Prime Medicine Inc. has announced encouraging preliminary results from the first patient dosed in a Phase 1/2 clinical trial of PM359, an investigational Prime Editor for Chronic Granulomatous Disease (CGD). The initial data revealed that a single dose of PM359 led to a significant improvement in DHR positivity, with levels reaching 58% by Day 15 and 66% by Day 30, surpassing those believed to be potentially curative. The treatment was well-tolerated with no serious adverse events reported. Prime Medicine plans to explore continued clinical development opportunities for PM359 outside the company. Additionally, the firm will concentrate on advancing its programs targeting genetic liver diseases like Wilson's Disease and Alpha-1 Antitrypsin Deficiency, and its in vivo Cystic Fibrosis program, supported by the Cystic Fibrosis Foundation. Prime Medicine also aims to develop Prime Edited CAR-T products in collaboration with Bristol Myers Squibb.