Invasive Fungal Infection Complicating Treatment With Ibrutinib

Ibrutinib is a selective Bruton’s tyrosine kinase inhibitor (BTKi) approved for the treatment of chronic lymphocytic leukemia (CLL) and other B-cell malignancies. Invasive fungal infections (IFIs) have recently been reported in patients on BTKis despite the absence of significant immunocompromise raising great interest among oncologists regarding the mechanism by which BTKi's permit fungal infections. Here, we describe a fatal case of cerebral aspergillosis in a patient with relapsed CLL while on treatment with ibrutinib. There are few hypotheses on the mechanism by which ibrutinib permits fungal infections. As it becomes more widely used in B-cell cancers, clinicians should be aware of the potential for decreased anti-fungal immunity with this drug.