Treating Rheumatoid Arthritis With Biologic Medications: A Quick Take

Traditional pharmacologic approaches to the treatment of rheumatoid arthritis (RA) have relied on combinations of nonsteroidal anti-inflammatory drugs, analgesics, glucocorticoids such as prednisone), and disease-modifying antirheumatic drugs (DMARDs) such as methotrexate, and are still widely used in RA patients. DMARDs not only control RA symptoms, they may also slow progression of the disease, lessen the severity of existing joint damage, and induce remission.

A better understanding of the inflammatory disease processes behind RA and other chronic health conditions led to the discovery of a class of DMARDs known as biologics, which have changed the lives of many RA patients, especially patients whose arthritis does not respond to traditional DMARDs. Biologics are genetically engineered drugs derived from human genes that target specific inflammatory cells, cellular interactions, and cytokines that mediate RA-related tissue damage. Biologics have been shown to help slow progression of RA where other treatments have failed.

Similar to the traditional small-molecule drugs, biologics can be associated with side effects. A common side effect of biologics is irritation and redness at the injection or infusion site. In addition, because biologics suppress components of the immune system that drive the inflammatory process behind RA, these medications come with risks associated with modulating the immune system. For example, patients taking biologics have increased risk of infections, and biologics can cause the reactivation of latent tuberculosis (TB); so TB skin tests are needed prior to beginning biologic therapy. There are other precautions that patients taking RA biologics should engage in, for example, not receiving live vaccines and stopping the biologic medication if they have a fever or infection of any kind. Pregnant women should take biologics only if deemed clearly necessary because the effects on a developing fetus are unknown. Biologics require regular monitoring and follow up by physicians, along with related lab work, tests, and examinations.

Biologics are also more expensive than traditional RA treatments. While most health insurance companies cover biologic therapies for RA, some may require patients try less costly treatments first. Additionally, drug makers offer payment assistance for biologic RA treatments for patients who have no insurance or inadequate coverage.

When one biologic doesn’t successfully control RA, or side effects become an issue, physicians may prescribe a different biologic from the same class. Biologics can be the sole medication used or be part of a combination approach using biologics and non-biologic medications (dual-DMARD therapy). Biologics are administered by infusion or injection (with the exception of tofacitinib [Xeljanz], which is taken orally).

Approved Biologics for RA

The first biologic approved for treatment of RA was etanercept (Enbrel, the first tumor necrosis factor [TNF]-antagonist), which was approved by the FDA in 1998. Other biologics have since been approved and marketed for RA:

• TNF antagonists Infliximab (Remicade) Adalimumab (Humira) Adalimumab-atto (Amjevita, a biosimilar* to Humira) Abatacept (Orencia) Golimumab (Simponi) Certolizumab pego (Cimzia)
• Interleukin [IL]-1 inhibitor anakinra (Kineret)
• T-cell co-stimulation blocker abatacept (Orencia)
• B-cell-depleting agent rituximab (Rituxan; Mabthera)
• IL-6 inhibitor tocilizumab (Actemra)
• Janus kinase inhibitor tofacitinib (Xeljanz).

References

1. Curtis JR, Singh JA. Use of biologics in rheumatoid arthritis: current and emerging paradigms of care. Clin Ther. 2011;33(6):679-707. doi: 10.1016/j.clinthera.2011.05.044.
2. Biologics for rheumatoid arthritis treatment. WebMD website. http://www.webmd.com/rheumatoid-arthritis/guide/biologics#1. Accessed February 6, 2017.