Administration of tirabrutinib suspension in a patient with primary central nervous system lymphoma: A case report

Tirabrutinib, a selective inhibitor of Bruton's tyrosine kinase, is approved in Japan for the treatment of relapsed or refractory primary central nervous system lymphoma (PCNSL). Dysphagia complicates oral tablet administration in patients with PCNSL. In the present case report, the safety, efficacy and plasma concentration of tirabrutinib administered as a suspension via a nasogastric tube is evaluated, providing insights into alternative administration methods and reviewing the relevant literature. In the present case, a 68-year-old man with PCNSL achieved two complete responses following methotrexate-based therapies but subsequently relapsed. Owing to severe dysphagia, tirabrutinib was initially administered as a suspension via a nasogastric tube and orally, and later transitioned to oral tablets. Plasma tirabrutinib concentrations were comparable following administration via nasogastric tube, oral suspension and oral tablets. After initiating tirabrutinib treatment, the patient remained clinically stable, with no recurrence of lymphoma for 1 year and no adverse events observed. A literature review identified 17 studies describing 19 patients who received a tyrosine kinase inhibitor (TKI) as a suspension. Tirabrutinib remains a crucial treatment option for refractory PCNSL; however, alternative administration routes are required for patients with dysphagia. The present case demonstrated the feasibility and safety of tirabrutinib suspension administration, with plasma concentrations comparable to those achieved with tablet administration. Further pharmacokinetic studies are warranted to evaluate the administration of TKI suspensions in a broader patient population.