everolimus + rituximab + fludarabine + cyclophosphamide

This is a combination regimen consisting of four drugs—everolimus, rituximab, fludarabine, and cyclophosphamide—used in the treatment of hematologic malignancies. Everolimus is an mTOR inhibitor that blocks cell growth and proliferation by inhibiting the mammalian target of rapamycin pathway. Rituximab is a monoclonal antibody targeting CD20 on B lymphocytes, leading to their destruction via immune-mediated mechanisms. Fludarabine is a purine analog that inhibits DNA synthesis and repair by interfering with DNA polymerase and ribonucleotide reductase activity. Cyclophosphamide is an alkylating agent that crosslinks DNA strands, resulting in apoptosis of rapidly dividing cells. While combinations such as fludarabine + cyclophosphamide + rituximab (FCR) are standard for chronic lymphocytic leukemia (CLL), everolimus has been studied in combination with rituximab for relapsed/refractory lymphoma but not widely established as part of this four-drug regimen[1][6][10]. The addition of everolimus may be considered investigational or under clinical evaluation.