Saturday, August 31, 2013

A Review of a New TNF Inhibitor for the Treatment of Rheumatoid Arthritis

Up until the 1980's, the treatment of rheumatoid arthritis was less than satisfactory. We used drugs such as gold salts, d-penicillamine, hydroxychloroquine (Plaquenil), sulfa drugs, and even tetracycline-derived antibiotics. For some patients who responded to these measures, the results were gratifying. But all too often patients either didn't respond or they developed horrendous side effects.

Approximately, fifteen years ago, biologic drugs such as the TNF inhibitors, entered the arena and revolutionized out treatment approach to rheumatoid arthritis.

While there are many biologic therapies with different mechanisms of action, this article will focus on one drug, a TNF inhibitor called Cimzia. The TNF inhibitors work by either attaching to tumor necrosis factor or blocking its ability to bind to its receptor on a cell. This action essentially renders tumor necrosis factor incapable of producing inflammation.

We currently have five TNF inhibitors available. I have adapted some of this information from a recent article by Dr. Phil Mease that appeared in Medscape.

Cimzia (CMZ) is a pegylated anti-TNF drug. What this means is that a polyethylene glycol chain has been attached to the TNF antibody. This attachment is supposed to keep the drug in circulation longer and also to keep it at the site on inflammation longer. This lengthier stay is supposed to enhance the effectiveness of the drug. CMZ is given as a subcutaneous injection every 2 or 4 weeks. One benefit is that it doesn't sting as much as some of the earlier TNF inhibitors such as Enbrel or Humira.

The safety and effectiveness of Cimzia in adult patients with active RA were established in three large phase III clinical trials, in which CMZ was given along with methotrexate or by itself. These studies showed that CMZ reduced the signs and symptoms of active rheumatoid arthritis and prevented the progression of joint damage.

The studies also evaluated factors such as patient reported outcomes and quality of life measures. After all, what good is the science if the patient doesn't feel that the medicine has helped them be able to get their life back?

All the clinical trials were in agreement in regards to the following: CMZ, in combination with or without methotrexate, improved the signs and symptoms of rheumatoid arthritis as early as the first week of treatment. CMZ also prevented joint damage as early as 16 weeks. Patients reported significant improvements in quality of life measures. They also had significant relief of arthritis pain and fatigue, following treatment with CMZ.

The potential side effects of CMZ are exactly the same as with all other TNF inhibitors and these potential problems need to be discussed with the patient prior to prescribing the drug.

In our office we also go over a teaching schedule and have a patient sign an informed consent form.

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