Phase 3 Open-Label Extension Study of TD-9855 for Treating Symptomatic nOH in Subjects With Primary Autonomic Failure

Inclusion Criteria: * Completion of Study 0170 and, in the opinion of the Investigator, would benefit from long-term treatment with ampreloxetine. * The subject must be able to understand the nature of the study and must provide written informed consent prior to the conduct of any study procedures (including any changes occurring in the subject's current therapeutic regimen). * The subject must be willing to continue on treatment and must continue to meet all the inclusion criteria for the preceding study (Study 0170) except, a score of \>4 in OHSA#1. Exclusion Criteria: * Subjects may not be enrolled in another clinical trial. * Psychiatric, neurological, or behavioral disorders that may interfere with the ability of subjects to give informed consent, or interfere with the conduct of the study. * Medical, laboratory, or surgical issues deemed by the Investigator to be clinically significant. * Hypersensitivity to ampreloxetine or the formulation excipients.