The Food and Drug Administration (FDA) recently approved the biologic drug sarilumab (Kevzara) for the treatment of rheumatoid arthritis (RA). Sarilumab blocks a protein called interleukin-6 (IL-6), which plays a key role in many inflammatory diseases, including RA. It’s the second IL-6 inhibitor to receive FDA approval for RA; the other, tocilizumab (Actemra), got the nod in 2010.
IL-6 blockers historically have not been used as first-line treatments for RA (because they were developed later). They’re usually tried after other treatments such as methotrexate and anti-tumor necrosis factor (anti-TNF) drugs have failed to relieve symptoms and/or adequately control disease activity.
There are five anti-TNFs, which are administered in different ways and in different doses.
“If a patient doesn’t respond to one anti-TNF, most rheumatologists will try a second,” says Rayford June, MD, a rheumatologist at the Penn Medical Center in Hershey, Pennsylvania. Instead of cycling through even more anti-TNFs, some doctors now turn to other biologic medications, including IL-6 blockers, he adds.
“Despite advances in rheumatoid arthritis treatment, responses to medications are often incomplete, and while we discuss remission for patients, more often than not, [they] don’t remain in sustained remission, so more options for treatment are needed,” he says.
Sarilumab performed well in clinical trials. Compared to people who received a placebo, patients taking sarilumab were twice as likely to have a 20 percent improvement after 24 weeks in measures such as pain and the number of tender and swollen joints. They were also five times more likely to be in remission at six months and had less disease progression after a year of treatment.
Sarilumab is very similar to tocilizumab, the other IL-6 inhibitor on the market. Donald Miller, PharmD, a professor of pharmacy practice at North Dakota State University, says the two drugs are essentially the same, targeting identical IL-6 receptors.
Sarilumab’s price is similar to tocilizumab, too, but while still very expensive (with an annual price tag of $39,000), it’s 30 percent lower than the cost of the two most commonly prescribed anti-TNFs, according to pharmaceutical industry data.
Dr. June says he might consider sarilumab for patients who haven’t responded to TNF blockers, but other doctors may stick with tocilizumab, which has been around longer and is better known.
Both have the same potential side effects as other biologics, which interfere with the immune system and can lead to serious infections, among other things.
Dr. June cautions that safety data for new biologic drugs lags behind data about effectiveness; patients should understand the potential side effects.
Linda Rath for the Arthritis Foundation