Stanford moves toward human trials in using CRISPR to repair sickle cells
Scientists at Stanford University School of Medicine were successful in using the CRISPR gene editing tool to repair the gene that causes sickle cell disease, paving the way for a potential cure for the disease, as they look forward to conducting human trials in 2018.
With its gene-editing capabilities, CRISPR’s core tech centers on a new method of re-engineering DNA.
Dr. Matthew Porteus, senior author of the study, believes his team has amassed enough proof to start planning the first human clinical trial using the powerful CRISPR-Cas9 gene editing system to correct the genetic mutation that causes sickle cell disease.
In an interview, Porteus said they think they have a complete data set to present to the Food and Drug Administration (FDA), showing that they’ve completed all pre-clinical trials and are ready for the next step.
Sickle cell anemia or sickle cell disease is an inherited form of anemia. It is a condition where the body makes mutant, sickle-shaped hemoglobin, the protein in red blood cells that carries oxygen to the body’s tissues. As a result, the body will not have enough healthy red blood cells to carry adequate oxygen throughout the body.
Caused by a single mutation in the gene that makes a hemoglobin protein, the disease affects nearly 100,000 people in the US and five million people globally.
Porteus and his colleagues used CRISPR to snip the faulty gene and then used a harmless virus to introduce the repair mechanism into cells.
After a series of tests in healthy cells, the team tested the gene editing system in blood-forming cells from four patients with sickle cell disease. They showed they could correct the mutation in 30-50% of these diseased cells.
The team also found the cells were still thriving in the bone marrow 16 weeks after they injected the cells into young mice.
Porteus said the findings were very encouraging because prior studies have shown that if you can correct mutations in 10% of cells, that should create enough to cure the disease.
The process will involve using chemotherapy to wipe out a patient’s blood system but not their immune system, as is done in a stem cell transplant. Then, the team would inject the patient’s own corrected stem cells, which the researchers hope would engraft into the bone marrow and produce healthy blood cells.
Porteus has equity interest in CRISPR Therapeutics of Cambridge, Massachusetts, but he said the sickle cell work has been independent of it. Work will be done in Stanford’s cell manufacturing labs and not in CRISPR Therapeutics.
Porteus also said the team plans to make an initial submission to the FDA in the next few months to map out the clinical trial, and hopes to treat the first patient in 2018.
