A double-blind, multi-centre, randomized, placebo-controlled cross-over clinical trial to assess the efficacy of doxyPEP in reducing the incidence of bacterial STIs among MSM and TGW living with HIV in Belgium

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Institute Of Tropical Medicine

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male

Therapeutic area

Diseases [C] - Bacterial Infections and Mycoses [C01]

Trial duration

5 Dec 2025 → ongoing

Decision date (initial)

2025-06-02

Transition trial

No

Low-intervention

Yes

Rare-disease indication

Yes

Vulnerable population

No

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Prophylaxis, Efficacy

Assess if there is a difference in the incidence rate of symptomatic Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT) and all Treponema pallidum (TP) infections among MSM and TGW living with HIV in Belgium whilst individuals are using doxyPEP compared with placebo.

Secondary objectives 10

1. Assess if there is a difference in antimicrobial consumption (tetracycline, macrolide, cephalosporin, penicillin) between arms
2. Assess if there is a difference in antimicrobial susceptibility of commensal Neisseria spp. and E. coli between arms
3. Assess if there is a difference in gut resistome/microbiome between arms
4. Assess if there is a difference in the incidence of symptomatic NG infections between arms
5. Assess if there is a difference in the incidence of symptomatic CT infections between arms
6. Assess if there is a difference in the incidence of symptomatic TP infections between arms
7. Assess if there is a difference in the incidence of all NG infections between arms
8. Assess if there is a difference in the incidence of all CT infections between arms
9. Assess if there is a difference in the incidence of TP infections between arms
10. Assess if there is a difference in tetracycline resistance among NG isolates between arms

Conditions and MedDRA coding

bacterial sexually transmitted infections

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 7

1. Able and willing to provide informed consent and adhere to the study procedures
2. Aged 18 years or older
3. Assigned male sex at birth
4. Identifying as gay, bisexual or other men who have sex with men or transgender women
5. Living with HIV
6. Having an undetectable viral load (<200 copies/mL) for 6 months or more
7. Having had at least one bacterial sexually transmitted infection in the preceding 24 months or having had >= 5 sex partners in the previous 6 months

Exclusion criteria 3

1. Hypersensitivity to doxycycline or other tetracyclines, any substance used in the IMP or placebo, or any of the excipients listed in section 6.1 of the SmPC.
2. Concomitant use of medication with significant interactions with doxycycline
3. Any contra-indication to the use of doxycycline, as mentioned in the summary of product characteristics

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. Incidence rate ratio of symptomatic NG, CT, and all TP infections in the doxyPEP vs placebo arms

Secondary endpoints 10

1. Rate ratio of tetracyclines, macrolides, cephalosporins, and penicillins in the doxyPEP vs placebo arms
2. MIC distribution (doxycycline/cefixime/ciprofloxacin) of commensal Neisseria spp. and E. coli in the doxyPEP vs placebo arms
3. Microbiota diversity, microbiota richness, abundance and diversity of Bifidobacteria, Fusobacterium, Lactobacillaceae, Enterobacteriaceae and Bacteroidaceae in both arms. Abundance of resistance genes (tetracyclines and other classes of antimicrobials) in both arms
4. Incidence rate ratio of symptomatic NG infections in the doxyPEP vs placebo arms
5. Incidence rate ratio of symptomatic CT infections in the doxyPEP vs placebo arms
6. Incidence rate ratio of symptomatic TP infections in the doxyPEP vs placebo arms
7. Incidence rate ratio of all NG infections in the doxyPEP vs placebo arms
8. Incidence rate ratio of all CT infections in the doxyPEP vs placebo arms
9. Incidence rate ratio of all TP infections in the doxyPEP vs placebo arms
10. Tetracycline MIC distribution of NG isolates in the doxyPEP vs placebo arms

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 1

Placebo 1

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Institute Of Tropical Medicine

Sponsor organisation

Institute Of Tropical Medicine

Address

Nationalestraat 155

City

Antwerp

Postcode

2000

Country

Belgium

Scientific contact point

Organisation

Institute Of Tropical Medicine

Contact name

Coordinating Investigator

Public contact point

Organisation

Institute Of Tropical Medicine

Contact name

Coordinating Investigator

Locations

1 EU/EEA country · 2 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 20 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

1 submissions — initial application plus substantial / non-substantial modifications