TNF Inhibitors Often Ineffective, Affecting Certain Aspects of Life for AS Patients, Study Says

Treatment with tumor necrosis factor inhibitors (TNFi) is not effective for many patients with ankylosing spondylitis (AS), causing them to switch therapies and leading to lower quality of life and less work productivity, a large international study reports.

The study, “Unmet needs in ankylosing spondylitis patients receiving tumour necrosis factor inhibitor therapy; results from a large multinational real-world study,” was published in the journal BMC Rheumatology.

Non-steroidal anti-inflammatory drugs (NSAIDs) are the first-line treatment to ease symptoms of AS, with biological disease modifying anti-rheumatic drugs such as TNFi — medicines that block the pro-inflammatory protein TNF — also often prescribed. 

However, a previous study showed that 22.5% of AS patients had to stop TNFi treatment after one year, often because they weren’t working or they were causing side effects. 

For those who don’t have an adequate response to TNFi treatment, interleukin (IL)-17A blockers such as Novartis‘ Cosentyx (secukinumab) and Eli Lilly‘s Taltz (ixekizumab) — antibodies that bind to IL-17A to stop inflammation — are recommended.

Researchers set up a multinational, Novartis-funded study in 18 countries to describe the use and switching of TNFi treatments in AS patients. They also assessed rates of TNFi treatment failure, and their association with patient-reported health-related quality of life (HRQoL), work productivity, and the ability to perform regular activities.

Patients were defined as failing TNFi treatment if, after three or more months on their current therapy, either the disease severity had worsened or remained severe, their disease activity was unstable or deteriorating, or physicians reported being dissatisfied with disease control. 

Among the 2,795 adults included in the study, 58.1% had received one TNFi therapy, 7.2% had been treated with two, and 2% had been given three or more.

In 59.9% of the 242 patients with available information, switching to another TNFi was due to primary (initial non-response) or secondary (loss of response over time) lack of efficacy. Other reasons included worsening condition, lack or no maintenance of remission, and no easing of pain.

Data from 34 patients who changed treatment due to primary lack of efficacy revealed a mean delay of 11.1 months until they switched to another TNFi.

“These findings indicate that patients may be maintained on failing therapy for significantly longer than the 12 weeks recommended by [American College of Rheumatology/Spondylitis Association of America/Spondyloarthritis Research and Treatment Network] treatment guidelines,” the researchers wrote.

Worldwide, 15.4% of the patients failed their TNFi  treatment. Specifically, the first TNFi treatment failed in 13.9% of patients, the second in 19.4%, and the third in 28.6%. 

“Clinical responses to TNFi declined with each subsequent treatment, evidenced by a higher incidence currently failing their 2nd or 3rd TNFi,” the team said.

Patients experiencing TNFi treatment failure reported worse HRQoL, measured by questionnaires (such as the 5-dimension EuroQoL) on general health status, as well as physical and mental status.

Less work productivity and more difficulty in performing daily activities were also seen in those failing TNFi treatment, as were absenteeism (regularly missing work) and presenteeism — lack of ability to fully function at work because of illness.

“This real-world, large multinational study of TNFi use in patients with AS demonstrates that TNFi do not consistently deliver sustained efficacy,” the scientists wrote. “Failing TNFi therapy is associated with poorer HRQoL, physical activity and work productivity.”

“Whether regular monitoring and earlier use of appropriate therapies upon identification of lack of efficacy leads to improvements in symptom control and HRQoL remains to be seen,” they added.

One of the study’s authors is an employee of Novartis. Others received funding/consulting fees or served on advisory boards for the company.