SpliceBio Advances Gene Therapy for Stargardt Disease with First Patient Dosed in Phase 1/2 Expansion Trial
核心洞察
SpliceBio (搜索) has successfully dosed the first patient in the dose-expansion portion of its Phase 1/2 ASTRA clinical trial for SB-007, a dual AAV gene therapy targeting Stargardt disease (搜索).
SB-007 utilizes innovative protein splicing technology to overcome size limitations of conventional AAV vectors, potentially treating patients across all ABCA4 (搜索) mutations that cause this inherited retinal disease (搜索).
The therapy has received FDA Fast Track designation and addresses a significant unmet medical need, as Stargardt disease (搜索) affects 1 in 8,000 to 10,000 people worldwide with no approved treatments currently available.
SpliceBio (搜索) has achieved a significant milestone in its gene therapy program for Stargardt disease (搜索), successfully dosing the first patient in the Part B dose-expansion portion of its Phase 1/2 ASTRA clinical trial. The trial is evaluating SB-007, a dual adeno-associated viral (AAV) vector gene therapy designed to treat the rare inherited retinal disease (搜索) that currently has no approved treatments.
Novel Dual-Vector Approach Addresses Treatment Challenges
SB-007 represents a breakthrough in gene therapy design, specifically engineered to overcome the size limitations that have historically prevented effective treatment of diseases caused by large genes. The therapy uses SpliceBio (搜索)'s proprietary protein splicing platform, which leverages engineered inteins to enable protein trans-splicing.
"Gene therapy has transformative promise in ophthalmology, but its application has been limited by the inability of single-AAV vectors to accommodate large, complex genes such as ABCA4 (搜索)," said Aniz Girach, M.D., Chief Medical Officer of SpliceBio (搜索). "SB-007 is a dual-AAV vector that can harness our protein splicing platform and is designed to reconstitute the full-length therapeutic ABCA4 protein."
The innovative approach allows the ABCA4 (搜索) gene to be split into two transgenes delivered using dual AAV vectors. Once inside target retinal cells, the transgenes are expressed and undergo protein trans-splicing to reconstitute the full-length native ABCA4 protein.
Addressing Significant Unmet Medical Need
Stargardt disease (搜索) affects an estimated 1 in 8,000 to 10,000 children and adults worldwide and is caused by biallelic mutations in the ABCA4 (搜索) gene. These mutations result in the accumulation of toxic vitamin A byproducts that damage photoreceptor cells in the central region of the retina, leading to progressive deterioration of central vision and ultimately blindness (搜索).
"This unique gene therapy modality has the potential to slow or even halt progression of this debilitating disease, which is the most common cause of inherited blindness (搜索) in children," commented Robert MacLaren, M.D., Ph.D., Professor of Ophthalmology at the University of Oxford. "We are delighted to have treated the first patient here in Oxford, in the critical second phase of the trial."
Clinical Trial Design and Regulatory Support
The ASTRA trial is a multicenter, global clinical study designed to evaluate the safety, tolerability, and efficacy of SB-007. Part B of the study will enroll approximately 57 patients aged 12 to 65 with Stargardt disease (搜索) in a randomized, controlled, and masked design. The trial will evaluate two dose levels of subretinal SB-007 compared to an untreated control group, with a follow-up period of 96 weeks.
The primary endpoint focuses on safety and tolerability, assessed by the incidence and severity of ocular and non-ocular adverse events, while secondary endpoints comprise multiple efficacy measures. Part A of the study previously evaluated three dose levels of subretinal SB-007 in an open-label, dose-escalation design.
SB-007 has received significant regulatory support, including FDA Fast Track designation, which facilitates development and expedites review of drugs treating serious conditions with unmet medical needs. The therapy also holds Orphan Drug designation from both the FDA and the European Commission.
Broader Implications for Gene Therapy
The dual-vector approach pioneered by SpliceBio (搜索) may have implications beyond Stargardt disease (搜索). "The use of two viral vectors that recombine once inside retinal cells is a unique approach to restoring the large gene needed in Stargardt disease, and dual vectors might have implications for treating other retinal degenerations," noted Dr. MacLaren.
Mariya Moosajee, M.B.B.S., Ph.D., Professor of Molecular Ophthalmology at University College London Institute of Ophthalmology, emphasized the broader significance: "The clinical insights generated through this study have the potential to advance medicine and, critically, bring new hope to patients and families living with this condition."
SpliceBio (搜索) is also conducting the POLARIS study, a natural history study in patients with Stargardt disease (搜索), to further understand the disease progression and support the development of SB-007.