Patients with psoriasis who received biologic treatments were at significantly lower risk of developing psoriatic arthritis, with women representing a potentially at-risk group.
Known to impact 30% of patients by 10 years after initial psoriasis diagnosis, PsA has been shown to further exacerbate the psychological and emotional burden associated with the inflammatory skin disorder.
Although conventional disease-modifying antirheumatic drugs (DMARDs) are recommended as first-line therapies for both conditions, researchers note that these medications have modest efficacy for the skin disease and questionable disease-modifying effects in various clinical types of PsA.
“Several biologic agents have been shown to be superior to DMARDs in treating PsA symptoms and have also shown effectiveness in slowing articular damage,” added the study authors. “However, they are not used as a first-line therapy in moderate to severe psoriasis, much due to their high cost.”
With prior research suggesting that biologic agents may slow PsA disease progression, researchers sought to evaluate whether these treatments would prevent or delay onset of PsA in patients with psoriasis.
They conducted a retrospective, nested case control study of electronic medical records of patients with psoriasis registered in the second largest health maintenance organization in Israel, Maccabi Healthcare Services.
After conducting propensity score matching, the investigators compared patients with a diagnosis of psoriasis who were not diagnosed with PsA before or at the time of biologic treatment initiation (n = 663) with those who did not receive biologic treatment (n = 663) for incidence of PsA over a maximum follow-up time of 10 years.
“Although the propensity score matching balanced the study arms, it [was] still unbalanced regarding the gender and the year of diagnosis. Thus, we adjusted for these factors and other PsA predictors such as age at psoriasis diagnosis and the time until treatment initiation using a multivariable Cox regression,” noted researchers.
Patients with psoriasis who had received biological treatments of adalimumab, etanercept, infliximab, ustekinumab, secukinumab, ixekizumab, or guselkumab were included in the biologic treatment group.
In their findings, a statistically significant increased risk of PsA was observed in the propensity score matched control group compared with the biologic treatment group, as measured by the Kaplan-Meier method and log rank test (P = .025).
Moreover, results of the multivariable Cox regression supported propensity score matched findings, with the control group exhibiting a significant 39% higher risk of PsA compared with the biologic treatment group (adjusted HR [aHR], 1.39; 95% CI, 1.03-1.87). Women were indicated to be at higher risk for developing PsA (aHR, 1.8; 95% CI, 1.34-2.42).
“These results may support initiation of treatment with biologic medications at an earlier stage in patients that present with significant risk factors for PsA,” concluded the study authors.
Rosenthal YS, Schwartz N, Sagy I, Pavlovsky L. Psoriatic arthritis incidence among patients receiving biologic medications for psoriasis: a nested case control study. Arthritis Rheumatol. Published online August 23, 2021. doi:10.1002/art.41946