Aim: Evaluate long-term real-world treatment patterns and associated effectiveness and safety outcomes in patients with diabetic macular edema (DME) treated ≥36 months with 0.5mg ranibizumab.
Methods: Open-label observational effectiveness study in 9 Belgian clinics. Included were primary treated eyes of 55 DME patients between August 2014 and March 2015 and followed for 3.5±1.8 years. Eyes were 21.8% treatment (TX)-naïve, 9.1% non-naïve with exclusive prior anti-VEGF treatment (PRIOR-anti-VEGF), and 63.6% non-naïve with other prior treatments (PRIOR-other). Intravitreal injections with ranibizumab were administered per ophthalmologists' best clinical judgment. Trend testing of changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) over time occurred using mixed regression analysis.
Results: The mean±SD number of treatments in the first year was 5.1±3.0 (TX-naïve), 4.5±2.7 (PRIOR-anti-VEGF) and 5.6±3.1 (PRIOR-other). At 12 months, BCVA increased by 8.9±16.4 letters from 59.7±9.3 at baseline in TX-naïve (p<0.0001), by 11.8±9.9 from 61.6±8.5 in PRIOR-anti-VEGF (p=0.03), and by 4.2±10.6 from 58.2±14.6 in PRIOR-other groups (p=0.0002). BCVA remained stable for the remainder of follow-up in all groups. CRT decreased over the first 2 months by monthly rates of -43.8µm in TX-naïve (p=0.04), -75.7µm in PRIOR-anti-VEGF (p=0.02), and -65.8µm in PRIOR-other eyes (p=0.0003), showing stability afterwards. No unknown adverse events were recorded; a painful eye following injection was registered with a possible relationship to the treatment.
Conclusion: This real-world study confirms the effectiveness of ranibizumab in preventing a decline in BCVA and demonstrated initial improvement and subsequent retention of BCVA in DME patients ≥36 months. Ranibizumab initially reduced and then maintained CRT. However, these data reveal that treatment intensity and BCVA and CRT outcomes are lower than those found in early efficacy trials. Under-treatment likely accounts for this efficacy-effectiveness gap. Yet, intravitreal ranibizumab is an effective and safe long-term treatment for DME under conditions of significant heterogeneity in patients and treatment patterns.