View clinical trials related to HIV Infections.
Filter by:Primary: To compare the pharmacokinetics of biweekly and monthly dose regimens of intravenous pentamidine in HIV-infected infants and children who require PCP prophylaxis and who are intolerant to oral trimethoprim - sulfamethoxazole. To determine the safety and tolerance of these regimens in this patient population. Secondary: To obtain information on the rate of PCP breakthrough in infants and children receiving parenteral pentamidine prophylaxis. Prophylaxis against Pneumocystis carinii pneumonia is recommended for all HIV-infected children considered to be at high risk. In children younger than 5 years of age with intolerance to trimethoprim - sulfamethoxazole, parenteral pentamidine may be a successful alternative.
Primary: To determine whether combination vaccination, i.e., priming with a vaccinia recombinant-containing HIV envelope (HIVAC-1e) followed by boosting with a recombinant subunit envelope protein (gp160 or gp120), provides enhanced immunogenicity compared to subunit vaccination with the individual recombinant envelope proteins only. To compare the relative immunogenicity of a panel of HIV envelope subunit vaccines when administered as boosters following recombinant HIV-vaccinia priming. To evaluate the relative immunogenicity of one versus two doses of recombinant HIV-vaccinia prior to the subunit protein boost. Secondary: To examine the safety of administering the individual subunit vaccines in combination with the HIV envelope vaccinia recombinant, and to extend the population to whom these proteins have been administered. Previous studies suggest that priming with an HIV-vaccinia recombinant followed by boosting with subunit envelope proteins offers the most promising strategy to date for a safe and immunogenic vaccine in humans. This study will further examine the combination vaccine approach and define an optimal prime-boost strategy.
To determine the relationship of viral susceptibility to zidovudine (AZT) and baseline viral load (as determined by plasma viremia and quantitative endpoint dilution). To determine the relationship between viral load and susceptibility during different antiretroviral therapy strategies. To correlate measures of viral load and short term clinical and laboratory markers (such as weight, CD4 count, p24 antigenemia, and beta2 microglobulin) on the different therapy arms. High-grade resistance to AZT has been detected in HIV isolates from approximately 25 percent of individuals with AIDS who received AZT for at least 1 year. To elucidate the clinical significance of in vitro AZT resistance, it is necessary to distinguish between clinical failure caused by AZT resistance and clinical decompensation caused by other factors.
Immunopathogenesis objectives: To compare and quantitatively determine HIV burden and HIV replication in peripheral blood (PB) and lymphoid tissue (LT). To determine the degree to which antiretroviral therapy alters HIV replication in LT. Clinical objectives: To gain insight into the degree of correlation between immunologic surrogate markers for HIV disease (e.g., CD4, beta-2 microglobulin) as compared to measures of HIV replication in PB and LT. To assess changes in PB and LT viral burden after antiretroviral therapy and to determine its ability to predict an antiviral response. One of the major problems in defining the immunopathogenic changes in HIV infections has been the inability to correlate the extent of loss of immunologic function with the number of HIV-infected CD4+ cells in the peripheral blood. Few studies exist that measure viral burden in lymph nodes of HIV-infected individuals. Researchers hope to find out whether the amount of HIV virus or markers for the virus in the body's lymph tissue is a better measure of disease progression than the amount of virus or markers for the virus in the blood.
PER 03/10/94 AMENDMENT: PART B. To determine whether there is an effect on plasma drug levels of azithromycin and rifabutin as measured by changes in the plasma concentration-time curve (AUC) when these drugs are taken concomitantly. ORIGINAL PRIMARY: To gain preliminary information about the safety and tolerance of clarithromycin and azithromycin in combination with rifabutin (three potential agents against Mycobacterium avium-intracellulare) in HIV-infected patients with CD4 counts < 200 cells/mm3. ORIGINAL SECONDARY: To determine whether there is an effect on the pharmacokinetics of the macrolide antibiotics or rifabutin when these drugs are taken concomitantly. To monitor the effect of rifabutin therapy on dapsone serum levels in patients taking dapsone for PCP prophylaxis. To monitor the effect of macrolide/rifabutin combination therapies on AZT or ddI serum levels. Two new macrolide antibiotics, clarithromycin and azithromycin, and rifabutin (a rifamycin derivative) have all demonstrated in vitro and in vivo activity against Mycobacterium avium-intracellulare, a common systemic bacterial infection complicating AIDS. Further information is needed, however, regarding the clinical and pharmacokinetic interaction of these drugs used in combination.
