Age, diabetes, prior infection linked to increased infection risk in PsA
Although TNF inhibitor use was associated with an increased risk of serious infection among patients with psoriasis and self-reported psoriatic arthritis, recent data published in BMC Rheumatology found these differences were not statistically significant.
Rather, the data suggested that older age, a Physician’s Global Assessment score of 4 or 5, prior infection and diabetes were associated with an increased risk for serious infection among those with self-reported PsA, regardless of biologic treatment.
“The impact of biologic use and infection risk is an area of significant interest to the rheumatology community,” Christopher T. Ritchlin, MD, MPH, of the University of Rochester Medical Center, and colleagues wrote. “An unmet need remains for longitudinal data to better address risks for [serious infections] in patients identified as having PsA in routine clinical practice.”
“Notably, the majority of available data regarding the impact of biologic therapies on [serious infection] risk has been directed at other inflammatory arthritides, such as RA, and less so for patients with PsA,” they added. “Consequently, an unmet need remains to assess the risk for [serious infection] in the PsA population and potentially identify any differences between outcomes of exposure in real-world use that may exist.”
To examine the incidence of serious infections among patients with psoriasis and self-reported PsA, specifically those treated with biologics compared with those receiving nonbiologic therapy, Ritchlin and colleagues studied data from the Psoriasis Longitudinal Assessment and Registry (PSOLAR). According to the researchers, PSOLAR is an international, observational study including 12,090 adults with psoriasis as of August 2015. It remains the largest psoriasis registry to date. All patients in the registry are either receiving, or are eligible for, biologics or conventional systemic agents.
Among the 12,090 patients in the registry, 4,315 had self-reported PsA. Focusing on an overall population of 2,401 patients with PsA, Ritchlin and colleagues organized these participants into cohorts based on treatment. These included 628 treated with ustekinumab (Stelara, Janssen), 1,413 receiving TNF inhibitors — 258 receiving infliximab (Remicade, Janssen), 481 treated with etanercept (Enbrel, Amgen), and 674 treated with adalimumab (Humira, AbbVie) — 54 who received other biologics, 98 on nonbiologic or methotrexate therapy and 208 receiving nonbiologic and nonmethotrexate treatment.
The researchers used multivariate analyses and Cox hazard regression to examine factors associated with time to first serious infection, and evaluated infection rates, as well as treatment-related risks, in patients with self-reported PsA.
According to the researchers, 138 serious infections were reported. Incidence rates per 100 patient-years were 1 for the ustekinumab cohort; 2.22 for TNF inhibitors — 2.12 for infliximab, 2.58 for etanercept, and 1.99 for adalimumab; 3.01 for nonbiologics and methotrexate; and 2.31 for nonbiologics/nonmethotrexate. In addition, age, a time-dependent Physician’s Global Assessment score of 4 or 5, prior infection and diabetes were associated with increased risk for serious infection (P<.05). All biologic groups other than ustekinumab demonstrated numerically higher rates of serious infection.
“According to recent guidelines for the treatment of PsA, serious infections were chosen as one of the critical outcomes for comparisons between therapies and are noted to be one of the greatest concerns for patients and physicians when choosing among the currently available therapies,” Ritchlin and colleagues wrote. “The findings presented here could potentially inform and assist health care professionals when selecting an appropriate treatment option for their patients with PsA.” – by Jason Laday
Disclosure: Ritchlin reports consulting fees from Amgen, Eli Lilly, Janssen, Pfizer and UCB, as well as consulting fees from AbbVie. Please see the study for all other authors’ relevant financial disclosures.