For those living with conditions with no known cure, the anxiety and anger can be too much to bear. Wanting and waiting for a solution to make symptoms and side effects disappear, sick patients everywhere continue to suffer. Gene therapies have made the seeming miracle a reality for some, using most advanced precision medicine to alter cells for the treatment of disease. Scientists and researchers have agreed – it’s hemoglobinopathies’ turn.
Hemoglobinopathies are genetic disorders affecting the structure or production of the hemoglobin molecule – hemoglobin being the red protein responsible for transporting oxygen in the blood. Produced by the beta-globin gene, hemoglobin disorders arise when this gene is dysfunctional. The most common hemoglobinopathies include sickle cell disease and thalassemia – combined affecting over 330,000 kids born worldwide every year. Hispanic-Americans and Black or African-American populations are at an increased risk for hemoglobinopathies, often carrying the inheritable trait. One out of every 365 Black or African-American births is affected by SCD. While sickle cell disease causes misshapen hemoglobin molecules, thalassemia disorder is the presence of less hemoglobin than normal. Both deprive the body of sufficient blood and oxygen, which damages nerves and organs, including the kidneys, liver, and spleen, and can be fatal.
A blood and bone marrow transplant from a Human Leukocyte Antigen (HLA) matched sibling is currently the only cure for sickle cell disease, and only a small number of people are able and eligible to have said transplant. There are treatments that can reduce symptoms and prolong life, effective to a certain extent. Thalassemia is managed (in severe cases) through frequent blood transfusions. More mild cases are often prescribed a supplemental B vitamin, known as folic acid, to help treat anemia. Folic acid can help red blood cells develop, but treatment with folic acid is usually done in addition to other therapies. But for those unresponsive to these treatments, and even those doing their best with existing symptom management, the obvious lack of cure is devastating.
Latest research in the hemoglobinopathy space has brought an experimental gene therapy for those suffering from sickle cell disease and thalassemia. Adding functional copies of a modified form of the beta-globin gene into a patient's own hematopoietic stem cells, the gene therapy gives patients the potential to make functional hemoglobin molecules, thus functional red blood cells. With the goal of reducing the presence of sickled red blood cells, hemolysis, and other complications, this new therapy represents the first-ever gene therapy for either of these conditions.
There are several ongoing trials exploring the therapy’s use in both sickle cell disease and thalassemia. Data released in June 2019 from the company’s ongoing Phase I/II study show robust production of gene therapy-derived anti-sickling hemoglobin. In the study, patients with six or more months of follow-up after treatment for sickle cell disease had median sickle hemoglobin levels reduced to 50% or less of total hemoglobin in the absence of blood transfusions. In thalassemia, data from Phase I/II Northstar studies of the therapy found sufficient hemoglobin production to reduce or eliminate the need for transfusion support among patients with thalassemia who would otherwise require chronic blood transfusions.
These results earned the therapy breakthrough designation from the FDA. In both indications, the therapy has either moved into Phase III or Phase II/III clinical trials with Conditional Marketing Authorization in the EU for the thalassemia indication.
Utilizing some of the greatest precision science to date, medical researchers are nearing an approved gene therapy to cure these chronic blood disorders – a Top 10 Medical Innovation if there ever was one.