Primary: To compare the efficacy of zidovudine ( AZT ) given alone versus AZT plus didanosine ( ddI ) versus AZT plus zalcitabine ( dideoxycytidine; ddC ) in delaying the occurrence of AIDS-related conditions in HIV-infected patients. Secondary: To compare the frequency and severity of adverse experiences in the three regimens. To compare the mortality rates in the three regimens. To compare the effects of antiretroviral regimens on CD4+ cell levels. Studies have indicated that maintenance therapy with AZT over extended periods may be limited by dose-dependent toxicity, primarily myelosuppression, and by the emergence of drug-resistant HIV strains. It is anticipated that the combination of AZT with either ddI or ddC may promote higher antiviral efficacy, with acceptable toxicity and less likelihood of development of drug-resistant strains, than AZT alone.
AMENDED 10/1/93: To evaluate the influence of prior immunization with an rgp120 vaccine on immune response to a subsequent immunization with a different strain of rgp120 (VEU 009X extension - in patients previously enrolled on VEU 009). ORIGINAL DESIGN: To evaluate the clinical and immunologic safety of MN rgp120/HIV-1 vaccine (MN rgp120 vaccine) given alone or concurrently with the IIIB rgp120/HIV-1 vaccine (IIIB rgp120 vaccine) in healthy HIV-1 seronegative adult subjects. To compare the immune response to MN rgp120 vaccine given at 100, 300, or 600 mcg. To determine the immune response to 300 mcg MN rgp120 vaccine and 300 mcg IIIB rgp120 vaccine given concurrently. Recent studies suggest that immunity to the HIV-1 rgp120 protein may prevent primary infection. MN rgp120 vaccine and IIIB rgp120 vaccine are both prepared by recombinant DNA technology. Because the two vaccines are derived from distinct HIV-1 strains, they may elicit some immunologic responses that differ. Unlike IIIB rgp120 vaccine, the MN rgp120 vaccine has not yet been evaluated in humans, although it is expected that the MN type will result in similar safety and immunogenicity as the IIIB type.
AMENDED 11/17/93: To determine whether the pattern of response to MN rgp120 vaccine is altered by pre-exposure to IIIB rgp120. ORIGINAL DESIGN: To evaluate the safety (clinical and immunologic) of rgp120/HIV-1IIIB vaccine (gp120 vaccine) immunization in healthy HIV-1 seronegative adult subjects. To compare the immune response to 100 mcg gp120 vaccine versus 300 mcg gp120 vaccine. To determine whether gp120 vaccine immunization causes a significant immune response as defined by specific parameters (e.g., induction of neutralizing antibodies to the IIIB isolate of HIV-1, gp120 antigen-specific lymphocytic proliferation). Recent evidence suggests that gp120 is the HIV-1 protein with the greatest potential as a vaccine against HIV-1 infection. The gp120 envelope protein may be produced by recombinant DNA technology, and studies have shown that the vaccine is capable of eliciting neutralizing antibody activity in both rodents and nonhuman primate species.
Part A: To compare the safety and immunogenicity of two dose levels of gp120 (CHO) in MF59 emulsion alone or with MTP-PE/MF59 adjuvant, administered at 0, 1, and 6 months. Part B: To evaluate the safety and immunogenicity of gp120 in MF59 when administered in five monthly injections. One experimental AIDS vaccine is the gp120 vaccine. The HIV envelope glycoprotein 120 is manufactured through recombinant DNA technology and used as an immunogen. Antibodies directed against gp120 can neutralize HIV-1, and gp120 can also stimulate certain types of cell-mediated immune responses. Because many immunogens, including candidate HIV vaccines, may evoke relatively weak immune responses, the use of adjuvants, or substances that augment immune responses to vaccines, is of interest. MTP-PE/MF59, composed of the immunomodulator MTP-PE combined with MF59 emulsion, appears to be a promising adjuvant and has been selected for studies with the gp120 vaccine.
To determine the pharmacokinetic profile of single doses of letrazuril in patients with AIDS-related cryptosporidial diarrhea; to determine the dose proportionality of single escalating doses of letrazuril; to determine steady-state concentrations of letrazuril; to evaluate the safety and efficacy of escalating doses of letrazuril, compared with placebo, for patients with AIDS-related cryptosporidial diarrhea. Letrazuril, the p-fluor analog of diclazuril, has been shown in an animal model to prevent infections by organisms closely related to the intracellular parasite Cryptosporidium. Reliable data are needed to show the effectiveness of letrazuril in treating AIDS-related cryptosporidial diarrhea.