Sickle cell disease is a set of genetic conditions where abnormalities in the structure of hemoglobin cause red blood cells to take on a long, curved, sickle-like shape, which can then impede blood flow. Gene therapies may make a huge difference in the lives of patients with sickle cell disease, but they require high-dose chemotherapy to eliminate the problematic stem cells in the patient’s bone marrow, which are then replaced. The chemo can also cause infertility by damaging sperm development and causing ovarian failure.
A new antibody-drug conjugate (ADC) which could replace this chemotherapy is particularly promising because it would avoid causing sterility. The compound, CD117-ADC, was tested on rhesus monkeys, and found to deplete bone marrow stem cells while leaving other cell types unaffected. Importantly, the female monkeys continued to menstruate after treatment, and when some of the monkeys were later transferred to a breeding colony, two of the four females gave birth, while both male monkeys were able to successfully impregnate females.