Gene editing without ex vivo culture evades genotoxicity in human hematopoietic stem cells.

Gene editing the BCL11A erythroid enhancer is a validated approach to fetal hemoglobin (HbF) induction for β-hemoglobinopathy therapy, though heterogeneity in edit allele distribution and HbF response may impact its safety and efficacy. Here, we compare combined CRISPR-Cas9 editing of the BCL11A +58 and +55 enhancers with leading gene modification approaches under clinical investigation. Dual targeting of the BCL11A +58 and +55 enhancers with 3xNLS-SpCas9 and two single guide RNAs (sgRNAs) resulted in superior HbF induction, including in sickle cell disease (SCD) patient xenografts, attributable to simultaneous disruption of core half E-box/GATA motifs at both enhancers.

Prospective Phase II Trial of Montelukast to Treat Bronchiolitis Obliterans Syndrome after Hematopoietic Cell Transplantation and Investigation into Bronchiolitis Obliterans Syndrome Pathogenesis.

Bronchiolitis obliterans syndrome (BOS) is a severe manifestation of chronic graft-versus-host disease (cGVHD) following hematopoietic cell transplantation (HCT). Montelukast interrupts cysteinyl leukotriene (CysLT) activity and may diminish the activation and homing of cells to bronchioles and subsequent fibrosis. We performed a prospective phase II trial to test whether montelukast altered lung decline for patients with BOS after HCT.

Parameters affecting successful stem cell collections for genetic therapies in sickle cell disease.

Emerging cellular therapies require the collection of peripheral blood hematopoietic stem cells (HSC) by apheresis for in vitro manipulation to accomplish gene addition or gene editing. These therapies require relatively large numbers of HSCs within a short time frame to generate an efficacious therapeutic product. This review focuses on the principal factors that affect collection outcomes, especially relevant to gene therapy for sickle cell disease.