Following “positive” topline results from its Phase 3 GENUINE clinical trial of TG-101 in combination with ibrutinib, shares of TG Therapeutics (TGTX 9.80, +4.45 +83.2%) trade to near 14-month highs. Before getting into the details, let’s take a quick look at TG Therapeutics. TGTX is a New York-based biopharma company which focuses on the acquisition, development and commercialization of novel treatments for B-cell malignancies and autoimmune diseases.
Currently, the company is developing two therapies targeting hematological malignancies and autoimmune diseases.
- TG-1101 (ublituximab) is a novel, glycoengineered monoclonal antibody that targets a specific and unique epitope on the CD20 antigen found on mature B-lymphocytes.
- TG Therapeutics is also developing TGR-1202, an orally available PI3K delta inhibitor. The delta isoform of PI3K is strongly expressed in cells of hematopoietic origin and is believed to be important in the proliferation and survival of B-lymphocytes.
Turning to today’s news, it was announced that TG-1101 (ublituximab), when used in combination with ibrutinib in patients with previously treated high risk Chronic Lymphocytic Leukemia, was shown to enhance the therapeutic benefit of ibrutinib in patients with previously treated high risk CLL, the patient population with the poorest outcome on ibrutinib.
The trial, which assessed the efficacy and safety of TG-1101 plus ibrutinib, met its primary endpoint, demonstrating a statistically significant improvement in Overall Response Rate (ORR) compared to ibrutinib alone in both the Intent to Treat (ITT) population (p=0.001) and Treated population (p<0.001). The ITT population includes all 126 randomized patients (64 in the TG-1101 + ibrutinib arm and 62 in the ibrutinib alone arm) while the Treated population includes all ITT patients that received at least one dose of either study drug (59 in the TG-1101 + ibrutinib arm and 58 in the ibrutinib alone arm).
All responses were assessed by independent blinded central review using the iwCLL 2008 guidelines. As of the date of the analysis, each arm had responders that were awaiting confirmation visits which are scheduled to occur over the next two months. During the study it was infrequent (less than 3% in the combination arm) for initial responses to fail to be confirmed. Median follow-up for the study was about 12 months.
In addition to ORR, observed advantages were seen for the combination in a number of secondary and other efficacy measures, including radiographic Complete Response (CR) rate, Progression Free Survival and Time to Response. From a safety standpoint, the combination was well tolerated with a safety profile consistent with the Phase 2 study of ublituximab plus ibrutinib recently published in the British Journal of Haematology.
Looking ahead, TGTX plans to have a full analysis of the Phase 3 GENUINE data at a medical meeting in the first half of 2017.