Genaera Corporation, a biopharmaceutical company, announced that the U S Food and Drug Administration (FDA) has granted Fast Track designation to squalamine, an intravenously administered, first in class, small molecule anti-angiogenic drug for the treatment of "wet" age-related macular degeneration (AMD).
Under the FDA Modernization Act of 1997, Fast Track drug development programs are designed to expedite the review and facilitate the development of a new drug that demonstrates the potential to address unmet medical needs for the treatment of a serious or life-threatening condition.
"Fast Track status will help accelerate the development and commercialization of squalamine," commented Roy C. Levitt, MD, president and chief executive officer. "This FDA designation recognizes the serious unmet medical need of patients with AMD and the potential of squalamine to affect this disease. All of our Phase II trials for squalamine in AMD are up and running. We anticipate reporting early data from our first Phase II study later this year with additional Phase II data expected, starting in the first half of 2005. We intend to begin Phase III in the first half of 2005 to run concurrently with our largest Phase II trial."
Squalamine is currently being evaluated in three Phase II clinical trials. MSI-1256F-209 is the cornerstone of Genaera's Phase II studies and is designed to evaluate the safety and efficacy of squalamine in 100 patients with AMD over a two-year period. This Phase II multi-center, randomized, double masked, controlled study will evaluate two dose levels of squalamine (20 mg or 40 mg) given once weekly for four weeks, followed by maintenance doses once every four weeks until week 48. At the end of 48 weeks of therapy, each patient will be followed for 12 months. Genaera anticipates using data analyses from this study in coordinating Phase III activities.
MSI-1256F-208 is the second Phase II trial designed to evaluate the effects of three different doses of squalamine in combination with an initial Visudyne treatment in 45 patients with AMD. Specifically, this study will evaluate the safety and effects of systemically administered squalamine before and after photodynamic therapy with Visudyne. Based on its mechanism of action, this squalamine pretreatment has the potential to improve the effect of Visudyne, and squalamine followed up treatment may inhibit the detrimental effects of the VEGF 'burst' that commonly occurs after Visudyne treatment. The multi-center, randomized, controlled, masked study also includes monthly squalamine maintenance therapy through six months, along with an additional twelve months follow-up for each patient.
MSI-1256F-207 is a Phase II pharmacokinetic and safety trial that will evaluate 18 patients with AMD at three different doses of squalamine over four months. In this open-label, parallel group study, squalamine is administered intravenously at three doses, once weekly for four weeks.
Squalamine Mechanism of Action Squalamine directly interrupts and reverses multiple facets of the angiogenic process. Working within activated endothelial cells, squalamine inhibits growth factor signaling including VEGF, integrin expression, and reverses cytoskeletal formation, thereby resulting in endothelial cell inactivation and apoptosis. Systemically administered squalamine inhibits abnormal angiogenesis in rodent models of retinopathy of prematurity, and the development of choroidal neovascular membranes in rat models of AMD. Additional preclinical studies have demonstrated that systemic squalamine administration is effective in reaching abnormal ocular blood vessels in primates, and leads to partial regression and inhibition of new abnormal vessels in the eye. These results support that squalamine may have a role in the treatment of human choroidal neovascular membrane formation that underlies the pathology of wet AMD.
Wet AMD resulting from angiogenesis is the leading cause of legal blindness among adults age 50 or older in the Western world. About 25 to 30 million people are affected globally and is expected to triple over the next 25 years.
AMD occurs in two types: the "dry" form and the more severe "wet" form. Wet AMD is caused by the growth of abnormal blood vessels, or choroidal neovascularization, under the central part of the retina, the macula. Dry AMD, or the avascular form is the more common and milder form of AMD, accounting for 85 per cent to 90 per cent of all cases. Dry AMD results in varying forms of sight loss and may or may not eventually develop into the wet form. Although the wet form of AMD accounts for only 10 per cent to 15 per cent of all AMD, the chance for severe sight loss is much greater. It is responsible for 90 per cent of severe vision loss associated with AMD. Approximately 500,000 new cases of wet AMD are diagnosed annually worldwide. In North America alone, approximately 200,000 new cases of wet AMD are diagnosed each year.