Trial of Azithromycin vs. Doxycycline for the Treatment of Rectal Chlamydia in MSM
Condition: Anal Chlamydia Infection
MeSH terms: Chlamydia Infections
Intervention: Azithromycin; Doxycycline; Placebo
Intervention description: 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.; 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.; Azithromycin placebo (4 capsules), administered orally as a single dose; Doxycycline placebo (1 capsule), administered orally twice daily for 7 days.
Intervention MeSH terms: Azithromycin; Doxycycline
Phase: Phase 4
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Enrollment: 177.0
Sex: Male
Minimum age: 18 Years
Maximum age: 99 Years
Healthy volunteers: No
Keywords: Azithromycin; Doxycycline; Efficacy; MSM; Phase 4; Rectal Chlamydia

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.
    

Eligibility criteria:

        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.