Overview of antibody therapy in B-cell non-Hodgkin's lymphoma

The main treatment modalities for lymphoma in the past decade have been radiation therapy and chemotherapy. Recently, molecular engineering provided humanized antibodies with promising clinical activity, and rituximab is the first commercially available antibody. This anti-CD20 monoclonal antibody (MoAb) showed little toxicity and demonstrated excellent clinical activity. Given as a single agent, it induces a high-response rate even in pretreated low-grade non-Hodgkin's lymphoma, the effect being higher if administered for a prolonged period of time. Its action is synergistic with chemotherapy, and combination treatment could improve survival in patients with aggressive lymphomas. Rituximab also demonstrated the ability to clear tumor cells from the circulation, allowing for an in vivo purging effect in the setting of peripheral stem cell collection and transplantation. Still, a number of issues related to its use need to be addressed, such as optimal dose and schedule and the situations in which rituximab should be given as a single agent or in addition to chemotherapy or other drugs, such as other MoAbs or interferons. We also need to understand when rituximab should be used in first-line treatment, with which type of chemotherapy the combination is most cost-effective, and patient population that will benefit most from this antibody treatment.