Rituximab in Relapsed Lymphocyte Predominant Hodgkin’s Disease (LPHD). Long-Term Results of a Phase-II Study from the German Hodgkin Lymphoma Study Group (GHSG).

Introduction: LPHD is a rare disease which accounts for 3–8% of all Hodgkin cases. Patients with LPHD relapse frequently and freedom from treatment failure is not significantly improved by intensification of polychemotherapy or radiotherapy. The malignant cells of LPHD are CD20+ and therefore the anti-CD20 antibody rituximab (R) may have activity with fewer adverse late effects.

Methods: This phase-II trial was initiated by the German Hodgkin Lymphoma Study Group (GHSG) to evaluate rituximab in patients with LPHD at first or higher relapse or progressive disease after at least one standard treatment. Histological slides were reviewed by a reference panel. Pts received 375mg/m2 of the anti-CD20 antibody rituximab once weekly for four weeks given as intravenous infusion in saline solution.

Results: Between 1999 and 2004 we treated twenty-one pts. with CD20-positive Hodgkin’s lymphoma according to the study protocol. Fourteen patients had stage I/II disease at the time of study entry and all patients were in their first to third relapse (median 2). The initial diagnosis of LPHD was confirmed in 17/21 cases. The remaining cases were reclassified as HD transformed to T-cell rich B-cell lymphoma (2) or CD20-positive classical HD (2). The overall response rate was 90%. Time to progression was 31 months (ms). The median follow-up 58 ms. Both T-cell rich B-cell lymphoma are in continous remission (PR 51ms+, CR 61ms+).

Conclusion: Single-agent therapy with rituximab is safe and showed high efficacy in relapsed LPHD. Therefore rituximab might be a non-toxic and efficient alternative treatment strategy compared to intensified chemo-and/or radiotherapeutic protocols in this young group of patients.