The new initiative will not focus on donor-related bone marrow transplants in sickle cell disease, but instead will home in on genetic modifications of a patient’s own stem cells.
Earlier this month, the National Institutes of Health (NIH) announced the beginning of a new initiative to find a cure for sickle cell disease (SCD). This development will not focus on donor-related bone marrow transplants and instead home in on genetic modifications of a patient’s own stem cells.
An inherited blood disease, SCD affects approximately 20 million people worldwide. The origin of the disease comes from hemoglobin, which is responsible for binding oxygen from the lungs and delivering it to other tissues in the body. Patients with SCD have a single genetic mutation that causes their red blood cells (RBCs) to form an abnormal sickle cell shape. The sickle shaped RBCs get stuck in blood vessels and deprive cells of oxygen. Lack of oxygen in organs causes severe pain known as sickle cell crisis. Damage to organs can also lead to premature death, mainly caused by infections and acute coronary syndrome.
The only cure for SCD remains a bone marrow transplant, a process where a patient receives bone marrow from a healthy, genetically compatible donor. However, transplants are dangerous because it can lead to serious complications such as graft-versus-host disease (GVHD), veno-occlusive disease, infections, and graft failure. When a patient with SCD receives the bone marrow of another person, there is the risk that the immune system of the patient with sickle cell rejects and attacks the donor cells. The chances of either instance even in matched-related transplants can be up to 10%. Veno-occlusive disease can also occur if the blood vessels near the liver become damaged. Infections can also occur after a patient receives the chemotherapy prior to the bone marrow transplant or from the immunosuppressant drugs the patient will need to take after the procedure.In September 2018, NIH announced the beginning of a new initiative named the Cure Sickle Cell Initiative to help accelerate the development of new cures for SCD to a broader group of patients. The purpose of this new initiative is to bring new genetic approaches and technological advances into clinical trials, so they can be used as alternative cures or treatments for patients with SCD who lack donors. Another program that the NIH has worked on is the Production Assistance for Cellular Therapies (PACT). The PACT program will be assisting investigators on cellular therapeutic products, including genetically modified cells, and will try to bring them to clinical trials within the coming years.
Each year, the NIH spends about $100 million on SCD research. For this year, the NIH already committed an extra $7 million to start off the initiative. Current research focuses on using a SCD patient’s own hematopoietic cells and genetically modifying them before being returned to the patient through a bone marrow transplant, thus eliminating the need to find a matching donor, and removing the risk of GVHD.
“Our scientific investments have brought us to a point where we have many tools available to correct or compensate for the defective gene that causes SCD. We are now ready to use these tools to speed up our quest for a cure,” said Gary H. Gibbons, MD, director of NIH’s National Heart, Lung, and Blood Institute, in a news release.