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Trial of Azithromycin vs. Doxycycline for the Treatment of Rectal Chlamydia in MSM

A Phase 4, Randomized, Double-Blinded, Placebo-Controlled Trial of Azithromycin Versus Doxycycline for the Treatment of Rectal Chlamydia in Men Who Have Sex With Men

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03608774
Enrollment
177
Registered
2018-08-01
Start date
2018-07-13
Completion date
2020-02-21
Last updated
2021-01-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Anal Chlamydia Infection

Keywords

Azithromycin, Doxycycline, Efficacy, MSM, Phase 4, Rectal Chlamydia

Brief summary

A clinical trial to compare the efficacy of azithromycin (Arm 1) vs. doxycycline (Arm 2) administered per CDC's STD Treatment Guidelines for rectal Chlamydia trachomatis (CT) in men who have sex with men (MSM). Subjects will be males aged = / \> 18 years with a microbiologically confirmed diagnosis of rectal CT and at least one male sex partner in the past 12 months. The trial will be conducted at two sites in the US and will enroll up to 274 total subjects to achieve 246 subjects who contribute to the primary analysis. The duration of this study will be approximately 16 months 22 months with subject participation duration 29 days. The primary objective of this study is to compare the efficacy of azithromycin vs. doxycycline for treatment of rectal CT infection in MSM based on microbiologic cure (negative NAAT) at Day 29.

Detailed description

A Phase 4, multi-center, randomized, double-blinded, placebo-controlled trial to compare the efficacy of azithromycin (Arm 1) vs. doxycycline (Arm 2) administered per CDC's STD Treatment Guidelines for rectal Chlamydia trachomatis (CT) in men who have sex with men (MSM). The effect of Lymphogranuloma Venereum (LGV) infection on microbiologic cure in MSM with rectal CT will also be assessed. Arm 1 will comprise of subjects receiving 1 gram of Azithromycin (4 capsules of 250 mg) orally as a single dose, and Doxycycline placebo (1 capsule) orally twice daily for 7 days. Arm 2 will comprise of subjects receiving 100 mg of Doxycycline (1 capsule) administered orally twice daily for 7 days, and Azithromycin placebo (4 capsules) administered orally as a single dose. Subjects will be males aged = / \>18 years with a microbiologically confirmed diagnosis of rectal CT and at least one male sex partner in the past 12 months. The trial will be conducted at two sites in the US and will enroll up to 274 total subjects to achieve 246 subjects who contribute to the primary analysis. The duration of this study will be approximately 22 months with subject participation duration 29 days. The primary objective of this study is to compare the efficacy of azithromycin vs. doxycycline for treatment of rectal CT infection in MSM based on microbiologic cure (negative NAAT) at Day 29. The secondary objectives are: 1) to assess the effect of LGV infection on microbiologic cure in MSM with rectal CT at Days 15 and 29 and 2) to compare the efficacy of azithromycin vs. doxycycline for treatment of rectal CT in MSM based on microbiologic cure at Day 15.

Interventions

DRUGAzithromycin

Azithromycin monohydrate is a macrolide antibacterial drug, FDA-approved in the US for the treatment of Chlamydia trachomatis (CT) in dose 1 gram (4 capsules of 250 mg), administered orally as a single dose.

DRUGDoxycycline

Doxycycline hyclate is an antibacterial drug synthetically derived from oxytetracycline, FDA-approved in the US for the treatment of Chlamydia trachomatis (CT) as a course of 100 mg (1 capsule), administered orally twice daily for 7 days.

OTHERPlacebo

Azithromycin placebo (4 capsules), administered orally as a single dose; Doxycycline placebo (1 capsule), administered orally twice daily for 7 days.

Sponsors

National Institute of Allergy and Infectious Diseases (NIAID)
Lead SponsorNIH

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
MALE
Age
18 Years to 99 Years
Healthy volunteers
No

Inclusion criteria

1. Willing and able to understand and provide written informed consent before initiation of any study procedures. 2. Willing and able to comply with planned study procedures for all study visits. 3. Male sex at birth and aged = / \> 18 years with valid contact information. 4. At least one male sex partner (oral or anal) in the past 12 months. 5. Untreated rectal CT diagnosed by a positive NAAT result. 6. Willingness to abstain from condomless receptive anal sex during the trial. 7. Willingness to complete a 7-day study drug regimen.

