Bendamustine-rituximab (BR) combined therapy for treatment of immuno-mediated neuropathies associated with hematologic malignancy.

In chronic polyneuropathies associated with hematologic malignancy (HM) the optimal treatment management is primarily focused on the HM, but the parallel response of the neuropathy is still unclear. Rituximab is a recognized therapeutic choice in anti-MAG antibody polyneuropathy, that might be useful also in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with HM. The efficacy of immunochemotherapy, which is the standard approach to malignant lymphoproliferative diseases, has been poorly investigated in polyneuropathies. We describe a six-months combined bendamustine-rituximab (BR) treatment in nine patients affected by CIDP or paraproteinemic IgM neuropathies with antibodies to peripheral nerve antigens in course of malignant HM. All patients had a long-lasting response with an average relapse free-survival (RFS) time of 31.5 months. Clinical improvement was evident at 6 months from the beginning of therapy, even earlier in 6/9 patients (<2 months). Two patients dramatically improved the disabling attitudinal and intentional tremor and pathogenic autoantibodies significantly declined in 4/5 patients. Neurological relapses occurred in three patients after a mean of 38 months of sustained stability, even if HM remitted. In such cases rituximab was administered but was associated with a shorter RFS time (1 year) compared to the previous BR scheme (3 years). In our case series, the combined BR regimen was a valid option in immune-mediated neuropathies associated with HM. Moreover, in some patients BR scheme allowed an earlier response and a long-lasting improvement than rituximab alone.