Efficacy of mycophenolic acid for the treatment of psoriasis.

The efficacy of orally administered mycophenolic acid (MPA), an inhibitor of guanosine monophosphate (GMP) synthesis, for the treatment of psoriasis, was studied in a double-blind fashion. Of twenty-one patients completing the study period, ten of eleven patients treated with MPA had a greater than 25% decrease in severity score compared with only two of ten patients treated with placebo. The placebo group had a slight increase in severity score compared to almost 50% reduction in the average severity score of the MPA-treated group. After termination of the double-blind portion of the study, the placebo group was treated with MPA and showed a 60% decrease in severity score. Adverse effects encountered included anorexia, nausea, vomiting, and diarrhea. One patient had an uncomplicated episode of herpes zoster. Other than a mild decrease hemoglobin, no hematologic toxicity was noted.