Merck & Co’s cancer treatment Keytruda was almost twice as successful at shrinking lung cancer tumours than a standard chemotherapy regimen, a study of the drug in previously untreated patients found.
In the 123-patient study, 55% of those on Keytruda plus two chemotherapy drugs saw their tumours get smaller, compared with 29% on just the chemotherapy drugs, Merck said in a statement.
They also went longer before their disease started growing again and had a lower risk of death.
The study, conducted by researchers at the Hospital at the University of Pennsylvania, found 33 of the 60 patients who received both Keytruda, also known as pembrolizumab, plus chemotherapy (carboplatin plus pemetrexed), responded to treatment, compared to 18 of 63 patients who received only chemotherapy, according to a statement from the company.
Chemotheraphy has long been a standard of care for lung cancer patients whose tumours have spread, and the new study could made Merck’s drug a key part of those treatments.
“This will change practice,” Roger Perlmutter, Merck’s head of research and development. “People will be treated differently going forward.”
Keytruda is currently approved for use in non-small cell lung cancer patients who have tried and failed chemotherapy.
Approving it as a first-line treatment could vastly expand use of the drug, which is projected by analysts to be a blockbuster – a drug selling more than $1bn annually. It’s also approved for use in melanoma, as well as head and neck cancers.
The drug triggers immune cells to attack tumours, destroying them with the body’s natural defences.
Matthew Hellmann, an oncologist who specialises in lung cancer at Memorial Sloan Kettering Cancer Center in New York, said that despite the results from combining Keytruda with chemotherapy, he predicted that Keytruda alone would be the standard of care.
The combination with chemotherapy is “a welcome addition to the field,” he said, but a larger sample size is needed to make a stronger conclusion.
Merck has been battling against Bristol-Myers Squibb Co for dominance of the new immune-oncology drugs.
Much of that contest has been focused on whether patients’ tumours need to express high levels of a marker called PD-L1 for the drugs to work. In August, Bristol-Myers announced that its competing drug, Opdivo, failed a trial testing the drug as a sole treatment for lung cancer, after the company included patients with lower levels of the marker.
Two months earlier, Merck announced that Keytruda had succeeded in a similar trial that included only patients with higher levels of the marker. Hellmann predicted that testing for the biomarker would become standard.
The combination of Keytruda with chemotherapy drugs was tested in all patients, regardless of their levels of the PD-L1 marker, and the result could widen use of Merck’s drug to an even bigger population.
The data were released in Copenhagen at the European Society for Medical Oncology’s annual meeting, and also published in the Lancet Oncology medical journal. In the study, which is called KEYNOTE-21, patients on Keytruda also went longer before their tumours started growing again, Merck said. Those getting the combination therapy had an average progression-free survival of 12 months, compared to 8.9 months with the standard of care. The risk of disease progression or death was reduced by 47%, according to the study.
Merck also released fuller results from the study it highlighted in June, where Keytruda was given as a sole treatment to those with high levels of the PD-L1 biomarker. In the study, called KEYNOTE-24, patients got either Keytruda or chemotherapy. Keytruda reduced the risk of death or cancer progression by 50%, Merck said, and it took 10.3 months on average for their cancer to progress, compared with 6 months on chemotherapy.
The results were published yesterday in the New England Journal of Medicine.
Those results could keep Merck ahead of Bristol-Myers, which will present more detailed data from its trial on Sunday at the medical meeting. Doctors and investors will be watching to see if certain groups of patients in the Bristol-Myers trial responded better.
Perlmutter, the head of research and development at Merck, predicted that patients whose tumors expressed the PD-L1 marker at least 50% of the time could get Keytruda as a single therapy, then add chemotherapy if that wasn’t effective.