Examining Minimal Residual Disease Remissions in Patients With CLL

Othman Al-Sawaf, MD, a physician with the University Hospital of Cologne in Germany, discusses an analysis of minimal residual disease (MRD) in patients with chronic lymphocytic leukemia (CLL) given venetoclax (Venclexta) and obinutuzumab (Gazyva) on the CLL14 (NCT02242942).

A majority of patients on the trial were MRD negative after 6 cycles out 12. When using next-generation sequencing to detect low levels of MRD, investigators saw that a third of patients had deepened remissions between cycles 7 and 12. The extra 6 cycles of therapy deepens the MRD negativity to the 10-6 in over half of patients who had undetectable MRD at the end of treatment. Al-Sawaf says this shows there is a rationale to use all 12 cycles and the design implemented in the CLL14 trial of venetoclax monotherapy.

The investigators also looked at patients who had detectable MRD at the end of treatment on the study. Among the approximate 20 patients with detectable MRD, about half had lower levels of MRD at cycle 7 compared with at the end of treatment. If those patients continued with treatment, they would probably not achieve deeper remissions since the patients had increasing MRD levels while on treatment, according to Al-Sawaf. He says these patients could potentially benefit in the future from treatment intensification or similar strategies depending on their ultimate goal of therapy.