Wilson Therapeutics Receives US Orphan Drug Designation for WTX101 for the Treatment of ALS

Jun 09, 2017

Wilson Therapeutics AB (publ), announced today that the U.S. Food and Drug Administration (FDA) has granted the company Orphan Drug Designation for WTX101 for the treatment of patients suffering from Amyotrophic Lateral Sclerosis (ALS). WTX101 (bis-choline tetrathiomolybdate) is an investigational first-in-class copper-protein binding agent with a unique mechanism of action.

ALS is a neurodegenerative disease, in which the nerve cells controlling the body’s muscles gradually degenerate, leading to general paralysis and respiratory failure. Median survival for an ALS patient is three to five years. Currently, the treatments available for ALS are hampered by limited efficacy so the focus of medical care is to provide symptomatic management of all patients with mild to moderate disease and palliative intervention in patients with severe or terminal disease.

Approximately 7% of the ALS patients have a mutation in a copper-dependent enzyme, superoxide dismutase 1 (SOD1). SOD1 is an enzyme with antioxidant properties important in the protection against free radicals, a highly reactive oxygen species that can damage cellular components via oxidative stress. The active ingredient of WTX101, tetrathiomolybdate, has been tested in mice that are genetically modified with a mutant form of human SOD1 and develop ALS. These studies show that tetrathiomolybdate can delay the onset of disease as well as reduce the symptoms after disease onset in this mouse model.

“ALS is a devastating disease with very limited treatment options. The Orphan Drug Designation is an important milestone for us and it recognizes the promise of WTX101 as a potential new treatment for ALS. The disease is notoriously hard to treat but pre-clinical data for WTX101 are promising so we are currently exploring the possibility of developing WTX101 for the treatment of the subset of ALS patients that suffer from SOD1-mutated ALS,” said Jonas Hansson, Chief Executive Officer of Wilson Therapeutics.

“However, our immediate development focus remains Wilson Disease, where we are expecting to initiate Phase 3 later this year,” concluded Jonas Hansson.

About Orphan Drug Designation
The FDA grants Orphan Drug Designation status to products that treat rare diseases, providing incentives to sponsors developing drugs or biologics. The FDA defines rare diseases as those affecting fewer than 200,000 people in the United States at the time of designation. Orphan Drug Designation provides the sponsor certain benefits and incentives, including a period of marketing exclusivity if regulatory approval of the drug is ultimately received for the designated indication, potential tax credits for certain activities, eligibility for orphan drug grants, and the waiver of certain administrative fees. The receipt of Orphan Drug Designation status does not change the regulatory requirements or process for obtaining marketing approval and designation does not mean that marketing approval will be received.

About SOD1-mutated Amyotrophic Lateral Sclerosis (SOD1-ALS).
Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease, in which the nerve cells controlling the body’s muscles gradually degenerate, leading to general paralysis and respiratory failure. Median survival for an ALS patient is three to five years. Muscle weakness results from progressive degeneration of motor neurons in different parts of the central nervous system. The cause of the damage to the neurons is unknown, but several theories have been proposed, including glutamate toxicity, protein misfolding and oxidative stress. The incidence of ALS in the US and in the EU is estimated at 1.5 to 2.5 per 100,000 people per year, with an estimated prevalence of 2.7 to 7.4 per 100,000 people, corresponding to approximately 30,000 individuals in the US and EU. The mean age of onset is about 57 years.

Approximately 7% of the ALS patients have a mutation in a copper-dependent enzyme called Superoxide Dismutase 1 (SOD1). SOD1 is an enzyme with antioxidant properties important in the protection against free radicals, a highly reactive oxygen species that can damage cellular components via oxidative stress. It has been shown in mice that are genetically modified with a mutant form of human SOD1 and develop ALS that different methods for lowering copper levels consistently improve symptoms of disease. Studies with the active ingredient of WTX101, tetrathiomolybdate, in this mouse model show that tetrathiomolybdate can delay the onset of disease as well as reduce the symptoms after disease onset.

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. WTX101, unlike current treatments for Wilson Disease, enables an alternative copper-protein transport mechanism by rapidly forming copper-protein complexes with high specificity for copper, which quickly de-toxifies copper in both the liver and the blood circulation. WTX101 reduces copper overload by promoting excretion of copper via the bile, the body’s natural route for excess copper elimination.

A Phase 2 study evaluating the efficacy and safety of WTX101 in Wilson Disease patients was successfully completed in 2016. In addition, the active ingredient of WTX101, tetrathiomolybdate, has been tested in several previous clinical studies in Wilson Disease patients. The data from these studies 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 has the 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 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 successfully completed 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 08.00 CET on 9 June, 2017.