Sangamo Therapeutics announces updated preliminary proof-of-concept clinical data from its zinc-finger nuclease gene-edited cell therapy for sickle cell disease

Sangamo Therapeutics announced updated preliminary proof-of-concept efficacy and safety data from the Phase 1/2 PRECIZN-1 study of SAR445136, a zinc finger nuclease gene-edited cell therapy candidate in development with Sanofi for the treatment of sickle cell disease (SCD). The therapeutic product is manufactured by ex vivo gene editing of a patient's own (autologous) hematopoietic stem cells using non-viral delivery of zinc finger nuclease technology targeting the BCL11a gene erythroid-specific enhancer (ESE) to increase endogenous fetal hemoglobin (HbF) production. None of the four treated patients required blood transfusions post engraftment, while total hemoglobin stabilized by Week 26 after treatment with SAR445136 for all patients. Fetal hemoglobin level increased from 0.1-11% at screening to 14-39% by Week 26 in all four patients and was 38% in the longest-treated patient at 91 weeks. Percent F cells increased to 64-96% by 39 weeks of follow-up in all four patients, persisting at 99% in the patient with 91 weeks of follow-up. The SAR445136 investigational drug product had on-target BCL11A gene modification (61-78%) in all four patients. Most adverse events reported in the screening, mobilization, apheresis and conditioning periods were SCD-related events. No adverse events related to SAR445136 were assessed. The study is ongoing. For more information: press release