Theravance Announces Positive Results From a Phase 2 Study of TD-9855 in Patients With Fibromyalgia
Theravance, Inc. (NASDAQ: THRX) today announced positive results from a Phase 2 study of TD-9855, an investigational norepinephrine and serotonin reuptake inhibitor (NSRI), in patients with fibromyalgia (FM). The study demonstrated statistically significant and clinically meaningful improvements in the primary and secondary endpoints at the 20 mg dose of TD-9855 compared to placebo. The 5 mg dose did not meet statistical significance for the primary endpoint. Both doses were generally well tolerated.
"We are very pleased with the positive results of our Phase 2 study of TD-9855 in patients with fibromyalgia," said Mathai Mammen, M.D., Ph.D., Senior Vice President of Research and Development. "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 2 study, TD-9855 demonstrated a beneficial impact on symptoms important to patients with fibromyalgia."
The primary efficacy endpoint of the Phase 2 study was the average of the daily pain score during the last week of the 6-week treatment period, using an 11-point Numerical Rating Scale (Pain-NRS). Pre-specified secondary endpoints were the Fibromyalgia Impact Questionnaire (FIQ) and the Patient Global Impression of Change scale (PGIC) measured on Day 43. Three hundred ninety-two patients were randomized to one of three treatment groups: placebo, 5 mg and 20 mg TD-9855.
"There continue to be substantial unmet needs in the management of fibromyalgia," said Dr. Lesley Arnold, Professor of Psychiatry at the University of Cincinnati College of Medicine. "Many patients with fibromyalgia do not respond to or tolerate currently available treatments. The results of this Phase 2 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."
TD-9855 met the primary efficacy endpoint at 20 mg, demonstrating a statistically significant reduction of 1.4 in weekly average pain score compared to 0.9 for placebo (one-sided p=0.022). On the FIQ, a measure of the impact of fibromyalgia symptoms, TD-9855 demonstrated a significant improvement on Day 43 compared to placebo (-16.2 vs. -10.4; one-sided p=0.010). In an analysis of effect on a patient's overall evaluation of treatment, as measured by the PGIC, TD-9855 had a significantly greater proportion of responders (with a rating of "very much improved" or "much improved" in PGIC) compared to placebo (48% vs. 32%; one-sided p=0.015). The study included exploratory endpoints to assess fatigue; positive treatment effects were seen with the 20 mg dose on global fatigue and cognitive fatigue endpoints. Furthermore, a composite responder analysis (Pain-NRS ≥ 30% reduction, PGIC < 2 and SF-36 Physical Component Summary > 6 point improvement), an index of overall treatment response, revealed improvement with the 20 mg dose of TD-9855 compared to placebo.
Both doses of TD-9855 were generally well tolerated in the study. The discontinuation rate in this trial was 20.2%, and was similar across treatment groups. The five most common treatment-emergent adverse events reported were headache, nausea, dizziness, insomnia and constipation. Changes in heart rate and blood pressure with TD-9855 were within the range of those seen in approved drugs in this class. Two serious adverse events were reported in TD-9855 treatment groups, with one assessed as possibly treatment related in the 5 mg group.
About the Phase 2 Study of TD-9855 in Fibromyalgia
The Phase 2 randomized, double-blind, parallel-group, placebo-controlled study evaluated the safety and efficacy of two doses of TD-9855 (5 mg and 20 mg) in 392 patients with fibromyalgia. Study medication was administered once-daily for up to 6 weeks. The primary endpoint of the study was improvement in pain. Secondary endpoints assessed improvement in core symptoms of fibromyalgia using established fibromyalgia measures, the Fibromyalgia Impact Questionnaire (FIQ) and the Patient Global Impression of Change scale (PGIC). Impact on common symptoms of fibromyalgia was also evaluated as exploratory endpoints.
TD-9855 is an investigational NSRI discovered by Theravance for the treatment of chronic pain and potentially other CNS disorders. TD-9855 has been administered to healthy volunteers in ascending single- and multiple-dose studies evaluating safety, tolerability and pharmacokinetics. The results of these studies showed that TD-9855 was generally well tolerated, had a predictable and linear pharmacokinetic profile and a long pharmacokinetic half-life (approximately 35 hours) supportive of once-daily dosing. Data collected from a Phase 1 positron emission tomography (PET) study confirmed CNS penetration and selectivity for norepinephrine over serotonin transporters. In preclinical studies, TD-9855 exhibited broad antinociceptive activity across a range of models of pain.
Fibromyalgia is a chronic pain syndrome that has been estimated to affect approximately 5 million individuals in the United States. While its etiology is unknown, fibromyalgia is believed to be a disorder of pain processing which results in amplification of sensory signals within the CNS. Agents that modulate central pain processing pathways are used in the pharmacological management of fibromyalgia. In addition to widespread pain, fibromyalgia is accompanied by other symptoms, such as fatigue, sleep, mood and cognitive difficulties that reduce patients' overall quality of life.
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