Lysogene and Sarepta Therapeutics Announce Dosing of the First Patient in AAVance, a Phase 2/3 Clinical Trial Investigating LYS-SAF302, a Gene Therapy for the Treatment of MPS IIIA (Sanfilippo Syndrome Type A)

Trial to assess efficacy on neurodevelopmental status of MPS IIIA patients

CAMBRIDGE, Mass. and PARIS – Feb. 14, 2019 – Lysogene (FR0013233475 – LYS), a pioneering biopharmaceutical company specializing in gene therapy targeting central nervous system (CNS) diseases, and Sarepta Therapeutics, Inc. (NASDAQ:SRPT), the leader in precision genetic medicine for rare diseases, announced today that the first patient has been dosed in AAVance, a global Phase 2-3 clinical trial of LYS-SAF302, a gene therapy for the treatment of Mucopolysaccharidosis Type IIIA (MPS IIIA).

“The first patient dosed in the AAVance trial is an important step in addressing this relentlessly progressing neurodegenerative disease. Our aim is to stabilize or improve the clinical status of patients with MPS IIIA by providing a permanent source of functional enzyme in the brain,” said Karen Aiach, Founder and Chief Executive Officer of Lysogene.

“MPS IIIA is a lethal neurological disease with debilitating symptoms for which there is currently no approved treatment,” said Principal Investigator Dr. Ronald Crystal, Chairman of the Department of Genetic Medicine and the Bruce Webster Professor of Internal Medicine at Weill Cornell Medicine, and a physician at NewYork-Presbyterian/Weill Cornell Medical Center, who is a paid consultant for Lysogene. “It is a great motivation to know that the work we are doing here has the potential to make a life-changing difference to so many unfortunate children, and I am very much looking forward to further advancing this innovative therapy.”

“Every day is an opportunity to make progress in bringing transformative treatments to patients and today’s milestone is an important advancement toward that goal,” said Doug Ingram, President and Chief Executive Officer, Sarepta. “Sarepta is committed to working with Lysogene to advance this program with the greatest urgency on behalf of patients.”

In accordance with the Worldwide License and Collaboration Agreement signed between Lysogene and Sarepta, the dosing of the first patient with LYS-SAF302 in a Phase 2-3 clinical trial triggers milestone payments of USD18 million from Sarepta to Lysogene.

www.lysogene.com