Rituximab and Other New Anti-CD20 MAbs for Non-Hodgkin’s Lymphoma Treatment

Non-Hodgkin’s lymphomas (NHLs) are a heterogeneous group of different haematological cancers with a wide range of aggressiveness. NHLs represent >80% of lymphomas and the majority of NHLs involve B cells. CD20 represents a good target for NHL immunotherapy because it is largely expressed on B cell NHL and not on B cell precursors and plasma cells. The anti-CD20 monoclonal antibody (mAb) rituximab (RTX) was the first antibody approved by the FDA for lymphoma therapy and has revolutionised B cell lymphoma treatment. Several clinical trials have demonstrated the high efficacy of RTX, resulting in a significant improvement in overall response rates and in NHL patient survival. However, RTX, both as a single agent and in combination with chemotherapy, induces several side-effects and resistance mechanisms. Remarkable efforts have been made to improve RTX efficacy, including conjugation to an active moiety (radionuclide, toxin, enzyme, or drug) and the development of new anti-CD20 mAbs. This review summarises the characteristics of RTX and other anti-CD20 mAbs for NHL treatment; the results of the main clinical trials are reported.