A form of arthritis, ankylosing spondylitis (AS) primarily affects the spine, although other joints can become involved. Generally, treatment for AS focuses on relieving pain and stiffness, reducing inflammation, preventing the condition from getting worse and enabling you to continue daily activities. Early diagnosis and treatment can help reduce pain, stiffness, inflammation and deformity.
Recently, the Assessment in Spondylarthritis International Society (SIS) modified its recommendations for managing AS so that patients with non-radiographic spondyloarthritis (SpA) could be considered for biological therapy.
What are TNF and TNF Blockers?
Also referred to as immunotherapy, biological therapy uses biologic response modifiers, such as TNF-alpha blockers, to restore the immune system’s ability to fight disease or infection.
Tumor necrosis factor-alpha (TNF-a) is one of the most important cells involved in AS because of its role in inflammatory reactions. It regulates immune cells and induces fever, apoptotic cell death, sepsis (blood pressure drops, resulting in shock) and inflammation. Further, TNF-a inhibits tumorigenesis (forming of tumors) and viral replication.
TNF blockers bind to tumor necrosis factor-alpha, rendering it inactive, and interfering with inflammatory activity. This, in turn, decreases joint damage.
Biologic Therapies for AS
The FDA has approved four TNF-a inhibitors, all of which have proven effective in treating AS: etanercept, infliximab, adalimumab and golimumab.
• Etanercept—reduces the active form of TNF, which helps reduce inflammation. Patients can self-administer the injection at home or receive it from a trained caregiver. Benefits of this TNF-a inhibitor include: reduced back pain (including nighttime pain), inflammation and morning stiffness as well as improved spinal mobility and better ability to do everyday tasks.
• Infliximab—an injection that comes as a powder that is mixed with sterile water, this therapy is typically administered by a doctor or nurse every two to eight weeks. The injections usually happen more often in the early stages treatment and less often as treatment continues. Patients who have used infliximab typically experience significant reduction in disease activity and improved function and mobility.
• Adalimumab—injected by you or a caregiver in the convenience of your own home. Adalimumab essentially binds to TNF-α, preventing it from activating TNF receptors. Typically, patients need to use adalimumab once every two weeks. In clinical trials, 58% of AS patients treated with the brand name form of this drug, Humira, showed 20 percent reduction in signs and symptoms.
• Golimumab—a human monoclonal antibody that targets and neutralizes excess TNF-alpha, golimumab is a patient-administered anti-TNF-a therapy. And it is the first such therapy to offer an effective, once-monthly treatment option.
Side Effects of TNF Blockers
TNF blockers affect your immune system and have the potential to lower your ability to fight infections. Some patients have experienced serious infections as a result of taking TNF blockers, including tuberculosis (TB) and infections caused by viruses, fungi, or bacteria that spread throughout the body. In some cases, these infections lead to a patient’s death.
More common, less serious side effects of TNF blockers include injection site reactions, upper respiratory infections (sinus infections) and headache.