KEYTRUDA Padcev MIBC Survival: New Era in Treatment Revealed by KEYNOTE-B15 Trial Results

KEYTRUDA Padcev MIBC Survival Breakthrough in Cisplatin-Eligible Patients

KEYTRUDA Padcev MIBC Survival benefits shone in the Phase 3 KEYNOTE-B15 trial, where perioperative KEYTRUDA (pembrolizumab) plus Padcev (enfortumab vedotin-ejfv) cut event-free survival (EFS) event risk by 47% and death risk by 35% versus neoadjuvant chemotherapy followed by surgery. Detailed in Merck’s press release, these late-breaking results after 33.6 months median follow-up showed median EFS not reached (vs. 48.5 months) and two-year survival of 86.9% (vs. 81.3%), marking the first immunotherapy-ADC combo to deliver such gains in this setting—and the sixth KEYTRUDA study with overall survival (OS) wins in earlier-stage cancers.

EFS and OS Risk Reductions Redefine Outcomes

The trial reported statistically significant EFS and OS improvements, plus enhanced pathologic response. Trial primary endpoint EFS—time to progression precluding surgery, surgical failure, residual disease, recurrence, or death—hit median not reached for KEYTRUDA Padcev MIBC Survival arm (79.4% two-year progression-free) vs. 48.5 months (66.2%) for gemcitabine-cisplatin. Secondary endpoints boosted pathologic complete response (pCR) to 55.8% (vs. 32.5%; difference 23.4%, p<0.0001), with median OS not reached but HR=0.65 favoring the regimen. These align with prior approvals in advanced urothelial cancer and cisplatin-ineligible MIBC, spanning three Phase 3 trials.

KEYNOTE-B15 Design Matches Real-World Needs

The open-label randomized setup pitted four neoadjuvant KEYTRUDA-Padcev cycles, cystectomy, and 13 adjuvant KEYTRUDA + five Padcev cycles against four gemcitabine-cisplatin cycles plus surgery—challenging a standard where half recur despite benefits. Safety mirrored profiles: grade ≥3 events in 75.7% (combo) vs. 67.2% (chemo), feasible amid 600,000+ global bladder cases yearly (25% MIBC).

Paradigm Shift Sparks Regulatory Momentum

KEYTRUDA Padcev MIBC Survival data signal shifts for cisplatin-eligible patients. The 47% EFS/35% OS cuts and doubled pCR justify value via quality-adjusted life years and recurrence cuts, balancing adverse events against gains—echoing KEYTRUDA’s 14 early-cancer wins. Implications: optimized care, lower metastatic costs, broader curative access pending real-world data.