Three monthly injections of ranibizumab, 0.3 and 0.5 mg, appear to provide benefit to patients with macular edema due to central retinal vein occlusion or branch retinal vein occlusion. Foveal thickness decreased significantly with both doses, and there was a concomitant increase in the visual acuity. Most patients require more than three injections to maintain the benefit. The average duration of treatment and the final visual outcomes are not yet known.
Fort Lauderdale, FL-Ranibizumab (Lucentis, Genentech) injections to treat macular edema (ME) associated with central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO) seem to be well-tolerated with no apparent toxicity to the retina. The results of a randomized trial comparing 0.3 and 0.5 mg of ranibizumab were reported by Peter A. Campochiaro, MD, at the annual meeting of the Association for Research in Vision and Ophthalmology. He is the Eccles Professor of Ophthalmology and Neuroscience at the Wilmer Eye Institute of Johns Hopkins University, Baltimore.
After three monthly injections of either dose, substantial improvements in foveal thickness and visual acuity (VA) were apparent. The median improvement in letters read at 4 m (ETDRS protocol) was 17 in the patients with CRVO who received 0.3 mg of ranibizumab and 14 in the patients who received the 0.5-mg dose. In the patients with BRVO, the respective increases were 10 and 18 letters.
Optical coherence tomography showed that the 0.5-mg dose resulted in a more rapid decrease in central retinal thickness compared with the 0.3-mg dose, and the decreases in the central retinal thickness on average lasted somewhat longer between injections; however, by the end of the study, the excess central retinal thickening had been reduced by roughly 90% in all four treatment groups.
Dr. Campochiaro said that the study data indicated that excess production of VEGF in the retinas of patients with CRVO or BRVO is a major contributor to ME and may influence the outcome of treatment with ranibizumab. These data support further investigation of both doses of ranibizumab in patients with ME due to vein occlusions, which is being done in the CRUISE and BRAVO phase III studies that are sponsored by the marketer of the drug.
Follow-up of patients beyond the primary endpoint has demonstrated that edema recurred in most of them. An amendment to the study allows treatment of recurrent edema with injections of ranibizumab. A major objective of the follow-up study was to determine if and when patients have prolonged resolution of edema and no longer require ranibizumab injections. The most important goal is to determine the level of VA (and the change in VA from baseline) when such stabilization is achieved, Dr. Campochiaro said.
Other investigators include Gulnar Hafiz, MD; Syed M. Shah, MD; Quan Dong Nguyen, MD; Howard Ying, MD; Diana V. Do, MD; Edward Quinlan, MD; Ingrid Zimmer-Galler, MD; Julia A. Haller, MD; Sharon D. Solomon, MD; Jennifer U. Sung, MD; Yasmin Hadi, BS; Kashif A. Janjua, MD; Nida Jawed, BS; David F. Choy, PhD; and Joseph Arron, PhD.