Tirabrutinib Maintenance Versus Placebo in Patients With Primary CNS Lymphoma in Complete Remission (JCOG2104)

Inclusion criteria

• Histopathological diagnosis of B cell lymphoma.
• Newly-diagnosed PCNSL confined to the cerebrum, cerebellum and brainstem. Patients with or without interocular lymphoma are eligible.
• Negative cerebrospinal fluid (CSF) cytology, or no evidence of leptomeningeal lymphomatosis in contrast-enhanced magnetic resonance imaging (MRI) of the brain and the whole spinal cord.
• No evidence of systemic lymphoma before induction chemotherapy, confirmed by contrast-enhanced CT including the neck, chest, abdomen, pelvic cavity and groin, or whole-body positron-emission tomography (PET) and CT.
• Patients with a single lesion, or multiple lesions, are eligible.
• Patients 18 years old or older at the time of registration.
• Eastern Cooperative Oncology Group performance status (ECOG PS) of 0, 1, 2.
• Have completed either of the following methotrexate (MTX)-based chemotherapy i) R-MPV (rituximab, MTX, procarbazine and vincristine) ii) MPV (MTX, procarbazine and vincristine) iii) R-MP (rituximab, MTX and procarbazine) iv) MP (MTX and procarbazine) v) R-M (rituximab and MTX) vi) MTX monotherapy
• Complete response (CR) or complete response unconfirmed (CRu) based on the International PCNSL Collaborative Group (IPCG) criteria.
• Within 60 days from the last dose of induction or consolidation chemotherapy.
• No treatment history of radiotherapy for PCNSL.
• Refused to receive consolidation radiotherapy.
• No treatment history of chemotherapy or radiotherapy, except for stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) for non-cancer diseases (such as arteriovenous malformations).
• Adequate organ function. i) Neutrophil count >=1,000/mm3 ii) Hemoglobin >= 8.0 g/dl iii) Platelet count >= 75,000/mm3 iv) AST <=120 U/L v) ALT <= 120 U/L vi) Total Bilirubin <= 2.25 mg/dl vii) Creatinine <= 1.5 mg/dL
• Written informed consent.

Exclusion criteria

• Synchronous or metachronous malignancies.
• Infections requiring systemic treatment at the time of registration.
• Body temperature >=38 degree celsius at the time of registration.
• Serious lung disorders, such as interstitial pneumonia, obstructive lung disease, hypersensitive pneumonitis, symptomatic bronchospasm) at the time of registration.
• History or presence of aspergillus pneumonitis or pneumocystis pneumonia.
• History of serious drug allergy or serious anaphylaxis.
• Heart failure (>= III in New York Heart Association functional classification), unstable angina pectoris, or history of myocardial infarction within the preceding 180 days prior to registration.
• Treated by anticoagulants at the time of registration.
• Treated by antiplatelets at the time of registration.
• Uncontrolled autoimmune hemolytic anemia (AIHA) or idiopathic thrombocytopenic purpura (ITP).
• Immune deficiency, such as acquired immunodeficiency syndrome (AIDS), X-linked agammaglobulinemia, chronic granulomatous disease, Wiskott-Aldrich syndrome, or any other iatrogenic immunosuppressive conditions.
• Post organ transplant immunosuppression.
• Prednisone use of >10 mg/day for condition other than intracranial tumor, or regular use of immunosuppressants.
• Uncontrolled diabetes mellitus.
• Treated either by CYP3A4 inhibitors, CYP3A4 inducers, or P-gp inducers within 14 days prior to registration.
• Gadolinium allergy.
• Positive HIV antibody.
• Positive HBs antigen.
• Positive HBs antibody or HBc antibody, and HBV-DNA positive.
• Positive HCV antibody.
• Unable to take oral medicine,
• Females during pregnancy, or within 28 days postpartum, or during lactation. Males who wish childbearing of his partner.
• Prior history of treatment by BTK inhibitors.
• Severe psychiatric disorders.