BridgeBio is reporting encouraging early data from its Phase I/II clinical study, CAN aspire, evaluating BBP-812, a gene therapy for Canavan disease. The findings, presented at the 31st annual European Society for Cell and Gene Therapy (ESCGT) meeting, suggest that BBP-812 can effectively deliver a functional copy of the aspartoacylase (ASPA) gene, which is mutated in individuals with Canavan disease, leading to a reduction in the levels of N-acetyl-aspartate (NAA), the toxic substrate responsible for the disease's pathology. This represents a significant step forward in the potential treatment of this rare and devastating neurodegenerative disorder.
Clinical Improvements Observed
According to Eric David, MD, CEO of Gene Therapy and U.K. R&D at BridgeBio, some participants in the trial have demonstrated unprecedented improvements in motor function. "We have a participant who’s walking unassisted, and others are walking with minimal support. We’re seeing things that we’ve never seen children with Canavan have been able to do. That’s a pretty good sign when you can say it’s the first-in-human case."
AAV9 and the Development of BBP-812
The development of BBP-812 is rooted in over three decades of research, beginning in the mid-1990s with Guangping Gao's cloning of the ASPA gene. Gao, known for his discovery of AAV9, has since focused on developing a gene therapy for Canavan disease. Early clinical trials using nonviral vectors showed safety but limited clinical improvements. Subsequent work in Gao's lab at the University of Massachusetts optimized an AAV-based gene therapy, demonstrating prevention and rescue of Canavan disease in mouse models. These preclinical studies paved the way for BridgeBio's BBP-812 and the CAN aspire trial.
Regulatory Pathway and Durability
BBP-812 has received Regenerative Medicine Advanced Therapy (RMAT) Designation from the FDA, which will facilitate more frequent interactions with the agency and potentially accelerate the approval process. The durability of the treatment is also noteworthy. David noted, "The ability to very quickly reduce the NAA levels and keep them down as far as three years out...correlate with improvements in these different metrics of clinical function, whether they be the gross motor scales or eye tracking, head control, reaching and grasping, sitting up."
Addressing Unmet Needs in Rare Diseases
BridgeBio is committed to tackling rare diseases, including those often considered too small for pharmaceutical companies to pursue. Andrew Lo, an MIT economist and co-founder of BridgeBio, developed a financial model that balances larger and smaller rare diseases to enable the company to address these unmet needs. Even after significant acquisitions in the gene therapy space, such as Novartis' acquisition of AveXis, diseases like Canavan were still deemed too small by many companies.
Therapeutic Modality Agnostic Approach
BridgeBio adopts a therapeutic modality-agnostic approach, selecting the most appropriate treatment option for each rare disease. Gene therapy is reserved for cases where other approaches are not feasible. The company also explores gene editing technologies like CRISPR as potential future treatments. To manage manufacturing costs, BridgeBio outsources clinical trial-scale and GMP manufacturing while optimizing vectors in-house.
Collaboration with Patient Communities
Central to BridgeBio's approach is collaboration with patient communities, recognizing their expertise in rare diseases. The company routinely invites community members to their labs to learn from their experiences and understand what outcomes would represent meaningful success. This collaborative approach ensures that clinical trials are designed and implemented with the needs and perspectives of patients and their families in mind.
