Multiple studies presented at last month’s American Association for Cancer Research conference in Philadelphia show promising results in favor of a new cancer immunotherapy drug, Merck & Co.’s Keytruda®, in the treatment of mesothelioma, lung cancer, and melanoma.
This new wave of drugs works to support the immune system by attacking and ultimately killing cancer cells. Specifically, Keytruda® targets a protein called Programmed death-ligand 1, or PD-L1, which is speculated to be an immune system suppressor.
One study comparing the efficacy of Keytruda® to Yervoy, Bristol-Myers Squibb’s market contender, showed 33 percent of melanoma patients on Keytruda® with shrinking or disappearing tumors, versus 12 percent of Yervoy patients, who also experienced serious side effects earlier and more often. In 495 patients with advanced non-small cell lung cancer, equally encouraging results were found with a high percentage of patients responding positively to the treatment, with shrinking or disappearing tumors and extended survival rates.
Dr. Hossein Borghaei, a lung cancer and mesothelioma specialist at Fox Chase Cancer Center in Philadelphia, noted that these outcomes, including the fact that Keytruda® extended survival about the same as regular chemotherapy, are “great news.”
Keytruda® and Mesothelioma
For mesothelioma specifically, a rare and fatal cancer caused by exposure to asbestos, Borghaei stated that, “It’s very encouraging to have the kind of results that the investigators are reporting…[especially] for an early-stage investigation into this terrible disease.”
In a study of 25 mesothelioma patients who had tumors with the PD-L1 protein, for which chemotherapy proved unsuccessful, 76 percent saw improvements after an average of 5½ months of treatment. Tumors shrank in 28 percent of patients while tumors stopped growing completely in another 48 percent. Compared to chemotherapy, the side effects of Keytruda® were also more tolerable.