Tremelimumab Does Not Prolong Overall Survival in Malignant Mesothelioma

Among patients with relapsed malignant mesothelioma, tremelimumab does not improve overall survival (OS) compared with placebo, according to a study published in The Lancet Oncology.¹

There are no second-line therapies that show survival benefit for malignant mesothelioma.  

For the double-blind DETERMINE trial (ClinicalTrials.gov Identifier: NCT01843374), researchers randomly assigned 569 patients with unresectable malignant mesothelioma 2:1 to receive intravenous (IV) tremelimumab 10 mg/kg or placebo every 4 weeks for 7 doses and then every 12 weeks until therapy discontinuation requirements were met. The primary study outcome was OS in the intent-to-treat (ITT) population.

Median OS was 7.7 months (95% CI, 6.8-8.9) in the tremelimumab arm vs 7.3 months (95% CI, 5.9-8.7) in the placebo arm (hazard ratio, 0.92; 95% CI, 0.76-1.12; P = .41).

At the time of data cutoff, 80% of patients in tremelimumab arm and 81% of patients in the placebo arm had died.

Sixty-five percent of patients in tremelimumab arm and 48% of patients in the placebo arm experienced grade 3 or greater treatment-emergent adverse events (AEs).

The most frequently observed AEs in the tremelimumab arm were diarrhea, dyspnea, and colitis. The types and rates of incidence of AEs were consistent with those previously reported for CTLA-4 inhibitors.

Reference

1. Maio M, Scherpereel A, Calabro L, et al. Tremelimumab as second-line or third-line treatment in relapsed malignant mesothelioma (DETERMINE): a multicenter, international, randomized, double-blind, placebo-controlled phase 2b trial. Lancet Oncol. 2017 July 17. doi: 10.1016/S1470-2045)17)30446-1 [Epub ahead of print]