according to Thomas W. Flaig, MD, vice chancellor for research at the University of Colorado Anschutz Medical Campus, Aurora.
Combination therapies involving enfortumab and nivolumab are demonstrating success in recent studies and have been incorporated into the latest guidelines, Dr. Flaig said in a presentation at the National Comprehensive Cancer Network (NCCN) annual conference.
What's New in The Updated Guidelines?
Advances in the treatment options for metastatic urothelial carcinoma in the last decade have been dramatic, with ongoing developments and new emerging treatment options, Dr. Flaig told the audience of his session.
This has led to the identification of new and effective immune checkpoint inhibitor combinations. Consequently, immune checkpoint inhibitors are currently included in all preferred/other recommended first-line treatment regimens, he said.
“Enfortumab vedotin plus pembrolizumab is now the sole preferred first-line regimen for locally advanced or metastatic disease.” Based on the recent research, the mindset regarding cisplatin-eligible patient selection may be changing, he added.
“We have used cisplatin eligibility as a key factor in determining first-line therapy for years, and that paradigm is now shifting with the emergence of enfortumab plus pembrolizumab, a new non–cisplatin containing regimen” Dr. Flaig noted.
Although the optimal choice for second- or third-line therapy after immune checkpoint inhibitors is not well-defined, options include platinum regimens, antibody-drug conjugate, and erdafitinib in eligible patients, he said.
Other Current Strategies for Localized Bladder Cancer Management
The incidence of bladder cancer has been stable for decades, with minimal therapeutic developments until the approval of immune checkpoint inhibitors in the last decade, Dr. Flaig said.
Bladder cancer is more common in older adults, with an average onset age of 73 years, and most patients (75%) are male, he said. Comorbid disease is common in these patients, and many have a history of smoking, Dr. Flaig added.
The traditional medical approach to treating bladder cancer has been based on combination therapies including cisplatin. This has also reflected the approach used in the treatment of lung cancer, historically, Dr. Flaig said.
Cisplatin, while effective, is a challenging therapy to administer and is not an option for all bladder cancer patients because of potential adverse effects, he noted. Antibody drug conjugates and immune checkpoint inhibitors are new alternatives for some who are not able to receive cisplatin.
What are the New Options for Treating Metastatic Urothelial Bladder Cancer?
The approval of antibody drug conjugates offers new treatment with a “specific target and therapeutic payload,” said Dr. Flaig in his presentation. Two antibody drug conjugates, enfortumab vedotin and sacituzumab govitecan, have been approved by the US Food and Drug Administration (FDA), he said. Enforumab vedotin was approved by the FDA in 2021 for adults with locally advanced or metastatic urothelial cancer for subsequent line therapy in select patients. In a 2021 study published in The New England Journal of Medicine, the primary outcome of overall response rate was significantly greater in patients with advanced urothelial carcinoma who were treated with enfortumab vedotin than in those treated with standard chemotherapy (overall response rate [ORR] 40.6% vs 17.9%, respectively).
Side effects associated with enfortumab vedotin “are intrinsic to the payload toxicity and the target distribution. Ideally, the target would be present on all of the cancer cells and none of the normal tissue,” said Dr. Flaig. With enfortumab, specific toxicities included neuropathy, skin reactions, and blood glucose elevation/diabetic ketoacidosis, he said.
A second agent, sacituzumab govitecan, was approved by the FDA for metastatic urothelial cancer patients in 2021, based on data from the TROPHY-U-O1 phase 2 open-label study of 113 individuals. In that study, the ORR was 27% at a median follow-up of 9.1 months. Adverse events included neutropenia, leukopenia, and diarrhea.
What Do the Latest Studies of Combination Therapy Show?
Immune checkpoint inhibitor combinations are significantly changing the landscape of bladder cancer treatment, Dr. Flaig explained.
A recent phase 3 study published in 2024 in The New England Journal of Medicine comparing enfortumab vedotin plus pembrolizumab to platinum-based combination chemotherapy showed an overall response rate of 67.7% vs 44.4% in favor of enfortumab/pembrolizumab, said Dr. Flaig. In addition, the risk of disease progression or death was approximately 55% lower in the enfortumab vedotin-pembrolizumab group vs the chemotherapy group (hazard ratio [HR], 0.45; P less than .001) and the median progression-free survival was approximately doubled (12.5 months vs 6.3 months).
Dr. Flaig described this study as “very notable”because “the enfortumab plus pembrolizumab arm was clearly more effective than the long-standing chemotherapy arm, now becoming the preferred, first-line treatment in the NCCN guidelines. Based on preliminary results of the study, this combination was approved by the FDA in 2023 for locally advanced or metastatic urothelial cancer patients regardless of their eligibility for cisplatin.
Another promising combination, nivolumab plus gemcitabine-cisplatin, was associated with significantly longer overall and progression-free survival in patients with previously untreated unresectable or metastatic urothelial carcinoma, Dr. Flaig said. The therapy was approved by the FDA in March 2024 for first-line therapy.
In a study of 608 patients published in The New England Journal of Medicine, median overall survival was 21.7 months for the nivolumab group vs 18.9 months for the gemcitabine-cisplatin alone group. The overall response rates were 57.6% in the nivolumab group vs 43.1% in the gemcitabine-cisplatin–alone group, and complete response rates were 21.7% and 11.8%, respectively. Serious adverse events (grade 3 or higher) were similar between the groups (61.8% and 51.7%, respectively).
What About Targeted Therapy?
Erdafitinib, a tyrosine kinase inhibitor of FGFR1–4, was approved by the FDA in January 2024 for adults with locally advanced or metastatic urothelial carcinoma who had susceptible FGFR3 genetic alterations, said Dr. Flaig, during his presentation. The limitation of this treatment to only those patients with an FGFR3 mutation is a recent update in its use, he noted.
“Up to 20% of patients with advanced urothelial carcinoma have FGFR alterations,” he said. In an open-label phase 2 study of 99 individuals with unresectable or metastatic urothelial carcinoma, past chemotherapy, and FGFR alterations, confirmed response to erdafitinib was 40% with a median overall survival of 13.8 months.
Dr. Flaig disclosed grant/research support from Agensys; Astellas Pharma US; AstraZeneca Pharmaceuticals LP; Bristol Myers Squibb; Genentech, Inc.; Janssen Pharmaceutica Products, LP; Merck & Co.; Sanofi-Aventis U.S.; and SeaGen. He also disclosed equity interest/stock options and intellectual property rights in Aurora Oncology, and serving as a consultant or scientific advisor for Janssen Pharmaceutica Product, LP, and Criterium, Inc.