In Psoriasis, Adalimumab and Infliximab Retention Rates Decrease After 10 Years

After 10 years of use, only a small proportion of patients with psoriasis treated with infliximab and adalimumab remained on their initial medication regimen, with the majority discontinuing treatment due to ineffectiveness, according to study results published in Dermatology.

Researchers conducted an observational retrospective study of 404 patients with psoriasis who received long-term treatment with adalimumab or infliximab between 2015 and 2020. Demographic and clinical data were extracted from patient medical records. Clinical information of interest included psoriasis severity, treatment regimen, date of treatment initiation, treatment duration, and date of discontinuation, if applicable. Reasons for discontinuation were also recorded.

Treatment efficacy was defined using Psoriasis Area and Severity Index (PASI) score and categorized by reductions of 75% (PASI 75), 90% (PASI 90), or 100% (PASI 100). Medication survival was defined as the average length of time until medication discontinuation and was calculated using the Kaplan-Meier method.

Of the 404 participants, 228 received adalimumab and 176 received infliximab. Demographic characteristics were similar between groups; there were no significant differences in age at study enrollment, age at disease onset, and sex. Baseline clinical characteristics were more severe among those in the infliximab group, with a greater median PASI score at baseline (10.5 vs 6.2) and a higher proportion of participants with psoriatic arthritis (55.1% vs 32.5%) compared with those in the adalimumab group (both P <.001). Use of the prescribed agent as a first-line biologic treatment was more common in the adalimumab group vs infliximab group (74.6% vs 62.5%; P =.042). The PASI 75, PASI 90, and PASI 100 rates were greater in the infliximab group at 12 and 24 weeks but higher in the adalimumab group after 36 weeks.

Among participants in the adalimumab group, a total of 75% of the discontinued the medication within 5 years; 21.5% received adalimumab for 5 to 10 years; and 3.5% continued use for more than 10 years. Similarly, the majority of participants in the infliximab group were receiving the medication for less than 5 years (75.6%), while 17% and 7.4% remained on infliximab for 5 to 10 years or more than 10 years, respectively.

There was no significant difference in 10-year retention rates different between groups, but median survival time was greater with infliximab compared to adalimumab (121.6±6.59 months vs 78.8±3.69 months; P <.01). In both groups, the most common reasons for discontinuation were primary ineffectiveness, secondary ineffectiveness, and patient dissatisfaction with treatment. In regression analyses, younger age at disease onset, higher body mass index, and the addition of isoniazid were protective factors against discontinuation.

The major limitation of the study was the retrospective design.

Researchers conclude, “The adherence of the patients diminished over time because of loss of efficacy after 3 years; thus, TNF inhibitors are effective for a short period but not long term.”

Disclosure: Several study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.