A Phase II Pilot Study of Nonmyeloablative Conditioning Hematopoietic Stem Cell Transplantation in Children With Sickle Cell Disease Who Have a Matched Related Major ABO-Incompatible Donor (Sickle-AID)

About the study

The aim of this study to evaluate the safety and efficacy of a nonmyeloablative conditioning regimen for allogeneic hematopoietic stem cell transplantation (HSCT) in pediatric patients with sickle cell disease (SCD) who have a matched related major ABO-incompatible donor. The nonmyeloablative regimen will use alemtuzumab, total body irradiation (TBI) and sirolimus for immune suppression. This study will expand the access of HSCT for patients with SCD who are currently not eligible because of donor restrictions.

Study point of contact

Greg Guilcher, MD
Tony Truong, MD, MPH


1 Canada site


1 Year - 19 Years




Phase 2

Study type







participation requirements

Patients must be ≥ 12 months and < 19 years of age at the time of study enrollment. Patients must have sickle cell disease as defined by hemoglobin electropheresis, as follows: homozygous Hb S disease (HbSS), sickle-Hb C disease (HbSC), sickle beta-plus-thalassemia (HbS/β+), or sickle beta-null-thalassemia (HbS/βo) Patients must meet standard eligibility criteria to undergo HSCT, including but not limited to one or more of the following: history of repeated (more than 1) bony (vaso-occlusive) crisis history of stroke elevated transcranial Doppler velocity not eligible for hydroxyurea, as per TWiTCH trial (ie. severe vasculopathy) history of acute chest crisis or splenic sequestration crisis history of priapism in males history of osteonecrosis pulmonary hypertension as documented by tricuspid regurgitation jet velocity (TRV) > 2.5 m/s on echocardiogram
red cell allo-immunization (≥ 2 antibodies) during long term transfusion therapy
Sickle complications should be present despite the use of hydroxyurea, but this is not an absolute requirement, if the treating team considers the patient to be at high risk for further crisis episodes.

participation restrictions

Patients who are unable to comply with or follow the study protocol.
Patients with known hypersensitivity to sirolimus, its derivatives or to any of its components.


  • Calgary, Alberta, Canada, Alberta Children's Hospital, T3B 6A8 [Recruiting]
Last updated 2021-05-25