Sequential Treatment With RO-MTX After Pomalidomide, Orelabrutinib, Rituximab (POR) in Newly-diagnosed PCNSL

There are 2 sections of this trial. Step1: the patients will be treated with 4 cycles of POR regimen （Pomalidomide 4mg d1-d14, Orelabrutinib 150mg d1-d21, Rituximab 375mg/m2 d1, 21 days per cycle). The response will be evaluated every 2 cycles. The patients with PD will drop out of the study. Step2: Patients with CR/PR/SD after 4 cycles of POR treatment will be treated with 2 cycles of RO-MTX regimen（methotrexate 3.5g/m2 civ d1, Orelabrutinib 150mg d1-d21, Rituximab 375mg/m2 d1, 21 days per cycle). After 6 cycles of induction therapy, all patients were followed for survival data every 12 week until disease progression, disease recurrence, death, or study termination. Patients with progression were also followed up for survival data as above. Overall survival will be followed up to 3 years after the last subject entered the study. Establishing the feasibility of chemo-free treatment in primary central nervous system lymphoma will provide the foundation for a larger study of efficacy and long-term outcomes of chemo-free therapy for patients with PCNSL.