IGNITE: Study of Tirabrutinib vs Rituximab/Temozolomide for Relapsed/Refractory Primary Central Nervous System Lymphoma (PCNSL)

Inclusion criteria

• Pathology report confirming the diagnosis of B-cell PCNSL
• Relapsed or refractory B-cell PCNSL with at least 1 prior high-dose methotrexate (HD-MTX) based therapy for PCNSL:

• Relapsed disease: Participants who achieved a response (CR, CRu, PR) to the last treatment and subsequently experienced disease progression.
• Refractory disease: Participants whose best response to the last treatment was stable disease or PD.
• One or more bi-dimensionally measurable brain lesions with a minimum diameter greater than or equal to (≥)1 centimeter (cm) × ≥1 cm in gadolinium-enhanced magnetic resonance imaging (MRI)
• Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0-2
• Adequate bone marrow, renal, and hepatic function per central lab values
• Participants must agree to comply with all defined contraceptive requirements

Exclusion criteria

• Participants with isolated intraocular PCNSL or spinal PCNSL with no brain lesions
• Participants with non-B-cell PCNSL
• Participants with systemic presence of lymphoma
• Refractory to temozolomide with or without rituximab-containing regimens in the last PCNSL treatment
• Concomitant systemic corticosteroid exposure within 14 days before starting study drug per Investigator assessment with the exception of the following:

• Equivalent of up to 10 milligram per day (mg/day) of prednisone for a disease other than PCNSL
• Equivalent of up to 50 mg/day of prednisone (equal to 8 mg/day dexamethasone) for participants with lesions of the brain and/or spinal cord
• Active malignancy, other than PCNSL requiring systemic therapy
• Poorly controlled comorbidity, or history of medical conditions contraindicated per Investigator assessment
• Participants who are unable to swallow oral medication
• Prior Bruton's tyrosine kinase inhibitor treatment