A serious adverse event in the first patient treated with an experimental genome editing therapy for sickle cell disease marked the beginning of the end for Graphite Bio. The company discontinued development of the treatment and eventually entered into a reverse merger with Lenz Therapeutics with a focus on improving vision. At the end of 2023, Kamau Therapeutics emerged from stealth following a strategic transaction with Graphite Bio that provided the new company with all of Graphite’s genome editing assets including next-generation platform technology and its lead program, a hematopoietic stem cell therapy engineered to restore adult hemoglobin by correcting a genetic mutation in people with sickle cell disease. We spoke to Matthew Porteus, co-founder of Graphite Bio and co-founder and CEO of Kamau Therapeutics, about the company’s genome editing technology, what’s now understood about the adverse event that occurred in the Graphite Bio clinical trial, and the development path forward for the therapy.