Conference Coverage
TNF inhibitors slow hip deterioration in ankylosing spondylitis
Key clinical point: Ankylosing spondylitis patients on tumor necrosis factor inhibitor treatment had substantially better maintenance of hip...
MADRID – At least 2 years of tumor necrosis factor–inhibitor treatment of patients with ankylosing spondylitis nearly halved the rate of spinal radiographic progression in a study involving 432 Swiss patients.
In addition, patients on a tumor necrosis factor inhibitor (TNFi) who achieved low disease activity, reflected in an Ankylosing Spondylitis (AS) Disease Activity Score of 1.3 or less, showed virtually no spinal radiographic progression during a 2-year follow-up, Adrian Ciurea, MD, reported at the European Congress of Rheumatology.
He cautioned, however, that the evidence only shows correlation and can’t prove a causal relationship between TNFi treatment and slowed spinal radiographic progression because of potential residual confounding.
Mitchel L. Zoler/Frontline Medical News
Dr. Ciurea and his associates analyzed records for AS patients enrolled in the Swiss Clinical Quality Management in Rheumatic Diseases cohort who underwent at least two spinal radiographs separated by a 2-year gap. They assessed the radiographs using the modified Stoke AS Spinal Score (mSASSS), and they defined progression as a gain of at least two units on the mSASSS during a 2-year period between radiographs.
The 432 AS patients in the study averaged 40 years old, two-thirds were men, and they had AS symptoms for an average of nearly 14 years. Their average AS Disease Activity Score (ASDAS) at entry was 2.8.
A multivariate analysis that controlled for several variables, including sex, smoking history, baseline mSASSS, and exercise, identified three parameters that had significant correlations with radiographic progression: Men had more than double the rate of progression, compared with women; higher baseline mSASSS was linked with a higher rate of progression; and a greater-than-2-year history of treatment with a TNFi was linked with a 48% reduced rate of progression, reported Dr. Ciurea, a rheumatologist at the Zürich University Hospital.
The duration of treatment also mattered. Patients who received at least 4 years of TNFi treatment had a statistically significant 68% reduced rate of radiographic spinal progression. In contrast, patients who received a TNFi for fewer than 4 years but more than 2 years had a 42% lower rate of progression that was of borderline statistical significance. TNFi treatment that started during the 2 years immediately preceding the radiograph failed to show a significant link with reduced progression.
Further analysis also showed a tight correlation between patients’ disease activity while on TNFi treatment and radiographic progression. Patients who maintained an average ASDAS of 2.1 or less during the 2 years prior to radiographic assessment showed an average mSASSS gain of 0.31 units over that 2-year period, compared with an average 1.45-unit mSASSS gain among patients whose average ASDAS remained above 2.1, a statistically significant difference between these two groups. Patients with even more inactive disease on TNFi treatment – those who maintained an average ASDAS of 1.3 or less – had an average 0.01-unit rise in their mSASSS after 2 years of treatment, compared with an average 0.52-unit mSASSS rise after 2 years in patients with an ASDAS of more than 1.3 but less than 2.1, he said.
The cohort study received partial support from Merck Sharpe & Dohme. Dr. Ciurea has been a consultant to or speaker for Abbvie, Celgene, Eli Lilly, Janssen-Cilag, Merck Sharp & Dohme, Novartis, Pfizer, and UCB.
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