Researchers in the Diabetic Retinopathy Clinical Research (DRCR) Retina Network has reported that the treatment of moderate vision loss due to diabetic macular edema found no evidence of a significant difference in visual outcomes over a 2-year period between aflibercept monotherapy, with “bevacizumab first” approach, with a switch to aflibercept, in the event of a sub-optimal response. The rationale of the study was aimed to support how best to control health costs. Health insurers have aimed to apply a treatment approach to treating first with a lower-cost medication and, only if that proves ineffective, switching to another, more costly medication. The costs of aflibercept and ranibizumab are substantially higher than that of bevacizumab, driving health insurers require a step therapy strategy to reduce costs.
The current multi-centre, randomized clinical trial was conducted by the DRCR Retina Network, including more than 160 academic and community-based clinical sites and more than 500 ophthalmologists who treat retinal disorders throughout the United States and Canada. The trial used 54 clinical sites and the study applied patients randomly, and the drug was also administered randomly, according to the prespecified retreatment protocol. Eyes in the bevacizumab-first group were switched to aflibercept therapy if protocol-specified criteria were met and the primary outcome was the mean change in visual acuity over the 2-year trial period. According to the results, 312 eyes (in 270 adults) underwent randomization, 158 eyes were assigned to receive aflibercept monotherapy and 154 to receive bevacizumab first. During the 2-year period, 70% of the eyes in the “bevacizumab-first” group were switched to aflibercept therapy. The mean improvement in visual acuity was 15.0 letters in the aflibercept-monotherapy group and 14.0 letters in the bevacizumab-first group (adjusted difference, 0.8 letters; 95% CI, −0.9 to 2.5; p=0.37). At 2 years, the mean changes in visual acuity and retinal central subfield thickness were similar in the two groups. Serious adverse events (in 52% of the patients in the aflibercept-monotherapy group and in 36% of those in the bevacizumab-first group) and hospitalizations for adverse events (in 48% and 32%, respectively) were more common in the aflibercept-monotherapy group.
In summary, the authors in the study concluded that the “treatment of moderate vision loss due to diabetic macular edema involving the centre of the macula, we found no evidence of a significant difference in visual outcomes over a 2-year period”. In addition, an accompaning editorial in the New England Journal of Medicine, stated that, “[s]witches from bevacizumab to aflibercept treatment during follow-up were frequent. At 24, 52, and 104 weeks, switching criteria were met in 39%, 60%, and 70% of the eyes, respectively, in the bevacizumab-first group. Even so, the cost savings to the health care system would probably be substantial if this treatment approach is widely embraced”.