At the 2014 American Society of Hematology (ASH) Annual Meeting, Dr Ian Flinn (Sarah Cannon Cancer Institute, Nashville, TN) discusses the preliminary results of a phase Ib study (GP28331) combining GDC-0199 (ABT-199) and obinutuzumab in patients with relapsed/refractory or previously untreated chronic lymphocytic leukaemia (CLL).