- Cycle A consists of the drugs: rituximab, cyclophosphamide, oncovin, doxorubicin and methotrexate (R-CODOX-M). The treatment cycle is approximately 14 days. A spinal tap is performed on day 1 and day 3 of the cycle and the patient will be hospitalized until between day 11 and day 13. After the patient's blood counts return to normal(usually around day 21),the next round of treatment will occur.