AveXis presents AVXS-101 IT data demonstrating remarkable increases in HFMSE scores and a consistent clinically meaningful response in older patients with SMA Type 2

  • Patients & Caregivers
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  • Society & ESG

  • SMA Type 2 patients between two and five years of age who received Dose B met the primary efficacy endpoint with a remarkable mean increase of 6.0 points in HFMSE scores from baseline to month 12, twice the clinically meaningful threshold, as measured by a validated, widely utilized and highly accepted scale developed specifically for older patients with SMA
     
  • Nearly all patients (92%) in this cohort achieved a clinically meaningful =3-point increase during the study period, demonstrating a consistent response following gene therapy
     
  • Increases observed in HFMSE reflect the preservation of motor neurons connected to key muscle groups impacted in SMA Type 2, allowing for motor development such as trunk control when rolling and sitting, and transitioning from lying to sitting
     
  • Adverse events observed in STRONG were consistent with the AVXS-101 IV program; no deaths were reported, and no new signals identified
     
  • In response to the partial clinical hold on the AVXS-101 IT program by the FDA in October 2019, AveXis provided data indicating no clinical reports of sensory neuronopathy in 335 patients following IV or IT treatment with AVXS-101; FDA is expected to respond by Q2 2020            

Basel, March 24, 2020  -  AveXis, a Novartis company, today announced that new data from the Phase 1/2 STRONG study demonstrated a one-time intrathecal (IT) administration of AVXS-101 in patients =2 years of age. HFMSE is recognized by global regulatory agencies due to its ability to monitor change in a broad spectrum of weaker and stronger patients.

  • A 3-point change on the HFMSE is agreed upon by experts to represent a clinically meaningful change involving two or three skills.
  • A 6-point improvement reflects achievements in three to six skills. Patients in STRONG achieved a broad array of improvements in motor skills, such as trunk control when rolling and sitting and transitioning from lying to sitting. In non-ambulatory patients, improved strength and consolidation of critical functions allows for better maneuverability, transitioning and integration of proximal and distal functions that enable more advanced use of their well-developed fine motor skills. These improvements were seen even in patients who were very weak at baseline. 

"As a result of evolving treatment options, older SMA Type 2 patients now expect to achieve meaningful improvements in motor function that enable them to perform important activities and set them on a path toward greater independence," said Olga Santiago, M.D., Chief Medical Officer, AveXis. "Given the robust response, these STRONG data indicate AVXS-101 delivered intrathecally could potentially be a new one-time treatment option for patients and their clinicians."

Phase 1/2 STRONG Data as of December 2, 2019
STRONG is an ongoing, open-label, multi-center trial designed to evaluate the efficacy, safety and tolerability of one-time intrathecal (IT) administration of AVXS-101 in SMA Type 2 patients who have three copies of the SMN2 gene, and who are able to sit but unable to stand or walk at the time of study entry. Patients were divided into two groups based on age at time of treatment: patients who are =2 years to <5 years old (n=12):

  • The primary efficacy endpoint of change in HFMSE score from baseline was achieved (P <0.0021) compared to a natural history control group.
    • To ensure appropriate comparison, a natural history group was matched with the treatment group inclusion criteria using the Pediatric Neuromuscular Clinical Research Network (PNCR) database.
  • Patients achieved clinically meaningful improvements in motor function, as demonstrated by 6.0-point increase from baseline in HFMSE scores at 12 months post-dosing.
  • Nearly all (11/12) patients in this group achieved a clinically meaningful =3-point increase in HFMSE during the study period.
  • Four motor milestones have been achieved among three patients in the Dose B group using Bayley-III, which is a scale created to assess normal development, including one patient who gained the ability to walk with assistance.
  • The secondary efficacy endpoint of the ability to walk independently for =5 steps was not achieved by any patient. 

