Randomized Directly Observed Therapy Study to Interpret Clinical Trials of Doxy-PEP (DOT-Doxy-PEP)

Rates of bacterial sexually transmitted infections (STIs) are rising globally, demanding innovative interventions beyond the scope of current efforts to prevent STIs. The United States Doxycycline Post-exposure Prophylaxis (DoxyPEP) Study has demonstrated the efficacy of doxycycline post-exposure prophylaxis (PEP) among men who have sex with men and transgender women; but puzzlingly, doxycycline PEP was found ineffective in cisgender women in the Kenyan doxycycline Post-Exposure Prophylaxis (dPEP) study, with preliminary data suggesting the low medication adherence may explain the null result. By study end, the investigators will have developed adherence measurement methods for doxycycline in hair, blood, and urine, and will use these techniques to help interpret the Kenyan dPEP study, and to examine the relative performance of these methods within the United States DoxyPEP trial, establishing adherence metrics for current and future rollout studies of doxycycline post-exposure prophylaxis

Study Overview

• Status: Not yet recruiting
• Conditions: Sexually Transmitted Diseases, Bacterial
• Intervention / Treatment: Drug: Doxycycline Pill

• Study Type: Interventional
• Enrollment (Estimated): 48
• Phase: Early Phase 1

Contacts and Locations

• Study Contact: Name: Kevin Sassaman; Phone Number: 415-878-6384; Email: DOTDoxyPEP@ucsf.edu

Study Locations

• United States
  • California
    • San Francisco, California, United States, 94110
      • University of California, San Francisco/San Francisco General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• not currently at risk of a sexually transmitted infection (no STI in the last 2 years and no partner with an STI in the last year);
• willing to provide hair, blood, and urine samples;
• not currently enrolled in other STI prevention studies;
• able to speak English or Spanish; and
• transgender women participants should be currently using estrogen gender affirming hormone therapy with blood estrogen levels demonstrating consistent use
• transgender men participants should be currently using testosterone gender affirming hormone therapy with blood testosterone levels demonstrating consistent use

Exclusion Criteria:

• any health condition that may interfere with participation or the ability to provide informed consent, including any debilitating or life-threatening conditions;
• pregnancy or plans to become pregnant;
• liver cirrhosis or fulminant liver disease;
• known hypersensitivity reaction to doxycycline.
• detectable doxycycline in hair at enrollment.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Daily Dosing; Participants will be randomized to take once daily doxycycline 200mg for six weeks.	Drug: Doxycycline Pill; 200mg Dose
Active Comparator: Three-times Weekly Dosing; Participants will be randomized to take one doxycycline 200mg dose three times a week (Monday, Wednesday, and Friday) for six weeks.	Drug: Doxycycline Pill; 200mg Dose
Active Comparator: Weekly Dosing; Participants will be randomized to take one doxycycline 200mg dose once week.	Drug: Doxycycline Pill; 200mg Dose
Active Comparator: Every Other Week Dosing; Participants will be randomized to take one doxycycline 200mg dose every other week.	Drug: Doxycycline Pill; 200mg Dose

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hair Doxycycline Concentration	Doxycycline concentrations will be measured using liquid chromatography tandem mass spectrometry within hair samples for each of the four dosing patterns within an intensive washout pharmacokinetic phase following initial dosing.	4 weeks
Plasma Doxycycline Concentration	Doxycycline concentrations will be measured using liquid chromatography tandem mass spectrometry within plasma samples for each of the four dosing patterns within an intensive washout pharmacokinetic phase following initial dosing.	4 weeks
Urine Doxycycline Concentration	Doxycycline concentrations will be measured using liquid chromatography tandem mass spectrometry within urine samples for each of the four dosing patterns within an intensive washout pharmacokinetic phase following initial dosing.	4 weeks

Collaborators and Investigators

• Sponsor: University of California, San Francisco
• Investigators: Principal Investigator: Matthew Spinelli, MD, MAS, University of California, San Francisco

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2024
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): September 1, 2028

Study Registration Dates

• First Submitted: May 9, 2024
• First Submitted That Met QC Criteria: May 13, 2024
• First Posted (Actual): May 16, 2024

Study Record Updates

• Last Update Posted (Actual): May 16, 2024
• Last Update Submitted That Met QC Criteria: May 13, 2024
• Last Verified: May 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Infections; Communicable Diseases; Disease Attributes; Bacterial Infections; Bacterial Infections and Mycoses; Urogenital Diseases; Genital Diseases; Sexually Transmitted Diseases; Sexually Transmitted Diseases, Bacterial; Anti-Infective Agents; Anti-Bacterial Agents; Antiprotozoal Agents; Antiparasitic Agents; Antimalarials; Doxycycline
• Other Study ID Numbers: AI186641

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No