Givosiran as subcutaneous injection is in clinical development for the treatment of acute hepatic porphyria (AHP). AHP is a rare genetic condition in which patients lack certain enzymes needed to produce haem, a component of the blood pigment haemoglobin. As a result, substances for making haem accumulate in the body (particularly in the liver) and become toxic, causing attacks of severe abdominal pain, vomiting and nervous system disorders, such as seizures (fits), depression and anxiety. Some patients may also experience skin problems, with skin becoming oversensitive to light. AHP is life-threatening due to the possibility of paralysis and respiratory arrest during attacks and debilitating in the long term because of symptoms such as pain, nausea, seizures and skin blistering.
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.
Ropeginterferon alfa-2b for injection is under development for the treatment of polycythaemia vera (PV), a rare blood disease in which the body makes too many red blood cells. The extra red blood cells make the blood thicker than normal and as a result, blood clots can form more easily. These clots may block blood flow through arteries and veins, which can cause a heart attack or stroke. Thicker blood also does not flow as quickly and may prevent organs from getting enough oxygen. A mutation, or change, in a gene called JAK2 is the major cause of PV. This gene makes a protein that helps the body produce blood cells. PV develops slowly and may not cause symptoms for years. PV has no cure, but treatments can help control the disease and its complications.