A cancer drug that boosts the immune system outperforms chemotherapy in fighting advanced lung cancer, a new trial shows.
Keytruda, or pembrolizumab, extended life four to eight months longer than chemotherapy in lung cancer patients whose immune systems had been duped by their cancer cells.
“This trial shows that pembrolizumab used alone improves survival as opposed to chemotherapy,” said lead researcher Dr. Gilberto Lopes, a medical oncologist with the Sylvester Comprehensive Cancer Center at the University of Miami Health System.
But while Keytruda works better than chemotherapy, the combination of the two is likely to be the best first choice for treatment of lung cancer, Lopes added.
“We do believe based on a study presented about a month ago that the combination of chemotherapy plus pembrolizumab probably is better than pembrolizumab alone,” Lopes said. “What we likely will see as the new standard of care is for us to combine both drugs.”
Keytruda fights cancer by “taking the brakes away from the immune system so our own defense cells can recognize cancer cells and kill them,” Lopes explained.
PD-L1 is found on cancer cells, and it essentially shoos away the immune system, fooling it into thinking that cancerous tissue is normal and healthy. Keytruda blocks that interference, allowing killer immune cells to find and destroy the cancer.
- Patients with PD-L1 in half of their tumors experienced 20 months average survival on pembrolizumab, compared to 12 months with chemotherapy.
- Those with PD-L1 in 20 percent of tumors had 17.7 months average survival with pembrolizumab, compared with 13 months for chemotherapy.
“For all the three groups we studied, pembrolizumab led to longer survival and higher overall survival rates than chemotherapy alone,” Lopes said.
The immunotherapy also proved to be a milder treatment than chemo. Only 18 percent of patients reported severe side effects with pembrolizumab, compared with 41 percent of patients on chemotherapy.
This would make pembrolizumab a strong option for older and sicker lung cancer patients who can’t safely handle the strain caused by chemo, said ASCO President Dr. Bruce Johnson, chief clinical research officer at the Dana-Farber Cancer Institute in Boston.
“You can give these therapies to people who are not feeling particularly well, because for most of the people it doesn’t have the kind of side effects that come with chemotherapy,” Johnson said.