Anti-infliximab antibody status related to psoriasis clinical response
MedWire News: Measuring antibodies to infliximab (ATI) in patients with psoriasis may be an important clinical strategy for avoiding or delaying loss of response to the drug, study findings suggest.
"Our study, which aimed to document the frequency of ATI formation in psoriatic patients receiving infliximab monotherapy on a regularly scheduled basis, showed that one-third of patients receiving infliximab for psoriasis developed ATI during their therapy," the team reports in The Journal of Dermatology.
"More importantly, we were able to show that the formation of ATI reflected the loss of efficacy of infliximab in these patients."
Esra Adisen and colleagues, from Gazi University in Ankara, Turkey, treated 15 patients with psoriasis with infliximab (5 mg/kg) every 8 weeks after an initial three-dose introduction treatment.
They used an enzyme-linked immunosorbent assay kit to analyze for the presence of ATI in the patients' sera.
In all, five patients developed ATI at the time of the 5th, 6th, 7th, 10th, and 13th infusion of infliximab therapy.
These patients did not differ significantly from those who did not develop ATI in terms of age, gender, duration, or type of psoriasis.
However, while in ATI-negative patients an average of 5.9 infliximab infusions resulted in Psoriasis Area and Severity Index (PASI) scores falling from a mean of 20.4 to 5.3, an average 9.0 infliximab infusions achieved a smaller PASI drop - from 23.3 to 10.0 - in ATI-positive patients.
Also, although the mean baseline PASI scores were similar between the groups, the mean final PASI scores were significantly higher in ATI-positive compared with ATI-negative patients, at 10.0 versus 5.3.
The team notes that all five patients with ATI presented with either new lesion development or a loss of efficacy, which was reflected by an increase in PASI in these patients.
Nevertheless, ATI disappeared in the ATI-positive patients after 8 weeks of additional methotrexate therapy, at doses ranging from 5-15 mg/week.
"Monitoring for the induction of ATI and rescue strategies should be developed to avoid or to maintain a delay in ATI development," say Adisen et al.
"Although our patient number is low, our results showed that the formation of ATI development may be responsible for the loss of efficacy of infliximab in long-term use, especially in patients whose clinical benefit wanes over time."
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By Lucy Piper