Guru Sonpavde, MD, medical director of genitourinary oncology at the AdventHealth Cancer Institute, discussed the promising findings of the CheckMate 901 trial exploring the potential of nivolumab plus gemcitabine-cisplatin in advanced urothelial carcinoma.
Guru Sonpavde, MD, medical director of genitourinary oncology, assistant director of the clinical research unit, and Christopher K. Glanz Chair for Bladder Cancer Research at the AdventHealth Cancer Institute, discussed the findings of the CheckMate 901 trial exploring the potential of gemcitabine-cisplatin plus nivolumab (gem-cis-nivo) in advanced urothelial carcinoma.
What were some key findings in the CheckMate 901 trial of nivolumab plus chemotherapy in urothelial carcinoma?
Quickly summarizing the outcomes, there was an improvement in both progression-free survival and overall survival. The overall survival improved with a hazard ratio of 0.78. The median survival improved to 21.7 months with cisplatin-gemcitabine plus nivolumab, and the control arm—cisplatin-gemcitabine alone—was 18.9 months. The progression-free survival also improved, with a hazard ratio that was even better: 0.72.
At the median time point, you don't actually see an improvement with around 7.6 and 7.9 months. But the unique thing about the progression-free survival was that there was separation of the curve for these 2 arms at around the 6-month time point, so that at the 2-year time point and even the 1-year time point, there was significant separation.
The other end point I wanted to highlight before I get into the importance of the data is that the response rate also improved. The really key factor was that the complete remission rate really significantly improved. The complete remission rate was 22% with cisplatin-gemcitabine plus nivolumab, and the duration of the complete remission was close to 3 years—it was 37 months, approximately. That was the most unique part of this really durable benefit in a subgroup of patients that had complete remission, which was 22% of patients, approximately.
Can you discuss the implications of these findings and directions for future research?
This combination was active and improved overall survival and progression-free survival, and the highlight was the complete remission rate of 22%, which was highly durable, with a median duration of complete response of 37 months. Now, one of the unique things I will point out is that the toxicity profile was very, very manageable and was consistent with what we see with cisplatin-gemcitabine and with nivolumab—so no excessive toxicity over what we see with these 2 regimens was seen.
One of the key aspects of this trial is that the chemotherapy component stopped at a maximum of 6 cycles, and thereafter, it was only nivolumab that continued after the gem-cis-nivo combination was completed for a total of up to 6 cycles. That really helps the patients because they don't accumulate toxicities of the cytotoxic regimen, because you're giving a finite duration of the chemotherapy for up to 6 cycles and then stopping chemotherapy.
I do bring up and contrast it with the other regimen that has been developed and has been in the news based on a positive phase 3 trial, which was the combination of EV—enfortumab vedotin—an antibody-drug conjugate, plus pembrolizumab, which also improved overall survival and progression-free survival. But in that case, the regimen is continued until progression or toxicity, which suggests that many patients might accumulate some of the toxicities if you continue the treatment until toxicities.
The next steps are to improve upon biomarkers. Can we predict the patients who have these extremely durable benefit and the durable [complete responses]? Who are those 22% of patients? Can we identify them? I think the field needs to go in that direction with this regimen. And again, the key aspect is that the chemotherapy was given for a finite duration of time—up to 6 cycles—and that really prevents some of the neurotoxicity or nephrotoxicity that might accumulate if we kept going beyond those number of cycles, so that is a key feature that might help with the quality of life of patients.
One thing I will also add from the societal standpoint, is that the cisplatin-gemcitabine backbone is very affordable and much cheaper than the other competing regimen that's going to emerge. And so that is something to also consider when looking at can these 2 regimens as first-line therapy.
van der Heijden MS, Sonpavde G, Powles T, et al. Nivolumab plus gemcitabine-cisplatin in advanced urothelial carcinoma. N Engl J Med. 2023;389(19):1778-1789. doi:10.1056/NEJMoa2309863