The mix of chemotherapy and pembrolizumab extended survival in patients with pleural mesothelioma. It was given as a first line treatment to adults with the cancer. Data shows that pembrolizumab and chemotherapy reduced death by 21 percent compared to chemotherapy alone. Doctors like the combination of pembrolizumab and chemotherapy because it is already used effectively to treat non-small cell lung cancer, so it should be safe enough for mesothelioma.
The phase 2 portion of the study, known as IND.227/KEYNOTE-483, showed great results when patients were given pembrolizumab alone and alongside chemotherapy used in treating malignant pleural mesothelioma. The study was performed by The Canadian Cancer Trials Group alongside the National Cancer Institute of Naples and Intergroup Francophone de Cancérologie Thoracique. The phase three trial wanted to assess the safety and efficacy of adding pembrolizumab, an anti-PD-1 checkpoint inhibitor to chemotherapy for patients who have advanced metastatic pleural mesothelioma who cannot receive surgery. There were 440 patients in the study who either received pemetrexed and cisplatin with or without pembrolizumab. Patients received 200 mg of pembrolizumab every three weeks for up to 35 cycles. The main goal was to find the overall survival of patients and the secondary objective was to find the objective response rate and safety of the treatment combination.
The trial found that pembrolizumab alongside chemotherapy was more effective and improved overall survival over chemotherapy alone. There was a 62.2 percent objective response rate in people who received pembrolizumab and chemotherapy compared to a 38.1 percent response rate for people who only received chemotherapy. There was also an improved progression free survival in people who received pembrolizumab and chemotherapy. The one-year progression free survival was 26 percent versus 17 percent for those who only received chemotherapy.
There were more frequent grade 3 or grade 4 adverse events from pembrolizumab compared with chemotherapy alone. These happened in 27 percent of patients treated with chemotherapy and pembrolizumab and 15 percent in patients who only received chemotherapy. Researchers have noted that the safety of the two-drug regimen is very similar to other immunotherapy treatments including Keytruda for non-small cell lung cancer patients.
Based on data found by researchers, the combination of pembrolizumab and chemotherapy is an effective second option for untreated malignant pleural mesothelioma. Doctors will have to make judgment calls and decide what treatment is best for an individual. This treatment is a good second option for mesothelioma patients and could be used instead of the first line therapy of nivolumab combined with ipilimumab.
