Lindsey Roeker, MD, spoke about phase 2 trial results which demonstrated efficacy of the combination of umbralisib and ublituximab added to ibrutinib for patients with chronic lymphocytic leukemia.
At the 2021 American Society of Hematology Annual Meeting, CancerNetwork® spoke with Lindsey Roeker, MD, a hematologic oncologist at Memorial Sloan Kettering Cancer Center in New York, about a phase 2 trial (NCT04016805) of umbralisib (Ukoniq) plus ublituximab added to ibrutinib (Imbruvica) for patients with chronic lymphocytic leukemia. Roeker also spoke about which results she was most interested to see come out of this study.
We’ve treated 28 patients on the study and 27 are evaluable for efficacy. We know that 77% of patients have achieved undetectable MRD [minimal residual disease] and have been able to enter a period of treatment-free observation. Among those who have entered treatment-free observation, only 1 patient has progressed and required retreatment. That patient progressed within the 6-month time frame and was not retreated with the triplet per protocol, but just went back on ibrutinib monotherapy and was able to achieve a response. We do have a number of patients who are still on therapy and could achieve undetectable MRD, and the average time to an undetectable MRD response is about 7 months in this cohort. It’s a group of patients who are able to go on triplet therapy, have that period of exposure to the drug, and then enter treatment-free observation. We’ve been watching MRD over time. But as I said, we’ve had very few progression events. The progression-free survival in this study looks excellent.
We know that the combination of ibrutinib and obinutuzumab [Gazyva] achieves undetectable MRD in about 35% of patients. The high rate of undetectable MRD [in this current study] was an incredibly pleasant surprise in this study. We obviously thought that the combination therapy was going to be effective, but I think it surpassed our expectations with this high rate of undetectable MRD. I think we’ve also seen some durability of treatment-free observation for many of these patients, which is absolutely a fantastic result in something that our patients are really excited about.
Roeker L, Leslie L, Soumerai J, et al. A phase 2 study evaluating the addition of ublituximab and umbralisib (U2) to ibrutinib in patients with chronic lymphocytic leukemia (CLL): A minimal residual disease (MRD)- driven, time-limited approach. Presented at the 2021 American Society of Hematology Annual Meeting. December 11-14, 2021. Abstract 395. https://bit.ly/3sKm471