The Addition of Temozolomide to Conditioning for Autologous Transplantation in Relapsed & Refractory CNS Lymphoma

Currently there is no standard of care for relapsed or refractory primary central nervous system (CNS) lymphoma. After high-dose methotrexate or radiation therapy, the best approach to relapsed disease is undefined. Common practice is the regimen RBEAM as a conditioning regimen in this patient population prior to transplantation. The RBEAM regimen includes R (rituximab), B (BCNU), E (etoposide), A (Ara-C (cytarabine)) and M (melphalan). In addition, dexamethasone is included in the regimen although not noted in the RBEAM mnemonic. However, the melphalan used in this combination is not thought to have much CNS penetration. Therefore, temozolomide, an alkylating agent known to penetrate the CNS and approved by the FDA for brain tumors will be used and evaluated in this study instead of melphalan. The aim of this study is to determine an effective and safe dose of temozolomide orally administered to patients with relapsed primary CNS lymphoma over the 5 days preceding autologous stem-cell transplantation. The hope is that the conditioning regimen DRBEAT \[D (dexamethasone) (R (rituximab), B (BCNU), E (etoposide), A (Ara-C (cytarabine)) and T (temozolomide)\] will significantly improve the survival of patients with relapsed CNS lymphoma.