US-based biopharmaceutical firm Theravance has revealed positive results from a Phase II trial of its investigational norepinephrine and serotonin reuptake inhibitor (NSRI) ' TD-9855' in patients with fibromyalgia (FM).
The randomised, double-blind, parallel-group, placebo-controlled Phase II trial assessed the safety and efficacy of two doses of TD-9855 (5mg and 20mg) in 392 patients with FM.
Patients were randomised to one of three treatment groups, including placebo, 5mg and 20mg TD-9855.
In the trial, medication was administered once-daily for up to six weeks and its primary endpoint was improvement in pain.
The trial's secondary endpoints evaluated improvement in core symptoms of fibromyalgia using established fibromyalgia measures, the fibromyalgia impact questionnaire (FIQ) and the patient global impression of change scale (PGIC).
According to the company, the impact on common symptoms of fibromyalgia was also assessed as exploratory endpoints.
The trial showed statistically significant and clinically meaningful improvements in the primary and secondary endpoints at the 20mg dose of TD-9855 compared to placebo.
The 5mg dose did not meet statistical significance for the primary endpoint and both doses were generally well tolerated.
Theravance senior vice-president R&D Mathai Mammen said: "Patients with fibromyalgia have a clear unmet medical need: a medicine that will treat their pain and address other symptoms of this disorder, including fatigue and cognitive impairment.
"In this Phase II study, TD-9855 demonstrated a beneficial impact on symptoms important to patients with fibromyalgia."
The primary efficacy endpoint of the trial was the average of the daily pain score during the last week of the six-week treatment period, using an 11-point numerical rating scale (Pain-NRS), while pre-specified secondary endpoints were FIQ and PGIC measured on Day 43.
University of Cincinnati College of Medicine professor of psychiatry Lesley Arnold said there continue to be substantial unmet needs in the management of fibromyalgia.
"Many patients with fibromyalgia do not respond to or tolerate currently available treatments," Arnold said.
"The results of this Phase II trial of a new norepinephrine and serotonin reuptake inhibitor provide hope that additional options might become available to patients with this common pain disorder.
"TD-9855 was generally well tolerated and, compared with placebo, significantly improved pain, as well as other symptoms commonly associated with fibromyalgia."