Exclusion criteria

1. Current clinical diagnosis of acute proctitis per the CDC's 2015 STD Treatment Guidelines: symptoms of anorectal pain, tenesmus, and/or rectal discharge with anoscopy findings confirming inflammation. 2. Concomitant untreated gonorrhea (rectal, pharyngeal, or urethral) or known exposure to gonorrhea in the time between CT testing and study enrollment. 3. Clinical diagnosis of concomitant untreated primary or secondary syphilis. 4. Known allergy to tetracyclines or macrolides. 5. Received antimicrobial therapy active against C. trachomatis within 21 days of positive rectal CT NAAT result, or between the positive CT NAAT result and study enrollment\*. \*This includes subjects treated empirically on the day of testing due to known exposure to gonorrhea or chlamydia, as well as enrollment in another study using antimicrobial therapy active against C. trachomatis, or planned enrollment in such a study during their time in this trial. Specifically, use of the following antibiotics is an exclusion criterion: azithromycin and other macrolides, doxycycline and related tetra- or glycylcyclines, fluoroquinolones, rifampin, quinupristin-dalfopristin, and linezolid. 6. Plans to move to another location that would preclude study follow-up appointments in clinic or by mail-in in the next 30 days. 7. Use of any investigational drug contraindicated to treatment with azithromycin or doxycycline within 7 days before enrollment. 8. Previous enrollment in this trial. 9. Any other condition that, in the opinion of the investigator, would interfere with participation in the trial.

Design outcomes

Primary

MeasureTime frameDescription
The Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) at Day 29Day 29Microbiologic cure was based on rectal CT (Chlamydia trachomatis) NAAT (nucleic acid amplification test) result. The proportion of subjects with microbiologic cure in each study arm at Day 29 is reported in this outcome measure.

Secondary

MeasureTime frameDescription
The Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) at Day 15Day 15Microbiologic cure was based on rectal CT (Chlamydia trachomatis) NAAT (nucleic acid amplification test) result. The proportion of subjects with microbiologic cure in each study arm at Day 15 is reported in this outcome measure.
The Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of Non-LGV (Lymphogranuloma Venereum) Infected at BaselineDay 15Microbiologic cure was based on rectal CT (Chlamydia trachomatis) NAAT (nucleic acid amplification test) result. The proportion of subjects with microbiologic cure in each study arm at Day 15 is reported in this outcome measure. LGV strains of CT were identified via multiplex PCR (Polymerase Chain Reaction) on positive CT NAAT specimens.
The Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of LGV (Lymphogranuloma Venereum) Infected at BaselineDay 15Microbiologic cure was based on rectal CT (Chlamydia trachomatis) NAAT (nucleic acid amplification test) result. The proportion of subjects with microbiologic cure in each study arm at Day 15 is reported in this outcome measure. LGV strains of CT were identified via multiplex PCR (Polymerase Chain Reaction) on positive CT NAAT specimens.

Countries

United States

Participant flow

Recruitment details

Participants recruited for the study were men who have sex with men diagnosed with rectal chlamydia based on a positive rectal Chlamydia trachomatis (CT) nucleic acid amplification test (NAAT) result. The first participant was enrolled on 13 July 2018, and the last participant was enrolled in January 2020.

Participants by arm

ArmCount
Azithromycin + Doxycycline Placebo
1 gram of Azithromycin (4 capsules of 250 mg) administered orally as a single dose on Day 1, and Doxycycline placebo (1 capsule) administered orally twice daily for 7 days starting on Day 1. N=89 Azithromycin: Azithromycin monohydrate is a macrolide antibacterial drug, FDA-approved in the US for the treatment of Chlamydia trachomatis (CT) in dose 1 gram (4 capsules of 250 mg), administered orally as a single dose. Placebo: Doxycycline placebo (1 capsule), administered orally twice daily for 7 days.
89
Doxycycline + Azithromycin Placebo
100 mg of Doxycycline (1 capsule) administered orally twice daily for 7 days starting on Day 1, and Azithromycin placebo (4 capsules) administered orally as a single dose on Day 1. N=88 Doxycycline: Doxycycline hyclate is an antibacterial drug synthetically derived from oxytetracycline, FDA-approved in the US for the treatment of Chlamydia trachomatis (CT) as a course of 100 mg (1 capsule), administered orally twice daily for 7 days. Placebo: Azithromycin placebo (4 capsules), administered orally as a single dose.
88
Total177

