Cynthia X. Qian, MD
Assistant Professor of Ophthalmology
University of Montreal
The “First-Time Results of Clinical Trials” session had two presentations from Allergan trials. The first talk introduced the Phase III results from the SEQUOIA and CEDAR studies, which examined the efficacy of abicipar for neovascular AMD. This was covered in yesterday’s post.
The second talk was by Dr. William Freeman, who presented the Phase IIb results of a brimonidine implant for geographic atrophy in dry AMD.
Dr. Freeman began his presentation by emphasizing that the treatment of dry AMD is an unmet medical need, since one third of all late stage AMD are non exudative and involve the inexorable advancement of geographic atrophy. Several therapeutic pathways have been explored to address this progression, including the use of antioxidants, anti-inflammatory agents, visual cycle inhibitors and complement inhibitors, all to little avail.
The neuroprotective properties of brimonidine is well known, both in in vitro and in vivo models and topical applications play an important role in delaying glaucoma progression. In this Phase IIb study (BEACON), the safety and efficacy of intravitreally delivered extended release brimonidone and its effects on geographic atrophy lesion size over 24 months were studied.
400ug of brimonidine is injected using a 25Ga injector akin to the Ozurdex injector on a q3 month schedule. Only patients with GA measuring between 1.25mm2 to 18mm2 were enrolled. 303 patients were randomized to receive sham or brimo DDS treatment. The 2 groups were well balanced and the mean lesion size prior to beginning of therapy was 5.48mm2 and 5.16mm2 respectively with a yearly progression of ~1.6mm2.
At 24 months and 30 months, GA area growth was reduced by 10% and 12% in the treatment group. These results were statistically significant. Subgroup analysis also revealed this reduction effect to be more marked in those with larger baseline GA lesions of ³4.5mm2 indicative of faster progression rate (13% at 24 mon and 14% at 30 mon).
Adverse effects were mostly mild, transient, and limited to the site of ocular injection only. The rate of nAMD development over time was comparable to that of the sham group.
Overall, these results show promise in the continued evaluation and study of Brimo DDS and have promoted the initiation and recruitment of larger study groups for an ongoing Phase III study.
