DI-086 Review of off-label use and economic impact of intravitreal dexamethasone implants in a tertiary hospital

Abstract

Background Intravitreal dexamethasone implants (DEXi) were approved by the European Medicines Agency in 2010 to treat macular oedema following either branch or central retinal vein occlusion and inflammation of the posterior segment of the eye presenting as non-infectious uveitis. However, they have also been used to treat other forms of macular oedema and associated pathologies as an off-label use. Purpose To describe the off-label use of DEXi in our hospital and to evaluate the cost of DEXi compared to the standard treatment in diabetic macular oedema (DME), ranibizumab. Materials and methods A longitudinal, retrospective and descriptive study was carried out on patients treated with at least one DEXi from June 2011 to January 2013. The next set of data was collected from medical records:(1) sex, (2) age at first DEXi, (3) diagnosis, (4) number of injections and (5) re-injection interval period (months). (3), (4) and (5) were distinguished for each eye. Annual Costs For Each Eye Treated (ACFEET) with DEXi was estimated by multiplying the drug manufacturers’ price (Ozurdex, 950 € per implant) by the estimated annual number of implants. Estimated annual number of implants was calculated by dividing 12 (months) by the median re-injection interval period (months) in this study. ACFEET with ranibizumab was estimated regarding 2 scenarios: A) the use of 1 vial to obtain 1 injection or B) the use of the amount left over in each vial to obtain 3 doses (injections) from 2 vials (33% dose optimisation) under aseptic and controlled conditions in the pharmacy department. A minimum of 6 and a maximum of 12 injections of 0.5 mg per year were considered in both scenarios. The manufacturers’price for ranibizumab (Lucentis) is 857.21 € for each vial. Results 39 patients (43 eyes) were treated with at least one DEXi during the study period. DEXi was used off-label in 30 eyes and 26 patients [16 women, median (P50) age 74 years (57.75–78.75)] which means 69.77% of total DEXi prescriptions. The pathologies related to off-label uses were: DME (17 patients), Cystic Macular Oedema (CME) not following either branch or central retinal vein occlusion (7 patients), postsurgical CME (4 patients), CME secondary to Age-Related Macular Degeneration (4 patients), choroidopathy-associated choroidal neovascular membrane (1 patient). 12 eyes (40% of all off-label DEXi) received more than one DEXi. P50 re-injection interval was 5 months (4.5–6). 4 patients with DME received DEXi in both eyes. ACFEET with DEXi (2.4 implants) were 2,280.00 €. ACFEET with ranibizumab in scenarios A and B were 5,143.26–10,286.52 € and 3,429.01–6,858.02 € respectively. Conclusions A high proportion of DEXi prescriptions consisted of off-label use. DME was the most common off-label use. However, DEXi did not mean any incremental annual cost compared to ranibizumab (the standard drug treatment) in DME, even considering dose optimisation. Further studies that better determine efficacy and safety in these patients are needed. No conflict of interest.