Korro Bio announced that its investigational medicine, KRRO-110, received orphan drug designation from the FDA for treating Alpha-1 Antitrypsin Deficiency (AATD). KRRO-110 is the first RNA editing candidate from Korro’s OPERA™ platform and is currently in a Phase 1/2a clinical trial called REWRITE. This designation recognizes the unmet need for AATD treatments and provides Korro with development incentives like tax credits and potential market exclusivity.
This FDA decision is notable because it validates the potential of RNA editing as a therapeutic approach for AATD, a rare genetic disorder affecting fewer than 200,000 people in the U.S. Current treatment options for AATD are limited, and KRRO-110 offers a novel mechanism of action by repairing the faulty gene responsible for the disease at the RNA level. This could lead to a more effective treatment targeting both liver and lung manifestations of AATD. The orphan drug designation also strengthens Korro’s competitive position in the rare disease space.
The Phase 1/2a REWRITE trial is a dose-escalation study evaluating the safety and tolerability of KRRO-110 in healthy adults and AATD patients. Interim data from the single ascending dose cohorts in healthy volunteers is expected in the second half of 2025, with study completion anticipated in 2026. The trial will also assess pharmacokinetic and pharmacodynamic parameters to inform dose selection for future studies. The orphan drug designation provides Korro with financial benefits that could support the continued development of KRRO-110.
This designation represents a significant step forward for Korro Bio and the development of KRRO-110. Positive clinical data and subsequent FDA approval could establish KRRO-110 as a leading therapy for AATD, potentially transforming the treatment landscape for this rare disease. This achievement also reinforces the potential of Korro’s RNA editing platform, OPERA™, to generate further innovative therapies for other genetic diseases.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
