Investigating minimal residual disease and long-term outcomes in patients with chronic lymphocytic leukemia who have been treated with venetoclax-obinutuzumab

This study aimed to investigate minimal residual disease (MRD) and long-term outcomes of patients with chronic lymphocytic leukemia (CLL) who were treated with venetoclax (Venclexta) and obinutuzumab (Gazyva). 

This study concluded that this treatment leads to an effective MRD reduction and has good long-term effectiveness.  

Venetoclax (ven) is a chemotherapy treatment that can be used to treat chronic lymphocytic leukemia (CLL). Obinutuzumab (obi) is a monoclonal antibody (immunotherapy). It can also be used in the treatment of CLL. The combination of ven-obi for one year has been shown to improve outcomes in patients with CLL. 

MRD is the small amount of cancer cells left remaining after treatment. A treatment goal for patients with CLL is negative MRD. This reduces the risk of cancer returning. It is important to evaluate the MRD effectiveness of one-year fixed-duration ven-obi treatment in the long term in patients with CLL. 

This study involved 432 patients with previously untreated CLL. 216 patients received 12 cycles of venetoclax and 6 cycles of obinutuzumab (ven-obi) and 216 received 12 cycles of chlorambucil (Leukeran) and 6 cycles of obinutuzumab (clb-obi). Patients were treated for one year and were evaluated after being off treatment for the last three years.  

Three months after stopping treatment, 40% of patients in the Ven-Obi group had undetectable MRD levels compared to 7% in the Clb-Obi group. After 29 months, 26.9% in the Ven-Obi group still had undetectable MRD compared to 3.2% in the Clb-Obi group.  

After an average follow-up of 52.4 months, patients in the Ven-Obi group had a 67% lower risk of cancer worsening compared to those in the Clb-Obi group. After 4 years, 74% of the Ven-Obi group were alive without cancer worsening compared to 35.4% for the Clb-Obi group.  

There was no significant difference in overall survival (OS) between the two groups

This study concluded that one-year fixed duration Ven-Obi treatment is effective in MRD reduction and has good long-term outcomes in patients with CLL. 

This study was funded by F. Hoffmann-La Roche Ltd and AbbVie Inc, the manufacturers of Ven-Obi.