following a phase 3 trial presented at the 2023 European Society for Medical Oncology annual meeting.
The combination soundly beat the current standard of care – platinum-based chemotherapy – with a median overall survival of 31.5 months among 442 subjects versus 16.1 months among 444 randomized to gemcitabine with cisplatin or carboplatin, an unprecedented 53% drop in the risk of mortality (P < .00001).
The elimination of chemotherapy also meant that there were substantially fewer grade 3 or higher adverse events with the new combination.
“This is the first time we’ve managed to beat chemotherapy in the first-line setting for overall survival despite multiple previous attempts.” The 30% remission rate with enfortumab vedotin plus pembrolizumab “is not something we’ve seen before,” said lead investigator Thomas Powles, MBBS, MD, a urologic oncologist and researcher at the University of London, who presented the findings.
“We welcome a new standard of care in the management of advanced, metastatic urothelial carcinoma, enfortumab vedotin plus pembrolizumab,” said Andrea Apolo, MD, a urologic oncology researcher at the National Cancer Institute in Bethesda, Md., and discussant on the trial, dubbed EV-302/KEYNOTE-A39.
The news overshadowed a second trial presented immediately after Dr. Powles’ that also showed improvement in overall survival versus standard platinum-based chemotherapy, CheckMate 901.
Instead of replacing chemotherapy, CheckMate 901 added nivolumab. With 304 patients randomized to each arm, nivolumab add-on led to a median overall survival of 21.7 months versus 18.9 months with stand-alone gemcitabine/cisplatin, a 22% drop in the risk of mortality (P = .0171).
It’s the first time that adding immunotherapy to first-line chemotherapy improved survival in metastatic urothelial carcinoma, said lead investigator Michiel van der Heijden, MD, PhD, a urologic oncologist and researcher at the Netherlands Cancer Institute, Amsterdam.
After decades of stagnation, Dr. Apolo said, it’s “monumental for our field” to have two trials that beat chemotherapy in the first-line setting.
However, she said that the much better survival with enfortumab vedotin/pembrolizumab means that the combination now “takes first place as the best first-line regimen in urothelial carcinoma.”
Major disruptions in the treatment paradigm
The crowning of a new first-line standard for locally advanced/metastatic urothelial carcinoma means that everything else in the treatment paradigm has to shift, Dr. Apolo said, and there are many new questions that need to be answered.
Among the most pressing, should the previous first-line standard – platinum-based chemotherapy – now move to the second line and be considered the treatment of choice after progression? Also, is there still a role for the previous second-line standards, pembrolizumab and other immunotherapies, if pembrolizumab fails in the first line?
Dr. Apolo said investigators also need to figure out if there is a role for enfortumab vedotin/pembrolizumab in earlier-stage disease, such as muscle-invasive bladder cancer, and if the dose and duration of enfortumab vedotin can be reduced to limit its peculiar ocular and other toxicities.
Finally, “we must discuss cost,” she said. Enfortumab vedotin plus pembrolizumab (EV+P) is expensive. “Will payers be able to afford” it?
Dr. Powles, the lead investigator on EV-302/KEYNOTE-A39, said he doesn’t know how negotiations are going with payers, but that he hopes they move quickly. “We’ve seen transformative results” with the combination for even aggressive cancers in very sick people. “I think it’s going to be a challenge with patients not to talk about these data.”