Theravance Biopharma, Inc. (NASDAQ: TBPH) (“Theravance Biopharma” or the “Company”) today announced dosing of the first patient in a registrational Phase 3 clinical trial of ampreloxetine (TD-9855) in patients with symptomatic neurogenic orthostatic hypotension (nOH). Ampreloxetine is an investigational, once-daily norepinephrine reuptake inhibitor (NRI) in development for the treatment of patients with symptomatic nOH.
The Phase 3 study is a four-week, multi-center, randomized, double-blind, placebo-controlled, parallel-group study designed to evaluate the efficacy, safety and tolerability of ampreloxetine in approximately 188 patients with symptomatic nOH caused by primary autonomic failure associated with multiple system atrophy (MSA), Parkinson’s disease (PD) and pure autonomic failure (PAF). Patients will be randomized to receive a single 10 mg dose of ampreloxetine or placebo once daily for four weeks. The primary endpoint of the study is change from baseline in dizziness severity, as measured by Orthostatic Hypotension Symptom Assessment (OHSA) Question #1 (OHSA #1, a measure of dizziness, lightheadedness or the sensation of being about to black out) at four weeks for ampreloxetine as compared to placebo. The study will evaluate additional efficacy assessments, as well as safety and tolerability measures.
“Given the limitations of currently available therapeutic options, we recognize a significant opportunity exists for a potentially safe and durable treatment for nOH. Positive four-week results achieved in our Phase 2 study provide the basis for advancing ampreloxetine into this registrational Phase 3 program,” said Brett Haumann, MD, chief medical officer at Theravance Biopharma. “We are pleased to begin 2019 with this milestone, and in the near term we also anticipate dosing the first patient in the Phase 2b/3 study of TD-1473, our gut-selective JAK inhibitor, in patients with ulcerative colitis.”
Theravance Biopharma previously announced positive four-week results from a Phase 2 clinical trial of ampreloxetine in patients with nOH. Findings showed that a majority of patients enrolled in the study’s single ascending dose portion demonstrated durable improvements in nOH symptom severity as measured by OHSA #1. Patients treated in the extension phase of the study showed a mean symptom improvement of 2.4 points at four weeks. Importantly, mean symptom improvement was greatest (3.8 points) in nOH patients who reported dizziness symptoms (OHSA #1 > 4) at baseline, a pre-defined regulatory and clinical threshold that will be used to enroll patients in Phase 3. Additionally, ampreloxetine consistently increased systolic blood pressure (SBP), including clinically meaningful increases in standing SBP at the three-minute assessment at all time points on all weekly clinic visits. There were no drug-related serious adverse events reported, and ampreloxetine was generally well tolerated in the study.