Treating Psoriasis With Injections
Treatment for psoriasis and many other inflammatory diseases was revolutionized with the introduction of biologics. But to understand how groundbreaking these types of drugs are for psoriasis, it’s important to look at how the condition was treated in the past.
Psoriasis is a chronic, inflammatory skin condition characterized by red, scaly plaques that typically show up on the knees, elbows and scalp. Psoriasis is characterized by over activity of certain parts of the immune system. Before biologics, patients were often treated using non-specific immunosuppressants that would knock out many parts of the immune system. Drugs most commonly used were cyclosporine and methotrexate, as well as drugs that are toxic to the blood cells like hydroxyurea. It’s almost like using a cannon when all that was needed was a sling shot.
But then some researchers started thinking, “What’s really going on with psoriasis? What specific immune processes are faulty?” Think of it this way: the inflammatory pathways involved in psoriasis are like a stream of molecules heading to and from the skin’s surface. In a person without psoriasis, these pathways activate the immune system when there’s a cut or scrape, sending cells to the skin’s surface to fight infection and heal wounds. If you have psoriasis, your immune response is overactive and may jump into action for no apparent reason.
As we began to understand more of which biological processes were really driving psoriasis and psoriatic lesions, drug companies started making medications that targeted specific pathways involved in the disease. Enter Enbrel (etanercept), the first drug approved by the Federal Drug Administration (FDA) in 2004 to treat psoriasis. Enbrel, along with drugs like Humira (adalimumab) and Remicade (infliximab), is classified as a tumor necrosis factor-alpha (TNF-alpha) blockers. TNF-alpha blockers are either self-injectable at home, or intravenous infusions administered by a doctor. Injection frequency varies from once or twice a week to every 6-8 weeks.
TNF-alpha is a cytokine, or protein, within your body that prompts the creation of inflammation. If you have psoriasis, you likely have excess production of TNF-alpha in the skin and possibly the joints, so by blocking this specific pathway, the goal is to slow or stop the inflammatory process in psoriasis -- and it works really well. In fact, we saw a dramatically higher rate of people responding to treatment--with up to 75% improvement, and very few side effects.
Specific Interleukin Blocking
Interleukins are naturally occurring proteins that regulate many aspects of the inflammation and immune response. The second class of biologics to come to market specifically target interleukin 12 and 23 (IL-12 and IL-23); of those, Stelara (ustekinumab) is the most well-known. The major difference between IL-12/23 blockers and TNF-alpha blockers is that the former works on two pathways known to be associated with inflammatory psoriasis; the latter, only one. Another major benefit of the IL-12/23 blockers, is that you only have to have it injected quarterly (every three months), rather than the more frequent dosing required of TNF-alpha inhibitor.
A newer class of injectable biologics, IL-17 blockers, is even more promising. IL-17 is another protein involved in immune responses. These new IL-17 blockers target block downstream in the most critical pathway in psoriasis and work faster than older injectable. Patients typically see vast improvement within two to four weeks. In comparison, some of the TNF-alpha blockers reach maximum efficacy at 12 to 16 weeks. Cosentyx (secukinumab) is the first approved IL-17 blocker. After taking weekly doses for the first four weeks on the medication, patients only have to inject on a monthly basis. Taltz (Ixekizumab) was recently FDA approved and is taken every 2 weeks for a period of time and then monthly.
THIS CONTENT DOES NOT PROVIDE MEDICAL ADVICE. This content is provided for informational purposes and reflects the opinions of the author. It is not a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified healthcare professional regarding your health. If you think you may have a medical emergency, contact your doctor immediately or call 911.
Aaron Mangold, MD, is an assistant professor of
dermatology at the Mayo Clinic in Arizona.
View his Healthgrades profile >
Healthgrades Operating Company, Inc. All rights reserved. May not be reproduced
or reprinted without permission from Healthgrades Operating Company, Inc. Use
of this information is governed by the Healthgrades User Agreement.