Single Dose YOLT-202 Gene-Editing Therapy Increases Functional AAT Levels in AATD

YolTech Therapeutics has 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).1

As described in a February 19, 2026, press release, findings 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.1

“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,” Yuxuan Wu, MD, Founder and CEO of YolTech Therapeutics, said in a statement.1 “Equally encouraging is the favorable safety profile we have seen to date, which reinforces the precision and thoughtful engineering behind YOLT‑202.”

YOLT-202 is an in vivo gene-editing therapy that corrects PiZ mutation to PiM for the treatment of AATD. It is engineered to achieve on-target editing with minimal bystander activity. YOLT-202 has previously been granted Orphan Drug Designation by the US FDA, and the Company is currently preparing to file an Investigational New Drug Application with the FDA to support clinical development of YOLT-202.1,2

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, 2026, 2 participants genetically confirmed as PiZZ genotype were enrolled and dosed with YOLT-202 in both the 35 mg and 45 mg dose groups.1

Following administration of YOLT-202, both patients showed rapid, robust and dose-dependent increases in AAT level as early as week 1. Of note, AAT levels in both patients reached above the protective threshold of 11 μM.1

Results additionally showed 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.1

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

The ongoing IIT study is evaluating single doses administered via intravenous infusion of YOLT-202 at 35 mg, 45 mg and 55 mg dose levels. In the release, YolTech described plans to file an IND with the FDA to support the global clinical development of YOLT-202 in AATD.1

“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. FDA as we continue our mission to bring durable, life‑changing therapies to patients,” Wu said.1

References

1. YolTech Therapeutics. YolTech Therapeutics Announces Positive Interim Data on YOLT-202 for the Treatment of Alpha-1 Antitrypsin Deficiency. February 19, 2026. Accessed February 19, 2026. https://www.businesswire.com/news/home/20260219197004/en/YolTech-Therapeutics-Announces-Positive-Interim-Data-on-YOLT-202-for-the-Treatment-of-Alpha-1-Antitrypsin-Deficiency

2. YolTech Therapeutics. YolTech Receives U.S. FDA ODD for YOLT-202 in Treating AATD. April 10, 2025. Accessed February 19, 2026. https://www.yoltx.com/news/press-release/84