Retina Today - News (May/June 2016)

摘要

CATT 5-Year Data Released The 5-year results of the CATT, a clinical trial assessing the role of anti-VEGF therapy in neovascular age-related macular degeneration (AMD) management, found that, although the vision gains made during the first 2 years of the study were not maintained at 5 years, half of the study eyes assessed had at least 20/40 vision.1 The study was published online ahead of print in Ophthalmology. The 5-year results confirm that anti-VEGF therapy is “a major long-term therapeutic advance for neovascular AMD,” the study authors concluded. In the CATT, researchers randomly assigned patients to bevacizumab (Avastin, Genentech) or ranibizumab (Lucentis, Genentech) treatment and to one of three dosing regimens. At the 2-year study endpoint, patients were released from the clinical trial protocol. At 5 years, patients were recalled, and 647 of 914 living patients were assessed. With an average of 5.5 years follow-up, 60% of patients assessed had been treated at least once with a drug other than their assigned drug. At the 5-year time point, 50% of eyes had visual acuity of 20/40 or better, and 20% had visual acuity of 20/200 or worse. On average, eyes lost 3 letters from baseline and 11 letters from the 2-year study endpoint. Between years 2 and 5, the group originally assigned to ranibizumab for 2 years lost 4 more letters than the bevacizumab group (P = .008); otherwise, no significant differences in visual acuity among study groups were observed. Of 515 eyes available for grading, geographic atrophy (GA) was present in 41%. Among 467 eyes with fluorescein angiography, mean total lesion area was 12.9 mm2, a mean of 4.8 mm2 larger than at 2 years. Mean foveal thickness was 278 µm, a decrease of 182 µm from baseline and 20 µm from the 2-year mean. Among patients originally assigned to ranibizumab, 7.6% experienced an arteriothrombotic event (ATE), compared with 4.5% originally assigned to bevacizumab (P = 0.04). Otherwise, there were no differences in serious safety events among the drug and dosing regimen groups. INDUSTRY RESPONSE In a statement reacting to the release of the CATT 5-year outcomes, Genentech pointed out that this assessment comes 3 years after patients were released from the study protocol. The company highlighted several of the study authors’ comments in the paper, wherein the authors suggest that the study results speak more to the effect on neovascular AMD of anti-VEGF therapy in general rather than to any specific drug or dosing patterns. Watch it Now EyewireTV: 5-Year CATT Data The study authors wrote, for example, that “Because very few patients continued to receive the originally assigned drug or dosing schedule between the end of year 2 and follow-up at approximately 5 years, the CATT Follow-up Study results provide information primarily on overall treatment outcomes with anti-VEGF drugs and limited information on effects of different drugs and dosing regimens.” The Genentech statement also notes that study authors cautioned that safety conclusions about the drugs should be considered with the study design in mind. The authors wrote, “With most patients changing drugs over time, the ability to identify differential safety effects of the two drugs is compromised. Because of the absence of any difference [in ATEs] when the history of drug exposure was certain, we do not believe that the difference in events observed when a large portion of patients were not receiving ranibizumab are meaningful.” PHYSICIANS’ RESPONSES Retina Today and EyewireTV spoke to retina specialists to gather comments on the study. Rahul Khurana, MD, said he sees many positives from the study. Speaking with EyewireTV, Dr. Khurana said, “In our previous treatment, even with photodynamic therapy, only about 15% [of patients] were 20/40 or better, so going up to 50% is a truly large advance and is very ex