The phase 3 EXPRESS II trial data show infliximab (Remicade, Centocor) maintenance treatment with regularly administered infusions is associated with better psoriasis control and fewer infusion reactions than intermittent, as-needed dosing. A composite analysis of infliximab phase 2 and 3 study data shows consistently dramatic improvements across all four body regions evaluated in the studies.
The results supported a maintenance regimen based on regularly scheduled infusions (every eight weeks) versus treatment administered as needed for disease worsening.
In addition, the dramatic benefit of infliximab identified in the primary efficacy analyses of Psoriasis Area and Severity Index (PASI) 75 response rates was shown in multiple studies to be consistent across the four body regions.
EXPRESS II was a multicenter, double-blind, placebo-controlled study randomizing 835 patients with moderate-to-severe psoriasis to infliximab 3 or 5 mg/kg or placebo.
All patients underwent an induction course consisting of three infusions administered at weeks zero, two and six.
Treatment response was assessed at week 10, and showed that approximately three-fourths of patients in both infliximab groups were PASI 75 responders.
At week 14, patients originally treated with infliximab were randomized into one of two maintenance therapy groups to continue receiving their original infliximab dose, administered every eight weeks or intermittently, only when their improvement from baseline PASI score fell below 75 percent.
Data were analyzed from follow-up through week 50 and showed that maintenance with regularly administered infusions was associated with better disease control as well as fewer infusion reactions than intermittent treatment.
"Responses to the induction course of infliximab are excellent and rapid. These results from the maintenance period of the phase 3 study reaffirm that waiting to re-treat until the disease begins to flare is not the strategy we should be following for managing patients with moderate-to-severe psoriasis," says Alan Menter, M.D., principal investigator in EXPRESS II and director, psoriasis research unit, Baylor Research Institute, Dallas.
"Our goal in this chronic disease should be to sustain consistent control. That is best achieved with routine dosing, possibly as intermittent dosing may allow for potential antibodies to infliximab and a decreased response," Dr. Menter tells Dermatology Times.
He says that in clinical practice, the maintenance regimen should also incorporate flexibility in dosing for optimal disease control.
The analysis of the EXPRESS II data through week 50 showed a high proportion of patients treated with intermittent infliximab were still able to achieve a PASI 75 response following retreatment.
Considering the subgroup of patients who were not given their first maintenance infusion for at least 16 weeks following the third induction dose, 76 percent of patients treated with infliximab 3 mg/kg and 84 percent of those treated with infliximab 5 mg/kg achieved a PASI 75 response at some time during follow-up.
However, the PASI 75 response rate at week 50 was higher among patients treated every eight weeks compared with those treated intermittently in both the infliximab 3 mg/kg (43.8 vs. 25.4 percent) and 5 mg/kg (54.5 vs. 38.1 percent) groups.