Rituximab in Hodgkin lymphoma: is the target always a hit?

In 1997, the anti-CD20 monoclonal antibody (MAb) rituximab became the first MAb approved for clinical use in oncology, and ushered in a new era of rationally designed targeted agents in cancer therapeutics. It is currently approved for use in non-Hodgkin lymphoma (NHL), chronic lymphoid leukemia (CLL), and rheumatoid arthritis (RA). Rituximab is non-mutagenic, associated with low treatment-related toxicity, and few, if any, long term adverse events, making it an attractive agent to be tried in off-label settings like Hodgkin lymphoma (HL). HL consists of two distinct subtypes - classic HL (cHL) and lymphocyte predominant HL (LPHL). CD20 is present in virtually all patients with LPHL, and in a significant minority of patients with cHL. In this CD20 positive sub-population, the use of rituximab is a rational intervention strategy. Rituximab has been used in patients with cHL as well as LPHL with good efficacy. In this article, we provide a clinically-oriented overview of the use of rituximab in the different sub-types of HL, and report updated results of our series of 8 LPHL patients treated with rituximab. A systematic review of the literature is also presented.