Studies focus on new strategies for pegaptanib treatment

With an aim to further improve efficacy and safety outcomes achieved with anti-VEGF therapy for AMD, ongoing studies with pegaptanib sodium (Macugen, OSI/Eyetech Pharmaceuticals) are evaluating the potential benefits of early treatment initiation and of using an induction/maintenance approach, said Anthony P. Adamis, MD, at the World Ophthalmology Congress.

Dr. Adamis explained that data from available retrospective studies suggest that early treatment leads to better outcomes with respect to proportions of patients achieving vision improvements. Based on those findings, a multicenter, prospective trial was designed and is now underway that will enroll 100 patients. Dr. Adamis is executive vice president of research and development and chief scientific officer of OSI/Eyetech Pharmaceuticals.

Another study is evaluating an induction/maintenance approach in which treatment is being initiated with bevacizumab (Avastin, Genentech) and then followed with pegaptanib maintenance. In that regimen, the bevacizumab is administered as a "powerful drying agent." However, recognizing the potential systemic safety concerns associated with its continued use, pegaptanib is being administered as a potentially safer drug for long-term use that could keep the retina dry.

"The induction/maintenance strategy is not a new concept but is something that has been used in oncology and by AIDS specialists for years," said Dr. Adamis. "Now, we are starting to think about this model in ophthalmology and testing it in clinical trials."