Treatment of Geographic Atrophy by the Topical Administration of OT-551: Results of a Phase II Clinical Trial

Journal Article

2010

Invest Ophthlmol Vis Sci

51

613

613-619

12/2010

Purpose: To investigate the safety and preliminary efficacy of OT-551, a disubstituted hydroxylamine with anti-oxidant properties, for the treatment of geographic atrophy (GA), the advanced atrophic form of age-related macular degeneration (AMD). Methods: The study was a single-center, open-label Phase II trial, enrolling 10 participants with bilateral GA. Topical 0.45% OT-551 was administered in one randomly assigned eye three times daily for 2 years. Safety measures were assessed by complete ophthalmologic examination, fundus photography, and review of symptoms. The primary efficacy outcome measure was the change in best-corrected visual acuity at 24 months. Secondary efficacy measures included changes in area of GA, contrast sensitivity, microperimetry measurements, and total drusen area from baseline. Results: Study drug was well tolerated and was associated with few adverse events. Mean change in BCVA at 2 years was +0.2+/-13.3 letters in study eyes, and -11.3+/-7.6 letters in fellow eyes (p = 0.0259). However, no statistically significant differences were found between study and fellow eyes for all other secondary outcome measures. Conclusions: OT-551 was well-tolerated by study participants and was not associated with any serious adverse effects. Efficacy measurements in this small study indicate a possible effect in maintaining visual acuity. However, the absence of significant effects on other outcomes measures in this study suggests that OT-551, in the current concentration and mode of delivery, may have limited or no benefit as a treatment for GA.