Study of the Safety and Efficacy of an Adeno-Associated Viral Vector Carrying the SMN Gene After a Single Intravenous Administration of Escalating Doses in Children With Spinal Muscular Atrophy (BLUEBELL)

This study (BLUEBELL) is testing a gene therapy called ANB-004 — which delivers a working copy of the SMN gene — in very young infants with Spinal Muscular Atrophy (SMA), a devastating genetic disease that destroys the motor nerve cells controlling movement and breathing. Without intervention, the most severe form (SMA type 1) is typically fatal within two years. Gene therapy aims to provide a single, one-time treatment that gives the body the genetic instructions it needs to produce the SMN protein, potentially halting or reversing disease progression. To be eligible, the child must be under 240 days (8 months) old at the time of consent, have a confirmed genetic diagnosis of 5q-SMA, and have 2 or 3 copies of the SMN2 gene. Children with HIV, hepatitis B or C, very high levels of antibodies against the viral delivery vehicle (AAV9), or who require breathing support for more than 16 hours per day are not eligible. Previous treatment with other SMA gene therapies also excludes participation. Participants will receive a single intravenous infusion of ANB-004 and be closely monitored for safety and developmental progress over 12 months. This research is critically important because SMA is the leading genetic cause of infant death. Early treatment before motor neurons are lost may preserve normal development, and this study offers hope for a definitive, long-lasting treatment for affected families.