Patients with self-reported psoriatic arthritis (PsA) receiving a tumor necrosis factor inhibitor (TNFi), including infliximab, adalimumab, and etanercept, have numerically higher, but not statistically significant, rates of serious infection, according to research results published in BMC Rheumatology.
Using patient data collected from PSOLAR (Psoriasis Longitudinal Assessment and Registry; ClinicalTrials.gov Identifier: NCT00508547), researchers conducted a modeled analysis of patients with self-reported PsA receiving biologic therapies to evaluate predictors of first-time serious infection as well as the incidence of serious infection in this patient population.
Researchers enrolled in the study patients aged >18 years with PsA who received or were eligible to receive biologic therapy and/or conventional systemic agents for psoriasis in PSOLAR. The cohort for this study included 4315 patients with psoriasis with a self-reported diagnosis of PsA, of whom 1719 reported that that their diagnosis had been confirmed by a provider.
Investigators stratified patient data based on exposure to specific biologic or nonbiologic therapies, including ustekinumab, infliximab, adalimumab, etanercept, all other biologics, nonbiologic/methotrexate (MTX), and nonbiologic/non-MTX.
Overall, the data of 2401 patients (7244 patient-years) were included in the total PsA population; 628 of these received ustekinumab, 1413 received TNFis, 258 received infliximab, 481 received etanercept, 674 received adalimumab, 54 received other biologics, 98 received nonbiologic/MTX, and 208 received nonbiologic/non-MTX. In total, 1163 patients (3101 patient-years) were included in the incidence population, while the bionaive population included 532 patients (1626 patient-years). The majority of patients were white (83.3%) and overweight (84.6%), with a mean age of 50 years. Over a quarter of patients (26.7%) had a history of infection requiring a prescription medication within the last 3 years.
Patients in the nonbiologic/non-MTX cohort had the highest use of systemic steroids (23.1%). In the biologic cohorts, MTX was the most commonly used immunomodulator, which was reported being used by 60.1% of patients in the infliximab group. Overall, 77.8% of patients had a history of biologics use, with 41.5% having used only 1 biologic.
Serious infection rates were highest in the etanercept, infliximab, and adalimumab cohorts (2.58, 2.12, and 1.99, respectively). In the ustekinumab cohort, patients had a numerically lower incidence rate (1.00) among individually tested biologics compared with the rates reported in 2 nonbiologic cohorts. No serious infection events were reported in the other biologics cohort.
Serious infection incidence rates were similar with those reported in the overall population, with an incidence rate of 1.91 (95% CI, 1.60-2.25; n=138) per 7244 person-years of exposure. Among biologic users, the highest incidence rates for serious infection were noted in the etanercept, TNFi, and infliximab cohorts (2.58, 2.22, 2.12, respectively); comparatively, the ustekinumab cohort had the lowest incidence rate (1.00). The most commonly reported serious infections included cellulitis and pneumonia, with the most cases reported in the TNFi cohort.
Multivariate analysis determined the predictors of time to first serious infection. Age, time-dependent disease activity Physician’s Global Assessment, infection history, and diabetes were all associated with increased risk for serious infection.
Study limitations included those inherent to the observational nature of the research, possible treatment selection, recall, and reporting biases, and the use of self-reported PsA data, which may not reflect the patients in the general rheumatology population.
“Our results showed that rates of [serious infections] were numerically higher among patients [with self-reported PsA] receiving [TNFis],” the researchers concluded. “Continued follow-up of these patients [with PsA] in the ongoing PSOLAR registry will provide additional safety information regarding patients with PsA in general.”
Disclosure: This clinical trial was supported by Janssen Biotech Inc. and Horsham, PA, USA. Please see the original reference for a full list of authors’ disclosures.
Ritchlin CT, Stahle M, Poulin Y, et al. Serious infections in patients with self-reported psoriatic arthritis from the Psoriasis Longitudinal Assessment and Registry (PSOLAR) treated with biologics. BMC Rheumatol. 2019;3:52.