2 The technology
2.1 Rituximab (MabThera, Roche) is a chimeric (mouse/human) genetically engineered monoclonal antibody. It targets the CD20 surface antigen of mature B-cell lymphocytes.
2.2 Rituximab has a marketing authorisation in relapsed non-Hodgkin's follicular lymphoma as follows.
Rituximab is indicated for the treatment of patients with stage III-IV follicular non-Hodgkin's lymphoma who are chemoresistant or who are in their second or subsequent relapse after chemotherapy.
Rituximab maintenance therapy is indicated for patients with relapsed/refractory follicular non-Hodgkin's lymphoma responding to induction therapy with chemotherapy with or without rituximab.
2.3 Allergic and skin reactions are the most common side effects of rituximab infusion. Infusion reactions can be complicated by bronchospasm and hypotension and can occasionally be severe or life threatening. Severe reactions are more common in patients with a high tumour burden, and the incidence and severity of infusion reactions decreases with successive infusions. Rituximab treatment is associated with blood and bone marrow toxicity manifested by neutropenia, leucopenia and infections. In addition, rituximab treatment is associated with flu-like symptoms and neurological problems. For full details of side effects and contraindications, see the summary of product characteristics.
2.4 A single dose of rituximab is 375 mg/m2 body surface area. When used as monotherapy, this dose is given every week for 4 weeks. When used in combination with chemotherapy for induction of remission, this dose is given with each cycle of chemotherapy. For maintenance therapy, the same dose is given every 3 months until relapse or for a maximum of 2 years (a total of eight doses). The cost of one 100-mg vial is £174.63 and one 500-mg vial is £873.15 (excluding VAT; 'British national formulary' [BNF] edition 53). For an average patient (body surface area 1.61.87 m2) the cost per dose is £1222. Costs may vary in different settings because of negotiated procurement discounts.