Two patients came off study; one with pneumonia and an intracranial abscess, who died, and another who discontinued due to mucositis/ulcers after four cycles.
Severe toxicities were uncommon in both studies, particularly the considerable immunosuppression and serious infections associated with standard chemo-immunotherapy, the investigators said. The most common event was diarrhea, which was experienced by 54% of patients receiving ibrutinib monotherapy and was largely grade 1 or 2 and resolved after the first couple of cycles, Dr. Byrd said.
Other events included fatigue (29%), upper respiratory infection (29%), rash (28%), nausea (26%) and bone pain (25%). Rates were similar in the combination therapy trial, with bruising also seen in both trials
One of the ongoing phase III trials is the 350-patient RESONATE study evaluating ibrutinib versus ofatumumab (Arzerra) in patients with relapsed or refractory CLL or SLL.
Dr. Byrd disclosed research funding from the study sponsor Pharmacyclics, which is developing ibrutinib. Dr. Burger reported consulting for and research funding from Pharmacyclics. Co-authors of both studies are Pharmacyclics employees. Dr. Dearden disclosed no conflicts of interest.