FDA Accepts Intellia's Lonvo-Z BLA with Priority Review — First In Vivo CRISPR Therapy Nears Approval

On September 8, 2026, Intellia Therapeutics announced the FDA accepted the Biologics License Application for lonvoguran ziclumeran (lonvo-z) and granted Priority Review, setting a PDUFA target action date of March 10, 2027. The FDA does not currently plan to hold an advisory committee. Lonvo-z is an in vivo CRISPR therapy that permanently inactivates the kallikrein B1 (KLKB1) gene in a single outpatient dose to prevent hereditary angioedema (HAE) attacks. The application is backed by the Phase 3 HAELO trial (80 patients), which showed an 87% reduction in mean monthly HAE attacks versus placebo and 62% of lonvo-z patients entirely attack-free, compared with 11% on placebo. If approved, lonvo-z would become the world's first approved in vivo CRISPR-based therapy, with a potential US launch in H1 2027.