Phase 3 Clinical Effect Durability of TD-9855 for Treating Symptomatic nOH in Subjects With Primary Autonomic Failure

Phase 3, multi-center, randomized withdrawal study to evaluate the sustained benefit in efficacy and safety of ampreloxetine in subjects with primary autonomic failures (MSA, PD, or PAF) and symptomatic nOH. The study consists of 3 periods: (i) 16-week open-label (OL) treatment with ampreloxetine, (ii) 6-week randomized placebo-controlled treatment, and (iii) 2-week follow-up (only for patients who do not enroll in Study 0171 (long-term extension safety study)).