Ublituximab Succeeds in Phase 3 Leukemia Trial

Ublituximab/ibrutinib combo improves response rate versus ibrutinib alone

Positive results have been reported from a phase 3 trial of ublituximab (TG Therapeutics) plus ibrutinib (Imbruvica, Pharmacyclics/Janssen Biotech) in patients with previously treated high-risk chronic lymphocytic leukemia (CLL). High risk was defined as having any one or more of the following: 17p deletion, 11q deletion, or p53 mutation.

Ublituximab is a glycoengineered monoclonal antibody that targets a specific epitope on the CD20 antigen found on mature B-lymphocytes. 

The GENUINE trial was a randomized, open-label, multicenter study designed to evaluate the safety and efficacy of ublituximab plus ibrutinib compared with ibrutinib alone in adults with high-risk CLL who had received at least one therapy for their disease. The study involved a total of 162 patients in the United States and Israel. The patients received oral ibrutinib (420 mg once daily) in both the treatment and comparator arms. In the treatment arm, the patients also received intravenous infusions of ublituximab (900 mg) on days 1, 8, and 15 of cycle 1 and on day 1 of cycles 2 through 6. Patients in the treatment arm who did not progress received quarterly 900-mg infusions of ublituximab maintenance.

The study met its primary endpoint, demonstrating a statistically significant improvement in the overall response rate with ublituximab plus ibrutinib compared with ibrutinib alone in the treated population (80% vs. 47%, respectively; P < 0.001). The treated population included all patients who had received at least one dose of either study drug (59 in the ublituximab/ibrutinib arm and 58 in the ibrutinib arm).

Source: TG Therapeutics; March 6, 2017.