Keytruda is already approved in more than 40 different oncology indications, but its latest label expansion is a first for the cancer blockbuster.
Merck announced Wednesday that the FDA cleared the immuno-oncology drug as a first-line treatment, in combination with chemotherapy, for patients with advanced stages of malignant pleural mesothelioma. It’s the first time that Keytruda has been given the green light for the disease in the US in any line of treatment.
The approval was based on Phase 2/3 data showing that Keytruda plus chemotherapy reduced the risk of death by 21% when compared with chemotherapy alone. Patients given Keytruda had a median overall survival of 17.3 months, compared with 16.1 for patients who only received chemotherapy. Those survival results were statistically significant.
Merck said that the treatment arm “also significantly improved progression-free survival,” but both the treatment arm and the chemotherapy-only arm reported a median PFS of 7.1 months. A spokesperson for the company pointed to the 0.8 hazard ratio as evidence of the “statistically significant improvement in PFS.”
The overall response rate for patients given Keytruda was 52%, compared with 29% for those who only received chemotherapy. Merck said the safety profile was similar to that seen in other patients who have received Keytruda in addition to pemetrexed and platinum chemotherapy.
The new approval follows a weekend of key I/O-related updates, including some for Keytruda, at the European Society for Medical Oncology. In a form of liver cancer, Merck found that patients staved off disease progression a bit longer when given Keytruda and Eisai’s VEGF inhibitor Lenvima on top of a procedure that directly delivers chemotherapy to the tumor. Patients who only received the procedure plus placebos had a median progression-free survival of 10 months compared to 14.6 in the combo treatment arm.
More on the minds of investors is whether or not Summit Therapeutics and Akeso have a viable shot to Keytruda’s throne. The two have recently touted data out of China showing their monoclonal antibody bested Keytruda in patients with lung cancer. Summit, who has US rights to ivonescimab, is currently running a global Phase 3 registrational trial to validate the results.