Prolonged remission with ibrutinib maintenance therapy following radiation in a patient with relapsed primary CNS lymphoma.

Background: Treatment for refractory or relapsed primary CNS lymphoma (r/r PCNSL) is challenging. Salvage whole-brain radiation therapy (WBRT) is an option but has a short duration of disease control, so additional treatment modalities are warranted. Case: A 75-year-old female with r/r PCNSL who had multiple progressions after multiple lines of treatment underwent salvage WBRT. The patient received ibrutinib, a Bruton's tyrosine kinase inhibitor, as maintenance therapy for 18 months following WBRT with the intention of increasing survival duration after salvage WBRT. She survived 81 months from diagnosis, including 57 months after completion of WBRT. Conclusion: This case presentation describes the experience of using ibrutinib as maintenance therapy in treating r/r PCNSL after salvage WBRT.