Using a TNF inhibitor for late-onset AS as safe, effective as early onset
Researchers drew from TURKBIO to collect data on biologics and their use
Tumor necrosis factor inhibitors (TNFi) appear to work as well and be as safe for adults with late-onset ankylosing spondylitis (AS) as they are for those with earlier symptoms, offering an additional treatment option for older patients, a real-world study suggests.
The study, “Assessing safety and efficacy of TNFi treatment in late onset ankylosing spondylitis: a TURKBIO registry study,” was published in Scientific Reports.
In AS, the joints become inflamed mainly in the spine and pelvis, which can be seen on X-rays. Symptoms like back pain and stiffness usually manifest before age 30, but may appear later too. Medications to ease inflammation are a common treatment.
TNFi and other biologics, or medications made from living organisms, may be prescribed when symptoms are not controlled well with nonsteroidal anti-inflammatory drugs (NSAIDs) and other painkillers. However, clinical data on using TNFi in late-onset AS are limited.
“Considering the potentially higher risk of [side effects] related to NSAID use in [late-onset AS] patients, it is advisable to proceed with TNFi therapy when it is warranted, provided that it is accompanied by proper indications and diligent follow-up,” wrote the researchers, who drew from the Turkish Biological (TURKBIO), a registry launched in 2011 to collect data on biologics and their use in rheumatic diseases in Turkey to see how well TNFi therapy works, how safe it is, and how well patients with late-onset AS adhere to it.
The study included 281 patients with late-onset AS and 2,573 with young-onset AS. Those whose symptoms started at age 45 or later were classified as having late-onset AS, while those whose symptoms started before age 45 were classified as having young-onset AS.
Safety, effectiveness in early- and late-onset AS
Patients with late-onset AS were a mean 19 years older than those with young-onset AS (61 vs. 42). They also were significantly more likely to be women (59.1% vs. 36.9%) and nonsmokers (55.2% vs. 38.8%). Patients with late-onset AS also had a shorter time since their diagnosis.
Mean Bath Ankylosing Spondylitis Metrology Index (BASMI) scores were significantly higher in those with late-onset AS (37.7 vs. 29.8 points). The higher the BASMI score, the more severe a patient’s limitation of movement due to AS.
Similarly, mean Bath Ankylosing Spondylitis Functional Index scores were significantly higher in patients with late-onset AS than those with young-onset AS (30.1 vs. 25.6 points), indicating a greater degree of functional limitation in activities of daily living.
Patients with late-onset AS were more likely to use disease-modifying anti-rheumatic drugs like methotrexate and sulfasalazine on top of TNFi therapy. Measures of disease activity showed that people with late-onset AS responded to TNFi therapy as well as did those with young-onset AS for up to two years.
Out of the 2,854 patients observed for two years, 822 (28.8%) stopped TNFi therapy. There were no differences between patients with late-onset and young-onset AS in how likely they were to continue TNFi therapy.
The most common reason for stopping TNFi therapy at two years was lack of efficacy, followed by side effects and remission. Being a woman, having greater functional limitation or more severe pain, and testing negative for HLA-B27, a known genetic risk factor for AS, were linked to discontinuing TNFi therapy.
Serious side effects were about as frequent in late-onset as in young-onset AS (11.7% vs. 8.7%). Examples included severe infection and tuberculosis, a bacterial infection that mainly affects the lungs, as well as allergic reactions and cancer.
While the study didn’t distinguish between specific biologics, it showed “comparable treatment responses to the first TNFi,” the researchers wrote, noting that further studies in late-onset AS are needed to validate the findings.
