Biotie Therapies has announced an agreement with the United States Food and Drug Administration (FDA) on a Special Protocol Assessment (SPA) for the company’s Phase 3 Parkinson’s disease study of tozadenant. The study (TOZ-PD) will evaluate both the safety and the efficacy of tozadenant in comparison to placebo in Parkinson’s patients currently taking levodopa and in cases of end-of-dose wearing off.
Parkinson’s disease is a progressive and chronic neurodegenerative condition that leads to motor symptoms like rigidity, tremors, slowed movements, mood disorders, cognitive impairment and autonomic dysfunction. According to the Parkinson’s Disease Foundation, there are almost one million individuals living in the United States with Parkinson’s disease.
A Special Protocol Assessment consists of a written agreement with the FDA that includes the design, size and analysis for a specific clinical trial. An SPA can only be altered through a written agreement between the sponsor and the FDA, or in a situation in which the FDA becomes aware of new modified public health concerns. Positive outcomes of the TOZ-PD trial after the outcomes of the already completed Phase 2b study are thought to be enough to support an efficacy claim for tozadenant in individuals with Parkinson’s disease and with motor fluctuations (end-of-dose wearing off) and could support an NDA submission. The final marketing approval will be dependent, among other factors, on the overall results of the trial.
The planned study is a double-blind, randomized and placebo controlled Phase 3 trial to assess 450 Parkinson’s disease patients currently in levodopa related end-of-dose wearing off. Enrollees will be selected randomly to receive twice daily doses of 120mg or 60mg of tozadenant or placebo as an addition to their regular anti-PD medications, for 24 weeks. The first endpoint will to reduce the time spent in the “off” state in those taking tozadenant in comparison to placebo between baseline and week 24. This double-blind stage of the trial will be followed by an open-label 1 year treatment.
Timo Veromaa, who is the CEO and President of Biotie, commented in a press release: “The agreement with FDA is another important milestone in our effort to bring tozadenant through the regulatory process and make it available to patients to address a significant unmet medical need.”