A Clinical Trial to Evaluate the Safety and Efficacy of RP-L201 in Subjects With Leukocyte Adhesion Deficiency-I

This is a pediatric non-randomized open-label Phase I/II clinical trial. The Phase I portion will include a safety evaluation and preliminary assessment of the efficacy of hematopoietic gene therapy consisting of autologous CD34+ enriched cells transduced with a lentiviral vector carrying the ITGB2 gene in subjects with severe LAD-I. CD34+ cells will be transduced ex vivo with the therapeutic vector followed by cryopreservation. If the number of CD34+ cells that are available for infusion is at least 2x10e6 total CD34+ cells/kg, subjects will undergo myeloablative conditioning with intravenous busulfan. Subjects will then receive infusion of gene-corrected hematopoietic cells approximately 24 hours following the final busulfan dose. The active agent is a self-inactivating lentiviral vector carrying the therapeutic ITGB2 gene, encoding for the human CD18 receptor (β2 integrin subunit). The therapeutic product is the subject's autologous hematopoietic stem cells that have been transduced with the lentiviral vector.