Safety and Immunogenicity of a Vaccine for Cutaneous Leishmaniasis Using Recombinant Human Interleukin-12 and Aluminum Hydroxide Gel as Adjuvants

While vaccination against cutaneous leishmaniasis, a chronic ulcerating protozoan infection of the skin, has been possible for decades using live parasites, the production and storage of live cultures are difficult. Since inoculation occasionally leads to severe infection, most experts now advocate against their use. We have shown excellent protection using a "heat-killed" vaccine that combines autoclaved leishmania antigen with recombinant human interleukin-12 (rhIL-12) and aluminum hydroxide gel as adjuvants in a rhesus macaque model of disease. To assess the safety and immunogenicity of this vaccine in humans, we now propose a rhIL-12 dose escalation Phase I/II trial.

While vaccination against cutaneous leishmaniasis, a chronic ulcerating protozoan infection of the skin, has been possible for decades using live parasites, the production and storage of live cultures are difficult. Since inoculation occasionally leads to severe infection, most experts now advocate against their use. We have shown excellent protection using a "heat-killed" vaccine that combines autoclaved leishmania antigen with recombinant human interleukin-12 (rhIL-12) and aluminum hydroxide gel as adjuvants in a rhesus macaque model of disease. To assess the safety and immunogenicity of this vaccine in humans, we now propose a rhIL-12 dose escalation Phase I/II trial.

Eligibility Criteria:
Male or non-pregnant female 18 - 50 years of age at the time of screening and willing to use effective birth control for one month post vaccination.

Free of obvious health problems as established by medical history and clinical examination before entering into the study.

Available to participate for the duration of the study (approximately 6 months).

Able to give signed informed consent.

May not have received an investigational leishmania vaccine or skin test, or recombinant human interleukin-12.

No use of an investigational drug or any vaccine other than the study vaccine within 30 days preceding the dose, or planned use during the study period.

No administration of chronic immunosuppressants (defined as more than 14 days) or other immune-modifying drugs within six months of vaccination. (For corticosteroids, this will mean prednisone, or equivalent, greater than 0.5 mg/kg/day. Inhaled and topical steroids are allowed.)

No history of prior leishmaniasis or of extensive travel to regions endemic for leishmaniasis, such as southern Mexico, Central and most of South America, the Mediterranean region and Middle East, Africa, and India.

No confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (HIV) infection.

No family history of congenital or hereditary immunodeficiency.

No history of significant allergic disease or reactions likely to be exacerbated by any component.

No acute disease at the time of enrollment, defined as the presence of a moderate or severe illness with or without fever.

No acute or chronic, clinically significant pulmonary, cardiovascular, hepatic or renal function abnormality, as determined by physical examination or laboratory screening tests.

No pregnant or lactating females.

Must not have suspected or known alcohol or drug abuse.

No other significant finding that, in the opinion of the investigator, would increase the risk of having an adverse outcome from participating in this study.