A Phase 2 study showed that combining Keytruda with BCG therapy achieved strong responses in patients with very high-risk, BCG-naive non–muscle-invasive bladder cancer.
Among 37 patients, 92% achieved a clinical complete response at six months, and no patients progressed to muscle-invasive or metastatic disease during follow-up. The 12-month high-grade recurrence-free survival rate was about 88%, while bladder preservation rates remained high, with only two patients eventually needing bladder removal surgery.
Researchers said the combination could offer a bladder-preserving alternative for patients who might otherwise undergo immediate cystectomy.
Side effects were common, with 32% experiencing severe treatment-related adverse events, including hepatitis, pneumonitis, and sepsis. One possible treatment-related death occurred before BCG treatment began.
The investigators noted that larger randomized trials, including the ongoing Phase 3 KEYNOTE-676 study, are needed to confirm the findings.