YolTech Therapeutics Announces Positive Clinical Results for YOLT-201, an Investigational In Vivo Gene Editing Therapy for Transthyretin Amyloid Cardiomyopathy (ATTR-CM)

Shanghai, China - March 11, 2025—YolTech Therapeutics, a clinical-stage in vivo gene editing company committed to pioneering the next generation of precision genetic medicines, today announced positive interim results from an investigator-initiated trial (IIT) evaluating YOLT-201, an investigational in vivo CRISPR-Cas-based gene-editing therapy in patients with transthyretin amyloid cardiomyopathy (ATTR-CM).This breakthrough indicates that due to the extremely low immunogenicity of LNP used in the YOLT-201 drug , makes it maintain excellent safety upon secondary administration and achieve a cumulative therapeutic effect, it holds the potential to reduce the pathogenic TTR protein in the blood to the lowest levels, paving the way for optimal efficacy in the future.

YOLT-201, wholly owned and developed by YolTech Therapeutics, utilizes lipid nanoparticles (LNPs) to deliver CRISPR-Cas encoding mRNA and a guide RNA targeting the transthyretin-encoding TTR gene to human hepatic cells. By inactivating the TTR gene, YOLT-201 has the potential to reduce misfolded TTR protein production and lower serum TTR protein levels, addressing the underlying cause of ATTR-CM.

The YOLT-201-IIT is an open-label, single-center, dose-escalation study to evaluate the safety, tolerability, preliminary efficacy and pharmacodynamics of YOLT-201 in ATTR-CM patients. Patient enrollment was completed in 2024, with a total of 7 patients enrolled across 4 dose levels. In all dose levels, YOLT-201 was generally all well-tolerated, with the most common treatment-related adverse events being infusion-related reactions (e.g. fever), transient ALT/AST elevation. No adverse events led to treatment discontinuation.

In the high-dose group, subjects achieved approximately 90% reduction in serum TTR after a single administration, with rapid, sustained, and stable declines, along with favorable safety and tolerability. For two patients in the low-dose group whose TTR reduction did not meet the target, a second administration was given, resulting in >95% reduction in serum TTR.

“These results support the potential of YOLT-201 to persistently lower serum TTR level, and to prevent the progression of amyloid deposition and improve cardiac function in ATTR-CM patients.” Dr. Yuxuan Wu, Founder and CEO of YolTech Therapeutics, commented: “We are encouraged by interim results from YOLT-201-IIT, which demonstrate the therapeutic potential of YOLT-204 to improve clinical outcomes in ATTR-CM patents. Currently, there is a significant unmet need for effective therapies in ATTR-CM. Our team is accelerating dose-expansion studies and exploring global collaborations to bring transformative therapies for patients.”

About ATTR-CM

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a rare, progressive, and fatal disease characterized by the deposition of misfolded transthyretin protein in the heart, leading to myocardial stiffness, impaired cardiac function, and ultimately heart failure. Transthyretin amyloid cardiomyopathy can be either age-related (wild-type form) or caused by mutations in the TTR gene (genetic, hereditary forms). It is a systemic disease, and while the genetic forms may exhibit a variety of symptoms, a predominant cardiac phenotype is often present. Globally, approximately 50,000 individuals are affected by hereditary transthyretin amyloidosis (ATTRv), while the wild-type form (ATTRwt) impacts between 200,000 and 500,000 people. To date, no cure exists for ATTR amyloidosis, and existing therapeutic options primarily aim to reduce the buildup of misfolded TTR proteins rather than addressing the root cause.

About YolTech

YolTech Therapeutics is a clinical-stage in vivo gene editing company committed to pioneering the next generation of precision genetic medicines. Our approach combines innovative gene editing technologies with an advanced lipid nanoparticle (LNP) delivery system, creating a versatile platform designed to address a wide range of serious diseases. Central to our mission is the development of internal capabilities, including end-to-end manufacturing, to ensure the highest standards of quality and scalability. Our lead candidate, targeting ATTR, marks a significant milestone as China's first LNP-mediated in vivo gene editing therapy to enter clinical development. With promising early clinical outcomes, YolTech is also advancing therapies for familial hypercholesterolemia (FH) and primary hyperoxaluria type 1 (PH1). As a company dedicated to transforming the treatment landscape, YolTech continues to push the boundaries of what is possible in gene editing.

For more information, please visit: www.yoltx.com