Abstract: Objective To evaluate the short-term efficacy and safety of a conditioning regimen involving cetiapib in patients with primary central nervous system lymphoma (PCNSL) who meet the indications for autologous stem cell transplantation (auto-HSCT). Methods The clinical data of PCNSL patients was analyzed who underwent auto-HSCT with a thiotepia-based BCNU-TT conditioning regimen (carmustine 400 mg·m^-2, administered via intravenous infusion 6 days before transplantation, thiotepia at 5 mg·kg^-1, administered via intravenous infusion every 12 hours 4 and 5 days before transplantation) and a TBC conditioning regimen (thiotepia at 6.4 mg·kg^-1, administered via intravenous infusion 1, 2 and 3 days before transplantation, busulfan at 30 mg·m^-2, administered via intravenous infusion every 6 hours 3, 4 and 5 days before transplantation, cyclophosphamide at 60 mg·kg^-1, administered via intravenous infusion 4 and 5 days before transplantation) between 2019 and 2023. The clinical characteristics of these cases were summarized before the outcomes and adverse reactions were compared. Results Among the eight PCNSL patients, one received the TBC regimen while the rest were treated with the BCNU-TT regimen. Three months after transplant, the CR rate was 100%. During a median follow-up of 466.5 days, regular assessments showed a CR rate of 100%. The primary adverse reactions and their severity ratings were febrile neutropenia (grade 3, 100%), nausea/vomiting (grade 1, 100%), diarrhea (grades 1-2, 75%), edema (grade 1, 37.5%), rash or lumps (grade 1, 50%), fatigue (grade 1, 62.5%), dizziness (grade 1, 37.5%), infections (grades 1-2, 50%), cough (grade 1, 37.5%), and liver function abnormalities (elevated transaminases grade 1 and grade 3, 37.5%). Conclusion The thiotepia-based conditioning regimen can effectively improve the short-term therapeutic efficacy and prognosis in auto-HSCT for PCNSL patients while demonstrating good tolerability in adverse reaction management.

Key words: Thiotepia, BCNU-TT Conditioning Regimen, TBC Conditioning Regimen, Primary Central Nervous System Lymphoma, Autologous Stem Cell Transplantation, Adverse Drug Reactions, Clinical Outcomes