Fovista® Anti-PDGF Therapy
Fovista® is designed to target platelet derived growth factor (PDGF) in combination with anti-VEGF drugs to disrupt the formation of abnormal new blood vessels in wet AMD. In clinical trials, the combination of Fovista® 1.5mg and an anti-VEGF therapy demonstrated statistically significant superiority compared to anti-VEGF monotherapy in terms of improvements in visual acuity, providing a 62% comparative benefit from baseline.
Fovista® binds to and inhibits PDGF expression, causing the loss or stripping of pericytes, leaving the endothelial cells unprotected and highly vulnerable to the effects of anti-VEGF therapy. Clinical data have shown that administration of Fovista® 1.5mg in combination with anti-VEGF drugs is likely to inhibit new blood vessel growth in patients with wet AMD more effectively than anti-VEGF monotherapy and may also enhance neovascular regression.
Zimura® – Anti-Complement
Zimura® targets complement factor C5, a central component of the complement cascade that is believed to be involved in the development of AMD. In a Phase 2a clinical trial of Zimura®, wet AMD patients who had not previously been treated with anti-VEGF therapy and who received six injections of Zimura® in combination with anti-VEGF treatment showed improvements in vision of a magnitude warranting further evaluation in subsequent studies.
Based on results of this trial, data from a third-party clinical trial and multiple published studies suggesting that the complement pathway plays a significant role in dry AMD, we plan to initiate a Phase 2/3 clinical trial investigating Zimura® for treatment of geographic atrophy, a severe form of dry AMD affecting approximately 8 million patients worldwide. In addition, a Phase 2 clinical trial is planned for Zimura® and Fovista™ in combination with anti-VEGF therapy for the treatment of anti-VEGF resistant wet AMD patients believed to have complement-mediated inflammation.
Ophthotech is evaluating a study of Zimura® in combination with anti-VEGF therapies in patients with wet AMD who do not respond adequately to treatment with anti-VEGF monotherapy on the basis of complement mediation inflammation.
Both Fovista® and Zimura® are aptamers, single strands of nucleic acid that bind with high specificity and affinity to targets such as PDGF, similar to a monoclonal antibody. Aptamers are synthetically derived, making their production predictable and reproducible. They are also chemically stable and do not generate an immune response that could limit efficacy.