Treatment with ustekinumab demonstrated similar safety and efficacy among younger vs older adults with psoriatic arthritis (PsA) over a 3-year period, according to results of a post-hoc analysis published in Arthritis Research & Therapy.
Psoriatic arthritis typically affects patients aged 30 years and older. However, the long-term safety and tolerability of certain biologic disease-modifying antirheumatic drugs (bDMARDs) in patients of more advanced age remains understudied. Investigators aimed to assess the 3-year safety, efficacy, and treatment adherence of ustekinumab among younger (patients aged <60 years) vs older (patients aged ≥60 years) adults with PsA.
Data were taken from the PsABio real-world study (ClinicalTrials.gov Identifier: NCT02627768), a multi-national, prospective, observational study. The study included patients with PsA who initiated first-, second-, or third-line biologic treatment with either a new tumor necrosis factor inhibitor or ustekinumab. For this post-hoc analysis, only outcomes centered on ustekinumab treatment were assessed.
Number and type of adverse events (AEs), measures of clinical Disease Activity Index for Psoriatic Arthritis (cDAPSA) low disease activity (LDA) and Minimal Disease Activity (MDA), Psoriatic Arthritis Impact of Disease-12 (PsAID-12) scores, and length of treatment duration were included in the analysis.
A total of 439 patients were included in the effectiveness analysis (336 younger adults vs 103 older adults) and 494 patients in the safety analysis (379 younger adults vs 115 older adults).
A higher percentage of older adults reported at least 1 AE vs younger adults (40.9% vs 32.7%). Severe AEs were reported by less than 10% of patients in both groups.
At 6 months, a total of 138 (51.7%) younger adults achieved cDAPSA-defined LDA vs 35 (43.8%) older adults. The number of patients achieving this goal increased at every 6-month time point among both groups, though the effect was less pronounced among older adults.
A total of 77 (29.8%) younger adults achieved MDA at 6 months vs 19 (24.1%) older adults. The number of patients achieving MDA increased at every 6-month time point among only younger adults.
Mean PsAID-12 scores were reduced among patients in both groups between baseline and 6 months. Further, PsAID-12 scores among younger adults continued to decrease at each 6-month time point. This effect was less pronounced among older adults, as their PsAID-12 scores appeared to plateau.
A numerically greater proportion of younger adults (51.5%; 95% CI, 46.0-56.9) discontinued treatment with ustekinumab or switched to a new bDMARD at 36 months, compared with older adults (45.6%; 95% CI, 35.8-55.7). The length of time from treatment initiation to discontinuation/switch was similar between the groups (mean, 1.98 vs 2.16 years, respectively).
Mean ustekinumab treatment duration was 24.22 months among younger adults vs 26.11 months among older adults.
This study was limited by inconsistencies and gaps in data collection. Additionally, wide and overlapping confidence intervals were present due to the small sample size of older adults.
The researchers concluded, “These data provide reassurance regarding the use of ustekinumab in an older, potentially more vulnerable, patient population.”
Gossec L, Theander E, Chakravarty SD, et al. Response to treatment in psoriatic arthritis, the effect of age: analysis of patients receiving ustekinumab in the PsABio real-world study. Arthritis Res Ther. Published online June 9, 2023. doi:10.1186/s13075-023-03078-8