AbbVie released interim results from a Phase Ib clinical trial of ABT-199/GDC-0199, an investigational B-cell lymphoma 2, BCL-2, selective inhibitor, in combination with rituximab. Results showed an overall response rate, ORR, of 84%, in patients with relapsed/refractory chronic lymphocytic leukemia, CLL, the most common leukemia in the United States. These results were presented at the 50th Annual Meeting of the American Society of Clinical Oncology, ASCO, May 30 – June 3 in Chicago. Of the 25 evaluable patients, 36% achieved either a complete response or complete response with incomplete blood count recovery, CR/CRi, and 48% achieved a partial response, PR, as of April 16. Additionally, of the patients who achieved a CR, 75% were identified as minimal residual disease,MRD, negative, indicating the detection of zero leukemic cells. "The data presented at ASCO evaluating ABT-199/GDC-0199 in combination and as a single agent therapy in patients with a variety of tumors will help guide the continued development of this compound, which is being evaluated in pivotal Phase II and Phase III trials," said Gary Gordon, M.D., divisional vice president, oncology clinical development, AbbVie. "Patients suffering from these difficult-to-treat malignancies are the driving force behind the continued clinical development of ABT-199/GDC-0199."