Ibrutinib is a drug for the treatment of rare diseases. It has been approved for the treatment of adults with chronic lymphocytic leukaemia (CLL) or with relapsed or refractory mantle cell lymphoma (MCL) since 2014, and since 2015 also for the treatment of adults with Waldenström macroglobulinaemia. Regarding the treatment of patients with CLL or MCL, the Federal Joint Committee (G-BA) already conducted a benefit assessment and made a decision in 2015.