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.
Romiplostim is a medicinal product that is being developed for the treatment of adult patients with idiopathic thrombocytopenic purpura (ITP) who are refractory to other treatments. ITP is the condition of having a low platelet count due to unknown cause. It is also known as immune thrombocytopenic purpura. Many people with ITP do not have symptoms, however people with very low platelet count can have symptoms such as pin prick rash, easy bruising, nosebleeds, gum bleeds, black mouth blisters, fatigue, and heavy periods. Most of the currently available treatments have significant side effects with some treatments leaving patients are at increased risk of infections.