As you know, retinal neovascularization can be a serious problem in premature babies with retinopathy and pa-tients who have either diabetic retinopathy or wet age-related macular degeneration (AMD). Now, an anti-angiogenic agent from Magainin Pharmaceuticals, Inc. -- squalamine -- has been the subject of two preclinical studies involving retinal neovascularization. Both studies have shown promising results.

In the first study, researchers investigated the effects of administering a single dose of squalamine on oxygen-induced retinopathy 15 days after birth. (This is the time when new blood vessel formation in the eyes has started to occur.) The results indicate that squalamine significantly inhibits retinal neovascularization.

Abnormal angiogenesis was already occurring at the time of treatment in this study, and squalamine also demonstrated the ability to arrest and regress abnormal vessel growth. This may be important for clinical therapy, where the abnormal vessel growth has usually occurred before therapy begins.

The second study found that squalamine as a single dose significantly inhibits retinal neovascularization and other measures of retinopathy, but leaves normal retinal vascular development intact.

Currently, no effective pharmaceutical therapies exist for diabetic or other forms of retinopathy. Surgical techniques in use include repetitive laser therapy that's partially effective at slowing vision loss, but is expensive and causes vision loss itself. Inhibition of proliferative retinal angiogenesis, with anti-angiogenic agents like squalamine, is a potentially promising mode of treatment for diabetic retinopathy.