Keytruda, the brand name for the immunotherapy drug pembrolizumab, has had ups and downs as a therapy for malignant mesothelioma.
Results from the latest phase 3 trial – titled “PROMISE-meso” – have ups and downs altogether.
The mixed results for Keytruda compared to chemotherapy seem to further move the mesothelioma treatment model away from the immune checkpoint inhibitor. While the response rate was a win for Keytruda, the overall and progression-free survival data for the mesothelioma immunotherapy were setbacks.
Keytruda is an immune checkpoint inhibitor targeting the PD-1/PD-L1 protein relationship. The goal is to block these proteins from linking and help T cells naturally fight cancer cells.
European Thoracic Oncology Platform sponsored the phase 3 clinical trial, which featured 144 participants split into two groups: one receiving Keytruda; the other receiving one of two chemotherapy drugs. The randomized trial had results posted on clinicaltrials.gov early in 2022.
How Keytruda Performed for Mesothelioma
Keytruda patients received the immunotherapy once every three weeks, at a dosage of 200 mg, for a maximum of two years. While 73 patients started the mesothelioma treatment, only eight made it the full two years.
Chemotherapy patients received gemcitabine or vinorelbine once every three weeks for a maximum of two years. Only five of 71 patients lasted this long in the trial, with most stopping due to disease progression.
Progression-free survival for Keytruda was just 2.5 months, whereas chemotherapy reached 3.4 months. Overall survival was 10.7 months in median for Keytruda and more than 12 months for chemotherapy. Nearly every patient in the Keytruda arm experienced an adverse event from treatment, while 93% of the chemotherapy arm fit this description.
The objective response rate – meaning the percentage of patients seeing a positive response to treatment – was 22% for Keytruda and only 5% for chemotherapy.
Sources & Author
- PembROlizuMab Immunotherapy Versus Standard Chemotherapy for Advanced prE-treated Malignant Pleural Mesothelioma (PROMISE-meso). Clinicaltrials.gov. Retrieved from: https://clinicaltrials.gov/ct2/show/NCT02991482. Accessed: 02/22/2022.
Sources & Author