Selumetinib is in clinical development for children with neurofibromatosis type 1 (NF1), also called von Recklinghausen’s disease. NF1 is a rare genetic disorder characterized by the development of multiple benign tumours of nerves and skin and areas of abnormal skin colour. NF1 is caused by mutation in a gene that regulates the production of a protein known as neurofibromin which is thought to function as a tumour suppressor. At birth or early childhood, affected individuals may have relatively large, benign tumours that consist of bundles of nerves and other tissue. These are known as plexiform neurofibromas (PNs). PNs may cause ongoing pain, motor dysfunction and disfigurement. Surgery may be used to remove PNs, but at high patient risk with the possibility of re-growth.
Selumetinib blocks an enzyme that is part of a signalling pathway in cells which can cause cells to grow, divide and copy themselves in an uncontrolled manner and may result in tumour growth. This pathway is improperly activated in patients with NF1, leading to the growth of tumours. Early studies have demonstrated the ability of selumetinib to shrink large tumours through its action on this pathway. Selumetinib may also aid in the improvement of health problems associated with PNs such as pain and motion problems. If licensed, selumetinib taken orally may provide the first pharmacological treatment option for NF1 and inoperable PNs.
BIIB092 is a product that is being investigated for the treatment of progressive supranuclear palsy (PSP). PSP is a rare condition that is a result of destruction of nerve cells in certain parts of the brain causing problems with balance, movement, vision, speech and swallowing. In patients with PSP, an abnormal form of a protein called tau accumulates in specific areas of the brain by spreading from brain cell to brain cell leading to their damage. Over time, PSP gets progressively worse, with people becoming severely disabled within three to five years of onset. Currently, there is no cure for PSP and no treatment to slow down the disease.