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

Inclusion Criteria: * A confirmed diagnosis of severe LAD-I as demonstrated by flow cytometry indicating CD18 expression on \<2% neutrophils (polymorphonuclear neutrophils (PMNs)). Subjects in which CD18+ PMNs are \>2% will be considered eligible with \<2% CD11a or CD11b expressing PMNs and if there is a documented ITGB2 mutation and clinical history consistent with LAD-I (or known family history). * At least one (1) prior significant bacterial or fungal infection US NCI CTCAE, v5.0, Grade ≥2). This criterion is not required for subjects with documented family history who meet the above inclusion criteria. * Age ≥3 months. * Considered to be an appropriate candidate for autologous transplantation of hematopoietic stem cells. * A competent custodial parent with legal capacity to execute an institutional review board (IRB)/ethics committee (EC)-approved consent form must be available to participate in the consent process. (Informed assent will be sought from capable subjects, in accordance with the directive of the IRB/EC and with local requirements). * Ability to comply with trial procedures including investigational therapy and follow-up evaluations. Exclusion Criteria: * Availability of a medically-eligible human leukocyte antigen (HLA)-identical sibling donor transplant. Subjects may not be included in this trial as an alternative to a clinically-indicated and feasible HLA-matched sibling donor hematopoietic stem cell transplant. If an HLA-identical sibling is identified…