Real-world evidence is increasingly validating the efficacy of novel treatment combinations for advanced urothelial carcinoma while revealing important insights about patient selection and biomarker-driven therapy decisions. Recent studies demonstrate that outcomes achieved in clinical practice closely mirror those observed in pivotal trials, providing confidence for clinicians treating diverse patient populations.
Clinical Trial Outcomes Replicated in Real-World Settings
The retrospective UNITE study, presented at the 2024 ESMO Congress, demonstrated that patients with advanced urothelial carcinoma who received enfortumab vedotin-ejfv plus pembrolizumab in real-world practice achieved an overall response rate of 51% (95% CI, 42%-60%) among 171 patients. While this represents a lower response rate compared to the 67.7% (95% CI, 63.1%-72.1%) observed in the phase 3 EV-302 trial, the real-world data provide valuable insights into treatment performance outside controlled trial conditions.
"Real-world studies are very helpful now that we have multiple treatment options for patients with bladder cancer," said David J. Benjamin, MD, a medical oncologist at Hoag Family Cancer Institute. "We have enfortumab vedotin plus pembrolizumab, platinum-based chemotherapy followed by maintenance with avelumab, and nivolumab plus cisplatin and gemcitabine."
Multiple real-world studies of avelumab maintenance therapy have consistently replicated the survival benefits observed in the phase 3 JAVELIN Bladder 100 trial. Studies conducted across different regions, including the AVENANCE study in France, the READY study in Italy, and database studies in the United States, have demonstrated similar efficacy profiles to the original clinical trial data.
Biomarker Insights Guide Treatment Selection
A unique aspect of the UNITE study was its examination of biomarkers, revealing that patients with TP53 or KMT2D mutations experienced worse outcomes with the enfortumab vedotin-pembrolizumab combination. This finding addresses a gap in the EV-302 publication, which did not include biomarker-based response data.
"Enfortumab vedotin targets Nectin-4, and features such as HER2 or Nectin-4 amplification may help determine response likelihood," explained Amit Mehta, MD, a physician consultant at Premier Hematology. Data presented at recent meetings showed that patients with Nectin-4 amplification who received enfortumab vedotin plus pembrolizumab experienced significant overall survival benefits compared to those with non-amplified status.
Patient Characteristics Influence Treatment Outcomes
Real-world data from the AVENANCE study demonstrated that avelumab maintenance therapy was particularly effective in patients with specific metastatic patterns. Patients with locally advanced disease (n = 47), nonvisceral metastases (n = 79), and lymph node-only metastases (n = 60) achieved median overall survival of not reached (95% CI, 17.4-not estimable), 27.2 months (95% CI, 16.5-not estimable), and not reached (95% CI, 19.9-not estimable), respectively.
Similarly, subset analysis of the CheckMate 901 study showed that patients with lymph node-only metastases who received cisplatin, gemcitabine, and nivolumab achieved a median overall survival of 46.3 months (95% CI, 24.0-not estimable) among 54 patients.
"There's a wide heterogeneity among patients with metastatic urothelial carcinoma," Mehta noted. "Some have distant, visceral metastases. There are patients with bone lesions, primarily in their metastatic presentation, and others have lymph node-only disease."
Addressing Clinical Trial Limitations
Real-world evidence helps address significant gaps in clinical trial data. In the EV-302 trial, over 60% of patients eligible for maintenance avelumab in the platinum-based chemotherapy arm did not receive it, potentially skewing survival benefit data. Additionally, patients with ECOG performance status of 2 represented only approximately 3% of the EV-302 study population, while such patients are encountered much more frequently in clinical practice.
"With real-world data, we can supplement and complement the clinical trial data where there are gaps," Benjamin explained. Real-world studies have also demonstrated efficacy in elderly patients, with one retrospective study of 26 patients with a median age of 86.5 years showing good responses to enfortumab vedotin plus pembrolizumab.
Treatment Sequencing and Dose Intensity Considerations
Real-world data have revealed important insights about treatment sequencing. Patients who received chemoimmunotherapy followed by avelumab maintenance could subsequently receive enfortumab vedotin or the enfortumab vedotin-pembrolizumab combination. However, platinum doublet chemotherapy following enfortumab vedotin plus pembrolizumab showed limited efficacy, suggesting alternative sequencing strategies may be more appropriate.
Studies presented at recent meetings indicated that patients experiencing more adverse effects had better responses and prognosis, suggesting that maintaining dose intensity while managing toxicities safely is crucial for optimal outcomes. "Patients who are maintaining dose intensity and staying on therapy as long as safely possible may likely benefit more," Mehta emphasized.
Safety Profile Considerations
All current standard treatments contain immunotherapy components, requiring careful monitoring for immune-related adverse events including pneumonitis, colitis, autoimmune hepatitis, and thyroid dysfunction. The familiarity with immunotherapy management across multiple tumor types has facilitated the implementation of these combinations in clinical practice.
"The key to this in real-world practice is having a plan for how to monitor for a given toxicity," Mehta advised. "You must educate your team and make sure everybody's up to speed about what to monitor for, how to diagnose if a problem is happening, and then treat when necessary."
