Effect of Antibiotics on Penile Microbiome and HIV Susceptibility Study in Ugandan Men

Study Overview
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Brief Summary
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This pilot study will assess the impact of four antimicrobial products (3 topical, one systemic) on the foreskin microbiome and HIV susceptibility of foreskin-derived CD4+ T cells. Participants will include HIV-uninfected Ugandan men presenting for elective male circumcision to reduce their HIV risk.

Detailed Description
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RATIONALE: The foreskin is the site of most HIV acquisition in uncircumcised heterosexual men, and male circumcision (MC) reduces HIV risk by almost 60%. However, cultural and practical barriers have led to suboptimal uptake. Foreskin inflammation, defined by elevated levels of pro-inflammatory cytokines in the prepuce, is a key determinant of HIV acquisition risk in uncircumcised men, and anaerobic bacteria within the foreskin microbiome may be an important cause of this inflammation. OBJECTIVES: A pilot in vivo - in vitro clinical study of four potential interventions to reduce HIV susceptibility in the foreskin by altering the microbiome. The study is a collaboration between the University of Toronto, IAVI-UVRI, and the Entebbe General Hospital. We will recruit 125 men presenting for elective MC, along with regular female sexual partners (if applicable). Participants will be randomized (n=25 per group) to immediate MC, or to one of four intervention arms: twice-daily application of topical metronidazole 0.75%; twice-daily application of topical clindamycin 2%; twice daily application of hydrogen peroxide 1%; or oral tinidazole 2g once a day for two days. Swabs for immune and microbiome studies will be collected before and after product. After 4 weeks the MC procedure will be performed; foreskin CD4+ T cell susceptibility to HIV will be quantified using a flow cytometry-based pseudovirus assay, and tissue immunohistochemistry performed. The primary and secondary endpoints are outlined below. A secondary study will assess the impact of penile topical antibiotic application on immunology and the microbiome in the genital tract of female sexual partners. OUTCOMES: This in vivo - in vitro clinical trial will define the causal role of the penile microbiome in HIV susceptibility, and will assess potential strategies to take forward into HIV efficacy trials in uncircumcised heterosexual men.

Official Title
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Testing the Ability of a Microbiome - Focused Intervention to Reduce HIV Susceptibility in Ugandan Men

Conditions
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Foreskin HIV Susceptibility

Intervention / Treatment
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* Drug: Oral Tinidazole
* Drug: Topical metronidazole
* Drug: Topical Clindamycin
* Drug: Topical Hydrogen Peroxide


Participation Criteria
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Eligibility Criteria
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Enrollment criteria include: Aged 18 years or older Biological male Uncircumcised HIV seronegative Willing to comply with the requirements of the protocol No current sexually transmitted infection (N. gonorrhoeae or C. trachomatis) No clinically relevant genital symptoms / signs

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Randomized, open label with 5 arms
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Control group<br>25 HIV-uninfected, uncircumcised men will be immediately circumcised following enrollment. This group will serve as the comparison to the four intervention groups. | |
| Active Comparator: Oral tinidazole group<br>25 HIV-uninfected, uncircumcised men will be randomized to receive oral tinidazole 2g once a day for two days. | Drug: Oral Tinidazole<br>* Please see description under arms<br>* Other names: FASIGYN 500mgs;|
| Active Comparator: Topical metronidazole (0.75%) group<br>25 HIV-uninfected, uncircumcised men will be randomized to apply topical 0.75% metronidazole cream to the foreskin twice a day for one week, and then twice a week for three weeks. | Drug: Topical metronidazole<br>* Please see description under arms<br>* Other names: Rozex 0.75%;|
| Active Comparator: Topical clindamycin (2%) group<br>25 HIV-uninfected, uncircumcised men will be randomized to apply topical 2% clindamycin cream to the foreskin twice a day for one week, and then twice a week for three weeks. | Drug: Topical Clindamycin<br>* Please see description under arms<br>* Other names: Dalacin cream 2%;|
| Active Comparator: Topical hydrogen peroxide (1%) group<br>25 HIV-uninfected, uncircumcised men will be randomized to apply 1% hydrogen peroxide cream to the foreskin twice a day for one week, and then twice a week for three weeks. | Drug: Topical Hydrogen Peroxide<br>* Please see description under arms<br>* Other names: Crystacide 1%;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| % HIV entry into foreskin derived CD4+ T cells | This measure will utilize a validated pseudovirus entry assay. | 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tissue density of HIV-susceptible CD4+ T cells | The density of CD4+ T cells in foreskin tissues will be assayed using immunohistochemistry, and the % pseudovirus entry (see primary endpoint, above) will be used to calculate the tissue density of HIV-susceptible CD4+ T cells. | 4 weeks | 
| CD4+ T cell subsets in foreskin tissue | Immunofluorescence microscopy (IF) will be used to quantify CD4+ T cell subsets foreskin tissue after circumcision. | 4 weeks | 
| Density of Langerhans cells in foreskin tissue | Immunofluorescence microscopy (IF) will be used to quantify Langerhans cells in foreskin tissue after circumcision. | 4 weeks | 
| Presence of foreskin inflammation | Cytokine/chemokines will be assayed by ELISA, and foreskin inflammation defined as the presence of ≥3/7 inflammatory cytokines within the top quartile for that cytokine. | 4 weeks | 
| Foreskin microbiome composition | The foreskin (prepuce) microbiome will be characterized based on 16S rRNA sequencing. | 4 weeks | 
| Foreskin tissue explant HIV susceptibility | Foreskin tissue susecptibility to HIV infection will be quantified, based on p24 ELISA after ex vivo incubation with a primary HIV isolate. | 4 weeks |