Droxidopa: Phase III amended

Chelsea said FDA has agreed to allow it to modify the primary endpoint and to enroll an additional 24 patients in the Phase III Study 301 trial. The double-blind, U.S and Canadian trial is comparing 100, 200, 300, 400, 500 and 600 mg oral droxidopa given thrice daily vs. placebo. The primary endpoint will now be the relative mean change in the Orthostatic Hypotension Questionnaire (OHQ) composite score, rather then the previous endpoint of improvement in dizziness or light-headedness, which represents a single item on OHSA. The company said the additional patients will increase the power of the study to >80%. The company initially completed enrollment of 118 patients in September but now expects to complete the additional enrollment in 2Q10, with top-line data expected in 3Q10. Chelsea has an SPA from FDA for Study 301.

In September, Chelsea reported that droxidopa missed the primary endpoint of significantly improving the dizziness or light-headedness component of the OHSA scale vs. placebo in the Phase III Study 302 trial (see BioCentury, Sept. 28). The company also said FDA requested an additional study to support an NDA for droxidopa. As a result, Chelsea said it plans to start the Study 306 trial early next year to evaluate droxidopa in about 35-45 Parkinson's disease patients with symptomatic NOH, which will be designed with the same revised primary endpoint as Study 301. Chelsea expects to complete this study by year end 2010 and to submit an NDA in early 2011. ...