Results published for two CGD patients treated with PM359, showing restored white-cell function

Prime Medicine/PM359 (CGD)

NEJM published results for the first two patients treated with PM359, a prime-edited stem-cell therapy for chronic granulomatous disease. Both patients achieved dihydrorhodamine-positive neutrophil percentages well above the 20% threshold thought necessary for clinical benefit, with durable results over months.

• Patient 1: 69% dihydrorhodamine-positive (DHR+) neutrophils by day 30; Patient 2: 83% by day 30.
• DHR activity remained stable over follow-up, indicating durable gene correction in bone marrow stem cells.
• One patient stopped colitis medication, suggesting clinical benefit.
• No safety concerns reported in the published Phase 1/2 data.