Abstract
Purpose :
Vascular endothelial growth factors (VEGF) inhibitors are commonly used in the treatment of diabetic macular edema (DME), sometimes with variable response. The REACT study analyzes patients with persistent DME that were previously treated with intravitreal bevacizumab and switched to ranibizumab. This analysis evaluates the pre-trial response to bevacizumab compares this to the subsequent response to ranibizumab.
Methods :
REACT is an IRB-approved, 12-month, prospective IND trial evaluating the efficacy of ranibizumab in eyes with bevacizumab-resistant DME (NCT#: NCT01982435). In this study, the medical record prior to enrollment in REACT was reviewed during initial bevacizumab treatment. For enrollment eligibility, all eyes were treated with a minimum of 6 bevacizumab injections in the previous 12 months, a minimum of 2 in the last 10 weeks, and 1 in the 6 weeks prior to enrollment. Analysis was based on visits with consecutive bevacizumab injections no more than 8 weeks apart. Clinical parameters including visual acuity and anatomic parameters on OCT [e.g., central subfoveal thickness (CST), macular volume (MV), intraretinal fluid (IRF), and subretinal fluid (SRF)] compared to the REACT study.
Results :
27 eyes with DME were enrolled in the REACT study. Prior to this, subjects received an average of 8.2 bevacizumab injections. Before REACT, 14.8% patients gained >3 lines following bevacizumab therapy, and vision loss of >3 lines was noted in 7.2% of patients. Following enrollment in REACT and switching to ranibizumab, 18.5% of the study group gained >3 lines, while 3.7% lost >3 lines. Initial mean CST was 463 um upon initiation of bevacizumab therapy. Anatomic response to initial bevacizumab showed a mean reduction of 44 um (-9.5%, p=0.19). Following ranibizumab therapy, there was an additional 100 um mean reduction (-24%, p<0.01).
Conclusions :
In this cohort of treatment-resistant eyes, bevacizumab therapy showed modest gains in visual acuity and only minimal anatomic response. Following initiation of ranibizumab therapy in the REACT study, eyes demonstrated significant reserve for improvement in both vision and anatomy. This study suggests that in-class switching (e.g., alternate VEGF inhibitor) may result in significant improvement in visual acuity and anatomy in select eyes.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.