A clinical trial to evaluate the safety and immunogenicity of the LEISH-F1 + MPL-SE vaccine when used in combination with meglumine antimoniate for the treatment of cutaneous leishmaniasis

Forty-four adult patients with cutaneous leishmaniasis (CL) were enrolled in a randomized, double-blind, controlled, dose-escalating clinical trial and were randomly assigned to receive three injections of either the LEISH-F1 + MPL-SE vaccine (consisting of 5, 10, or 20 μg recombinant Leishmania polyprotein LEISH-F1 antigen + 25 μg MPL^®-SE adjuvant) (n = 27), adjuvant alone (n = 8), or saline placebo (n = 9). The study injections were given subcutaneously on Days 0, 28, and 56, and the patients were followed through Day 336 for safety, immunological, and clinical evolution endpoints. All patients received chemotherapy with meglumine antimoniate starting on Day 0. The vaccine was safe and well tolerated. Nearly all vaccine recipients and no adjuvant-alone or placebo recipients demonstrated an IgG antibody response to LEISH-F1 at Day 84. Also at Day 84, 80% of vaccine recipients were clinically cured, compared to 50% and 38% of adjuvant-alone and placebo recipients. The LEISH-F1 + MPL-SE vaccine was safe and immunogenic in CL patients and appeared to shorten their time to cure when used in combination with meglumine antimoniate chemotherapy.