Systemic Sclerosis (SS) is a rare disease caused by the immune system attacking the tissue which lines underneath the skin and internal organs (connective tissue). The exact cause of SS is not known but it is thought to happen when immune cells attack the body’s own tissues leading to the cells in the connective tissue producing too much collagen which causes scaring and thickening of the tissue. There are 2 types of SS; limited cutaneous SS (a milder form of SS affecting only parts of the body) and diffuse cutaneous SS (a more severe form of SS which can affect the whole body). The main symptoms of diffuse cutaneous SS are hardening of the skin, acid reflux, vomiting and diarrhoea, muscular pain, weakness and cramps. The outlook for people with diffuse cutaneous SS is generally poor due to high risk of life threatening complications such as heart, lung and kidney problems.
Lenabasum is being developed for diffuse cutaneous SS as a tablet to be taken twice per day. It works by binding to immune cells and triggers a process which reduces inflammation and the scaring and thickening of tissues which usually happens in SS. If licensed, lenabasum has the potential to reduce the scaring which happens in diffuse cutaneous SS and improve symptoms.
Apremilast works by suppressing the activity of inflammatory pathway caused by molecules such as interleukins and tumour necrosis factors. In turn this reduces inflammation. Currently, specific curative treatment options for Behçet’s disease are very limited and treatment relies on controlling symptoms and relieving pain. Apremilast has shown promise in targeting oral ulcers in patients with Behçet’s disease, and if licensed it could be an effective treatment option for this patient group.