Orelabrutinib Combined With Rituximab and Chemotherapy for Relapsed/Refractory B-Cell Lymphoma Patients With Central Nervous System Involvement

Inclusion Criteria:

* 14 to 80 years old;
* Histopathologically confirmed CD20 positive B-cell lymphoma according to the 5th edition of the World Health Organization (WHO) Classification of Haematolymphoid Tumours;
* After systemic treatment of the CNS lesions;
* Life expectancy of \> 3 months (in the opinion of the investigator);
* No non-haematologic adverse events, except alopecia, higher than grade 1 according to Common Terminology Criteria for Adverse Events (CTCAE) v5.0;
* Absolute Neutrophil Count (ANC) ≥ 1.0×10\^9/L, Platelet Count ≥ 50×10\^9/L and Haemoglobin ≥ 60 g/L, without transfusion or any use of pharmacologically hematopoietic drugs in 2 weeks;
* Serum Creatinine (SCr) ≤ 1.5 times the Upper Limit of Normal (ULN) or Creatinine Clearance Rate (CCR) ≥ 30 mL/min;
* Serum total Bilirubin (tBil) ≤ 1.5 × ULN and both Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) ≤ 2.5 × ULN without hepatic metastases, otherwise tBil ≤ 3 × ULN and AST, ALT ≤ 5 × ULN respectively;
* International Normalized Ratio (INR) ≤ 1.5 and activated Partial Thromboplastin Time (aPTT) ≤ 1.5 × ULN;
* Left Ventricular Ejection Fraction (LVEF) ≥ 50%;
* Agreeing to provide written informed consent prior to any special examination or procedure for the research on their own or legal representative.

Exclusion Criteria:

* Pregnant or lactating women;
* Known Hepatitis B Virus (HBV) and/or Hepatitis C Virus (HCV) infection (HBV infection refers to HBV-DNA \> detectable limit);
* With acquired or congenital immunodeficiency;
* With congestive heart failure in 6 months before enrollment, New York Heart Association (NYHA) heart function class III or IV, or LVEF \< 50%;
* Known to be allergic to the test drug ingredients;
* Diagnosed with or being treated for malignancy other than lymphoma;
* With severe infection;
* Substance abuse, medical, psychological, or social conditions that may interfere with the subjects' participation in the study or evaluation of the study results;
* Deemed unsuitable for the group.