Rituximab: clinical development and future directions

The availability of effective monoclonal antibodies (mAbs) has revolutionised the management of patients with B-cell malignancies. The most widely studied of these agents is rituximab (Rituxan(TM), IDEC Pharmaceuticals, San Diego, CA), a chimeric anti-CD20 antibody. Using the standard 4-weekly administration schedule, rituximab induces responses in almost half of patients with relapsed follicular/low-grade (F/LG) non-Hodgkin's lymphoma (NHL) with complete remissions in 6%. Lower response rates (RRs) have been noted in chronic lymphocytic leukaemia (CLL) using the standard dose and schedule. The drug has been well tolerated in most patients with common adverse events including mild to moderate fevers and chills and rare occurrences of a serious syndrome related to cytokine release and rapid tumour clearance. This antibody is also active against aggressive NHL, mantle cell NHL, post-transplant lymphoproliferative disorder (PTLD), lymphoplasmacytic NHL and hairy cell leukaemia and is also being evaluated in autoimmune disorders. Combinations of rituximab with chemotherapy regimens such as CHOP (cyclophosphamide, adriamycin, vincristine, predinisone) may alter the therapeutic paradigm for these diseases. The future promise of this antibody is a foundation on which to develop new strategies to increase the cure of patients with lymphoid malignancies.