In Dose B patients =6 months to <2 years old (n=13)

  • The primary and secondary efficacy endpoints were the ability to stand without support for =5 steps, respectively.
    • 1 patient achieved the ability to stand alone and walk independently
  • Five of the six (83%) patients who became old enough to be evaluated on the HFMSE achieved a 3.0-point increase from baseline at any time after 24 months of age, in-line with the older cohort.
  • 18 motor milestones were achieved among six out of the 13 patients, including one patient who gained the ability to stand independently, and went on to walk alone. 

Efficacy data from four patients currently enrolled in Dose C were not presented, and further enrollment has been suspended. In October 2019, the U.S. Food & Drug Administration (FDA) placed a partial hold on the AVXS-101 IT program following findings from a small, AveXis-initiated pre-clinical study in which animals treated with intrathecal AXVS-101 showed dorsal root ganglia mononuclear cell inflammation, sometimes accompanied by neuronal cell degeneration or loss. AveXis submitted a response to the FDA with further characterization and a commitment to further study these preclinical findings, along with a thorough analysis of clinical safety to date showing no clinical reports of sensory neuronopathy in 335 patients following treatment with AVXS-101 (intravenous and intrathecal administration) as of December 31, 2019. The FDA is expected to respond to the submission by Q2 2020.

Adverse events (AEs) observed in STRONG were consistent with the intravenous AVXS-101 program. No new clinical safety signals were detected in the study. Nearly all patients in STRONG study experienced at least one adverse event (AE) and 12 patients (38%) were reported to have an AE considered by the investigator to be related to treatment. Serious AEs were reported in 22% (n=7) of patients. A total of 13 serious AEs were reported in seven patients: pneumonia (n=2), influenza, bronchitis, rhinovirus infection, respiratory tract infection, elevated ALT, elevated AST, acute respiratory failure, asthma, respiratory failure (n=1 each), blood alkaline phosphatase increased (n=2). Many of these AEs (i.e. respiratory infections) are consistent with events experienced by children with SMA and the general population. Transaminitis events in two patients were considered probably related to treatment and resolved completely. There were no deaths reported.

Novartis will conduct a conference call with investors to discuss this news release on Monday, March 30, 2020 at 3 p.m. Central European Time and 9 a.m. Eastern Time. A simultaneous webcast of the call for investors and other interested parties may be accessed by visiting the Novartis website. A replay will be available after the live webcast by visiting www.novartis.com/inv­estors/event-calendar.

About AVXS-101 Intrathecal Administration
Investigational IT administration of AVXS-101 is being evaluated in SMA Type 2 patients in a Phase 1/2 clinical trial.

AveXis has an exclusive, worldwide license with Nationwide Children’s Hospital to both the intravenous and intrathecal delivery of AAV9 gene therapy for the treatment of all types of SMA; has an exclusive, worldwide license from REGENXBIO for any recombinant AAV vector in its intellectual property portfolio for the in vivo gene therapy treatment of SMA in humans; an exclusive, worldwide licensing agreement with Généthon for in vivo delivery of AAV9 vector into the central nervous system for the treatment of SMA; and a non-exclusive, worldwide license agreement with AskBio for the use of its self-complementary DNA technology for the treatment of SMA.

About Spinal Muscular Atrophy
SMA is the leading genetic cause of infant death.2 If left untreated, SMA Type 1 leads to death or the need for permanent ventilation by the age of two in more than 90% of cases.3
SMA is a rare, genetic neuromuscular disease caused by a lack of a functional SMN1 gene, resulting in the rapid and irreversible loss of motor neurons, affecting muscle functions, including breathing, swallowing and basic movement.4 It is imperative to diagnose SMA and begin treatment, including proactive supportive care, as early as possible to halt irreversible motor neuron loss and disease progression.5 This is especially critical in SMA Type 1, where motor neuron degeneration starts before birth and escalates quickly. Loss of motor neurons cannot be reversed, so SMA patients with symptoms at the time of treatment will likely require some supportive respiratory, nutritional and/or musculoskeletal care to maximize functional abilities.6 More than 30% of patients with SMA Type 2 will die by age 25.1