Originally published by our sister publication Clinical Oncology News

By Clinical Oncology News Staff

The FDA has approved pembrolizumab (Keytruda, Merck) with pemetrexed and platinum-based chemotherapy as first-line treatment of unresectable advanced or metastatic malignant pleural mesothelioma (MPM).

Efficacy was investigated in KEYNOTE-483 (ClinicalTrials.gov. Identifier: NCT02784171), a randomized, open-label trial in patients with unresectable advanced or metastatic MPM and no prior systemic therapy for advanced/metastatic disease. Patients were randomized (1:1) to receive either pembrolizumab for up to two years in combination with pemetrexed and platinum-based chemotherapy for up to six cycles (n=222) or pemetrexed and platinum-based chemotherapy for up to six cycles (n=218).


The main efficacy outcome measure was overall survival (OS). Additional efficacy outcome measures were progression-free survival (PFS), objective response rate (ORR) and duration of response (DOR), as assessed by blinded independent central review, according to modified RECIST version 1.1 for mesothelioma. The trial demonstrated a statistically significant improvement in OS for patients treated with pembrolizumab with chemotherapy compared with those who received chemotherapy alone. Median OS was 17.3 months (95% CI, 14.4-21.3 months) versus 16.1 months (95% CI, 13.1-18.2 months) (hazard ratio [HR], 0.79; 95% CI, 0.64-0.98; P=0.0162).  

Median PFS was 7.1 months (95% CI, 6.9-8.1 months) versus 7.1 months (95% CI, 6.8-7.7 months) in pembrolizumab plus chemotherapy group and chemotherapy alone arm, respectively (HR, 0.80; 95% CI, 0.65-0.99; P=0.0194). Confirmed ORR was 52% (95% CI, 45.5%-59.0%) in the pembrolizumab plus chemotherapy arm and 29% (95% CI, 23.0%-35.4%) in the chemotherapy alone arm. Median DOR was 6.9 months (95% CI, 5.8-8.3 months) and 6.8 months (95% CI, 5.5-8.5 months), respectively.

Adverse reactions occurring in patients with MPM were similar to those receiving pembrolizumab with pemetrexed and platinum-based chemotherapy. See the prescribing information for complete details.

The full prescribing information for Keytruda will be posted here at a later date. 

Based on a press release from the FDA.