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
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
“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
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.
Tioga Pharmaceuticals, Inc.
Jessica Yingling, Ph.D.
Little Dog Communications Inc.