Single-Dose Gene Therapy Cuts LDL Cholesterol by 68% in Primate Study
Scribe Therapeutics reports a one-time epigenetic therapy slashed LDL cholesterol up to 68% for nearly two years in primates.
Summary
A single injection of an experimental CRISPR-based therapy called STX-1150 reduced LDL cholesterol by up to 68% and a key cholesterol-regulating protein by up to 90% in non-human primates. Remarkably, even the lowest dose maintained more than 50% LDL reduction for over 22 months with effects still ongoing. Unlike traditional gene editing, this approach silences genes without permanently altering DNA, targeting the liver via lipid nanoparticles. The therapy showed no significant off-target effects or liver toxicity in preclinical tests. A first-in-human Phase 1 trial is now enrolling in Australia, with New Zealand sites planned. For the millions at risk from high LDL-driven cardiovascular disease, a durable single-dose treatment could be a game-changer compared to daily statins or biweekly injections.
Detailed Summary
High LDL cholesterol remains one of the most significant modifiable risk factors for cardiovascular disease, the world's leading cause of death. Current treatments — statins, PCSK9 inhibitors, and newer RNA-based therapies — require daily pills or repeated injections. A truly durable, single-dose solution could transform how we manage cholesterol and cardiovascular risk across a lifetime.
Scribe Therapeutics presented striking preclinical data at the 94th European Atherosclerosis Society Congress. Their investigational therapy, STX-1150, delivered a single dose that reduced LDL cholesterol by up to 68% and suppressed PCSK9 — a protein that limits the liver's ability to clear LDL — by up to 90% in non-human primates. Even the lowest tested dose maintained greater than 50% LDL reduction for more than 22 months, with effects still ongoing at the time of reporting.
STX-1150 uses CRISPR-based epigenetic silencing, meaning it switches off the PCSK9 gene without cutting or permanently rewriting DNA. The therapy is packaged in liver-targeting lipid nanoparticles, the same delivery technology used in mRNA vaccines. Crucially, lab tests in human liver cells showed at least five times greater potency than in monkey cells, suggesting human doses could be meaningfully lower than those used in primates.
Safety data were encouraging. No off-target gene expression changes were detected at three times the effective concentration, liver enzyme levels remained comparable to saline controls, and a formal toxicology study found no adverse findings linked to the therapy.
Scribe has received regulatory clearance from Australia's Therapeutic Goods Administration and has begun enrolling participants in a Phase 1 human trial. While preclinical results are promising, human trials will determine whether the magnitude and durability of LDL reduction translates, and long-term safety data over years will be essential before broader clinical use.
Key Findings
- Single STX-1150 dose reduced LDL cholesterol up to 68% and PCSK9 up to 90% in primates.
- Lowest dose sustained over 50% LDL reduction for more than 22 months with effects still ongoing.
- Human liver cells showed 5x greater potency than primate cells, suggesting lower human doses may suffice.
- No off-target gene changes, liver toxicity, or adverse findings detected in preclinical safety studies.
- Phase 1 human trial is actively enrolling in Australia, with regulatory clearance secured.
Methodology
This is a news report summarizing late-breaking preclinical data presented at the European Atherosclerosis Society Congress 2026. The source, Longevity.Technology, is a credible longevity-focused outlet, but data come from a company press release and conference presentation, not yet a peer-reviewed publication. Evidence is preclinical, based on non-human primate and in vitro human hepatocyte studies.
Study Limitations
All efficacy and safety data are preclinical; human trial results are not yet available. Data were presented at a conference, not published in a peer-reviewed journal, limiting independent verification. Long-term durability and safety in humans over multiple years remain unknown and critical for regulatory approval.
Enjoyed this summary?
Get the latest longevity research delivered to your inbox every week.