostimogene in patients with BCG-unresponsive non–muscle-invasive bladder cancer. That's a very difficult to treat population. Historically, these are patients that have been treated with adequate BCG according to the FDA criteria, which is usually at least 7 doses of BCG, and they have a recurrence soon after having received their last dose. So, these are patients that are not responding to conventional therapy. They've been treated with intravenous immunotherapies or intravesical chemotherapies. They've had a lot of treatment.

The idea behind this study is to try to give them one more shot at saving their bladder, keeping the cancer from recurring and progressing before having to take more drastic measures, like radical cystectomy. So, that's the rationale of the study. It's a single arm trial, 112 patients, patients get the classic induction and maintenance BCG paradigm, but instead of BCG, they get cretostimogene once a week for 6 weeks, and then cycles of 3 every so often, and then mandatory biopsies at a year. Complete response rate and durability of response were the end points, among others. That's what was reported this week at the SUO.

What were the key findings that were presented at this weekend?

In terms of the cohort itself, baseline characteristics are pretty standard for these populations. A lot of older patients, usually men. In this particular case, this was a global phase 3, so there were some patients from Asia Pacific sites, but 2/3 of the patients came from the United States. In terms of results, complete response rate at any time point for the cohort was 74.5%. That's a weird end point, maybe worth describing to your viewers. Complete response at any time point is either complete response at the first disease assessment [at] 3 months, or if they had disease at that disease assessment, they could undergo another TURBT, clear the bladder, and then have a second induction course. If they then had a complete response, then they would be considered a complete responder. That number, 74.5%, reflects the cohort's disease-free status at either that 3- or 6-month time point. In terms of durability of response, the median duration of response hasn't yet been reached, but so far has 27 months, which speaks to cretostimogene's excellent durability.

In terms of landmark analysis, 46% of the cohort was in complete response at 12 months. The denominator for that number is 110. There are 2 patients who haven't had yet had a year of follow-up. So, that number is all-comers. But if you look at just among the responders, at a median of 14.5 months of follow-up, the number of patients that maintain their complete response to 12 and 24 months was 63.5%and 56.6%, respectively. So, very good durability. If it works, it really works. That's why we see that long, flat tail at the end of the KM curve. More data to come in future years, longer follow-up, those kinds of things. But very good start for cretostimogene.

In terms of tolerability, very well-tolerated. Mostly grade 1, grade 2 AEs. There were no grade 3 treatment-related adverse events, which is unusual to not have any. Very promising results. No treatment-related discontinuations. Again, that's a differentiator. It's not common for you not to have at least a few treatment-related discontinuations, but we didn't see any of that. It's very encouraging. All the patients, for the most part, 97.5%, were able to get all the protocol-directed treatment. In terms of safety, tolerability, also very good results.

This transcript was AI generated and edited by human editors for clarity.