A two-year clinical trial that compared three drugs for diabetic macular edema (DME) found that gains in vision were greater for participants receiving the drug Eylea (aflibercept) than for those receiving Avastin (bevacizumab), but only among participants starting treatment with 20/50 or worse vision. Gains after two years were about the same for Eylea and Lucentis (ranibizumab), contrary to year-one results from the study, which showed Eylea with a clear advantage. The three drugs yielded similar gains in vision for patients with 20/32 or 20/40 vision at the start of treatment. The clinical trial was conducted by the Diabetic Retinopathy Clinical Research Network (DRCR.net), which is funded by the National Eye Institute, part of the National Institutes of Health.
“This rigorous trial confirms that Eylea, Avastin, and Lucentis are all effective treatments for diabetic macular edema,” said NEI Director Paul A. Sieving, M.D., Ph.D. “Eye care providers and patients can have confidence in all three drugs.”
Eylea, Avastin, and Lucentis are all widely used to treat DME, a consequence of diabetes that can cause blurring of central vision due to the leakage of fluid from abnormal blood vessels in the retina. The macula is the area of the retina used when looking straight ahead. The drugs are injected into the eye and work by inhibiting vascular endothelial growth factor (VEGF), a substance that can promote abnormal blood vessel growth and leakage. Although the drugs have a similar mode of action, they differ significantly in cost. Based on Medicare allowable charges, the per-injection costs of each drug at the doses used in this study were about $1850 for Eylea, about $60 for Avastin, and about $1200 for Lucentis.
DRCR.net investigators enrolled 660 people with DME at 89 clinical trial sites across the United States. When the study began, participants on average were 61 years old with 17 years of type 1 or type 2 diabetes. Only people with a visual acuity of 20/32 or worse were eligible to participate (to see clearly, a person with 20/32 vision would have to be 20 feet away from an object that a person with normal vision could see clearly at 32 feet). At enrollment, about half the participants had 20/32 to 20/40 vision. The other half had 20/50 or worse vision. In many states, a corrected visual acuity of 20/40 or better in at least one eye is required for a driver’s license that allows both day- and nighttime driving.
Each participant was assigned randomly to receive Eylea (2.0 milligrams/0.05 milliliter), Avastin (1.25 mg/0.05 mL), or Lucentis (0.3 mg/0.05 mL). Participants were evaluated monthly during the first year and every 4-16 weeks during the second year. Most participants received monthly injections during the first six months. Thereafter, participants received additional injections of assigned study drug until DME resolved or stabilized with no further vision improvement. Subsequently, injections were resumed if DME worsened. Additionally, laser treatment was given if DME persisted without continual improvement after six months of injections. Laser treatment alone was the standard treatment for DME until widespread adoption of anti-VEGF drugs a few years ago.