Fixed-duration treatment typically combines various medications that attack leukemia cells in different ways. The treatment aims to reduce the number of cancer cells as much as possible, sometimes to levels undetectable by highly sensitive testing. Then, you can potentially stop treatment as long as remission lasts, says Kovacsovics.
Stopping treatment after a fixed period may not mean it’s any less effective than continuous treatment for CLL. A large study found that, over around three years, fixed-duration therapy using venetoclax-based combinations controlled CLL just as effectively as continuous targeted therapy in people with previously untreated CLL.
While the field is developing, cancer specialists currently recommend two fixed-duration regimens for CLL.
BCL-2 Inhibitors + Monoclonal Antibodies
The most common fixed-duration regimen for people receiving their first CLL treatment combines the targeted medication venetoclax (Venclexta) with the monoclonal antibody obinutuzumab (Gazyva), Kovacsovics says.This treatment combination typically lasts 12 months. The U.S. Food and Drug Administration (FDA) approved it in May 2019.
Venetoclax blocks B-cell lymphoma 2 (BCL-2), a protein that helps CLL cells stay alive. Without that protein, the leukemia cells die. People take venetoclax as a daily pill for the full year.
Obinutuzumab attaches to a protein called CD20 on the surface of CLL cells, helping your immune system to recognize and destroy the cancer cells. Doctors administer obinutuzumab by infusion through a vein, known as intravenous (IV) infusion, during the first six months only.
If CLL comes back after treatment, your cancer care team may combine venetoclax with another monoclonal antibody called rituximab (Rituxan) instead of obinutuzumab, says Kovacsovics. Rituximab works similarly to obinutuzumab by binding to CD20 on CLL cells and helping the immune system destroy them. This regimen typically lasts 24 months, with healthcare professionals administering rituximab by IV during the first six months and the individual taking venetoclax daily throughout the planned course of treatment.
Next-Gen Doublets (BCL-2 + BTK Inhibitors)
Another fixed-duration option combines venetoclax with acalabrutinib (Calquence), a Bruton tyrosine kinase (BTK) inhibitor, says Burke.
Acalabrutinib blocks BTK, a protein that helps cancer cells grow. Together with venetoclax, which targets BCL-2, these drugs attack the disease through different mechanisms. You’d take both medications by mouth. Treatment runs for 14 months, with acalabrutinib taken twice daily, and venetoclax added in the third month.
The FDA approved this combination treatment in February 2026 for people with previously untreated CLL whose CLL cells don’t have del(17p) or a TP53 mutation. The approval was based on results from a clinical trial involving 867 people showing that those who received acalabrutinib plus venetoclax were no less likely to be alive with their CLL under control at three years compared with those who received long-term chemotherapy.
Researchers continue to study new fixed-duration combinations and different ways to use existing medications to treat CLL. That work could lead to even more treatment options in the years ahead.
