Patients with a minimal residual disease (MRD) count ≥ 10-4 had a shorter overall survival than did those with MRD < 10-4.
“We are currently working up to understand which group of patients experiences these tremendous long term remissions,” Dr. Al-Sawaf said, “and we will keep you posted on this.”
He also showed that the time to next treatment (TTNT), defined as time to death or next anti-leukemic treatment, was significantly longer with venetoclax-obinutuzumab, with the median not reached before the current data lock versus 52.9 months with the chemotherapy-based regimen.
This equated to a hazard ratio in favor of the experimental combination of 0.44 (P < .0001), and a 6-year TTNT rate of 65.2% versus 37.1% for chlorambucil-obinutuzumab.
That second treatment was a Bruton’s tyrosine kinase inhibitor in 59.0% of cases in the venetoclax-obinutuzumab arm and 53.4% in the chlorambucil-obinutuzumab group.
Dr. Al-Sawaf noted, however, that 23.1% and 30.1%, respectively, of patients were given a chemotherapy or chemo-immunotherapy regimen, “which we nowadays would not necessarily consider a standard of care.”
“This ultimately reflects, as in many global clinical studies, the disparities that we still have across the world in terms of access to state-of-the-art therapies.”
The study was sponsored by Hoffmann–La Roche, and conducted in collaboration with AbbVie, and the German CLL Study Group. Dr. Al-Sawaf disclosed relationships with AbbVie, Adaptive, Ascentage, AstraZeneca, BeiGene, Gilead, Janssen, Lilly, and Roche.