BBP-812

CANaspire (NCT04998396) is an open-label Phase 1/2 trial for about 26 children aged up to 30 months. Its main measures are side effects through week 52 and the change in NAA in the urine and in the brain, measured by MRI spectroscopy, after 12 months. It excludes children with antibodies to AAV9, earlier AAV treatment, high-dose immune-suppressing medicines, or advanced disease such as constant abnormal posturing, repeated prolonged seizures or seizures not controlled on 3 or more medicines.

ClinicalTrials.gov lists UCSF Benioff Children's Hospital Oakland, Lurie Children's Hospital in Chicago and Mass General in Boston as recruiting; the record was last updated in April 2026, and its estimated primary completion date of October 2026 has passed without an update ^[6].

BridgeBio reported in October 2024, with 11 children dosed, that urine NAA fell an average of 64% at 12 months after the low dose and 73% at 3 months after the high dose, and that NAA in the spinal fluid fell 70% at 12 months after the low dose. It said most children showed better myelination on MRI and that the low-dose group gained on 2 motor scales, the GMFM-88 and HINE-2, compared with children followed without treatment in its earlier CANinform natural history study ^[1].

These results come from the company, without a control group, and have not yet appeared in a peer-reviewed paper.

BridgeBio describes BBP-812 as generally well tolerated, with a safety profile consistent with other AAV9 gene therapies given into the bloodstream ^[1]. In slides Aspa presented to families in April 2025, with data as of December 2024, 14 children had been dosed, 8 at the low dose and 6 at the high dose, and 18 serious side effects had been reported in 9 of them; 2 were considered related to BBP-812 and 1 possibly related, and every participant had at least 1 side effect, most of them mild or moderate.

There were no infusion reactions ^[5]. Which serious events were related has not been disclosed. No clinical hold or death has been reported.

Aspa Therapeutics is a BridgeBio company ^[1]. The FDA granted orphan drug, rare pediatric disease and Fast Track designations, and the European Medicines Agency granted orphan designation ^{[2] [1]}. The FDA granted RMAT designation, an FDA program for cell and gene therapies that brings more frequent FDA advice, on September 10, 2024, based on 12 months of data from the first 8 patients ^[3].

BridgeBio said in April 2025 that recent talks with the FDA showed alignment on an accelerated approval pathway, a faster route based on an early marker, using CANaspire with urine NAA as that marker, and it set a goal of finishing enrollment later that year ^[4]. BridgeBio has not announced whether enrollment finished, and its quarterly releases since then have not given an update on the program. No filing has been announced.