Scribe Therapeutics Demonstrates Breakthrough CRISPR Therapy for Cardiovascular Disease with >90% Lp(a) Reduction
Key Insights
Scribe Therapeutics (search)' STX-1200 (search) achieved >90% apolipoprotein(a) (search) knockdown in preclinical models, representing the first proof-of-concept for CRISPR-based Lp(a) lowering therapy.
The CasXE-based therapy demonstrated exceptional safety with no detectable off-target editing even at supersaturating doses 10 times higher than the effective concentration.
The company unveiled DeepXE, an AI platform that delivers 2x higher hit rates in CRISPR design and outperforms conventional Cas9-based machine learning models.
Scribe Therapeutics (search) has achieved a significant breakthrough in cardiovascular disease treatment with the development of STX-1200 (search), a novel CRISPR-based therapy that demonstrated >90% reduction of apolipoprotein(a) (search) (Apo(a)) in preclinical studies. The company presented late-breaking data at the European Society of Cardiology (ESC) Congress 2025, showcasing what researchers describe as the first preclinical proof-of-concept for an exceptionally safe and effective CRISPR-based genetic medicine targeting elevated lipoprotein(a) (Lp(a)).
Addressing a Major Unmet Medical Need
Elevated Lp(a) represents a prevalent, genetically driven risk factor for cardiovascular disease that affects approximately 20% of the global population. Despite its significance as an emerging priority in cardiovascular disease management, no FDA-approved therapies currently exist to address this condition. Scribe has designed STX-1200 (search) to tackle the key unmet need in cardiovascular disease treatment: the lack of effective, long-term therapeutic adherence.
"STX-1200 (search) expands our cardiometabolic portfolio with a direct approach to a major unsolved ASCVD risk factor, elevated Lp(a). Our CRISPR therapy is designed to deliver profound and durable Lp(a) lowering for patients worldwide," said Benjamin Oakes, Ph.D., co-founder and CEO of Scribe.
Exceptional Potency and Safety Profile
The preclinical study demonstrated that a single very low dose of STX-1200 (search) achieved highly efficient hepatic LPA (search) gene editing and >90% Apo(a) knockdown in a pharmacologically relevant transgenic LPA mouse model. The therapy's CasXE-based approach enables selective LPA gene editing, leading to substantial permanent reduction of the apolipoprotein(a) (search) protein, which serves as the key component of the Lp(a) particle.
Comprehensive off-target assessment revealed no detectable off-target editing, even at a supersaturating dose of 10X EC90. This finding highlights STX-1200 (search)'s unmatched specificity profile and demonstrates its design for safe and targeted LPA (search) editing. According to Oakes, "Scribe's XE platform is the only CRISPR approach to demonstrate Lp(a) gene editing without off-target effects, even at supersaturating doses."
AI-Powered Platform Accelerates Development
At the 11th Genome Engineering: CRISPR Frontiers meeting hosted by Cold Spring Harbor Laboratory, Scribe introduced DeepXE, its proprietary AI-enabled CRISPR design platform. This breakthrough technology accurately predicts editing efficiency for the company's X-Editor (CasXE)-based therapeutics, fundamentally changing the speed and efficiency of next-generation therapeutic development.
DeepXE represents the first machine learning model capable of accurately predicting on-target editing efficiency for XE, a highly engineered variant of wild-type CRISPR-CasX. The platform addresses a critical gap for next-generation XE-based genome editing therapies and demonstrates robust predictive performance with high accuracy.
Superior Performance Metrics
The AI model delivers a 2x higher hit rate with less than 10% false negatives and achieves sensitivity exceeding 90%, significantly outperforming Cas9-based conventional machine learning models. When assessed across multiple engineered XE variants, target genes, and assay conditions, DeepXE exhibited strong generalizability, highlighting its broad applicability for different therapeutic programs.
The platform enables faster and more cost-effective design of potent molecules, achieving a greater than 50% reduction in screening size. This advancement streamlines efforts for developing more precise and effective treatments across Scribe's growing pipeline.
Expanding Therapeutic Portfolio
Scribe Therapeutics (search) is developing optimized in vivo CRISPR-based genetic medicines designed to become standard of care treatments for patients with highly prevalent diseases, beginning with cardiometabolic disease. The company's lead candidate, STX-1150, represents a novel liver-targeted therapy designed to epigenetically silence the PCSK9 gene, resulting in significant and durable reduction of LDL-C levels.
The company has established strategic collaborations with world-leading pharmaceutical companies including Sanofi and Eli Lilly to broaden and accelerate the impact of its engineered CRISPR technologies. Co-founded by Nobel Prize winner Jennifer Doudna and backed by leading life sciences investors, Scribe continues to engineer the future of genetic medicine through its CRISPR by Design™ approach.