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ABSTRACT: Background
Intravenous immune checkpoint inhibition is an effective anticancer strategy for bacillus Calmette-Guérin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC) but may be associated with greater systemic toxicity compared with localized therapies.Objective
We assessed the safety and antitumor activity of intravesical pembrolizumab combined with BCG.Design, setting, and participants
A 3 + 3 phase 1 trial of pembrolizumab + BCG was conducted in patients with BCG-unresponsive NMIBC (NCT02808143).Intervention
Pembrolizumab was given intravesically (1-5 mg/kg for 2 h) beginning 2 weeks prior to BCG induction until recurrence. Urine profiling during treatment and spatial transcriptomic profiling of pre- and post-treatment tumors were conducted to identify biomarkers that correlated with response.Outcome measurements and statistical analysis
Safety and tolerability of immune checkpoint inhibition were assessed, and Kaplan-Meier survival analysis was performed.Results and limitations
Nine patients completed therapy. Median follow-up was 35 months for five patients still alive at the end of the trial. The trial was closed due to the COVID-19 pandemic. Grade 1-2 urinary symptoms were common. The maximum tolerated dose was not reached; however, one dose-limiting toxicity was reported (grade 2 diarrhea) in the only patient who reached 52 weeks without recurrence. One death occurred from myasthenia gravis that was deemed potentially related to treatment. The 6-mo and 1-yr recurrence-free rates were 67% (95% confidence interval [CI]: 42-100%) and 22% (95% CI: 6.5-75%), respectively. Pembrolizumab was detected in the urine and not in blood. CD4+ T cells were significantly increased in the urine after treatment, and a transcriptomic analysis identified decreased expression of T-cell exhaustion markers in late recurrences.Conclusions
We demonstrate that intravesical pembrolizumab is safe, feasible, and capable of eliciting strong immune responses in a clinical setting and should be investigated further.Patient summary
Direct application of pembrolizumab to the bladder is a promising alternative for non-muscle-invasive bladder cancer unresponsive to Bacillus Calmette-Guérin and should be investigated further.
SUBMITTER: Meghani K
PROVIDER: S-EPMC9669228 | biostudies-literature | 2022 Dec
REPOSITORIES: biostudies-literature
European urology 20220823 6
<h4>Background</h4>Intravenous immune checkpoint inhibition is an effective anticancer strategy for bacillus Calmette-Guérin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC) but may be associated with greater systemic toxicity compared with localized therapies.<h4>Objective</h4>We assessed the safety and antitumor activity of intravesical pembrolizumab combined with BCG.<h4>Design, setting, and participants</h4>A 3 + 3 phase 1 trial of pembrolizumab + BCG was conducted in patients w ...[more]