Unlike traditional chemotherapy, the EV+pembrolizumab combination is producing a "tail on the curve" in survival data. This indicates a significant minority of patients with metastatic bladder cancer are achieving durable, long-term responses—a phenomenon previously unseen and a paradigm shift for the disease.

The transformative efficacy of EV-Pembro has ushered in a new, aggressive treatment philosophy for both muscle-invasive and metastatic bladder cancer. The approach is to administer the combination upfront to gain rapid disease control, and only then make subsequent decisions about surgery, radiation, or further therapy.

The B15 trial shows EV-Pembro is superior to chemotherapy in muscle-invasive bladder cancer. However, the true benchmark is now the Niagara study (chemo + durvalumab), which already beat chemo alone. The debate will focus on whether EV-Pembro offers a significant enough improvement to become the definitive standard over this new chemo-IO combination.

The practice-changing Keynote B15 trial showed strong efficacy for neoadjuvant EV-Pembro. However, about half of patients discontinued treatment due to side effects. This creates a clinical paradox: patients who complete the full regimen may be over-treated, while those who stop early due to toxicity may be under-treated, complicating patient management and counseling.

The anticipated approval of the highly effective EV-Pembro combination in the perioperative setting will create a new clinical challenge. When these patients eventually relapse years later, clinicians will face a dilemma: re-challenge with the same potent regimen that worked before or switch to older, likely less effective chemotherapies.

The demonstrated superiority of the enfortumab vedotin (EV) and pembrolizumab combination over platinum chemotherapy has effectively made the Galski criteria, used for determining cisplatin eligibility, irrelevant. This marks a major paradigm shift in how frontline bladder cancer is approached, moving beyond platinum-based decisions.

Giving EV Pembro perioperatively for muscle-invasive bladder cancer provides the best chance for a cure. Waiting to use it in the first-line metastatic setting is a major gamble, as many patients relapse and may not get a second chance at effective therapy. The consensus is to use the best treatment upfront.

A key lesson in bladder cancer is that patient attrition is rapid between lines of therapy; many who relapse from localized disease never receive effective later-line treatments. This reality provides a strong rationale for moving the most effective therapies, like EV-pembrolizumab, to earlier settings to maximize the number of patients who can benefit.

With pathologic complete response rates approaching 67% in patients completing neoadjuvant EV-Pembro, a majority of cystectomies are now removing cancer-free bladders. This creates an ethical and clinical imperative to rapidly launch prospective trials to validate bladder preservation strategies and avoid overtreatment.