YolTech to Present Late-Breaking Proof-of-Concept Clinical Data from YOLT-202 Clinical Trial in PiZZ Alpha-1 Antitrypsin Deficiency (AATD) Patients at European Respiratory Society Congress 2026

Updated Early Phase I results support YOLT-202 as a curative one-time in vivo base editing therapy targeting the root genetic cause of AATD

SHANGHAI – September 4, 2026 - YolTech Therapeutics, a late clinical-stage biotechnology company pioneering in vivo gene-editing therapies, will unveil updated, late-breaking proof-of-concept clinical data from an ongoing investigator-initiated trial (IIT, NCT07193615) of YOLT-202 as a potentially curative treatment for PiZZ Alpha-1 Antitrypsin Deficiency (AATD) at the European Respiratory Society (ERS) Congress 2026, taking place September 5–9, 2026 in Barcelona, Spain.

The ERS Congress is one of the world’s largest and most authoritative respiratory medicine conference, uniting pulmonologists, translational researchers and biotech innovators globally to unveil cutting-edge breakthroughs in respiratory disease diagnosis and therapeutics.

“PiZZ AATD remains a serious, progressive genetic disease with limited treatment options that merely address the symptoms of the disease, not its underlying cause,” commented Simon Krooss, MD, PhD from Hannover Medical School, Germany. ”The updated interim data from the YOLT-202 clinical trial are highly encouraging, demonstrating robust and long-term restoration (>6 months) of functional AAT levels above the established protective threshold, alongside a favorable safety profile. Most notably, patients from the 45 mg cohort achieved near-physiological or normal levels of circulating AAT levels. Direct evidence was obtained in a liver biopsy of one patient at the 35mg dose resulting in up to 57% genetic correction rate. These findings provide compelling clinical proof-of-concept for a one-time in vivo base editing approach and support the potential of YOLT-202 to deliver durable, disease-modifying benefit by directly addressing the genetic root cause of AATD. We believe this represents an important step toward redefining the treatment paradigm for patients living with this devastating disease."

The early Phase I clinical trial is an open-label, single-dose escalation study evaluating the safety and pharmacodynamic activity of YOLT-202 in AATD patients. Conducted at Renji Hospital, Shanghai, the study is supported by the Sino-German Center for Cell and Gene Therapy and in collaboration with Hannover Medical School, Germany. Previously reported early data showed dose-dependent serum AAT increases above the protective threshold of 11 μM, with the 45mg dose achieving normal levels (>20 μM) and corrected M-AAT exceeding 95%, along with a favorable safety profile. Updated results from this ongoing study will be presented at the congress.

Presentation Details

Presentation Title: Late Breaking Abstract - Clinical Proof-of-Concept for In Vivo Base Editing in PI*ZZ Alpha-1 Antitrypsin Deficiency: Results from the YOLT-202 Early P1 Trial

Session:                  PS-8 Session 377: From experimental models to therapeutic innovation in lung disease

Date and Time:     September 7, 2026, 12:30 – 14:00 CEST

Venue:                    Fira Gran Via (Halls 1–3), Barcelona, Spain

Presenter:              Simon Krooss, MD, PhD, Hannover Medical School

About YOLT-202

YOLT-202 is an in vivo gene-editing therapy that corrects PiZ mutation to PiM for the treatment of AATD. Utilizing YolTech’s proprietary adenine base editor, YOLT-202 is engineered to achieve on-target editing with minimal bystander activity. The U.S. Food and Drug Administration (FDA) has granted Regenerative Medicine Advanced Therapy (RMAT) and Orphan Drug designations to YOLT-202 for the treatment of AATD.

About PiZZ AATD

PiZZ AATD is a severe, progressive genetic disease stemming from PiZ mutations in the SERPINA1 gene, which cause AAT proteins to misfold and accumulate in the liver and drastically reduce functional circulating AAT, leading to irreversible emphysema and liver complications such as fibrosis and cirrhosis. Largely underdiagnosed, this condition is currently managed with lifelong recurring plasma AAT infusions that merely relieve symptoms without correcting the genetic root, creating an urgent unmet clinical need for curative therapies targeting the underlying disease driver.  The rapidly expanding global AATD treatment market further underscores the critical demand for innovative disease-modifying gene-editing therapeutics for affected patients.

About YolTech Therapeutics

YolTech Therapeutics is a clinical-stage biotechnology company pioneering next-generation in vivo gene editing medicines for patients with serious genetic, cardiometabolic and autoimmune diseases. The company has built a fully integrated platform that combines HEPDONE™, its proprietary gene editing technologies, with AI-enabled discovery capabilities and targeted lipid nanoparticle (LNP) delivery systems designed to enable precise, one-time treatment with the potential for lifelong benefit. YolTech is advancing a broad portfolio of wholly owned and partnered programs spanning rare genetic diseases, cardiovascular and metabolic disorders, and autoimmune diseases, with multiple assets in clinical development. Founded on the vision of redefining genetic medicine through precision in vivo editing, YolTech is committed to developing transformative therapies that address the underlying cause of disease and improve outcomes for patients worldwide.