Introduction: The appearance of monoclonal antibodies, and specifically, rituximab, has provided a new approach to treating non-Hodgkin's lymphomas and rheumatoid arthritis. The purpose of this study is to analyse whether this drug is used according to its package leaflet in clinical practice, evaluate the treatment's efficacy and determine its cost.
Methods: Ambispective, observational single-centre study of medication use set up as a prescription evaluation for the indication of rituximab in a tertiary hospital between March 2003 and 31 December 2007.
Results: 82 of the 221 patients who were treated (37.1 %) received the drug for a condition that does not appear in the package leaflet. 51.1 % and 27.5 % of response and progression were registered for approved diagnoses and 34.9 % and 47 % for non-approved diagnoses; the death rate was 25.3 % and 41.5 % respectively. The mean cost per treatment episode was the highest for idiopathic thrombocytopenic purpura (11,683 euro), whilst the highest treatment cost per patient was associated with follicular lymphoma (15,940 euro).
Discussion: We found that the main cause of the high rate of non-compliance with the package leaflet is patient lack of response to standard treatments, together with clinical practice guides that support the use of rituximab for conditions other than those for which it is indicated. Nevertheless, most of the clinical trials evaluating the efficacy of rituximab for these unauthorized diagnostic profiles have poor methodology, are in phase II, are open studies, have low patient numbers, or in some cases, are not comparative.