From the Guidelines
Rituximab has been shown to improve outcomes in CD20-positive acute lymphoblastic leukemia (ALL) when added to standard chemotherapy, particularly in patients under 60 years of age, as demonstrated in the most recent study by 1. The use of rituximab in ALL has been evaluated in several studies, including the MDACC study, which combined hyper-CVAD with eight doses of rituximab, resulting in an increase in 3-year complete remission (CR) duration rate from 40% to 67% 1. Key findings from the studies include:
- Improved event-free survival and overall survival in patients with CD20-positive Philadelphia chromosome-negative ALL when rituximab is added to standard chemotherapy 1
- Increased CR duration rate and overall survival rate in patients under 60 years of age when rituximab is added to hyper-CVAD 1
- Higher molecular remission rate and 5-year overall survival rate in standard-risk patients receiving rituximab in induction and consolidation cycles 1
- Typical dosing of rituximab is 375 mg/m² given during induction, consolidation, and sometimes maintenance phases, with optimal benefit seen in patients with CD20 expression on at least 20% of leukemic blasts 1
- Rituximab is generally well-tolerated, with infusion reactions being the most common adverse effect, which can be managed with premedication 1 The most recent and highest quality study, 1, supports the use of rituximab in CD20-positive ALL, particularly in patients under 60 years of age, and should be considered in the treatment of these patients to improve outcomes.
From the Research
Overview of Rituximab in Acute Lymphoblastic Leukemia (ALL)
- Rituximab is a chimeric monoclonal antibody that targets the CD20 antigen, which is expressed on the surface of B cells, including those in B-cell acute lymphoblastic leukemia (ALL) 2, 3, 4, 5, 6.
- Several studies have investigated the efficacy and safety of rituximab in combination with chemotherapy for the treatment of CD20-positive ALL.
Efficacy of Rituximab in ALL
- A prospective phase II study found that the addition of rituximab to multiagent chemotherapy improved the outcome of CD20-positive ALL patients, with a complete remission rate of 95.1% in Philadelphia (Ph)-negative ALL patients and 100% in Ph-positive ALL patients 2.
- A randomized trial found that rituximab improved event-free survival in younger adults with CD20-positive, Ph-negative ALL, with a hazard ratio of 0.66 (95% CI, 0.45 to 0.98; P=0.04) 4.
- Another study found that rituximab potentially improves clinical outcomes of CAR-T therapy for relapsed/refractory B-ALL by sensitizing leukemia cells to CAR-T-mediated cytotoxicity and reducing CAR-T exhaustion 6.
Safety and Tolerability of Rituximab in ALL
- The addition of rituximab to chemotherapy was found to be tolerable, with no significant increase in severe adverse events 2, 4.
- However, one study found that patients who received rituximab had fewer allergic reactions to asparaginase compared to those who did not receive rituximab 4.
Subgroup Analysis
- A study found that patients with higher CD20 positivity experienced more favorable relapse-free survival (p < 0.001) and overall survival (p = 0.06) compared to those with lower CD20 positivity 2.
- Another study found that patients who received ≥ 2 cycles of rituximab after transplantation had significantly improved relapse-free survival (hazard ratio, 0.31; p = 0.049) and overall survival (hazard ratio, 0.29; p = 0.021) compared to those who received < 2 cycles 2.