Background: Alefacept (Amevive®) was the first biologic agent to be approved by the FDA for use in moderate to severe chronic plaque psoriasis and remains one of the safest systemic agents. However, alefacept is the least utilized of all the biologic agents due to the finding that it is only effective in a small proportion of patients and its maximal efficacy is not seen until approximately 6 weeks after treatment completion.
Objective: To determine whether intralesional injections with a biologic agent can predict who will be a responder or a non-responder to the medication.
Methods: This was a single-center 22-week study consisting of three phases: i) intralesional injection to a target plaque, ii) intramuscular alefacept injections for 12 weeks (standard dose) and iii) post-treatment follow-up.
Results: There appears to be a perfect correlation between patients who show a response to an intralesional injection of alefacept to a small, target plaque and those who eventually respond to a full 12-week systemic course of the medication (achieve at least 70% improvement in their PASI scores from baseline) (p = 0.0003).
Limitations: This study had a small sample size and was limited by the fact that it was open-label without a control arm.
Conclusion: The results from this pilot study demonstrated that alefacept appears to work intralesionally and this may be usable to predict systemic response. More importantly, these results strongly suggest that a biologic agent can work locally - a novel concept that contradicts the common notion that biologic agents must work "systemically".