CHICAGO – Patients with psoriasis treated with infliximab had the highest incidence of serious infections in a retrospective analysis of commercial claims data.
After 5 years of follow-up among 22,753 patients, there were 554.7 hospitalized infectious events (HIEs) per 10,000 patient-years of exposure to infliximab (Remicade).
Among the other treatment groups, the incidence of HIEs varied within a comparatively narrow range of 261.2 for phototherapy to 341.4 per 10,000 patient-years of exposure to nonbiologic therapies, Dr. Alexa B. Kimball reported at the American Academy of Dermatology summer meeting.
Dr. Alexa Kimball
The biologics etanercept (Enbrel), ustekinumab (Stelara), and adalimumab (Humira) fell somewhere in between with HIE incidence rates of 261.5, 287.1, and 321.9 per 10,000 patient years, respectively.
"It is reassuring that some of the rates we reported for patients on biologics were similar to that found in the phototherapy-treated population, which is not expected to have a reduced immune response to infection," Dr. Kimball of Massachusetts General Hospital, Boston, said in an interview. "Still, in any given patient, individual risk and benefits are important to assess when starting or continuing therapy."
In one other study evaluating the safety of anti–tumor necrosis factor agents, rates of serious infections and lymphoma were higher among patients with psoriasis and psoriatic arthritis treated with infliximab and adalimumab, compared with etanercept (Immunopharmacol. Immunotoxicol. 2012;34:548-60).
In the current analysis, hospitalizations for an infectious event were also higher in patients on concomitant corticosteroid therapy at baseline, Dr. Kimball reported.
Five-year HIE incidence rates were higher in patients with systemic corticosteroid exposure versus those without, regardless of treatment group: nonbiologics (649.2 vs. 251.6); etanercept (676.9 vs. 198.1); adalimumab (424.5 vs. 260.9); infliximab (990.2 vs. 443.3); ustekinumab (542.4 vs. 201.2); and phototherapy (320.3 vs. 235.3).
"This finding reinforces that combination therapy, especially with systemic steroids, may confer additional risk," Dr. Kimball said. "Patients on infliximab were also more likely to have psoriatic arthritis and may have a different underlying level of disease severity and risk, which we could not ascertain from these data."
The retrospective analysis was based on data obtained from the MarketScan Commercial Claims and Encounters and Medicare Supplemental and COB databases for patients with a diagnosis of psoriasis on or before Dec. 31, 2006, and at least one prescription claim for one of the above-mentioned therapies. Patients could belong to more than one treatment group.
A new HIE was defined as at least one overnight hospitalization with an ICD-9 infection code. Patients hospitalized in the previous 3 months for the same ICD-9 code were not eligible.
In all, there were 5,857 patients with any exposure to nonbiologics, 6,856 to etanercept, 3,314 to adalimumab, 1,044 to infliximab, 526 to ustekinumab, and 5,156 to phototherapy.
Unique exposures to these agents totaled 2,700; 3,433; 719; 301; 0; and 3,482, respectively, according to the poster.
Amgen sponsored the study. Dr. Kimball is a consultant for Amgen and several other pharmaceutical companies.