SOHO 2020: Debulking Regimens Prior to Venetoclax Therapy for CLL
Posted: Thursday, September 24, 2020
Treatment of patients with chronic lymphocytic leukemia (CLL) using obinutuzumab with or without bendamustine reduced the tumor burden after two cycles, allowing for the initiation of venetoclax and decreasing the risk of tumor-lysis syndrome. Jeff Sharman, MD, of the Willamette Valley Cancer Institute and US Oncology Research in Eugene, Oregon, presented this study on behalf of his colleagues during the virtual edition of the 2020 Society of Hematologic Oncologists (SOHO) Annual Meeting (Abstract CLL-076).
This phase IIIb trial recruited 110 patients with untreated CLL/SLL (small lymphocytic leukemia) who did not have a deletion in 17p and had a medium-to-high tumor burden. Patients received between two and six cycles of obinutuzumab with or without bendamustine debulking therapy. Patients were then switched initially to venetoclax plus obinutuzumab once the tumor burden was low, continuing with venetoclax alone afterward.
At the time of data collection, 76 patients had been given obinutuzumab and 34 had received obinutuzumab plus bendamustine. The baseline tumor burden was medium in 73% of patients and high in 26%. A low tumor burden was attained in 87% of all patients, representing 92% of the obinutuzumab group and 77% of the obinutuzumab-plus-bendamustine group. The median decrease in lymph node size was 0.5 cm with obinutuzumab and 3 cm with the combination treatment after two cycles, further decreasing after more cycles.
Grade 3 or higher adverse events were seen in 68% of patients treated with obinutuzumab plus bendamustine and 38% of patients treated with obinutuzumab alone. Grade 3 or higher adverse events were similar among the groups during the venetoclax phase, but the rate of venetoclax interruptions and dose reductions was higher in the group initially in receipt of debulking therapy with obinutuzumab and bendamustine compared with obinutuzumab alone. During the debulking phase, tumor-lysis syndrome occurred in two patients given obinutuzumab and five patients given obinutuzumab plus bendamustine.
Disclosure: No disclosure information was provided.