Bristol-Myers Squibb ($BMY) has emerged, at least temporarily, as the leader in a race to develop the first new PD-1 drug to fight cancer.
In a preview of the data to be discussed at ASCO, investigators told reporters that the drug, in combination with Yervoy, achieved an objective response rate of 40% among the 53 patients treated in a small study. And in close to a third of the patients with advanced melanoma, tumors were reduced more than 80% in 12 weeks.
"I think it was really the rapidity and the magnitude of the responses that was impressive to us," noted Jedd D. Wolchok of the Memorial Sloan-Kettering Cancer Center, according to a report in The New York Times.
Yervoy itself offers only a limited ability to help patients, but when nivolumab is added to the approved therapy, Bristol-Myers appears to have the leg up over competing programs at Merck ($MRK) and Roche ($RHHBY). And that could translate into billions of dollars in future sales.
"The combination is potentially important because Merck and Roche are developing their own drugs that work similarly," wrote Forbes' Matthew Herper. "If combining them with Yervoy leads to better efficacy, Bristol is likely to emerge a winner no matter what. From a Wall Street perspective, this could be the biggest news of the meeting."
The drug programs are intended to strip away a key defense mechanism used by tumor cells to guard against T-cells, the immune system's attack dogs.
Merck's lambrolizumab, meanwhile, reportedly shrank advanced tumors by 35%, while Roche's experimental MPDL3280A demonstrated an ability to shrink tumors in 29 of 140 advanced cancer patients with various tumor sizes.
Anxious to keep its lead, Bristol-Myers has already begun a Phase III study of its combination therapy for melanoma. And there are 5 other studies of nivolumab underway for various cancers.