Tioga Pharmaceuticals Announces Initiation of Phase 2 Clinical Study of Asimadoline in Patients with Pruritus Associated with Atopic Dermatitis

June 11, 2015

SAN DIEGO – Tioga Pharmaceuticals, a clinical stage biotechnology company, today announced the initiation of a Phase 2 clinical study of asimadoline, a novel, well-studied kappa-opioid receptor specific agonist, for the treatment of pruritus or itching. The double-blind, placebo-controlled clinical study is designed to evaluate the safety, tolerability, and clinical efficacy of asimadoline in patients with pruritus due to atopic dermatitis and is being conducted at 20 clinical study centers in the United States. Because of its mechanism of action, asimadoline has the potential to treat pruritus associated with a variety of conditions, including atopic dermatitis, psoriasis, end-stage renal disease, liver diseases such as cholestatic disease and primary biliary cirrhosis, malignancies, adverse drug effects, and certain orphan diseases.

Chronic pruritus, which is defined as pruritus lasting six weeks or more, is associated with significant decrease in quality of life, including impact on sleep, anxiety, depression, and ability to work and lacks effective treatment options. Chronic pruritus is estimated to occur in approximately 20 percent of the general population (lifetime prevalence), with a very high incidence in certain dermatological and systemic conditions.

“Chronic pruritus is a major debilitating symptom associated with a wide variety of diseases and for which there are no effective therapies. Patients with chronic pruritus have severely reduced quality of life, making the unmet medical need high. I am very excited to be a part of this Phase 2 clinical study testing the treatment potential of asimadoline in patients with pruritus associated with atopic dermatitis,” said Gil Yosipovitch, M.D, a Principal Investigator for the study and Professor, Chair of Dermatology, and Director of the Temple Itch Center at Temple University School of Medicine.

The kappa-opioid system plays a pivotal role in the sensory transmission and processing of itch sensation from the skin to the brain. Animal models of chronic pruritus have demonstrated decreased kappa-opioid receptor activation or down regulation, coupled with increased mu-opioid receptor activation. Asimadoline has demonstrated efficacy in animal models of pruritus by significantly reducing the frequency of scratching induced by intra-dermally injected Substance P and significantly inhibiting scratching behavior induced by intra-dermally injected histamine or dinitrofluorobenzene.

“We believe the scientific rationale for asimadoline in pruritus is excellent. In addition, the safety and tolerability profile for asimadoline is very encouraging, with over 1,900 clinical trial participants exposed to date. We are excited about starting this Phase 2 proof-of-concept study and look forward to sharing top-line results next year, as well as moving into pivotal trials in pruritus,” said Stuart Collinson, Ph.D., Chairman of Tioga Pharmaceuticals.

About Asimadoline
Asimadoline is an orally active, highly selective kappa-opioid receptor agonist with approximately 500-fold greater affinity for human kappa-, as compared with either delta- or mu-opioid receptors. Due to its high selectivity for the kappa-opioid receptor, asimadoline does not produce mu-opioid like side effects. Asimadoline has demonstrated efficacy in reducing scratching behavior in several animal models of experimental itch. In addition, a similar compound, nalfurafine (Remitch®, Toray Industries, Inc.), has demonstrated efficacy in clinical studies of uremic pruritus and is approved in Japan for patients with pruritus undergoing hemodialysis.

About Tioga Pharmaceuticals
Tioga Pharmaceuticals, Inc. is a clinical-stage pharmaceutical company focused on developing novel treatments for pruritus. Tioga is headquartered in San Diego. For more information, please visit www.tiogapharma.com.