First-Line Keytruda Treatment May Support Longer Mesothelioma Survival

New data suggests first-line Keytruda treatment helps lung cancer patients more than chemotherapy – even if chemotherapy patients add Keytruda later. The news is likely to have implications for people with pleural mesothelioma, too.

German researchers presented the data earlier this week at the World Lung Cancer Conference in Barcelona. 

The presentation was based on three years of the KEYNOTE-024 trial. The trial focused on lung cancer. But Keytruda is also an up-and-coming drug for malignant pleural mesothelioma. Pleural mesothelioma is a lung-related cancer similar to non-small cell lung cancer. 

Blocking PD-L1 with First-Line Keytruda Treatment

Keytruda is the brand name for pembrolizumab. It is an immune checkpoint inhibitor that blocks a protein called PD-L1. To be eligible for first-line Keytruda treatment, study participants had to have a PD-L1 score of at least 50 percent. 

PD-L1 helps cancers like non-small cell lung cancer and malignant mesothelioma hide from the immune system. An Australian study found more than 70 percent of mesothelioma tumors overexpress PD-L1. 

In the KEYNOTE-024 trial, patients were randomly selected to receive first-line Keytruda treatment or standard chemotherapy. The Keytruda group received 200 mg for two years. The chemotherapy group had four to six cycles of a platinum-based combination.

Chemotherapy patients had the option to also go on Keytruda if their disease progressed after treatment.

Immunotherapy Continues to Impress

Like pleural mesothelioma, non-small cell lung cancer grows and spreads quickly. The chemotherapy patients in the trial had a median survival of just 14.2 months. But the median survival for patients in the Keytruda group was more than two years (26.3 months). 

Forty-three percent of patients on pembrolizumab were still alive at 36 months. That compares to just 25 percent in the chemotherapy group. 

And even though the first-line Keytruda treatment patients were on medicine for two years, they had fewer serious side effects than people on chemotherapy. 

Keytruda even worked as a retreatment in 70 percent of people whose cancer came back. This is potentially significant for mesothelioma patients. There is no second-line mesothelioma treatment. 

“First-line pembrolizumab monotherapy continued to provide durable long-term overall survival  benefit vs chemotherapy despite a majority of patients assigned to chemotherapy crossing over to pembrolizumab,” said Dr. M. Reck, Member of the German Center for Lung Research. 

Reck says most patients who had 35 cycles of first-line Keytruda treatment were still alive at the end of the trial. 

Keytruda is the most talked-about in a growing field of immunotherapy treatments for mesothelioma. In 2015, Keytruda gained national attention as a potential mesothelioma treatment after 72 percent of mesothelioma clinical trial participants showed a response to it. In about a quarter of those patients, Keytruda shrunk their mesothelioma tumors.

Source:

“KEYNOTE-024 Three-Year Survival Update: Pembrolizumab Effective as First-Line Therapy for Advanced Non–Small-Cell Lung Cancer”, September 10, 2019, International Association for the Study of Lung Cancer presentation, News Release, https://wclc2019.iaslc.org/wp-content/uploads/2019/09/Keynote-024-Finalbbedits.pdf