TG Therapeutics announced positive topline results from its Phase 3 GENUINE clinical trial of TG-1101 (ublituximab) plus ibrutinib in patients with previously treated high risk Chronic Lymphocytic Leukemia (CLL). For the study, high risk was defined as having any one or more of the following: 17p deletion, 11q deletion or p53 mutation.
The multicenter, randomized trial (NCT02301156), 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).
Overall Response Rates
| TG-1101 plus Ibrutinib | Ibrutinib | P-value | |||
| Treated Population (n) | n=59 | n=58 | |||
| Overall Response Rate | 80 | % | 47 | % | P < 0.001 |
All responses were assessed by independent blinded central review using the iwCLL 2008 guidelines. Per iwCLL guidelines, responders require confirmation of response for a minimum duration of 2 months. 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 approximately 12 months.
The GENUINE study was designed to demonstrate the value of adding TG-1101, a highly potent next generation glycoengineered anti-CD20 monoclonal antibody to ibrutinib monotherapy in high risk CLL, and was powered to show a statistically significant improvement in ORR, with a minimal absolute detectable difference between the two arms of approximately 20%. The absolute difference between the arms was approximately 30% resulting in a p-value of ≤ 0.001. Results from registration directed studies included in the ibrutinib prescribing information demonstrate single agent ibrutinib response rates ranging from 43% to 58% in patients with previously treated CLL, with the findings from the GENUINE study of 47% ORR for ibrutinib fitting well within historical experience.
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. Sufficient data on MRD negative status and bone marrow confirmation of radiographic CRs were not available at the time of analysis. 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.
A full analysis of the Phase 3 GENUINE data along with detailed efficacy and safety results will be submitted for presentation at a medical meeting in the first half of 2017 and the Company plans to meet with the FDA as soon as possible thereafter to discuss the filing of the data for accelerated approval.
“TG-1101 is a highly potent next generation glycoengineered anti-CD20 monoclonal antibody. We believe the data today demonstrate that the addition of TG-1101 to ibrutinib enhances the therapeutic benefit of ibrutinib in patients with previously treated high risk CLL, the patient population with the poorest outcome on ibrutinib. We believe the results observed in the combination arm are extremely compelling and the regimen has the potential to become the standard of care for treating patients with high risk CLL that have progressed from other therapies,” said Michael S. Weiss, Executive Chairman and Chief Executive Officer of TG Therapeutics. Mr. Weiss continued, “We believe that using combination therapy to accelerate and deepen response in poor prognosis high risk CLL is critically important for patient outcomes and we look forward to sharing these data with the FDA in the coming months to discuss filing for accelerated approval. Most importantly, we would like to thank the investigators and their patients for participating in this significant research.”
Dr. Jeffrey Sharman, the GENUINE Phase 3 Study Chair and the Medical Director for Hematology Research for the US Oncology Network, commenting on the results stated, “Ibrutinib has been a great addition to our CLL armamentarium, however we have long believed that ibrutinib alone may not be enough, particularly for patients with high-risk disease. This study demonstrates that the addition of ublituximab, can significantly enhance the response rates without compromising safety. We believe that the rapid responses seen in our Phase 2 study with ublituximab plus ibrutinib are validated here in our Phase 3 GENUINE study and are important markers of improved overall efficacy and patient outcomes. I look forward to the presentation of the results at an upcoming medical meeting.”
Filed Under: Drug Discovery
