Off-label uses of Aflibercept, Ranibizumab and Dexamethasone implant for diabetic retinopathy in Turkey

Objective: Diabetic retinopathy (DRP) is the most common retinal vascular disease leading to blindness. There is limited data about the off-label drug use for DRP and diabetic macular edema (DME) in literature. The aim of the article was to evaluate the applications for off-label drug use in patients with DME and DRP in Turkey in terms of demographic and clinical characteristics. Methods: Applications for off-label drug use from hospitals across Turkey to the Turkish Medicines and Medical Devices Agency for DRP in 2018 were reviewed retrospectively. Results: 112 approved applications for 167 eyes were included in our study. The mean age of the cases was 61.24 ± 10.23 years, of them 57.1% were males and 42.9% were females. Of these applications, 41.1% were for aflibercept (n:46), 33.9% for ranibizumab (n:38), and 25% for dexamethasone implant (n:28). There was no application for bevacizumab. In terms of referring hospitals, public university hospitals were in the first place with a rate of 70.5%. The most common reasons for applications were drug switchback request and failure to complete loading dose, respectively. Discussions: DRP treatment can sometimes be challenging. The effectiveness of the intravitreal drugs may decrease over time and drug switching may be necessary. In Turkey, intravitreal drugs are only approved and reimbursed for DRP patients in case of macular edema. Off-label drug use may be preferred in non-approved indications and for reasons such as the need for additional drug doses to the determined limits. However, permission must be obtained from TMMDA for off-label drug use in Turkey. Conclusion: Anti-vascular endothelial growth factor drugs are the first-line treatment options for DME. TMMDA currently approves stepwise therapy for diabetic macular edema, initiated with bevacizumab. Bevacizumab administration does not require approval for off-label application. Additionally, ranibizumab, aflibercept, and dexamethasone implant are reimbursed only in case of failure to respond to 3 doses of bevacizumab injection. Our report provides information about off-label drug preferences and drug use regulations in DRP treatment in Turkey. Abbreviations:DME = diabetic macular edema, DRP = Diabetic retinopathy, FFA = fundus fluorescein angiography, TMMDA = Turkish Medicines and Medical Devices Agency, VEGF = vascular endothelial growth factor