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Biologic agents

Biologic agents are immunosuppressant disease modifying drugs used in the treatment of psoriasis. They are made from biological (human or animal-based) proteins rather than artificial chemicals, much in the way that insulin was made from animal sources in the past.

Biologics are now available in two forms.  The originator form and a version called biosimilar.  These versions are offered as an alternate of the original form and are approved according to the same standards of pharmaceutical quality, safety and efficacy that apply to all biological medicines.

It is thought that overactive cells in the immune system set off a series of events in the body, eventually causing psoriasis to develop on the skin surface, with skin cells piling up and inflammation at the base. These treatments work by blocking the action of specific immune cells that cause these cells to misbehave, by either reducing the number of these cells in the skin and blood or by blocking the activation of the immune cells or the release of chemicals from them.

This type of treatment targets overactive cells in the body. Some target a type of immune cell called a T-cell, while others target the chemical messages they release.

In psoriasis, certain T-cells are mistakenly activated, producing TNF-α (tumour necrosis factor alpha) in excessive amounts, and move into the skin. Once in the skin they begin to act as if they are fighting an infection or healing a wound; the messages the TNF-α communicates leads to a rapid growth of skin cells – much faster than normal. This overproduction is what causes cells to pile up at the skin’s surface. Some products act by preventing the activation and/or migration of T-cells, by reducing the number of psoriasis-involved T-cells in the body, or both.

For those prescribed one of these treatments, there is a certain level of commitment required as they need to be stored correctly (in a refrigerator between 2°C and 8°C). Regular and frequent monitoring, such as blood tests, are also required. The products are given by injection. Once educated and instructed on how to self-inject, most people are able to manage this on their own, but a nurse service is often available to help some individuals.

The long-term safety of these immunosuppressant therapies has not yet been completely established.  As a result they are not considered first-line therapy. There is a pathway criteria outlined by the National Institute of Health and Care Excellence (NICE) so that people can access them after they have tried phototherapy and other disease modifying drugs.