When it is time to treat CLL/SLL, or chronic lymphocytic leukemia/small lymphocytic lymphoma, many people choose between two approaches: fixed-duration therapy and continuous therapy.
This article focuses exclusively on CLL/SLL types of treatment, which can be broadly categorized into:
- Fixed-duration therapy – treatment taken for a set, planned time, usually 1 to 2 years, and then stopped.
- Continuous therapy– treatment taken each day for as long as it keeps helping and is tolerable.
The main take-away:
The path forward may be one that is chosen carefully, weighing personal preferences, overall medical status, and whether the CLL carries certain high-risk features.
Why some people may opt for continuous therapy:
- A fully oral start with little early tumor lysis risk and usually no infusions
- Responses that may deepen the longer treatment continues
- Flexibility to adjust the dose to manage side effects without giving up the treatment approach
Why some people may opt for fixed-duration therapy:
- A planned finish line and a possible treatment-free period afterward
- The chance of achieving a deep remission (meaning very low levels of remaining leukemia that can sometimes lead to a period without treatment) may allow some people to be considered for retreatment later, depending on their individual situation and treatment options
That said, the early weeks of fixed-duration therapy may involve:
- A gradual dose ramp-up over about five weeks, paired with extra fluids and a protective medicine, to lower the risk of a serious complication called tumor lysis syndrome, or TLS
- This TLS risk tends to be higher for people who have bulkier lymph nodes, a very high white blood cell count, or reduced kidney function, so the healthcare team may plan extra precautions for them
- More frequent visits and blood tests early on, and for some people a short hospital stay for the first dose
- Treatment combinations that include an anti-CD20 therapy will require a series of infusion visits
- Low blood counts and infections may be more common, so the healthcare team may monitor closely.
For those who opt for continuous therapy, monitoring may include:
- Cardiovascular (heart) surveillance to check for blood pressure and risk of atrial fibrillation (flutter)
- Bleeding / bruising risk
- Low blood counts and infections may occur, so healthcare team may monitor closely.
An important point for high-risk genomic features in CLL:
Some people have high-risk genomic features, which may include certain changes doctors may find on specialized testing of the CLL cells, such as del(17p), a TP53 mutation, or unmutated IGHV. For some people with these features, particularly TP53 aberrations, fixed-duration approaches may provide shorter periods of disease control. For people with certain higher-risk features, especially TP53 aberrations such as del(17p) or TP53 mutation, many experts and guidelines often favor continuous BTK inhibitor-based therapy because it may provide longer disease control.
Action points:
When it comes time to choose a treatment for your CLL, infection risk should be part of the conversation. Ask your doctor to consider your personal health history, age, disease biology and of course your past experience with infections when selecting a therapy. For example:
- Ask whether the CLL has been fully tested for all the high-risk genomic features before starting, including del(17p), a TP53 mutation, and IGHV status.
- Ask which treatment approach may fit best given the specific CLL diagnosis and other health conditions.
- If considering fixed-duration treatment, ask what the first weeks involve, including the ramp-up, blood test schedule, infusions, and any hospital time.
- If considering continuous therapy, ask what the monitoring plan may look like to monitor for potential side effects.
- Share what matters most, whether it be a planned end date, time off treatment, how the start of treatment may look, or long-lasting control.
References
- Al-Sawaf O, Stumpf J, Zhang C, et al. Fixed-Duration versus Continuous Treatment for Chronic Lymphocytic Leukemia. N Engl J Med. 2025.[1]
- Eichhorst B, Niemann CU, Kater AP, et al. First-Line Venetoclax Combinations in Chronic Lymphocytic Leukemia. N Engl J Med. 2023.[2]
- Kater AP, Harrup R, Kipps TJ, et al. The MURANO Study: Final Analysis and Retreatment/Crossover Substudy Results of VenR for Patients With Relapsed/Refractory CLL. Blood. 2025.[3]
- Shadman M. Diagnosis and Treatment of Chronic Lymphocytic Leukemia: A Review. JAMA. 2023.[4]
- Jain N, Wierda WG, O’Brien S. Chronic Lymphocytic Leukaemia. Lancet. 2024.[5]
- Allan JN. Have Fixed-Duration (FD) Regimens Delivered on Their Promise in Chronic Lymphocytic Leukemia and What Is the Future of FD Regimens? A Narrative Review. Adv Ther. 2026.[8]
- Fürstenau M, Niemann CU, Robrecht S, et al. Venetoclax Combinations in Untreated CLL: 5-Year Results and Patient-Reported Outcomes Analysis of the CLL13/GAIA Trial. Blood. 2026.[9]
- Castonguay M, Seymour JF. Contemporary Management of Relapsed or Refractory Chronic Lymphocytic Leukemia. J Clin Oncol. 2026.[10]
- Food and Drug Administration. Venclexta (venetoclax) prescribing information. 2026.[11]
- Bociek RG, Lunning M. Tumor Lysis Syndrome. N Engl J Med. 2025.[12]
- Food and Drug Administration. Gazyva (obinutuzumab) prescribing information. 2025.[13]
- Itsara A, Rogness VM, Samples L, et al. A Decade of Ibrutinib for CLL With and Without TP53 Aberration. Blood. 2026.[6]
- National Comprehensive Cancer Network. CLL/SLL: Suggested Treatment Regimens (CSLL-D). 2025.[7]
- National Comprehensive Cancer Network. CLL/SLL: Prognostic Variables (CSLL-A). 2025.[7]
- Caserta S, Martino EA, Lofaro D, et al. First-Line Treatment of IGHV-Unmutated Chronic Lymphocytic Leukemia: A Network Meta-Analysis of Targeted and Chemoimmunotherapy Regimens. Eur J Haematol. 2026.[14]
