Promising preliminary long-term data from WTX101 Phase 2 extension study to be presented at AASLD Annual Meeting

Oct 01, 2017

Wilson Therapeutics (publ) announced today that preliminary data from the ongoing extension part of the Phase 2 trial of WTX101 (bis-choline tetrathiomolybdate), an investigational oral first-in-class copper-protein binding agent for the treatment of patients with Wilson Disease, have been accepted for poster presentation at The Liver Meeting®, the annual meeting of the American Association for the Study of Liver Diseases (AASLD) in Washington DC, October 20-24, 2017.

The abstract, published online today, highlights that the initial improvements seen after 24 weeks were continued. Free copper levels, hepatic function and neurologic status were maintained or further improved after treatment for 48 weeks with WTX101 during the extension study.

All 22 patients who completed the 24-week open-label, single-arm, Phase 2 study opted to continue once-daily WTX101 treatment in the extension phase. The results at 48 weeks showed that copper levels remained controlled. Mean levels of non-ceruloplasmin bound copper (NCCcorrected) were further reduced from 0.9 µM to 0.5 µM between 24 to 48 weeks.

Liver function parameters remained unchanged or improved at week 48 compared to week 24, indicating stability of liver function.

Patients showed continued improvements in both patient-reported disability and neurological status. Disease related patient-reported disability measured by the Unified Wilson Disease Rating Scale (UWDRS) Part II further improved from mean 4.1 to 2.1 between week 24 and week 48 and neurological status assessed by UWDRS Part III further improved from mean 16.6 to 12.5.

WTX101 was generally well tolerated. Reversible liver enzyme elevations that were observed in about one-third of patients in the Phase 2 trial were not observed in the extension period.

Accepted abstracts are published today on the AASLD website at www.aasld.org.

Poster title: An Ongoing Extension of a Phase 2 Study of WTX101 in Newly Diagnosed Patients with Wilson Disease.
Poster number:
802
Authors:
Michael L. Schilsky, Frederick K. Askari, Anna Czlonkowska, Peter Ferenci, Jeff Bronstein, Danny Bega, Aftab Ala, David Nicholl, Karl Heinz Weiss
Presentation date
: October 21, 2017
Time:
17:30-19:30 ET
Session
: Genetic and Metabolic Liver Disease
Place:
Walter E. Washington Convention Center, Washington DC

About the Phase 2 Study
WTX101-201 was a 24-week open-label Phase 2 study evaluating the efficacy and safety of WTX101 monotherapy in 28 newly-diagnosed patients with Wilson Disease, aged 18 years and older, who had received either no prior treatment for Wilson Disease or a standard of care agent for up to two years. Patients recruited in the study had various degrees of hepatic impairment at the time of enrollment and the majority also had neurological symptoms at study start. The study was conducted at 11 sites in the U.S. and Europe. Patients received WTX101 at individualized doses between 15 and 120 mg/day. The primary endpoint was defined as achieving or maintaining normalized levels of less than 2.3 µM of free blood copper, or reaching a reduction of at least 25% in free copper in blood from baseline, after 24 weeks of treatment. Free copper in blood was measured as non-ceruloplasmin bound copper, corrected for the amount of copper bound to tripartite tetrathiomolybdate-Cu-albumin complexes in blood (NCCcorrected). Secondary endpoints included reduction of serum free copper from baseline, neurological disability and status measured as Unified Wilson Disease Rating Scale (UWDRS) part II and III respectively, liver status measured as the Modified Nazer Score and quality of life measured through EuroQOL 5 Dimensions Visual Analogue Scale (EQ VAS).

About WTX101 (bis-choline tetrathiomolybdate)
WTX101 (bis-choline tetrathiomolybdate) is a first-in-class copper-protein binding agent with a unique mechanism of action, under investigation as a novel therapy for Wilson Disease. In contrast to current treatments, WTX101 provides an alternative copper-protein binding mechanism by forming a tripartite complex with copper and albumin. WTX101 thereby detoxifies excess copper in both liver and blood, and promotes copper clearance through biliary excretion (the body’s natural route of elimination).

A Phase 2 study evaluating the efficacy and safety of WTX101 in Wilson Disease patients has successfully been completed. In addition, the active moiety of WTX101, tetrathiomolybdate, has been tested in several previous clinical studies in Wilson Disease patients. The data from these studies suggest that WTX101 can lower and control free copper levels, and improve symptoms and associated disabilities. The data also suggest that WTX101 is generally well tolerated with a low risk of neurological worsening. The tolerability profile and the expected once-daily dosing regimen have the potential to improve compliance in Wilson Disease patients, leading to fewer treatment failures and ultimately improved outcomes. WTX101 has received orphan drug designation for the treatment of Wilson Disease in the US and EU.

In addition, WTX101 has shown potential as a treatment for several other medical conditions including Amyotrophic Lateral Sclerosis (ALS). WTX101 has received US orphan drug designation for the treatment of ALS.

About Wilson Disease
Copper is an essential trace element that plays a critical role in key physiological cellular processes. Due to its toxic potential, copper is normally tightly bound to copper-carrying proteins inside the liver, and excess copper is eliminated from the body via biliary excretion. Wilson Disease is a rare genetic disorder of impaired copper transport and excretion, caused by loss of function of the ATP7B copper-binding protein. This leads to copper overload in the liver, release of free copper into the blood, and damaging accumulation of copper in the brain and other organs. Untreated Wilson Disease inevitably leads to various combinations and severity of hepatic, neurologic and psychiatric symptoms, and is ultimately fatal.

Wilson Disease affects approximately one in every 30,000 people worldwide, corresponding to a prevalence of approximately 10,000 patients in the US and 15,000 patients in the EU. The therapies currently being used in Wilson Disease were introduced in the 1950s and 60s. Since then, no new treatment options have been developed and considerable unmet medical needs still exist.

About Wilson Therapeutics
Wilson Therapeutics is a biopharmaceutical company, based in Stockholm, Sweden, that develops novel therapies for patients with rare diseases. Wilson Therapeutics’ lead product, WTX101, is in development as a novel treatment for Wilson Disease. A Phase 2 clinical study has been completed successfully and preparations for a pivotal Phase 3 study are ongoing. Wilson Therapeutics is listed in the Mid Cap segment on Nasdaq Stockholm with the stock ticker WTX.

Visit www.wilsontherapeutics.com for more information.

For further information contact:
Jonas Hansson, CEO, Wilson Therapeutics AB
Telephone: +46 8 796 00 00

Email: jonas.hansson@wtx.se

Wilson Therapeutics AB (publ)
Org nr 556893-0357
Kungsgatan 3
 
SE-111 43 Stockholm

The information in the press release is information that Wilson Therapeutics is obliged to make public pursuant to the EU Market Abuse Regulation. The information was submitted for publication, through the agency of the contact person set out above, at 18.00 CET on October 1, 2017.