Patients with previously untreated or R/R CLL requiring therapy were eligible for the study. Treatment was given for 14 cycles of 28 days with OBIN, IBR, and VEN started sequentially over the first 3 cycles.
The study enrolled a total of 50 patients; 25 were previously untreated and 25 were R/R. In terms of safety, hematologic toxicities were most frequent, with 80% of patients experiencing all-grade thrombocytopenia and 76% experiencing neutropenia. The most frequent all-grade nonhematologic toxicities were hypertension (70%), infusion-related reactions (66%), bruising (52%), myalgia (50%), and nausea (50%). Grade ≥3 adverse events included neutropenia (56%) and thrombocytopenia (34%).
The median follow-up for the study was 21.5 months for the R/R cohort and 24.2 months for the previously untreated cohort. The overall response rate (ORR) in R/R patients at end of treatment was 84% for treatment naïve patients and 88% for R/R patients. A total of 67% and 50% of treatment-naïve and R/R patients achieved MRD-negative status at end of therapy, respectively, 28% of whom achieved complete responses in both groups.
In conclusion, the combination of OBIN, IBR, and VEN showed a tolerable safety profile in both R/R and previously untreated CLL patients. This triple-agent regimen has a high ORR in treatment-naïve and R/R patients, with promising early MRD-negative responses. Long-term follow-up is needed to determine PFS.
Rogers KA, et al. ASH 2018. Abstract 693.