The treatment of psoriasis is changing quickly as new treatments emerge in the management of this disease. The latest treatment to hit the world of psoriasis is that of biologics.
Biologic drugs, also called "biologics," are a fairly new class of treatment options for psoriasis and psoriatic arthritis. They are given by injection or intravenous (IV) infusion. Biologics are protein-derived drugs created in a laboratory from extraction out of living cells such as bacteria which have been engineered to make the protein.
The difference between biologics and regular immune system drugs is that the biologics attack only specific aspects of the immune system and traditional systemic agents have an impact on the entire immune system. Biologics can block the action of proteins in the immune system or can block the action of T cells in the immune system. Some of the proteins blocked by the biologics include tumor necrosis factor-alpha (TNF-alpha) or some of the interleukins in the immune system. These are cells and proteins which play a large role in how people get psoriatic arthritis and psoriasis.
One T-cell blocker is called Amevive (Alefacept) which blocks the activation of T cells, which are white cells, found in great numbers in the skin of psoriasis. T cells mistake the skin for a foreign invader and there is a series of events that happen to inflame the skin and cause psoriasis. Amevive is delivered by injection and works within several weeks.
Enbrel, Humira, Remicade and Simponi are all medications that block TNF-alpha. TNF-alpha acts as an immune system mediator (a cytokine) that controls and promotes inflammation. In psoriasis, it has been found that TNF-alpha is produced in excess in the skin and joints of psoriasis sufferers and causes the rapid proliferation of skin tissue as well as damage to the tissue around the joints. If you block the TNF-alpha signal, it blocks the inflammatory cycle involved in psoriasis and related diseases.
Medications that block interleukin 12 and interleukin 23 include Stelara (ustekinumab). This drug is selective against the cytokines known as interleukin 12 and interleukin 23. They are found in large numbers in the skin of psoriasis sufferers. They are believed to be what activates the T cells in the body.
Biologics are all given by intramuscular injection or by intravenous use. Amevive is given by means of an intramuscular injection and Enbrel, Simponi and Humira are injected into the legs, abdomen or arms. You can get them at home and can be given by the individual or a family member. Stelara is a subcutaneous injection given at the doctor's office. Remicade is given by IV at a hospital or doctor's office. They are used in patients with an intact immune system who have moderate to severe cases of psoriatic arthritis or plaque psoriasis. They take several weeks to work and not everyone can find relief from them. In addition, you cannot take the injections if you have an active, ongoing infection.
Doctors generally screen for the basic infections before giving these drugs, including screening for tuberculosis. The risks of taking these biologic agents include giving the individual an infection. It is unknown whether or not the biologics affect a fetus so they cannot be given to pregnant mothers.
Side effects of taking biologics include frequent respiratory infections, having flu-like systems or having localized reactions at the site of the injection. Rarely disorders such as multiple sclerosis, eye inflammation called optic neuritis, seizures, blood disorders or certain types of cancer can occur.