Sickle cell disease (SCD) is an inherited blood disorder characterized by the production of an altered form of haemoglobin in red blood cells. In sickle cell disease, haemoglobin polymerizes and becomes fibrous, causing red blood cells to become rigid and change form so that they appear ‘sickle-shaped’ instead of soft and rounded. Patients with sickle cell disease suffer from debilitating episodes of sickle cell crises, which occur when the rigid, adhesive and inflexible red blood cells block other blood vessels. Sickle cell crises cause excruciating pain as a result of insufficient oxygen being delivered to tissues, referred to as tissue ischemia, and inflammation. These events may lead to a variety of other adverse outcomes that require hospitalization.
The amino acid L-glutamine has been developed as an oral powder formulation to reduce the acute complication of sickle cell disease. It is thought L-glutamine works by reducing cell inflammation and promote the cellular uptake of oxygen. If licensed, L-glutamine oral powder may offer an additional therapy option for those with sickle cell disease who currently have few effective therapies available.
Givosiran is made of a short, synthetic strand of genetic material called ‘small interfering RNA’ (siRNA) that has been designed to interfere with the production of an enzyme involved in an early step in making haem. By blocking this early step of haem production in patients with AHP, givosiran is expected to prevent the next steps which produce substances that accumulate in the body and cause the symptoms of the disease.