Adding mitoxantrone to oral FCR (fludarabine, cyclophosphamide & rituximab) does not improve treatment response

This study examined whether adding mitoxantrone (Novantrone) to the treatment combination known as FCR improves outcomes for chronic lymphocytic leukemia (CLL). Researchers reported no significant benefit when mitoxantrone was added to FCR.

For physically fit CLL patients, the chemotherapy and immunotherapy combination known as FCR has become the standard of care. FCR consist of the chemotherapies fludarabine (Fludara) and cyclophosphamide (Cytoxan) and the immunotherapy rituximab (Rituxan). Early results have suggested that adding the chemotherapy mitoxantrone to FCR could improve remission rates in CLL patients. It is also not clear whether oral forms of FCR are as effective as the more commonly used intravenous (through an IV into a vein) forms.

215 CLL patients were randomly assigned to be treated with either FCR or FCR plus mitoxantrone. All patients received oral FCR. Treatment outcomes were compared over an average period of 5 years.

The complete remission rates were similar between the two groups. 69.3% of patients treated with FCR plus mitoxantrone and 69.8% of patients treated with FCR showed complete remission. 90.7% of patients treated with FCR plus mitoxantrone and 86.9% of patients treated with FCR achieved at least a partial response.

59.3% of patients treated with FCR were negative for minimal residual disease (small number of leukemia cancer cells that remain after treatment). It was similar for patients treated with FCR plus mitoxantrone (50.5%). No significant differences in overall survival or disease progression were noted.

The rate of side effects was acceptable in both groups. 34.3% of patients treated with FCR reported serious side effects. 37.4% of patients treated with FCR plus mitoxantrone reported serious side effects. The most common serious side effects were infections and infestations.

This study concluded that the addition of mitoxantrone to FCR does not improve treatment outcomes. However, the study also determined that oral FCR was associated with high response rates comparable to those previously found with IV FCR.