cyclophosphamide + filgrastim + rituximab

This is a combination therapy regimen that includes: - Cyclophosphamide: An alkylating agent that damages DNA and prevents cell division - Filgrastim (G-CSF): A granulocyte colony-stimulating factor that stimulates bone marrow to produce neutrophils and stem cells - Rituximab: A monoclonal antibody targeting CD20 on B cells The combination is used primarily for: 1. Treatment of non-Hodgkin lymphoma, particularly in older patients 2. Stem cell mobilization prior to autologous stem cell transplantation 3. Treatment of ANCA-associated vasculitis 4. Management of other B-cell malignancies The regimen works by targeting cancer cells with cyclophosphamide while rituximab depletes B cells. Filgrastim is added to reduce the risk of neutropenia and allows for administration of full chemotherapy doses, particularly important in older patients[2].