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Research at Wilmer: Targeted Eye Delivery to Manage Macular Degeneration

Ran Zeimer, Ph.D. PI and Morton F. Goldberg, MD co-PI


Age related macular degeneration (ARMD) is the leading cause of vision loss in patients over the age of 50 years, Up to 90% of patients with ARMD experience vision loss over a period of several years. Over 500,000 new cases of ARMD associated with growth of choroidal new blood vessels are diagnosed annually in the U.S. and Europe. A new treatment based on photodynamic therapy has been introduced recently after clinical trials have shown a difference in vision maintenance between treated and non-treated patients. However, the therapy is effective only in a relatively small portion of the afflicted population and it necessitates repeated treatments because the effect appears to be temporary. A therapy that is effective and applicable to the two forms of choroidal new blood vessels ('occult' and 'classic') but causes only minimal collateral damage is needed. This need has been acknowledged in the NEI National Plan 1999-2003 and selected as a Program Goal. We have developed a new technology, 'Light Targeted Drug Delivery' (LTD), that provides delivery of drugs and medical dyes to specific tissues in the eye. Our pre-clinical laboratory data have demonstrated that when LTD is used with a dye, one can detect ARMD lesions (new blood vessels) in a manner unmatched by existing clinical methods. This diagnostic method (Light Targeted Angiography) can alleviate the current problems in detecting all areas with new blood vessels and provide reliable monitoring of treatment. But, more importantly, we have demonstrated that LTD can be used to target photodynamic therapy specifically to the abnormal new blood vessels. LTD has been shown to occlude the abnormal new blood vessels while preserving healthy adjacent tissues necessary for long term preservation of vision. We also have evidence that the treatment is applicable to both 'classic' as well as 'occult' diseases. The transition from the laboratory to tests in ARMD patients can now be achieved only through collaborative multidisciplinary research. The inventor and a world renown retina specialist are joined by seven groups of other experts. This team will perform all the pre-clinical studies required by the FDA. Subsequently, the safety of this therapy will be assessed in a phase I dose escalation study in ARMD patients. Since a phase II clinical study exceeds the resources provided by this NEI program, we have designed the phase I study to act also as a robust proof of concept. Such a proof would then pave the way for extensive phase II and III clinical studies. A company ready to take on this task is part of this multidisciplinary effort to develop a novel therapy to restore or prevent loss of vision in an eye disease that is reaching epidemic proportions.


Principle of conventional photodynamic therapy for macular degeneration
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Principle of macular degeneration therapy by Light Targeted Delivery
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Laser Targeted Angiography of a CNV before and after Light Targeted Delivery treatment
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Laser targeted photo-occlusion of rat choroidal neovascularization without collateral damage
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Nishiwaki H, Zeimer R, Goldberg MF, et al.
Photochem. Photobiol. 2002;75:149-158.

Novel ophthalmic therapeutic modalities based on noninvasive light- targeted drug delivery to the posterior pole of the eye.
Zeimer R and Goldberg MF.
Adv Drug Deliv Rev. 2001;52:49-61