The addition of Rituxan (rituximab) to standard chemotherapy-based regimens improves outcomes among patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) that is CD20-positive. These results were reported at a plenary session at the 2015 annual meeting of the American Society of Hematology in Orlando, Florida.
B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is an aggressive type of leukemia that occurs in both children and adults. Immature immune cells, called B-cells, replicate uncontrollably and crowd out healthy cells in both the blood and bone marrow.
Approximately 30%-50% of adult BCP-ALL is considered to be CD20-positive. This means that the protein, CD20, is found on the surface of more than 20% of the leukemia cells.
Rituxan is an agent that is commonly used in the treatment of several different types of lymphomas and leukemias. When infused into the patient’s body, Rituxan binds to the CD20 protein, which stimulates the immune system to attack the cancerous cell.
Researchers recently conducted a clinical trial to evaluate the effectiveness of adding Rituxan to standard chemotherapy-based treatment for adults with BCP-ALL that is CD20-positive. Patients in the trial did not have the Philadelphia chromosome genetic mutation, and were therefore considered Philadelphia-chromosome (Ph)-negative.
The trial included 220 patients from 56 medical centers. They were treated with either Rituxan plus standard therapy (GRAALL protocol), or just standard therapy. Patients were allowed to undergo a stem cell transplant during their first complete remission.
The rates of a cancer recurrence at 2 years was 18% among patients treated with rituximab, compared with 30.5% of patients who did not receive rituximab.
When data was collected from all patients, there was no overall significant survival difference among patients. However, among patients who did not undergo a stem cell transplant, survival was significantly improved with the addition of Rituxan (74% for those treated with Rituxan, compared to 63% for those who did not receive Rituxan).
The researchers stated that the addition of Rituxan to standard chemotherapy-based regimens improves outcomes for adult patients with B-cell, CD20-positive, Ph-negative ALL. The optimal dosing of Rituxan for these patients is still under determination; however, its use in this setting is promising and appears to result in a change in the standard of care for these patients.
Reference: Maury S, Chevret S, Thomas X, et al. Addition of rituximab improves the outcome of adult patients with CD20-positivee, Ph-negative, B-cell precursor acute lymphoblastic leukemia (BCP-ALL): results of the randomized graall-R 2005 study. Proceedings from the 2015 meeting of the American Society of Hematology. Abstract #1.