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyHealth related event01
Overall StudyLost to Follow-up55
Overall StudyNot eligible at enrollment01
Overall StudyProtocol Violation10
Overall StudyWithdrawal by Subject10

Baseline characteristics

CharacteristicAzithromycin + Doxycycline PlaceboDoxycycline + Azithromycin PlaceboTotal
Age, Continuous33.6 years
STANDARD_DEVIATION 10.8
33.9 years
STANDARD_DEVIATION 11.6
33.7 years
STANDARD_DEVIATION 11.2
Ethnicity (NIH/OMB)
Hispanic or Latino
16 Participants21 Participants37 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
71 Participants67 Participants138 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
2 Participants0 Participants2 Participants
Inguinal Lymphadenopathy
No
86 Participants83 Participants169 Participants
Inguinal Lymphadenopathy
Not Available
0 Participants1 Participants1 Participants
Inguinal Lymphadenopathy
Yes
3 Participants4 Participants7 Participants
Race (NIH/OMB)
American Indian or Alaska Native
1 Participants1 Participants2 Participants
Race (NIH/OMB)
Asian
10 Participants12 Participants22 Participants
Race (NIH/OMB)
Black or African American
3 Participants5 Participants8 Participants
Race (NIH/OMB)
More than one race
16 Participants6 Participants22 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
2 Participants1 Participants3 Participants
Race (NIH/OMB)
Unknown or Not Reported
3 Participants5 Participants8 Participants
Race (NIH/OMB)
White
54 Participants58 Participants112 Participants
Rectal CT Symptomatic Status
Asymptomatic
71 Participants74 Participants145 Participants
Rectal CT Symptomatic Status
Not Available
0 Participants1 Participants1 Participants
Rectal CT Symptomatic Status
Symptomatic
18 Participants13 Participants31 Participants
Region of Enrollment
United States
89 participants88 participants177 participants
Sex: Female, Male
Female
0 Participants0 Participants0 Participants
Sex: Female, Male
Male
89 Participants88 Participants177 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 890 / 87
other
Total, other adverse events
0 / 00 / 0
serious
Total, serious adverse events
0 / 891 / 87

Outcome results

Primary

The Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) at Day 29

Microbiologic cure was based on rectal CT (Chlamydia trachomatis) NAAT (nucleic acid amplification test) result. The proportion of subjects with microbiologic cure in each study arm at Day 29 is reported in this outcome measure.

Time frame: Day 29

Population: The Complete Case population included randomized subjects who met all inclusion/exclusion criteria at enrollment, had a positive baseline rectal CT NAAT result, and had a Day 29 microbiologic result available.

ArmMeasureValue (NUMBER)
Azithromycin + Doxycycline PlaceboThe Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) at Day 290.74 proportion of participants
Doxycycline + Azithromycin PlaceboThe Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) at Day 291.00 proportion of participants
p-value: <0.00195% CI: [0.16, 0.36]Chi-squared
Secondary

The Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) at Day 15

Microbiologic cure was based on rectal CT (Chlamydia trachomatis) NAAT (nucleic acid amplification test) result. The proportion of subjects with microbiologic cure in each study arm at Day 15 is reported in this outcome measure.

Time frame: Day 15

Population: The Complete Case population included randomized subjects who met all inclusion/exclusion criteria at enrollment, had a positive baseline rectal CT NAAT result, and had a Day 15 microbiologic result available.

ArmMeasureValue (NUMBER)
Azithromycin + Doxycycline PlaceboThe Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) at Day 150.84 proportion of participants
Doxycycline + Azithromycin PlaceboThe Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) at Day 150.94 proportion of participants
95% CI: [0, 0.22]
Secondary

The Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of LGV (Lymphogranuloma Venereum) Infected at Baseline

Microbiologic cure was based on rectal CT (Chlamydia trachomatis) NAAT (nucleic acid amplification test) result. The proportion of subjects with microbiologic cure in each study arm at Day 15 is reported in this outcome measure. LGV strains of CT were identified via multiplex PCR (Polymerase Chain Reaction) on positive CT NAAT specimens.

