By Fred Gebhart
SAN FRANCISCO -- October 28, 2009 -- Ranibizumab can maintain vision in 90% of patients with age-related macular degeneration (AMD) for up to 2 years, according to data presented at the 2009 Joint Meeting of the American Association of Ophthalmology and Pan-American Association of Ophthalmology (AAO-PAAO).
"We have seen patients regain vision," said Maria Berrocal, MD, University of Puerto Rico, San Juan, Puerto Rico. "The change can be dramatic, especially if we catch patients early in the progression of the disease. The real problem is cost."
Ranibizumab can maintain and improve vision in patients with neovascular ("wet") AMD using monthly dosing, according to results from the Minimally Classic/Occult Trial of the Anti-VEGF Antibody Ranibizumab (MARINA) and Anti-VEGF Antibody for the Treatment of Predominantly Classic Choroidal Neovascularization in AMD (ANCHOR) trials, published in 2007. Quarterly dosing can improve visual acuity, but improvement is about half that seen with monthly dosing, according to the data from the Efficacy and Safety of Ranibizumab in Patients With Subfoveal Choroidal Neovascularization Secondary to AMD (EXCITE) trial.
A variety of follow-up trials have produced similar results, Dr. Berrocal noted at a symposium on Emerging Pharmacotherapies for the Treatment of Posterior Segment Diseases on October 25. Monthly treatment produces the most consistent gains in visual acuity, but many patients see some improvement even with fewer doses. Multiple dosing regimens are still being studied, but the key points seem to be immediate benefit from an initial 3 loading doses and regular, monthly vision exams with follow-up injections as needed. More results are expected to be released in 2010, she added.
Ranibizumab has also shown benefit in diabetic macular oedema (DME). Diabetes remains the leading cause of new blindness in the United States, Dr. Berrocal noted. There are currently 15 million patients with diabetes in the country, and 29% can expect to develop macular oedema after 20 or more years with the disease.
Effective treatment of DME has been problematic, Dr. Berrocal continued. The Ranibizumab for Edema of the Macula in Diabetes (READ) 1 trial with ranibizumab showed an 8-letter gain in visual acuity at 12 months and a 77% reduction in foveal thickness. READ 2, which compared monthly ranibizumab with focal laser and ranibizumab + laser, showed similar results. Ranibizumab alone produced a 6.4-letter gain at 12 months compared with 2 letters for laser alone and 4.4 letters for laser + ranibizumab. The 24-month results are expected in 2010. Higher-dose trials are also underway.
For now, Dr. Berrocal said, ranibizumab results in DME are promising, but multiple questions remain, including the ideal dosage, dosing regimens, and combinations with laser, steroids, and other treatments.
"DME is a multifocal disease that is affected by renal function, high blood pressure, anaemia, and poor glycaemic control," she said. "It is likely that a combination modality will be needed to adequately deal with this complex condition."
The neovascular form of AMD leads to vascular leakage and progressive loss of central vision, and affects at least 153,000 new individuals in the United States each year.
[Presentation title: Emerging Pharmacotherapies for the Treatment of Posterior Segment Diseases, Ranibizumab (Lucentis) in AMD & DDME. Abstract SYM 44]
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