Durable Responses Achieved With Venetoclax Plus Obinutuzumab in CLL/SLL

Treatment of relapsed/refractory chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) with venetoclax plus obinutuzumab (Ven-O) resulted in durable responses, according to the results of a retrospective study published in Leukemia & Lymphoma.

The approved venetoclax regimen includes rituximab, whereas Ven-O is commonly used off-label. “We aimed to generate real-world evidence on the safety and efficacy of Ven-O,” the authors wrote.

The observational study evaluated data from 40 patients with relapsed/refractory CLL/SLL who received Ven-O between 2019 and 2022. At baseline, the median age was 72 and 22.5% of patients were female. There were 28.2% of patients with a 17p deletion (del[17p]) or TP53 mutation, 65.6% with unmutated IGHV, and 28.2% had a complex karyotype. The median number of prior lines of therapy was 1 (range, 1-6). 

The overall response rate was 90%, which included a complete response or complete response with incomplete hematologic recovery of 27.5%. The ORR was 86.4% among patients who had previously received a BTK inhibitor and 100% among patients with a del(17p) or TP53 mutation.

Progression-free survival (PFS) was 81.2% at 2 years in the entire cohort, and 70.3% among patients previously treated with a BTK inhibitor and 81.8% among patients with a del(17p) or TP53 mutation. Of the 16 patients assessed for minimal residual disease, 56.3% demonstrated undetectable levels.

There were 30% of patients who developed tumor lysis syndrome, which were primarily grade 1-2 in severity. There were no grade 4 or higher IRRs. There were 50% of patients who experienced grade 3-4 neutropenia, 45% with grade 3-4 thrombocytopenia, and 25% with grade 3-4 anemia. Infections requiring treatment occurred among 65% of patients, with 30% requiring intravenous antibiotics. 

“We found that Ven-O achieves frequent, durable responses and can be safety administered to previously treated patients with CLL or SLL,” the authors concluded.

Disclosures: Some of the study authors declared affiliations with biotech, pharmaceutical, or device companies. Please see the original reference for a full list of disclosures.

This article originally appeared on Hematology Advisor