Beta
thalassemia

What is beta thalassemia? Beta thalassemia is an inherited blood disorder that affects the red blood cells, which are essential for carrying oxygen to all organs and tissues of the body. A lack of red blood cells, also known as anemia, is the primary manifestation of beta thalassemia. Because of this anemia, people living with beta thalassemia may experience fatigue and shortness of breath, and infants may develop failure to thrive, jaundice and feeding problems. Complications of beta thalassemia can also include an enlarged spleen, liver and/or heart; misshapen bones; and delayed puberty. Treatment for beta thalassemia is personalized and depends on the severity of disease that each person experiences. Many people have to get regular blood transfusions to deliver healthy donated blood to their body. This requires many hospital visits and can also lead to an unhealthy buildup of iron. Beta thalassemia requires lifelong treatment and significant use of health care resources, and ultimately results in reduced life expectancy, decreased quality of life and reduced lifetime earnings and productivity.

How is beta thalassemia diagnosed? Beta thalassemia is diagnosed based on characteristic symptoms and a set of tests, including blood tests and genetic testing. People with the disease are often diagnosed before age 2, typically around 3-6 months.   

What is the underlying cause of disease? Beta thalassemia is caused by a mutation in the beta-globin (HBB) gene. The HBB gene encodes for a key component of hemoglobin, the oxygen-carrying molecule in red blood cells. This mutation leads to issues with the production of hemoglobin, leading to anemia. 

The cause of transfusion-dependent beta thalassemia (TDT) has been known for decades, yet treatment options have been limited. Over the last several years, our teams at Vertex have become pioneers in the cell and genetic therapy space,  discovering and developing treatments that target the underlying cause of beta thalassemia.  

We advanced the first-ever CRISPR/Cas9 gene-edited therapy into the clinic in 2018, and this treatment is now approved in some countries for certain eligible people living with TDT. This autologous, ex vivo CRISPR/Cas9 gene-edited therapy aims to edit a person’s hematopoietic stem cells to produce fetal hemoglobin (HbF; hemoglobin F). HbF is a form of hemoglobin that is naturally present at birth, which then switches to the adult form of hemoglobin. Hemoglobin is the protein that carries oxygen throughout the body. The aim is to use the body’s own machinery to switch back to producing fetal hemoglobin. 

We know our work is not done. We are working to discover and develop novel targeted conditioning regimens that may enhance the hematopoietic stem cell transplant process, including transplants conducted as part of treatment with gene therapies. We are also investigating other conditioning regimens to potentially support expansion of stem cell transplant opportunities. In addition, we have an internal research program exploring small molecule treatment options for people living with beta thalassemia. 

These programs are investigating treatments or outcomes that have not all received approval from a health authority. The information presented is not intended to convey conclusions of safety or efficacy. There is no guarantee that the outcome of these studies will result in approval by a health authority.

For more information about our beta thalassemia studies in the U.S., visit the clinical trials website. For information about non-U.S. sites, visit clinicaltrials.gov.

For more information from Vertex on beta thalassemia, please visit the Newsroom.