YolTech Therapeutics, a late clinical-stage biotechnology company developing in vivo gene editing therapies, announced positive interim data from an investigator-initiated trial (IIT) of YOLT-202, the Company’s investigational in vivo base editing therapy, for the treatment of Alpha-1 Antitrypsin Deficiency (AATD) that demonstrated positive safety and tolerability as well as meaningful increases in AAT levels in evaluated patients treated with the 35 mg and 45 mg dose levels.

“These interim findings mark an exciting and important milestone for YolTech and for patients living with severe AATD. The rapid, robust, and dose‑dependent increases in functional AAT levels observed in this study—particularly among individuals with the PiZZ genotype—underscore the transformative potential of in vivo base editing as a one‑time treatment approach,” stated Yuxuan Wu, M.D., Founder and CEO of YolTech Therapeutics. “Equally encouraging is the favorable safety profile we have seen to date, which reinforces the precision and thoughtful engineering behind YOLT‑202. With these results in hand, we are more confident than ever in YOLT‑202’s potential to redefine the treatment paradigm for AATD, and we look forward to advancing this program toward an Investigational New Drug (IND) filing with the U.S. Food and Drug Administration (FDA) as we continue our mission to bring durable, life‑changing therapies to patients.”

YOLT-202 is being evaluated in a first-in-human, open-label, single dose escalation study in adult AATD patients, aiming to evaluate safety and tolerability. As of February 6^th, two participants genetically confirmed as PiZZ genotype, were enrolled and dosed with YOLT-202 in both the 35 mg and 45 mg dose groups.

Following administration of YOLT-202, both patients showed rapid, robust and dose-dependent increases in AAT level as early as in Week 1. AAT levels in both patients reached above the protective threshold of 11 μM. Additionally, AAT levels increased to normal range (>20 μM) in the 45 mg dose group. These newly produced AAT proteins were both structurally corrected (M-AAT) and functional, with the proportion of corrected M-AAT increasing to >95% in the 45 mg dose group.

YOLT-202 demonstrated favorable safety and tolerability with manageable adverse events (AEs). No severe AEs or AEs leading to discontinuation of YOLT-202 were reported, and all AEs were classified as Grade 1. The most common AE was infusion-related reaction (IRR). Elevation of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were asymptomatic, mild and soon recovered without medication.

The ongoing IIT study (NCT07193615) is evaluating single doses administered via intravenous infusion of YOLT-202 at 35 mg, 45 mg and 55 mg dose levels. YolTech is actively preparing to file an IND with the FDA to support the global clinical development of YOLT-202 in AATD.