ASH 2020: PI3K Inhibitor Plus Monoclonal Antibody Versus Chemoimmunotherapy for CLL
Posted: Monday, December 14, 2020
According to John G. Gribben, MD, DSc, of the Queen Mary University of London, United Kingdom, and colleagues, patients with treatment-naive or relapsed or refractory chronic lymphocytic leukemia (CLL) experienced superior progression-free survival after treatment with umbralisib plus ublituximab compared with those who were treated with standard chemoimmunotherapy. The multicenter phase III UNITY-CLL trial results were presented during the virtual edition of the 2020 American Society of Hematology (ASH) Annual Meeting and Exposition (Abstract 543).
“Umbralisib is an oral, once-daily, novel, dual inhibitor of phosphatidylinositol-3-kinase-delta and casein kinase-1ε,” the investigators noted. “Ublituximab is a novel anti-CD20 monoclonal antibody.”
Initially, patients were randomly assigned in a 1:1:1:1 ratio to receive umbralisib plus ublituximab, obinutuzumab plus chlorambucil, umbralisib monotherapy, or ublituximab monotherapy. Subsequently, the patients were randomly assigned in a 1:1 ratio to receive umbralisib plus ublituximab (n = 210) or obinutuzumab plus chlorambucil (n = 211).
The median duration of progression-free survival with umbralisib plus ublituximab and obinutuzumab plus chlorambucil was 31.9 versus 17.9 months, respectively (P < .0001). The estimated 24-month progression-free survival rate was higher with umbralisib plus ublituximab (60.8%) than with chemoimmunotherapy (40.4%). This progression-free survival benefit was also observed in the treatment-naive (median 38.5 vs. 26.1 months) and relapsed or refractory (median 19.5 vs. 12.9 months) subgroups.
The independent review committee–assessed objective response rate was 83.3% with umbralisib plus ublituximab and 68.7% with chemoimmunotherapy (P < .001). Among patients who were previously treated with ibrutinib (6%), the objective response rate was higher with umbralisib plus ublituximab than with chemoimmunotherapy (57% vs. 25%, respectively). Neutropenia, thrombocytopenia, diarrhea, infusion-related reaction, elevated levels of aspartate transaminase/alanine transaminase, colitis, and pneumonitis were among the most frequently reported grade 3 or 4 adverse events.
Disclosure: For full disclosures of the study authors, visit ash.confex.com.
