Rituximab: An innovative therapy for non-Hodgkin's lymphoma

The epidemiology, etiology, classification, and treatment of non-Hodgkin's lymphoma (NHL) are reviewed,and rituximab, a newly available therapy, is di scussed. NHL comprises a group of lymphoproliferative disorders the frequency of whi ch continues to rise. Although many classification systems exist for identi fying specific histological subtypes, NHL is generally divided into indolen t (low-grade) and aggressive. (intermediate- and high-grade) forms. Low-gra de NHL is characterized by a slowly progressive, continually relapsing cour se, with eventual transformation to a more rapidly progressive form that is usually fatal. Several options are available for the management of indolen t NHL; none is curative. Rituximab, a human-mouse monoclonal antibody that targets the CD20 antigen expressed in over 90% of B-cell NHLs, provides an alternative to conventional chemotherapy that is relatively safe and effect ive. In a Phase III trial involving 166 patients with re; lapsed;or refract ory low-grade B-cell NHL, rituximab produced an overall response of 48%, wi th 20 of 80 responders still in remission more than 36 months after treatme nt. Study results in patients with bulky disease and those requiring retrea tment have also been encouraging. Most adverse effects associated with ritu ximab are mild to moderate. Infusion-related reactions occur more commonly during initial infusions and in patients with evidence of increased tumor b urden but can be effectively managed with premedication, supportive care, a nd adjusted infusion rates. Hematologic effects are generally mild and tran sient, and adverse immune responses are rare. Rituximab is an alternative to conventional chemotherapy for the treatment of relapsed or refractory low-grade or follicular CD20-positive B-cell NHL.