<qa>  What is the history of allergic reactions attributed to?- History of allergic reactions attributed to compounds of similar chemical or biologic composition to ABT-888, bendamustine or mannitol; patients enrolling in the cohort expansion or phase 2 portions of the study who have been intolerant of repeated doses of rituximab in the past will be excluded patients who have had infusion reactions to their initial dose of rituximab will not be excluded 