A Phase I Multicenter Clinical Trial to Evaluate the Safety and Immunogenicity of Immuno-AG Recombinant HIV gp160 in Asymptomatic HIV Seropositive Individuals

A Phase I Multicenter Clinical Trial to Evaluate the Safety and Immunogenicity of Immuno-AG Recombinant HIV gp160 in Asymptomatic HIV Seropositive Individuals

To determine the safety and immunogenicity of vaccinia-derived HIV-1 recombinant envelope glycoprotein (gp160) in asymptomatic HIV-infected adult volunteers. To compare safety and immunogenicity of two different schedules of gp160 administration. To examine the effects of gp160 and hepatitis B vaccine (Engerix-B) on various markers of viral load and on selected immune parameters.

Potentiation of a patient's immune response to HIV might possibly prolong the period of clinical latency and protect the patient indefinitely. Preliminary results from a study of Immuno-AG recombinant gp160 vaccine in healthy volunteers not infected with HIV suggest that the vaccine is safe and produces antibodies against the virus. Because another previous study failed to demonstrate a specific anti-HIV response in patients injected with a recombinant vaccinia virus containing HIV-1 genes, this study is also testing the immunotherapeutic role of other immunizations (such as hepatitis B vaccination) that would be expected to induce a nonspecific immune response in HIV-infected persons.

Potentiation of a patient's immune response to HIV might possibly prolong the period of clinical latency and protect the patient indefinitely. Preliminary results from a study of Immuno-AG recombinant gp160 vaccine in healthy volunteers not infected with HIV suggest that the vaccine is safe and produces antibodies against the virus. Because another previous study failed to demonstrate a specific anti-HIV response in patients injected with a recombinant vaccinia virus containing HIV-1 genes, this study is also testing the immunotherapeutic role of other immunizations (such as hepatitis B vaccination) that would be expected to induce a nonspecific immune response in HIV-infected persons.

Fifty-five healthy HIV-positive volunteers are randomly assigned to one of the following treatment arms: six injections (arm I) or four injections (arm II) of HIV-1 gp160 vaccine, four injections of hepatitis B vaccine as a non-HIV viral vaccine control (arm III), or six placebo injections consisting of the adjuvant vehicle used for the gp160 vaccine (arm IV). Immunizations or placebo are given at 4-week intervals for 5 months. To maintain blinding, adjuvant vehicle placebo is administered on days 84 and 112 to those volunteers receiving four instead of six vaccine injections (arms II and III). Volunteers are followed at 4-month intervals for 2 years.

Inclusion Criteria

Concurrent Medication: Recommended:

• Prophylaxis with isoniazid in patients not previously treated.

Patients must have:

• HIV seropositivity by Western blot.
• Normal history and physical exam (generalized lymphadenopathy is acceptable).
• Mean CD4 cell count = or > 600 cells/mm3 for all visits (minimum 2 counts) within 60 days prior to study entry, with no single count < 450 cells/mm3.
• Negative PPD test or normal chest x-ray with positive PPD (induration = or > 5 mm).

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms or conditions are excluded:

• Hepatitis B surface antigen positive.
• Evidence of an AIDS- or ARC-defining opportunistic infection.
• Evidence of disseminated tuberculosis, severe or persistent candidiasis, oral hairy leukoplakia, prolonged or very severe diarrhea, herpes zoster, or herpes simplex persisting more than one month.
• Active syphilis.

Patients with the following prior conditions are excluded:

• Evidence of psychiatric disorder within the past year that would impair adherence to the protocol.
• History of an AIDS- or ARC-defining opportunistic infection.
• History of disseminated tuberculosis, severe or persistent candidiasis, oral hairy leukoplakia, prolonged or very severe diarrhea, herpes zoster, or herpes simplex persisting more than one month.

Prior Medication:

Excluded:

• Immunomodulating agents (e.g., isoprinosine, imuthiol, lithium) within 90 days of screening.
• Immunosuppressive medications within the previous 3 months.
• Zidovudine (AZT) or any antiviral agent (including interferon) within the previous 6 months.
• Vaccination against other pathogens within 4 weeks of initial screening laboratory work.

Use of illicit drugs or significant amounts of alcohol that could significantly interfere with study compliance.