A systematic review to assess the “Treat-and-Extend” dosing regimen compared to monthly and as-needed dosing for neovascular age-related macular degeneration using ranibizumab

Abstract

Purpose : Age related macular degeneration (AMD) is the leading cause of irreversible blindness in the developed world. Monthly or as-needed (PRN) dosing of intravitreal ranibizumab have been established as efficacious treatment options for neovascular AMD. More recently, the “Treat-and-Extend” dosing regimen (TREX) is increasingly being adopted in clinical practice as it represents a patient-centric and economical option, reducing treatment burden by extending injection intervals when possible. However, the efficacy of TREX remains to be defined. This systematic review aims to evaluate the effectiveness of TREX compared to monthly and PRN ranibizumab dosing.

Methods : A systematic review was performed to assess the current evidence for TREX using MEDLINE, Embase and PubMed. Only studies which included ranibizumab treatment of neovascular AMD using TREX were included. The primary outcome measure was mean change in best-corrected visual acuity (BCVA) at one year, using Early Treatment Diabetic Retinopathy Study (ETDRS) letters. Secondary outcome measures included mean number of injections at one year.

Results : Of 1,733 studies identified, 11 studies were included in our analysis, consisting of one randomized controlled trial (RCT), three prospective and seven retrospective studies. The RCT demonstrated mean BCVA improvements of 9.2 and 10.5 letters in the monthly and TREX cohorts at one year, respectively (P=0.60). One retrospective comparative study demonstrated mean BCVA improvements of 10.8 and 2.3 letters in the TREX and PRN cohorts at one year, respectively (P=0.036). No other studies compared TREX to regular or as-needed dosing. Full data for mean BCVA improvement and mean number of injections were obtained for nine studies comprising 748 eyes. BCVA improvement was 9.00 letters at one year, as a weighted mean accounting for numbers of study eyes; mean number of injections was 7.66 (S.D. 1.89) at one year.

Conclusions : Previously, the landmark ANCHOR and MARINA trials reported gains of 11.3 and 7.2 letters, respectively, using monthly ranibizumab, while the PrONTO trial reported a 9.3 letter gain using PRN ranibizumab (mean of 5.6 injections) at one year. Our analysis suggests that comparable results can be achieved using TREX, but further RCTs are needed to fully evaluate the long-term efficacy and economy of TREX.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.