AVXS 101 results from STRIVE trial for spinal muscular atrophy .-AveXis Inc.

AveXis, Inc. will present initial results from the Type 1 U.S. Pivotal trial (STR1VE) and 24-month follow-up data from the Phase 1 trial of AVXS 101 for the treatment of spinal muscular atrophy (SMA) Type 1 at the 2018 Annual Meeting of the American Academy of Neurology (AAN) Annual Meeting in Los Angeles. �With a population closely matched to the Phase 1 trial, preliminary safety data and the early and rapid increases in CHOP-INTEND scores achieved by infants in this pivotal STR1VE trial are consistent with results of the Phase 1 trial of AVXS 101 in SMA Type 1,� said John W. Day, MD, PhD, Professor, Neurology & Pediatrics, and Director of the Stanford Neuromuscular Program, Stanford University Medical Center, who will present these data at AAN. �These early signs of efficacy and safety are promising, and I look forward to seeing the trial progress.�

Initial Data from Pivotal Trial of AVXS 101 in SMA Type 1 (STR1VE) as of April 11, 2018; As of April 11, 2018, 11 patients were enrolled in the trial, and six patients were symptomatic and at least one-month post gene therapy treatment. All patients had homozygous deletion of SMN1 and two copies of SMN2; no patient had the known SMN2 gene modifier mutation (c.859G>C). The patient population and baseline characteristics are closely matched to the Phase 1 trial. Event-free Survival and Safety: All patients (6/6) were alive and event-free as of April 11, 2018. AVXS 101 appeared to have a favorable safety profile and to be generally well tolerated. At the time of gene transfer, the mean age was 3.2 months, with the oldest patient being 5.0 months of age. In the six patients who were at least one-month post gene transfer, a cumulative total of 25 adverse events (AEs) were reported. Two patients experienced transient elevations in transaminases greater than 3x ULN that were not clinically significant and all resolved with prednisolone treatment without any clinical manifestations or sequelae. There were no serious adverse events (SAEs) reported.

Motor Function Achievement : Children�s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) scores increased by an average of 7.8 at one month after gene transfer (in six patients) and 17.3 at three months after gene transfer (in three patients), reflecting improvement in motor function. These data correlate to CHOP-INTEND achievement by the proposed therapeutic dose cohort (Cohort 2) in the Phase 1 trial, which experienced mean increases of 9.8 points at one month and 15.4 points at three months. Early CHOP-INTEND increases have been observed to be associated with eventual milestone achievement.

The open-label, single-arm, single-dose, multi-center trial � known as STR1VE � is designed to evaluate the efficacy and safety of a one-time IV infusion of AVXS 101 of 1.1 x 1014 vector genomes/kg in patients with SMA Type 1 who are less than six months of age at the time of gene therapy, have one or two copies of the SMN2 backup gene as determined by genetic testing, and have bi-allelic SMN1 gene deletion or point mutations. The intent-to-treat population is defined as patients who are less than six months of age and symptomatic at the time of gene therapy, with two copies of the SMN2 gene as determined by genetic testing, bi-allelic SMN1 gene deletion and no c.859G>C mutation in SMN2.

The co-primary efficacy outcome measures include the achievement of the developmental milestone of independent sitting for at least 30 seconds at 18 months of age and event-free survival at 14 months of age, with an event defined as either death or at least 16 hours per day of required ventilation support for breathing for 14 consecutive days in the absence of acute reversible illness or perioperative change. Co-secondary outcome measures include the ability to thrive and the ability to remain independent of ventilatory support at 18 months of age.

24-Month Follow-Up Data from Phase 1 Trial of AVXS 101 in SMA Type 1 : The following 24-month follow-up data from the Phase 1 trial will be presented during platform presentations by Samiah Al-Zaidy, MD, Co-Investigator for the trial; Linda Lowes, PhD, Director of Clinical Therapies Research and a member of the Center for Gene Therapy at the Research Institute of Nationwide Children�s Hospital; and Richard Shell, MD, member of the Section of Pulmonary Medicine at Nationwide Children�s Hospital.