of patients had at least a minimal response that was classified as a clinical benefit, but that still means that about two-thirds of patients didn’t respond to therapy. Onyx doesn’t really know why some patients responded while others didn’t, Kauffman says.
For those lucky enough to respond to carfilzomib therapy, the news is much better, partly because of its tolerability. “What’s exciting about carfilzomib, we have been able to give it for two years without significant side effects accumulating,” Kauffman says. About 12 percent of patients dropped out of the study because of side effects, he says.
Siegel, the investigator who’s presenting the carfilzomib results, said he expects doctors to continue prescribing the hit Celgene product lenalidomide (Revlimid) and Millennium’s bortezomib as they are used today. The Onyx drug will initially be used in patients who stop responding to the others. But he raves about the side effects and tolerability of the new product. Onyx, and many investigators, clearly see potential in moving the new drug ahead with patients at earlier stages of treatment.
“It works well, and when it does work, it’s not a 15-minute kind of thing,” Siegel says. “It’s exceptionally well-tolerated. It’s a triple.” Some of his peers may question how sick some of the patients in this study really were, and how many were truly resistant to other therapy, or refractory. The criticisms, Siegel predicts, won’t stand up over time.
Onyx executives plan to discuss the findings in detail today on a webcast with investors at 10 am Eastern/7 am Pacific time.
