PsA Patients Benefit from bDMARDS Regardless of Affected Joint Count

Biologic disease-modifying antirheumatic drugs (bDMARDs) should not be withheld from patients with psoriatic arthritis (PsA) who present with a low count of affected joints, investigators stated in Rheumatology.

“A lack of representation in pivotal trials currently limits guidance for the use of biologic DMARDs in psoriatic arthritis patients with a low number of actively inflamed joints,” the authors wrote. “The aim of this study was to compare the effectiveness of a first bDMARD in PsA patients with a low vs high number of affected joints.”

The researchers divided patients with PsA who had 66/68 joint count assessments into low joint count (LJC) patients who presented with <3 tender or <3 swollen joints, or high joint count (HJC) patients with ≥3 joints in both categories. “We studied drug retention as a joint count independent effectiveness variable in LJC and HJC patients in univariate and multivariable adjusted Cox regression models.”

Among the low joint count patients, 197 differed in the number of tender/swollen joint counts and also presented with lower rates of enthesitis, dactylitis, and disability and  a better health-related quality of life when first initiated on bDMARD therapy than 190 high joint count patients. However, the authors reported, patients with low joint counts were less likely to be on treatment with conventional synthetic DMARDs (csDMARDs).

“Despite these differences at baseline, bDMARD retention was not significantly different between LJC and HJC patients in both crude and adjusted analyses [hazard ratio (HR) 1.09 (95% CI 0.76, 1.58), P = 0.52].” In addition, bDMARD retention significantly higher [HR 0.63 (95% CI 0.47, 0.85), P < 0.002] when administered as cotherapy with csDMARDs.

 “In the setting of absent remission and a significant disease burden, bDMARDs should not be withheld from patients because they exhibit only a low joint count,” the authors concluded.

Möller B, Scholz GA, Amsler J, et al. Biologic disease-modifying anti-rheumatic drugs are equally effective in psoriatic arthritis patients with low and high joint counts. Rheumatology. 2024;63(6):1528–1533

https://doi.org/10.1093/rheumatology/kead455