Preliminary Efficacy of Orelabrutinib Targeted Therapy in Induction Therapy of Primary Central Nervous System Diffuse B-Cell Lymphoma

Objective: To evaluate the efficacy and safety of the induction regimen of targeted therapy of Orelabrutinib combined with chemotherapy in primary central nervous system diffuse B-cell lymphoma. Methods: Patients aged 18 years and above with primary central nervous system diffuse B-cell lymphoma received ROM induction regimen (Orelabrutinib 150mg qd，rituximab 375mg/m2 day1, high-dose MTX 3.5 g/m2 day2, /28 days) for 3 courses. Patients who did not achieve partial remission (PR) or complete remission (CR) after 3 courses were excluded from the study. Patients who achieved PR or CR received consolidate treatment of autologous stem cell transplantation (ASCT), whole brain radiotherapy, or another 3 courses of ROM chemotherapy. Preliminary exploration the efficacy and safety of ROM induction therapy. Results: From March 2021 to April 2024, a total of 30 patients with primary central nervous system diffuse B-cell lymphoma in our hospital received ROM induction regimen. The median age was 56 years (34-72), with 15 males and 15 females. Two patients experienced disease progression and died after two courses of treatment. After three courses of ROM induction therapy, 14 patients achieved CR, 11 patients achieved PR, and 3 patients had stable disease. The overall response rate (ORR) for all patients was 83.3%. The median onset time for PR is 1 course, and the median onset time for CR is 2 courses. After induction therapy, 9 patients received ASCT consolidation, 6 patients received whole brain radiotherapy consolidation, and 15 patients continued consolidation chemotherapy. After a median follow-up of 10 (2-37) months, the estimated 1-year OS was 84.6% and PFS was 76.0%. No grade III-IV hematological or non-hematological adverse events were observed in all patients. Conclusion: The ROM regimen is an effective and safe induction therapy for primary central nervous system diffuse B-cell lymphoma, with a total response rate of 83.3% and a median onset time of 1 course for PR and 2 courses for CR. It is a promising induction therapy for primary central nervous system diffuse B-cell lymphoma.