In rheumatoid arthritis, four main biologic therapies have been developed. They are effective at reducing symptoms and improving quality of life but they are very expensive and their long-term risks and benefits are still being evaluated. They are only prescribed for patients with severe, ongoing symptoms despite DMARD therapy and are used in combination with a DMARD (usually methotrexate). They are given by injection or intravenous drip.

• Anti-TNF therapies attack an inflammatory chemical called TNF (tumour necrosis factor), dampening down the inflammatory process. Examples include infliximab, etanercept and adalimumab.
• Anti-IL-1 therapies target a chemical called IL-1 (interleukin 1), which carries messages between immune cells. By blocking these messages, the immune response is reduced. Anakinra is an example of an anti-IL-1 therapy.
• Anti-B-cell therapies destroy a type of immune cell called a B-cell, which produces antibodies. These reduce the production of auto-antibodies and reduce the inflammatory process. Rituximab is an anti-B-cell therapy.
• Anti-T-cell therapies prevent the activation of a type of immune cell called a T-cell, reducing the inflammatory response. Abatacept is an example of an anti-T-cell therapy.