Antigens from Leishmania amastigotes induced clinical remission of psoriasis

While injecting volunteers in Venezuela with a vaccine for prevention of leishmaniasis, we observed 100% clinical remission of a psoriatic lesion in one subject. Subsequently, the vaccine (AS100) was evaluated in psoriatic patients with an open label, single center study. The study was conducted in 2,770 subjects and included plaque (79%), guttate (10%), plaque and guttate (10%), palm/plantar, erythrodermia, inverse, plaque and arthritis and nail psoriasis. Baseline PASI compared with post-treatment values were: PASI 100, 23%; PASI 75, 45%; PASI 50, 13%; PASI 10, 9% and <PASI 10, 3% of patients. Adverse events, attributed to the treatment drug were rated mild or moderate in severity, with none being classified as serious. Subsequently, the results were confirmed in a double-blind, placebo-controlled, parallel group study, of multiple doses of AS100. In conclusion, AS100 demonstrated a favorable benefit/risk profile and merits further development for the treatment of psoriasis.