Ranibizumab treatment of diabetic macular edema with bimonthly monitoring: 18-month outcomes of the Phase IIIb multicenter RELIGHT study

Abstract

 

Purpose

 

In Europe ranibizumab 0.5 mg is licensed for visual impairment due to diabetic macular edema (VI-DME) using a pro re nata dosing regimen addressing individual patient needs with reduced treatment burden; however, the product information recommends monthly monitoring and retreatment primarily based on visual acuity (VA). RELIGHT investigates the impact of bimonthly follow-up and individualized retreatment, after a monthly follow-up for 6 months (M) on maintaining improvements in best-corrected visual acuity (BCVA).

 

Methods

 

RELIGHT was an 18M, prospective, open-label, multicenter, single-arm, phase IIIb, UK study. Patients received three initial monthly ranibizumab injections (Day0-M2), followed by individualized VA- and optical coherence tomography (OCT)-guided retreatment with monthly (M3-M5), and subsequent bi-monthly follow-up (M6-M18). Key outcome measures: mean change in BCVA from baseline-M12 (primary), mean change in BCVA and central retinal thickness (CRT) from baseline-M18, gain of ≥10 and ≥15 letters, and incidence of adverse events over 18M.

 

Results

 

Overall, 99 (90.8%) of 109 enrolled patients completed the study, with a mean duration of DME of 40M. Mean baseline BCVA was 62.9 letters and 77.1% of patients had received prior laser treatment. Mean change in BCVA was +4.9 letters (M12) and +6.5 letters (M18) achieved with a mean of 6.8 and 8.5 injections, respectively. CRT decreased from −127µm (M12) to −150µm (M18). The proportion of patients gaining ≥10 and ≥15 letters were 24.8% and 13.8% at M12 and 35% and 19% at M18, respectively. A subgroup analysis on BCVA based on the duration of DME shows that patients with shorter duration of DME (<3M, >3-<12M; Figure 1) achieve greater BCVA improvements compared to patients with a longer duration of DME >12M). No new safety findings were reported.

 

Conclusions

 

VA gains were maintained with a bimonthly monitoring regimen over 12M, offering a regimen with a lower number of monitoring visits as a viable option for the long term management of some patients with VI-DME. Duration of DME influences VA outcome.

 

 

BCVA gain from baseline at Months 12 and 18 by duration of DME

 

Keywords: 499 diabetic retinopathy • 609 neovascularization • 585 macula/fovea