More Research Needed to Understand Why AS Patients Quit Taking TNF Blockers, Study Concludes

Many ankylosing spondylitis (AS) patients who start treatment with a TNF-blocker switch treatments, use additional medications, or stop the treatment completely within a year, a recent study shows.

These real-world findings suggest there is room for improvement in the treatment of AS. But for better treatment strategies to emerge, researchers need to understand why people are quitting, as well as to understand their needs, researchers from the University of Utah and Novartis suggest.

The study, “Treatment patterns of biologics in US patients with ankylosing spondylitis: descriptive analyses from a claims database,” examined treatment patterns in 426 AS patients by gathering data from the U.S. Optum Research administrative claims database.

Almsot half of the patients — 45.1 percent — started treatment with Enbrel (etanercept) as their first TNF-blocker. Other included drugs were Humira (adalimumab), used by 28.6 percent; Simponi (golimumab) in 11.7 percent; infliximab — sold under the brand name Remicade or as biosimilars Inflectra and Renflexis — also in 11.7 percent; and finally, Cimzia (certolizumab pegol), used by 2.8 percent of AS patients.

Results, published in the Journal of Comparative Effectiveness Research, showed that patients who started treatment with Humira, maintained the therapy for the longest amount of time, with an average of 243 days. Those on Enbrel were on the other side of the spectrum, maintaining their treatment for only 192 days on average.

Only about 40 percent of all patients continued with their initial therapy for 12 months or more. When looking at rates of 12-month persistence, Simponi scored highest at 50 percent, while Cimzia had the lowest rate at 33.3 percent.

Nearly 60 percent stopped the treatment before one year. Among them, 31 percent entirely stopped treatment with TNF inhibitors, while 21.4 percent switched to another TNF blocker. In addition, 7 percent stopped but later resumed the same drug they had initially received.

Among the 333 patients who continued using their medication for more than 90 days, the majority also used other medications. Patients most commonly added corticosteroids (16.8 percent), opioids (12.9 percent), nonsteroidal anti-inflammatory drugs (NSAIDs; 10.2 percent), and antidepressants (7.2 percent).

In addition, 7.2 percent of patients increased the dose of their TNF-blocking medication — a practice that was far more common in patients who received intravenous, rather than subcutaneous, treatment.

While the study shows that many patients use additional treatments — particularly those targeting pain and inflammation — researchers have not adequately looked into the practice. Pain control, they said, has been identified as one of the most important issues for patients — and more research is needed to develop optimal add-on therapy strategies.

As the data was gathered from a claims database, researchers had no possibility of looking into the reasons why people discontinued or modified their treatment. To improve treatment in AS, scientists need to understand this.

“These findings provide an understanding of real-world treatment patterns of patients with AS and suggest that concomitant treatment options in addition to biologic therapy or alternate therapies for patients with AS are important,” the researchers wrote.

“Inadequate control of symptoms may cause patients to discontinue biologic therapy, which can contribute to unfavorable outcomes. The importance of routinely evaluating patient symptom control and the need to better understand optimal therapy strategies necessitates further study in patients with AS,” the team concluded.