Bladder Cancer · Medical Oncology · Evidence review 2026-10-14

KEYNOTE-057

For patients with BCG-unresponsive CIS who decline or are ineligible for cystectomy, can pembrolizumab provide bladder-preserving disease control?

Population

Cohort A included 96 evaluable patients with BCG-unresponsive high-risk NMIBC with carcinoma in situ, with or without papillary tumours, who declined or were ineligible for radical cystectomy.

Experimental treatment

Pembrolizumab 200 mg IV every 3 weeks for up to 24 months or until recurrence, progression or unacceptable toxicity.

Comparator

Single-arm phase II study; no randomized comparator.

Study design

Single-arm phase II study

Key reported outcomes

Values are reproduced from the linked sources. Bars are a visual aid and are scaled within each outcome row; do not compare bar lengths across different endpoints.

Complete response at 3 months

Treatment

41%

41%

Responders maintaining response ≥12 months

Treatment

46% of responders

46% of responders

Median duration of complete response

16.2 months

Time-to-event summary; shown as a numeric endpoint rather than a percentage bar.

Clinical complete response at 3 months was 41% (39/96); median duration of response was 16.2 months. Of responders, 46% maintained a response for at least 12 months.

Critical appraisal

Single-arm study; response is not equivalent to cure and recurrences remain common. Radical cystectomy remains the standard for surgically fit patients with BCG-unresponsive high-risk disease; bladder-preserving therapy requires close cystoscopic surveillance and shared decision-making.

Absolute-effect discipline: NNT/NNH is not calculated unless a defensible absolute difference and a common time horizon are available. Median survival differences and hazard ratios alone are not converted into NNT.

Current-practice context

Reviewed 2026-10-14; this is a dated evidence-context note, not a substitute for local guidelines or individual clinical judgement.

Pembrolizumab remains a bladder-preserving option for selected patients with BCG-unresponsive CIS who are ineligible for or decline cystectomy in the US. Newer bladder-preserving strategies and local approvals should be reviewed before treatment selection.

Freshness status: this page has a dated context and source links, but is not a claim that every relevant guideline or subsequent publication has been exhaustively reviewed.

Sources

Patient-level visual

At 3 months, 41 of 100 patients in this single-arm cohort achieved complete response. This is response evidence, not a randomized absolute benefit versus cystectomy or another bladder-preserving treatment.