Computed tomography assessment was used for the primary end point to allow comparison to the ibrutinib monotherapy study, which did not use positron emission tomography for restaging. “Our study was designed to have 80% power to reject a complete response rate of 9% (at a one-sided alpha level of 0.05) if the rate of complete response was at least 30%,” the investigators noted.
Complete response rate assessed by positron emission tomography at week 16 was 62%, and was 71% overall.
In all, 67% of patients had absence of minimal residual disease by flow cytometry. At 15 months, 78% of the responses were ongoing, and at 18 months, 57% of patients were alive and progression free.
“Such outcomes appear to be substantially better than those that have been reported for ibrutinib or venetoclax monotherapy,” the investigators wrote.