Tumor Necrosis Factor Inhibitors (TNFi)
If a person with AS cannot take an NSAID, or if their symptoms like pain and stiffness are not improved with NSAID therapy, a TNF blocker is usually recommended. Tumor necrosis factor (TNF) is a protein involved in the inflammatory process, so by inhibiting its production, inflammation in the body is reduced.
The good news about TNF blockers is there is ample scientific evidence to support their benefit in reducing disease activity in ankylosing spondylitis—in other words, quieting the inflammation down in the body.5
TNF blockers are not completely benign therapies. They do have risks, and this must be weighed carefully for each person.
Due to the fact that TNF blockers suppress a person’s immune system (albeit an overactive one in the cases of those with ankylosing spondylitis), they can increase a person’s risk of both mild infection and serious infection. An example of a mild infection is a common cold. On the other hand, a serious infection that doctors especially worry about when a person is taking a TNF inhibitor is tuberculosis.
Due to the risk of tuberculosis reactivation, a TB test is required before initiating TNF blocker therapy. Rarely, TNF blockers have been linked to an increased chance of developing certain cancers.
It’s also important to know that certain people are not candidates for taking TNF blockers. Conditions that would prevent a person from being able to take TNF blockers would be considered contraindications.
Contraindications for TNF Blockers
- Multiple sclerosis
- Heart failure
- An active infection like pneumonia
Women who are pregnant or breastfeeding may not be candidates for TNF blocker therapy.
According to current medical guidelines, a person should only be considered for a TNF blocker if their disease does not improve with at least two different types of NSAIDs (at a maximum dose tolerated).
The TNF blockers used to treat ankylosing spondylitis are:
- Enbrel (etanercept)
- Remicade and Renflexis (infliximab)
- Humira (adalimumab)
- Simponi (golimumab)
- Cimzia (certolizumab)
Remicade, Inflectra, and Renflexis (infliximab) are given as an infusion through the vein, while Enbrel (etanercept), Humira (adalimumab), Simponi (golimumab), and Cimzia (certolizumab) are given as subcutaneous (into the fat tissue) injections.