Audentes Therapeutics Announces Dosing of First Patient in VALENS, a Phase 1/2 Clinical Trial of AT342 for the treatment of Crigler-Najjar Syndrome

SAN FRANCISCO, Feb. 12, 2018 /PRNewswire/ -- Audentes Therapeutics, Inc. (Nasdaq: BOLD), a biotechnology company focused on developing and commercializing gene therapy products for patients living with serious, life-threatening rare diseases, today announced it has commenced dosing of patients in VALENS, a Phase 1/2 clinical trial of its product candidate AT342 for the treatment of Crigler-Najjar Syndrome.  VALENS is a multicenter, multinational, open-label, randomized, ascending dose study designed to evaluate the safety and efficacy of AT342 in approximately 12 Crigler-Najjar patients one year of age and older.  Audentes expects preliminary data from VALENS to be available in the second quarter of 2018.  In addition, FDA has granted Rare Pediatric Disease and Fast Track designations for AT342.

"Crigler-Najjar is a devastating rare disease characterized by severe jaundice, extremely high levels of unconjugated bilirubin in the blood, and the consequent risk of irreversible neurological damage and death," stated Suyash Prasad, M.D., Senior Vice President and Chief Medical Officer.  "There are no approved products to treat Crigler-Najjar.  The current standard of care requires most patients to spend more than 10 to 12 hours per day under phototherapy lights, and natural history data from our LUSTRO run-in study demonstrate that even with this burdensome treatment, bilirubin may only be reduced to levels just below those considered to be neurotoxic."

Dr. Prasad continued, "We greatly appreciate the opportunity to work with the Crigler-Najjar community and view the initiation of VALENS as an important milestone in our development of AT342 for this severe disease."

In addition to VALENS, the clinical development program for AT342 includes LUSTRO, a prospective natural history run-in study in Crigler-Najjar patients.  The primary objectives of LUSTRO are to characterize the disease course and natural history of Crigler-Najjar, assess the burden of disease on patients and caregivers, identify subjects for potential enrollment in VALENS, and serve as a longitudinal baseline and within-patient control for VALENS.

"We are also pleased to announce today that the FDA has granted Rare Pediatric Disease and Fast Track designations for AT342," stated Matthew R. Patterson, President and Chief Executive Officer.  "These designations provide significant benefits, including opportunities to work with the FDA to expedite the development of AT342, and the potential to obtain a valuable Rare Pediatric Disease Priority Review Voucher upon approval.  We are eager to leverage these benefits and to work closely with the FDA and Crigler-Najjar patient community as we advance the development of AT342."

About AT342 for Crigler-Najjar Syndrome 
AT342 is an AAV8 vector containing a functional copy of the UGT1A1 gene for the treatment of Crigler-Najjar Syndrome, a rare monogenic disease characterized by severely high levels of unconjugated bilirubin in the blood and risk of irreversible neurological damage and death.  The current standard of care for Crigler-Najjar Syndrome is daily, persistent phototherapy, usually for longer than 10 to 12 hours per day. Phototherapy wanes in effectiveness as children age, and a liver transplant may be required for survival.  Data from LUSTRO, a prospective natural-history run-in study in Crigler-Najjar patients, demonstrate that even with strict adherence to a persistent daily phototherapy regimen, bilirubin may only be reduced to levels just below those considered to be neurotoxic.  A single administration of AT342 generated durable, dose-responsive and clinically-relevant decreases in total bilirubin levels in a mouse model of Crigler-Najjar, with no significant AT342-related adverse events or safety findings.

AT342 has been granted orphan drug designation in both the United States and European Union, and Rare Pediatric Disease and Fast Track designations by the FDA.

