10177-ML-5 HIGH-DOSE CHEMOTHERAPY FOLLOWED BY AUTOLOGOUS STEM CELL TRANSPLANT FOR RECURRENT CNS LYMPHOMA Open Access

The prognosis of relapsed central nervous system lymphoma (CNSL) is poor, and effective standard treatment has not been established. The BTK inhibitor or HD-MTX-based chemotherapy is re-administered if the patient responds to HD-MTX-based therapy at initial treatment, but durable remission is difficult to achieve. Thiotepa (TT) was approved in Japan as a pre-treatment for autologous hematopoietic stem cell transplantation in malignant lymphoma, and autologous stem cell transplantation (ASCT)-assisted high-dose chemotherapy (HDC) can be performed. TBC (TT, busulfan, and cyclophosphamide) and BCNU+TT are used in Europe and the US, but treatment-related mortality (TRM) has been reported in about 10% of patients. The regimen approved in Japan is BuTT (busulfan and TT) and there is little information on its efficacy and safety in relapsed CNSL. In this study, we examined the efficacy and safety of HDC-ASCT at Saitama Medical University. Subjects: Nine patients with recurrent CNSL (primary CNSL: 6 cases, secondary CNSL: 3 cases) since May 2021, age ≤ 65 years, KPS ≥ 70, are included in this study.

After response to induction (R)MPV regimen, peripheral blood stem cells were harvested after administration of G-CSF and plerixafol, pretreated with BuTT regimen (Bu: 3.2 mg/kg, day-8 to -5, TT: 5 mg/kg, day-4, -3), and transplanted on Day 0.

Adverse events of Grade 3 or higher were febrile neutropenia in 5 cases, neutropenia in 9 cases, thrombocytopenia in 9 cases, pharyngitis in 5 cases, oral candida in 1 case, pleuritis in 1case, abdominal pain in 1 case, nausea in 1 case, and sepsis 1 case, but all recovered, and no TRM was observed. Six patients with primary CNSL and two with secondary CNSL are currently alive without recurrence, and one with non-CR secondary CNSL died of progression in two months.

HDC-ASCT is an effective salvage treatment for relapsed CNSL.