) today announced data from the oral presentation of the Phase IB/II study of the Btk inhibitor, PCI-32765, in chronic lymphocytic leukemia / small cell lymphocytic lymphoma (CLL/SLL) at the 2011 American Society of Clinical Oncology Annual Meeting. A daily oral dose of 420mg was tested initially, and an additional cohort of patients with relapsed/ refractory disease treated with 840mg daily was enrolled following closure of the 420mg qD relapsed/ refractory cohort. This group of patients had a shorter median follow-up time and were included only for initial response assessment and summary safety data. Overall, PCI-32765 has been well-tolerated; discontinuation of treatment for adverse events occurred in only 3 of 83 patients. Diarrhea, nausea/ vomiting, and dyspepsia were the most frequently reported events and were typically of modest severity.