“Step therapy” effective for diabetic macular edema

Researchers report that a therapeutic “step strategy,” in which patients with diabetic macular edema begin their treatment with a less expensive drug and, if vision fails to improve, switch to a more expensive medicine, produces similar results to beginning with the more expensive drug.

The findings were published on July 14, 2022 in the NEJM/New England Journal of Medicine.

“Our study showed that switching treatments when needed is a reasonable strategy,” said lead author Chirag Jhaveri, M.D., Austin Research Center for Retina in Austin, Texas.

As background, the authors noted that injection treatment with either Avastin (bevacizumab) or Eylea (aflibercept) improve vision in people with diabetic macular edema. However, though Eylea is approved by the U.S. Food and Drug Administration to treat diabetic macular edema, “off-label” Avastin is much less expensive and is sometimes required by insurers as a first-line treatment.”

The investigators enrolled 270 subjects diagnosed with diabetic macular edema. Some subjects were treated in both eyes. They randomized to treatment a total of 312 eyes, assigning initial treatment of 158 eyes to aflibercept and 154 to bevacizumab.

Subjects who required treatment for both eyes started treatment in each eye with a different drug.

At baseline, all subjects had best-corrected visual acuity between 20/50 and 20/320.

The subjects received either Avastin or Eylea injections every four weeks for 24 weeks.

Starting at 12 weeks, eyes treated initially with Avastin that failed to achieve improvement benchmarks were switched to Eylea.

After 24 weeks, physicians could taper injections according to the individual need for maintenance of visual acuity.

The investigators tracked improvement in visual acuity for two more years.

Over the 2-year period, clinicians switched 70% of the eyes in the bevacizumab-first group to aflibercept therapy.

At 2 years, mean improvement in visual acuity was 15 letters in the aflibercept monotherapy group and 14 letters in the bevacizumab-first group, a non-significant difference. At 2 years, mean changes in visual acuity and in retinal central subfield thickness were similar in both groups.

Notably, serious adverse events appeared in 52% of subjects in the aflibercept-monotherapy group and in 36% of subjects in the bevacizumab-first group, with hospitalizations for adverse events occurring among 48% of the aflibercept-monotherapy group and 32% of the bevacizumab-first group.

The authors concluded, “In this trial of treatment of moderate vision loss due to diabetic macular edema involving the center of the macula, we found no evidence of a significant difference in visual outcomes over a 2-year period between aflibercept monotherapy and treatment with bevacizumab first with a switch to aflibercept in the case of suboptimal response.”