YOLT-202 Receives FDA Orphan Drug Designation

April 10, 2025 – Shanghai, China — YolTech Therapeutics, a clinical stage biotechnology company developing next-generation in vivo gene editing therapies, today announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) to YOLT-202, an investigational in vivo base editing therapy for the treatment of Alpha-1 Antitrypsin Deficiency (AATD).

YOLT-202 is based on YolBE, YolTech’s proprietary adenine base editor engineered from a novel deaminase derived from Hafnia paralvei. Through three years of high-throughput enzyme engineering, YolBE has been optimized to enable both potent and precise correction of the SERPINA1 PiZ mutation, the most common and the most severe disease-causing variant in AATD. Notably, YolBE achieves on-target editing at this locus with minimal bystander activity, offering a potential one-time treatment therapy with durable therapeutic benefits.

This is the second program at YolTech to receive Orphan Drug Designation from the FDA, following FDA ODD and RPDD designation for YOLT-203, a first in class in vivo genome editing therapy for the treatment of primary hyperoxaluria type 1 (PH1).