NEW YORK, Feb. 11, 2013 (GLOBE NEWSWIRE) -- TG Therapeutics, Inc. (TGTX) today announced that it has amended its Phase I/II study of single agent ublituximab to initiate its first expansion cohort following early signs of clinical activity. The protocol has been expanded to enroll up to 25 additional patients at the 900 mg dose level in the Phase I/II trial evaluating the safety, tolerability and efficacy of ublituximab, the Company's novel third-generation anti-CD20 monoclonal antibody, for patients with rituximab (Rituxan®) relapsed or refractory B-cell non-Hodgkin's lymphoma (NHL). Dose escalation will continue as planned to the 1200 mg dose cohort. Following successful completion of the dose escalation component of the study, an additional expansion cohort may be added at the highest dose of 1200 mg. The trial, entitled "An Open Label Phase I/II Trial of the Efficacy and Safety of Ublituximab in Patients with B-cell Non-Hodgkin Lymphoma who have Relapsed or are Refractory After CD20 Directed Antibody Therapy," (NCT01647971) has completed enrollment in 3 cohorts (450, 600 and 900mg) in the Phase I dose escalation component. All patients continue to be stratified by subtype of B-cell Lymphoma and all enrolled patients will be relapsed or refractory to Rituxan® or a Rituxan® containing regimen, and in most cases multiple other lines of therapy. In addition to the cohort expansion, the study was amended to now allow enrollment of patients with Chronic Lymphocytic Leukemia (CLL), Small Lymphocytic Lymphoma (SLL) as well as Primary Central Nervous System Lymphoma (PCNSL). Phase I data from a trial conducted in France with ublituximab administered as a single agent at a dose of 450 mg to relapsed and refractory CLL patients reported an objective response rate of 45%, with a manageable safety profile. Dr. Owen O'Connor, Professor of Medicine and Director, Center for Lymphoid Malignancies at New York Presbyterian Columbia Medical Center, and the principal investigator of the trial stated "Ublituximab has been well-tolerated at all dose levels tested with no dose limiting toxicities seen to date. Coupled with the clinical activity seen in both rituximab relapsed and refractory patients across the dose levels tested thus far, we made the determination to expand the 900mg dose while we continue dose escalating. We look forward to expanding the study to better evaluate the safety and efficacy profile of ublituximab in multiple sub-types of B-cell malignancies."