Wilson Therapeutics presents updated preliminary clinical data on WTX101 at the AASLD Liver Meeting

Wilson Therapeutics AB (publ), today announced that updated preliminary data from the company’s ongoing Phase 2 clinical trial for WTX101 (bis-choline tetrathiomolybdate; Decuprate®) in Wilson Disease will be presented at the Liver Meeting®, organized by the American Association for the Study of Liver Diseases (AASLD), in Boston, Massachusetts, November 11-15.

The preliminary data continue to show that once-daily dosing with WTX101 reduces serum free copper and improves hepatic and neurologic status in patients with Wilson Disease. The poster presentation will take place today, and will be given by Michael Schilsky (MD, FAASLD), Associate Professor at Yale Medical Center and Director, Center of Excellence for Wilson Disease.

“Wilson Disease is a rare genetic disorder of impaired copper metabolism that causes serious copper poisoning. Although treatments have been available since the 1950’s, there is a significant need for new therapies that can rapidly control free copper, yield a higher initial response rate, have a more benign safety profile and offer a simplified dosing regimen,” said Dr. Schilsky. “The study is still ongoing so the data presented today are preliminary, but we are very encouraged as they indicate that WTX101 may have the potential to address these needs. With the possibility of once daily dosing that could improve patient convenience and adherence, a successful outcome for the trial could lead to significant improvements for Wilson Disease patients.”

WTX101-201 is an open-label Phase 2 clinical trial evaluating the efficacy and safety of once-daily WTX101 monotherapy in 28 newly-diagnosed patients with Wilson Disease, aged 18 years and older, who have received either no prior treatment for Wilson Disease or a standard of care agent for up to two years. The study is being conducted at 11 sites in the U.S. and Europe, and follows patients on WTX101 for 24 weeks. Patients completing the 24-week study period can elect to stay on WTX101 in an extension phase of the study.

The poster presents preliminary data up to 24 weeks. As of October 5, the cut-off date for the current analysis, all 18 patients who had reached the end of the 24-week study period had elected to continue WTX101 treatment in the extension phase. 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 presented preliminary data show that treatment with WTX101 leads to rapid control of free copper (Cu), with average levels reduced to and below the upper limit of normal after eight weeks. 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.

Preliminary data also show that liver status, measured using the Modified Nazer Score, improved or remained stable in 22 out of 27 evaluable patients at the last observation available in the 24-week study period compared to baseline. Three of the five patients who did not improve or remain stable during the 24-week period, stabilized or improved when treated for a longer period during the extension phase.

Neurological impairment, measured as mean Unified Wilson Disease Rating Scale Part 3 score, a neurology scale specific for Wilson Disease, also improved over the course of therapy.

Treatment with WTX101 was generally well tolerated and no drug-induced neurological worsening was observed upon treatment initiation. Most reported adverse events were mild (grade 1) to moderate (grade 2). Reversible liver test elevations were observed in approximately 1/3 of patients and these elevations were generally mild to moderate, asymptomatic and normalized with dose adjustments.

"In clinical practice, treatment of Wilson Disease patients with neurological symptoms is a particular concern, as approximately 25% of these patients experience a significant drug-induced worsening of neurological symptoms upon initiation of treatment with current therapies,” said Carl Bjartmar, MD, PhD, Chief Medical Officer of Wilson Therapeutics. “The preliminary data from our ongoing trial is therefore very encouraging as we so far have not seen any cases of this initial drug-induced worsening.”

“We are very pleased with the progression of this study and we look forward to reporting topline data from the study later this year”, says Jonas Hansson, Chief Executive Officer of Wilson Therapeutics. “With final Phase 2 data we expect to go back to the regulatory authorities to discuss and agree on the pivotal Phase 3 program.”

About WTX101 (bis-choline tetrathiomolybdate)
WTX101 (bis-choline tetrathiomolybdate; Decuprate®) is a first in class copper modulating agent with a unique mechanism of action, under investigation as a novel therapy for Wilson Disease. WTX101, unlike current treatments for Wilson Disease, exhibits a specific copper buffering activity and acts in the liver where it removes copper from the overloaded copper buffer. WTX101 also rapidly neutralizes toxic free copper in tissue and blood by forming complexes with excess copper and albumin. The excess copper is excreted via the bile, the body’s natural route for excess copper elimination.

The active ingredient of WTX101, tetrathiomolybdate, has been tested in several clinical studies in Wilson Disease patients and the data from these studies, as well as preliminary data from the Company’s ongoing Phase 2 study, suggest that WTX101 can rapidly lower and control toxic free copper levels and improve clinical symptoms in these patients. The data also suggest that WTX101 is generally well-tolerated and may have potential for a reduced risk of neurological worsening after initiation of therapy. WTX101 is expected to have a once-daily dosing regimen which may potentially translate into improved compliance in Wilson Disease patients, leading to fewer treatment failures and ultimately improved outcomes as a result. WTX101 has received orphan drug designation for the treatment of Wilson Disease in the US and EU.

About Wilson Disease
Wilson Disease is a rare genetic disorder of impaired copper metabolism that causes serious copper poisoning. The genetic defect severely affects the body´s ability to regulate copper balance, resulting in life-threatening damage to the liver, the brain and further organs if left untreated. 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 1950’s and 60’s and since then there have been no new treatment options developed for patients with this disease.

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 initially being developed as a novel treatment for Wilson Disease and is currently being evaluated in a Phase 2 clinical study. 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 no 556893-0357
Västra Trädgårdsgatan 15
SE-111 53 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 14.00 CET on November 11, 2016.

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