All monkeys anti-AAV1 NAb positive by week 27, no anti-otoferlin antibodies; NAbs not associated with safety signal; minimal cochlear infiltrates
“There were no serum or CSF samples positive for anti-otoferlin antibodies at any time point.”
✓ VerifiedFDA pharmacology/toxicology review, p. 25Source ↗
Biodistribution & persistence
Cochlear retention through 27 weeks; transient plasma/CSF; low neural off-target expression; none in gonads; shedding only Day 2
“Viral shedding was detected in multiple samples (buccal swabs, nasal swabs, feces, and urine) on Day 2 post-administration in monkeys but was absent by 7 weeks, indicating clearance from excretory pathways.”
✓ VerifiedFDA pharmacology/toxicology review, p. 16Source ↗
“However, the long-term consequences of low-level transgene expression in non-target neural tissues (brain, DRG, spinal cord) remain unknown and warrant continued monitoring in human subjects.”
✓ VerifiedFDA pharmacology/toxicology review, p. 22Source ↗
Anti-drug antibodies: animals
Monkeys: no anti-otoferlin antibodies; anti-AAV1 NAb titers (pre-existing or induced) not associated with any safety signal
“There were no serum or CSF samples positive for anti-otoferlin antibodies at any time point. Preexisting or post-DB-OTO administration positive serum or CSF anti-AAV1 NAb titers were not associated with any safety signal.”
✓ VerifiedFDA pharmacology/toxicology review, p. 25Source ↗
Anti-drug antibodies: patients
All patients developed anti-AAV1 NAbs through Week 12 (10/15 titer >10000); 7/15 (46.7%) developed anti-OTOF antibodies
“All patients developed anti-AAV1 neutralizing antibody responses through Week 12, with 10/15 (66.7%) having titer >10000, 3/15 (20.0%) having titer 1000 to 10000, and the rest having titer <1000. A total of 7/15 (46.7%) patients developed anti-OTOF antibody responses through Week 12,”
✓ VerifiedFDA summary basis for approval, p. 16Source ↗