Participate

Participants will be recruited from clinical sites with a high proportion of eligible participants in Vancouver, Calgary, Toronto, Hamilton, Ottawa, and Montreal.

For recruitment inquiries, visit Contact Us

Participants must be at least 18 years of age, must have any sexual activity with more than one male partner in the preceding 12 months, have the intention to remain sexually active with more than one male partner in the next 12 months, and at least one prior episode of a previously diagnosed syphilis, gonorrhea or chlamydia infection within 12 months prior to starting the study.

Potential participants will be screened by the site study coordinator using an inclusion/exclusion checklist at a scheduled Screening visit. Eligible participants will then be randomized and commence a schedule of study visits: baseline, week 4, week 12, week 24, week 36, week 48, and week 60. At baseline, participants will be randomized in a 1:1 fashion to one of two groups:

  1. STI PrEP arm: doxycycline capsules 100mg orally daily for 48 weeks.
  2. STI PEP arm: doxycycline 200mg orally once within 24-72 hours following each sexual encounter deemed at risk (i.e. condomless anal or oral sex), to a maximum of six pills (i.e. 600 mg total) per week

Note*: All participants will receive standard of care resources/material: condoms, sexual health and STI education, risk reduction counselling and STI testing.

The following will be collected during study visits: (1) demographic information (age, sex, ethnicity, etc.); (2) HIV information (only for participants living with HIV: year of diagnosis, treatment details, CD4 and viral load data); (3) medical history; (4) current medication list; (5) sexual behaviours over the last 3 months; and, (6) STI testing. At baseline, weeks 24, and 48, rectal swabs for microbiome analysis will be collected. Table 1 describes the specific testing and data collected at each study visit.

All participants will receive $50 for baseline and final visits, and $20 honorarium for all other visits.

Table 1. Study Visit Schedule

Study Weeks

 

W0

W4

W12

W24

W36

W48

W60

Study Visits

Screening

 

Baseline

(+/- 3 d)

V3

(+/-7d)

V4

(+/- 7d)

V5

(+/- 14d)

V6

(+/- 14d)

V7

(+/- 14d)

V8

(+/- 14d)

Visit Duration (hours)

0.5

1

1

1

1

1

1

1

Informed Consent Form

X

 

 

 

 

 

 

 

Eligibility Criteria Assessment

X*

 

 

 

 

 

 

 

Medical History

 

X

 

 

 

 

 

X

Alcohol, Drug, and Smoking History

 

X

 

 

 

 

 

 

Demographics Information

 

X

 

 

 

 

 

 

Concurrent Medication Review

 

X

X

X

X

X

X

X

 

Randomization

 

X

 

 

 

 

 

 

Initiation of Doxycycline1

 

X1

 

 

 

 

 

 

Adherence pill count1

 

 

X1

X1

X1

X1

X1

 

Adverse event Review

 

 

X

X

X

X

X

X

Targeted Physical Exam

 

X

X

X

X

X

X

X

Bloodwork

(CBC and differential, Creatinine, ALT)

X

 

X

X

X

X

X

X

Syphilis, Gonorrhea, Chlamydia Screens2

 

X

X

X

X

X

X

X

HIV serology3

 

x

x

x

x

x

x

x

Doxycycline Level1

 

 

X1

X1

X1

X1

X1

 

Rectal Swab for Microbiome

 

X

 

 

X

 

X

 

Nasal/Throat Swabs for Microbiology

 

 

X

 

 

X

 

X

 

Sexual History Questionnaire

 

X

 

X

X

X

X

X

Adherence questionnaires:

  • For STI PrEP participants: ACTG1 & Simple Medication1
  • For STI PEP participants: Adherence questionnaire

 

 

X1

X1

X1

X1

X1

 

Alcohol and Drug Use Questionnaires

 

X

 

X

X

X

X

 

Depression Risk Questionnaire

 

X

 

 

 

 

 

 

Abbreviations: ALT, alanine aminotransferase; CBCD, complete blood count with differential; CT, Chlamydia trachomatis; GC, Neisseria gonorrhoeae; NAAT, nucleic acid amplification test; PCR, polymerase chain reaction; STI, sexually transmitted infection.

1 For STI PrEP and PEP groups only

2 If anogenital lesions present, anal and mouth swab will be collected for CT/GC NAAT and syphilis PCR (testing to detect the bacteria’s genetic material once after it is amplified.)

3 For participants who are HIV-negative

Note*: If you do not meet the eligibility criteria, you will not be asked to provide the remaining information for the baseline visit.

 

For recruitment inquiries, visit Contact Us

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