Time frame: Day 15

Population: The Complete Case population included randomized subjects who met all inclusion/exclusion criteria at enrollment, had a positive baseline rectal CT NAAT result, had a baseline LGV infection status result, and had a post-baseline microbiologic result available. Furthermore, participants in this subgroup analyses were LGV infected at baseline.

ArmMeasureValue (NUMBER)
Azithromycin + Doxycycline PlaceboThe Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of LGV (Lymphogranuloma Venereum) Infected at Baseline0.75 proportion of participants
Doxycycline + Azithromycin PlaceboThe Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of LGV (Lymphogranuloma Venereum) Infected at Baseline1.00 proportion of participants
95% CI: [-0.28, 0.7]
Secondary

The Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of LGV (Lymphogranuloma Venereum) Infected at Baseline

Microbiologic cure was based on rectal CT (Chlamydia trachomatis) NAAT (nucleic acid amplification test) result. The proportion of subjects with microbiologic cure in each study arm at Day 29 is reported in this outcome measure. LGV strains of CT were identified via multiplex PCR (Polymerase Chain Reaction) on positive CT NAAT specimens.

Time frame: Day 29

Population: The Complete Case population included randomized subjects who met all inclusion/exclusion criteria at enrollment, had a positive baseline rectal CT NAAT result, had a baseline LGV infection status result, and had a post-baseline microbiologic result available. Furthermore, participants in this subgroup analyses were LGV infected at baseline.

ArmMeasureValue (NUMBER)
Azithromycin + Doxycycline PlaceboThe Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of LGV (Lymphogranuloma Venereum) Infected at Baseline0.75 proportion of participants
Doxycycline + Azithromycin PlaceboThe Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of LGV (Lymphogranuloma Venereum) Infected at Baseline1.00 proportion of participants
95% CI: [-0.28, 0.7]
Secondary

The Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of Non-LGV (Lymphogranuloma Venereum) Infected at Baseline

Microbiologic cure was based on rectal CT (Chlamydia trachomatis) NAAT (nucleic acid amplification test) result. The proportion of subjects with microbiologic cure in each study arm at Day 15 is reported in this outcome measure. LGV strains of CT were identified via multiplex PCR (Polymerase Chain Reaction) on positive CT NAAT specimens.

Time frame: Day 15

Population: The Complete Case population included randomized subjects who met all inclusion/exclusion criteria at enrollment, had a positive baseline rectal CT NAAT result, had a baseline LGV infection status result, and had a post-baseline microbiologic result available. Furthermore, participants in this subgroup analyses were non-LGV infected at baseline.

ArmMeasureValue (NUMBER)
Azithromycin + Doxycycline PlaceboThe Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of Non-LGV (Lymphogranuloma Venereum) Infected at Baseline0.84 proportion of participants
Doxycycline + Azithromycin PlaceboThe Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of Non-LGV (Lymphogranuloma Venereum) Infected at Baseline0.94 proportion of participants
95% CI: [-0.01, 0.21]
Secondary

The Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of Non-LGV (Lymphogranuloma Venereum) Infected at Baseline

Microbiologic cure was based on rectal CT (Chlamydia trachomatis) NAAT (nucleic acid amplification test) result. The proportion of subjects with microbiologic cure in each study arm at Day 29 is reported in this outcome measure. LGV strains of CT were identified via multiplex PCR (Polymerase Chain Reaction) on positive CT NAAT specimens.

Time frame: Day 29

Population: The Complete Case population included randomized subjects who met all inclusion/exclusion criteria at enrollment, had a positive baseline rectal CT NAAT result, had a baseline LGV infection status result, and had a post-baseline microbiologic result available. Furthermore, participants in this subgroup analyses were non-LGV infected at baseline.

ArmMeasureValue (NUMBER)
Azithromycin + Doxycycline PlaceboThe Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of Non-LGV (Lymphogranuloma Venereum) Infected at Baseline0.74 proportion of participants
Doxycycline + Azithromycin PlaceboThe Proportion of Subjects With Microbiologic Cure (Negative Rectal CT NAAT Result) Within the Subgroup of Non-LGV (Lymphogranuloma Venereum) Infected at Baseline1.00 proportion of participants
95% CI: [0.15, 0.38]

Source: ClinicalTrials.gov · Data processed: Feb 16, 2026