A Prospective Clinical Research Protocol of Allogeneic CCR5 delta32/delta32 Cord Blood Cell Transplantation to Cure HIV Infection

Allogeneic hematopoietic cell transplantation from a CCR5 Δ32/Δ32 unrelated donor, performed for the first time in the "Berlin patient", provides the only evidence to date of long-term control of HIV infection. Stringent criteria to select human leukocyte antigen (HLA)-matched conventional donors and low prevalence of the CCR5 Δ32/Δ32 homozygous genotype (<1%) made the pursuit of "patient number 2" unsuccessful for many years. Cord blood (CB) transplantation allows more permissive HLA-matching criteria, making the search for HLA-compatible Δ32/Δ32 CB units potentially feasible for transplantation of HIV-infected individuals.

The investigator team involved in this trial has recently reported the first such case of CCR5 delta32/delta32 CB transplantation in a patient with HIV infection, showing a reduction of the patient's latent viral reservoir and, upon achievement of full CB chimerism, resistance of his CD4 T-lymphocytes to infection by HIV. This proof of concept led the Spanish National Transplant Organization (ONT) to generate an inventory of over 150 CCR5 Δ32/Δ32 CB units readily available for transplant.

From this initial evidence and repository of CB units, financial support from the Fundación Mutua Madrileña (FMM) has allowed the investigators to launch this first pilot clinical trial in this indication. The study was launched in January 2016 at Hospital Universitario Puerta de Hierro Majadahonda. All HIV virology and reservoir analyses are carried out by the AIDS Immunopathology Unit at the Spanish Instituto de Salud Carlos III. Three additional transplant centres in Spain will also shortly open the trial.