Possible future adjunctive role for anti-VEGF drugs in DME

Anti-vascular endothelial growth factor (VEGF) drugs may have arole in the treatment of diabetic maculopathy, according toRobert Avery, MD, of Santa Barbara, CA.

Dr. Avery injected bevacizumab 1.25 mg (Avastin, Genentech) intopatients with proliferative diabetic retinopathy and found a"very nice response" 1 week after the treatment. The leakage fromthe neovascularization resolved, but larger more mature vesselsremained.

He said low doses of the drug are effective in these patients and1 week after treatment, there will be a dramatic change in theappearance of the abnormal vessels.

"These vessels are quite sensitive to anti-VEGF therapy," hesaid. "We can lower the dose below one-tenth of the normal doseand still obtain a response."

Bevacizumab provides a temporary effect and will not replacelaser to treat these patients, because the maculopathy willcontinue to recur, Dr. Avery said. He theorized an adjunctive rolefor bevacizumab, in that the drug can be used to quiet the eyefollowed by vitrectomy or before laser treatment.

"In the long term, laser will be the mainstay of treatment," hesaid. "Bevacizumab also can be used in cases of bleeding or withrubeosis."

The DCRnet trial is evaluating ranibizumab (Lucentis, Genentech)for treating proliferative diabetic retinopathy. In patients witha great deal of ischemia and edema, there was a response toranibizumab after 1 month. Evaluation of bevacizumab in a 12-weekstudy showed significant improvement in the optical coherencetomography scans 3 weeks after treatment.

The READ-2 study is evaluating ranibizumab for DME alone and incombination with laser. The drug group had initial better resultsin visual acuity and retinal thickness than laser alone, but thelaser effects must be evaluated over the long term, according toDr. Avery.

"Anti-VEGF therapy may hold promise for treating DME," heconcluded. "The responses of DME are not as sensitive as theresponses by proliferative diabetic retinopathy to anti-VEGFtherapy. Long-term evaluations are needed to determine thelong-term effects of laser."