ClinicalTrials.gov recorded primary completion on 20 February 2019 for a Phase 3 trial comparing pembrolizumab with standard chemotherapy in advanced, pretreated malignant pleural mesothelioma. Among the reported measurements, objective response was 21.9% with pembrolizumab versus 5.6% with chemotherapy, while median overall survival was 10.7 months and 12.4 months, respectively.

Background

The study evaluated pembrolizumab in patients with advanced pretreated malignant pleural mesothelioma. The comparator was standard chemotherapy using gemcitabine or vinorelbine. The registry described the trial as a comparison of standard treatment with pembrolizumab treatment in this patient population.

Trial design

This completed Phase 3 trial enrolled 144 participants with advanced malignant pleural mesothelioma. Its registered interventions were pembrolizumab, gemcitabine, and vinorelbine. The study compared a pembrolizumab arm with a standard chemotherapy arm. The listed progression-free survival outcome was assessed by independent radiological review, as was objective response rate.

Key results

Median progression-free survival was 2.5 months in the pembrolizumab arm and 3.4 months in the standard chemotherapy arm. Objective response rate was 21.9% with pembrolizumab compared with 5.6% with standard chemotherapy.

  • Median overall survival: 10.7 months with pembrolizumab versus 12.4 months with standard chemotherapy.
  • Median time to treatment failure: 2.8 months with pembrolizumab versus 2.3 months with standard chemotherapy.
  • The supplied registry data include a log-rank p-value of 0.76, without identifying the associated outcome or comparison in the record provided.
  • For the listed adverse-event and serious-adverse-event measurements, the registry reports counts of 70 and 50 participants in the pembrolizumab arm, and 65 and 52 participants in the chemotherapy arm. The supplied data do not specify which count represents adverse events and which represents serious adverse events.

What this means

The completed trial reported a higher objective response rate with pembrolizumab, but the listed median progression-free and overall survival values were longer in the standard chemotherapy arm. Time to treatment failure was slightly longer with pembrolizumab. Because the supplied record does not connect the log-rank p-value to a named outcome and does not provide confidence-interval values, the data do not support a more detailed statistical interpretation here. The event was a trial primary completion, not a new approval or label change.

Source

Source: ClinicalTrials.gov, trial record and results for NCT02991482, with the primary completion date listed as 20 February 2019. The registry record is available at clinicaltrials.gov/study/NCT02991482.