Merck reports positive results for Keytruda combination in malignant pleural mesothelioma

Merck & Co (Merck) – known as MSD outside the US and Canada – has reported positive results from a phase 2/3 study of its anti-PD-1 therapy Keytruda (pembrolizumab) in combination with chemotherapy for certain malignant pleural mesothelioma patients.

Malignant mesothelioma is a type of cancer that starts in the linings of certain parts of the body, with new cases numbering 30,000 worldwide in 2020.

Pleural mesothelioma, which develops in the lining of the lungs, is the most common form of the disease, accounting for about 75% of all cases.

“Malignant pleural mesothelioma is a rapidly progressing cancer that develops in the lining of the lungs and has a poor prognosis,” explained Dr Eliav Barr, senior vice president, head of global clinical development and chief medical officer at Merck Research Laboratories.

The phase 2/3 CCTG IND.227/KEYNOTE-483 trial was sponsored and conducted by the Canadian Cancer Trials Group (CCTG) in collaboration with investigators in Italy and France.

At the final analysis of the study, Keytruda plus chemotherapy showed a statistically significant and clinically meaningful improvement in overall survival compared to chemotherapy alone in patients with unresectable advanced or metastatic malignant pleural mesothelioma.

The safety profile of the combination was also consistent with previously reported studies, Merck reported.

“Patients are in need of new treatments that can improve survival outcomes, and these positive results support the potential of Keytruda in combination with chemotherapy as a first-line treatment for patients with the most common form of malignant mesothelioma,” Barr said.

Dr Quincy Chu, CCTG’s study chair of the trial, added: “The results from the trial have the potential to make a difference for patients with this disease who have had limited treatment options available to them.”

Merck said it plans to share full details from the trial at an upcoming medical meeting.

Keytruda’s combination with platinum-based chemotherapy has already become a standard of care in certain metastatic non-small cell lung cancer patients.

The drug was granted breakthrough therapy designation in the US in February, in combination with Merck and Moderna’s investigational personalised mRNA cancer vaccine, as an additional treatment for high-risk melanoma patients.

This was based on positive results from a phase 2b trial in which the combination reduced risk of recurrence or death by 44% compared with Merck’s anti-PD-1 therapy alone.