A Phase I/II Study of a New Gene Therapy for Sickle Cell Disease


Full Title

A First-in-Patient Phase I/II Clinical Study to Investigate the Safety and Efficacy of Genome-edited Hematopoietic Stem and Progenitor Cells in Subjects with Severe Complications of Sickle Cell Disease


The purpose of this study is to assess the safety and effectiveness of two new treatments designed to reduce or prevent the complications of sickle cell disease. These treatments, OTQ923 and HIX763, are made from blood cell-producing stem cells that are genetically changed to prevent the bone marrow from making abnormal (sickle-shaped) red blood cells and increase the production of a type hemoglobin called fetal hemoglobin, which may reduce the harmful effects of sickle cell disease on the body.

The only cure for sickle cell disease is a stem cell transplant from a matched donor, but not everyone is able to have this treatment. Because OTQ923 and HIX763 are made from a patient’s own stem cells, they may work better than treatments made from donor cells and avoid problems such as the limited number of matched donors and immune system responses to cells that come from outside the body. Patients will receive OTQ923 and HIX763, but not both.


To be eligible for this study, patients must meet several criteria, including but not limited to the following:

  • Patients must have complications of sickle cell disease.
  • Patients may not have already received a stem cell transplant or gene therapy or have an available stem cell donor.
  • Patients must be able to walk and do routine activities for more than half of their normal waking hours.
  • This study is for patients ages 2-40.

For more information about this study and to inquire about eligibility, please contact 1-833-MSK-KIDS.





Disease Status

Newly Diagnosed