# KEYNOTE-057: pembrolizumab for BCG-unresponsive non-muscle-invasive bladder cancer with carcinoma in situ

Source: https://onco.cc/key-papers/paper-keynote-057-lancet-oncol-2021/  
OnCo record `paper-keynote-057-lancet-oncol-2021` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

In patients whose high-risk bladder cancer no longer responded to BCG and who could not or would not have their bladder removed, pembrolizumab cleared the disease in about four in ten, with a response lasting a year or more in roughly half of those.

## Summary

Single-arm phase 2 study of 101 patients with BCG-unresponsive carcinoma in situ, with or without papillary tumours, treated with pembrolizumab every three weeks for up to two years.

The complete response rate at three months was 41 percent and the median duration of response was 16.2 months. On these data pembrolizumab became the first systemic drug approved for BCG-unresponsive non-muscle-invasive bladder cancer, as an alternative to immediate cystectomy.

## Fields

- Kind: Key paper
- Last checked: 2026-09-17
- Journal: The Lancet Oncology
- Year: 2021
- DOI: 10.1016/S1470-2045(21)00147-9
- Authors: Balar AV, Kamat AM, Kulkarni GS, et al.
- Findings: Complete response at three months in 41 percent of patients with carcinoma in situ.; Median duration of complete response 16.2 months; 46 percent of responses lasted at least 12 months.
- What it means: Patients facing cystectomy for BCG-unresponsive disease have a bladder-sparing option, though most will eventually relapse and need close cystoscopic surveillance. The choice is a trade between keeping the bladder and the risk of progression while waiting.
- Caveats: No randomised comparator; cystectomy remains the curative standard.; Progression to muscle-invasive disease occurred in a minority during follow-up.

## Sources

- Lancet Oncol 2021: https://doi.org/10.1016/S1470-2045(21)00147-9
- PubMed: https://pubmed.ncbi.nlm.nih.gov/34051177/

## Connected records

- cancers: [Non-muscle-invasive bladder cancer](https://onco.cc/cancers/non-muscle-invasive-bladder-cancer/)
- drugs: [Pembrolizumab](https://onco.cc/drugs/pembrolizumab/)
- trials: [KEYNOTE-057](https://onco.cc/trials/keynote-057/)
- journals: [The Lancet Oncology](https://onco.cc/journals/lancet-oncology/)

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