About VALENS, the Phase 1/2 Clinical Study of AT342
VALENS is a multicenter, multinational, open-label, randomized, ascending dose study to evaluate the safety and preliminary efficacy of AT342 in approximately 12 Crigler-Najjar patients one year of age and older. The study is expected to include nine AT342 treated subjects and three delayed-treatment concurrent control subjects. Primary endpoints include safety (adverse events and certain laboratory measures, including immunological parameters) and efficacy (changes in serum bilirubin and number of hours on phototherapy within a 24-hour period).  Subjects are expected to remain on prescribed phototherapy for 12 weeks following administration of AT342, and those with a prespecified decrease in bilirubin at week 12 will be weaned off phototherapy over the subsequent five-week period.  Subjects are expected to be followed for a minimum of five years to assess long term safety and durability of effect.

About the Rare Pediatric Disease Priority Review Voucher and Fast Track Programs 
A Rare Pediatric Disease designation may be granted by the FDA to drugs and biologics intended to treat orphan diseases affecting fewer than 200,000 patients in the United States, primarily age 18 years or younger. The designation provides incentives to advance the development of rare disease drugs, including access to the FDA's expedited review and approval programs. In addition, under the FDA's Rare Pediatric Disease Priority Review Voucher program, a sponsor that receives approval for a biologics license application for a rare pediatric disease may be eligible to receive a voucher for a priority review of a subsequent marketing application for a different product. The priority review voucher may be used by the sponsor, sold or transferred.

The Fast Track program was created by the FDA to facilitate the development and expedite the review of new drugs which show promise in treating a serious or life-threatening disease and address an unmet medical need. Drugs that receive this designation benefit from more frequent communications and meetings with FDA to review the drug's development plan including the design of the proposed clinical trials, use of biomarkers and the extent of data needed for approval. Drugs with Fast Track Designation may qualify for priority review to expedite the FDA review process, if relevant criteria are met.

About Audentes Therapeutics, Inc.
Audentes Therapeutics (Nasdaq: BOLD) is a biotechnology company focused on developing and commercializing gene therapy products for patients living with serious, life-threatening rare diseases.  We are currently conducting Phase 1/2 clinical studies of our lead product candidates AT132 for the treatment of X-Linked Myotubular Myopathy (XLMTM), and AT342 for the treatment of Crigler-Najjar Syndrome.  We have two additional product candidates in development, including AT982 for the treatment of Pompe disease, and AT307 for the treatment of the CASQ2 subtype of Catecholaminergic Polymorphic Ventricular Tachycardia (CASQ2-CPVT).  We are a focused, experienced and passionate team committed to forging strong, global relationships with the patient, research and medical communities.

For more information regarding Audentes, please visit www.audentestx.com.

Forward Looking Statements
This press release contains forward-looking statements within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995, including, but not limited to: the timing of preliminary data availability from VALENS, and the ability of LUSTRO to be used as a longitudinal baseline and within patient control for VALENS.  All statements other than statements of historical fact are statements that could be deemed forward-looking statements. Although the company believes that the expectations reflected in such forward-looking statements are reasonable, the company cannot guarantee future events, results, actions, levels of activity, performance or achievements, and the timing and results of biotechnology development and potential regulatory approval is inherently uncertain. Forward-looking statements are subject to risks and uncertainties that may cause the company's actual activities or results to differ significantly from those expressed in any forward-looking statement, including risks and uncertainties related to the company's ability to advance its product candidates, obtain regulatory approval of and ultimately commercial its product candidates, the timing and results of preclinical and clinical trials, the company's ability to fund development activities and achieve development goals, the company's ability to protect intellectual property and other  risks and uncertainties described under the heading "Risk Factors" in documents the company files from time to time with the Securities and Exchange Commission. These forward-looking statements speak only as of the date of this press release, and the company undertakes no obligation to revise or update any forward-looking statements to reflect events or circumstances after the date hereof.

Audentes Contacts:

Investor Contact:
Andrew Chang
415.818.1033
[email protected]

Media Contact:
Paul Laland
415.519.6610
[email protected]

SOURCE Audentes Therapeutics, Inc.