Safety, False-Positive Reactions and Sensitizing Properties of Leishmania Tropica Skin Test Antigen

Nielsen BioSciences

Status and phase: Completed; Phase 2

Conditions: Cutaneous Leishmaniasis

Treatments: Biological: Leishmania tropica Skin Test Antigen Placebo (Placebo); Biological: Leishmania tropica Skin Test Antigen (LtSTA)

Study type: Interventional

Funder types: Industry; Other U.S. Federal agency

Identifiers

NCT00633009

LtSTA-08

Details and patient eligibility

About

The efficacy of LtSTA as a skin test antigen depends upon the sensitivity and specificity of the product. This study has been designed to measure the skin test responses to 15, 30, or 50µg doses of LtSTA. The measurements of non-specific reactivity due to components of the antigen solution and the product's ability to sensitize lymphocytes of Leishmania naïve persons when administered intradermally. The presence or absence of a local inflammatory response to the first skin test with each of three doses of LtSTA will provide insight on the specificity of the antigen in a naïve population. The local inflammatory response to LtSTA following the first and second repeat skin tests will indicate if the antigen is sensitizing after intradermal administration.

Enrollment: 50 patients

Sex: All

Ages: 18 to 60 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Male or Female in good health;
• Age 18 - 60 years;
• No past history of leishmaniasis or prior participation in a Leishmania study;
• No prior skin test with a Leishmania antigen;
• No occupational, residential, or travel exposure to Leishmania;
• Positive Candin® or Trichophyton skin test (>= 5 mm induration).

Exclusion criteria

• History of adult atopic dermatitis, contact dermatitis to multiple agents, unexplained urticaria, or asthma;

• Active allergic rhinitis or conjunctivitis;

• History of allergy or reactions to phenol, polysorbate 80, or glycerol;

• Medications: currently taking (within the last month) antihistamines or recent history of taking (within the last 1 year) corticosteroids, immunosuppressants;

• Splenectomy;

• Active medical disease*;

  *Active Medical Disease: Any active physical or psychiatric condition that may increase the risks associated with participation in the study or interferes with the interpretation of study results. Included chronic medical illnesses are cardiovascular disease, renal insufficiency, chronic respiratory illness, cirrhosis, chronic hepatitis, chronic pancreatitis, chronic diarrhea, malnutrition, malignancy, autoimmune disease, and asthma.

• Pregnancy or lactating;

• Immunization within 4 weeks;

• History of leishmaniasis;

• Occupational exposure to Leishmania;

• Prior participation in a Leishmania study;

• Prior skin test with Leishmania antigen;

• Travel history to Leishmania endemic areas;

• Abnormal screening lab results;

• Keloid scar formation

Trial design

Primary purpose: Screening

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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50 participants in 3 patient groups

LtSTA 15 ug

Active Comparator group

Description:

Naive volunteers tested with 15 ug injection of LtSTA. Participants were skin tested on visits 3, 6 and 9 of the study. The results of the skin tests were read after 48 hours (+/- 6 hours) on visits 4, 7 and 10. A final evaluation was performed on visit 11, fourteen days after visit 10.

Treatment:

Biological: Leishmania tropica Skin Test Antigen Placebo (Placebo)

Biological: Leishmania tropica Skin Test Antigen (LtSTA)

LtSTA 30 ug

Active Comparator group

Description:

Naive volunteers tested with 30 ug injection of LtSTA.Participants were skin tested on visits 3, 6 and 9 of the study. The results of the skin testes were read after 48 hours (+/- 6 hours) on visits 4, 7 and 10. A final evaluation was performed on visit 11, fourteen days after visit 10.

Treatment:

Biological: Leishmania tropica Skin Test Antigen Placebo (Placebo)

Biological: Leishmania tropica Skin Test Antigen (LtSTA)

LtSTA 50 ug

Active Comparator group

Description:

Naive volunteers tested with 50 ug injection of LtSTA.Participants were skin tested on visits 3, 6 and 9 of the study. The results of the skin testes were read after 48 hours (+/- 6 hours) on visits 4, 7 and 10. A final evaluation was performed on visit 11, fourteen days after visit 10.

Treatment:

Biological: Leishmania tropica Skin Test Antigen Placebo (Placebo)

Biological: Leishmania tropica Skin Test Antigen (LtSTA)