Venetoclax Plus Obinutuzumab in Patients With Untreated CLL
Posted: Wednesday, September 4, 2019
According to the results of the phase III CLL14 trial, presented at the 2019 American Society of Clinical Oncology (ASCO) (Abstract 7502), the BCL2 inhibitor venetoclax plus the monoclonal antibody obinutuzumab improved progression-free survival in patients with previously untreated chronic lymphocytic leukemia (CLL), compared with obinutuzumab and chlorambucil. Kirsten Fischer, MD, of the Center of Integrated Oncology Köln Bohn at the University Hospital, Cologne, Germany, and colleagues found that a fixed-duration of venetoclax plus obinutuzumab induced “deep and long-lasting” minimal residual disease rates.
In this clinical trial (ClinicialTrials.gov identifier NCT02242942), the investigators enrolled 432 patients who were randomly assigned to receive venetoclax plus obinutuzumab (216 patients) or obinutuzumab plus chlorambucil (216 patients). All patients had a Cumulative Illness Rating Scale score of at least 6 or calculated creatinine clearance of < 70 mL/min.
After a median follow-up of 29 months, patients treated with venetoclax plus obinutuzumab exhibited superior progression-free survival than those treated with obinutuzumab plus chlorambucil (hazard ratio = 0.35), with a rate of 88.2% versus 64.1%, respectively, at 24 months. The authors observed the progression-free survival benefit for venetoclax and obinutuzumab in subgroups with TP53 deletion, mutation—or both—and in patients with unmutated immunoglobulin heavy-chain genes.
Minimal residual disease was significantly higher with venetoclax plus obinutuzumab than obinutuzumab plus chlorambucil as well, in both peripheral blood (76% vs. 35%) and bone marrow (57% vs. 17%), 3 months after treatment completion.
Disclosure: The study authors’ disclosure information may be found at coi.asco.org.