FM in the context of chemotherapy means a chemotherapy regimen used as first-line therapy in indolent lymphomas. In combination with rituximab it is called R-FM or RFM or FM-R or FMR.

The [R]-FM regimen consists of:

1. (R)ituximab - an anti-CD20 monoclonal antibody that is able to kill both normal B cells and malignant ones;
2. (F)ludarabine - an antimetabolite;
3. (M)itoxantrone - a synthetic anthracycline analogue (an anthraquinone) that is able to intercalate DNA and prevent mitosis.^[1]

This regimen is also sometimes used in some autoimmune disorders that are inherently sensitive to rituximab, fludarabine and mitoxantrone in monotherapies (e.g. multiple sclerosis).