Comparative Effectiveness of Neoadjuvant Pembrolizumab Versus Cisplatin-based Chemotherapy or Upfront Radical Cystectomy in Patients with Muscle-invasive Urothelial Bladder Cancer.

BACKGROUND

Recent progresses in the use of immune checkpoint inhibitor (ICI) have challenged the therapeutic standards in patients with muscle-invasive urothelial bladder carcinoma (MIBC).

OBJECTIVE

To compare neoadjuvant pembrolizumab followed by radical cystectomy (RC) versus neoadjuvant chemotherapy (NAC) and RC or upfront RC, according to cisplatin eligibility.

DESIGN, SETTING, AND PARTICIPANTS: We conducted two separate analyses for cisplatin-eligible and cisplatin-ineligible cT2-4N0M0 MIBC patients. We used a propensity score adjustment that relied on inverse probability of treatment-weighting (IPTW).

INTERVENTION

Pembrolizumab within the PURE-01 trial, and NAC and RC or upfront RC from a high-volume tertiary care referral center.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint in both analyses was event-free survival (EFS), defined as freedom from recurrence, and/or death from any cause indexed from the date of treatment initiation or RC. The secondary endpoints included EFS in propensity score-matched patients, pathologic response rate, and recurrence-free survival (RFS) after RC.

RESULTS AND LIMITATIONS

A total of 458 patients who underwent RC, with or without NAC, at Moffitt Cancer Center between October 2005 and October 2020, and 146 patients enrolled in PURE-01 were analyzed. In cisplatin-ineligible patients, EFS was superior in those receiving pembrolizumab (p < 0.001). The estimated 3-yr EFS was 77.8% (95% confidence interval [CI]: 63.5-95.2) for pembrolizumab and RC, and 36.1% (95% CI: 28.6-45.5) for upfront RC. EFS remained superior in those receiving neoadjuvant ICI (NICI) following IPTW (p < 0.001). In cisplatin-eligible patients, EFS was superior in those receiving pembrolizumab and RC (p < 0.001). The estimated 3-yr EFS was 86.9% (95% CI: 80.9-93.3) for pembrolizumab and 63.5% (95% CI: 56.5-71.4) for NAC. EFS remained superior in those receiving NICI following IPTW (p < 0.001). Pathologic responses and RFS in pembrolizumab-treated patients were also superior to those in NAC-treated patients. Results are limited by the retrospective nature of the study.

CONCLUSIONS

In the first ever reported comprehensive comparison of outcomes between neoadjuvant ICI and NAC, followed by RC, or upfront RC, we report increased responses and improved oncologic outcomes with neoadjuvant ICI in patients with MIBC.

PATIENT SUMMARY

We compared the results obtained from the use of pembrolizumab and radical cystectomy with standard-of-care treatments in patients with bladder carcinoma infiltrating the muscle layer. We reported increased response and survival rates possibilities with the use of immunotherapy, anticipating the possibility to set new therapeutic standards in these patients, pending the results of ongoing randomized studies.