TOPLINE:

In patients with Mycoplasma genitalium (MG) infection, a 10-day regimen of moxifloxacin 400 mg daily yielded significantly higher microbiologic cure rates than a 6-day regimen of azithromycin 500 mg daily, supporting its use as a potential first-line treatment where resistance testing is unavailable.

METHODOLOGY:

• Researchers conducted a phase 4 trial at a tertiary care hospital in Italy from January 2018 to June 2024 to demonstrate the superiority of moxifloxacin over azithromycin for treating MG infection in the absence of resistance testing.
• Overall, 358 patients with MG infection (median age, 36 years; 96.6% men) detected using multiplex polymerase chain reaction were randomly assigned to receive either moxifloxacin 400 mg once daily for 10 days (n = 193) or azithromycin 500 mg once daily for 6 days (n = 165); of them, 53 patients who did not respond to the first-line regimen received re-treatment.
• Asymptomatic patients received the allocated antibiotic upon laboratory confirmation, whereas symptomatic patients with anogenital discharge received syndromic treatment with intramuscular ceftriaxone 1 g plus doxycycline 100 mg twice daily for 7 days, followed by the study drug after completion of the doxycycline regimen.
• The primary endpoint was microbiologic cure, defined as a negative test of cure at least 28 days after treatment completion.
• Secondary objectives were to determine the effect of doxycycline on microbiologic cure, microbiologic and clinical cure after failure of first-line regimen, and the effect of immunosuppression on microbiologic cure.

TAKEAWAY:

• Across all patients who initiated treatment and those who completed the course per protocol, microbiologic cure rates were higher with moxifloxacin than with azithromycin (87.0% vs 61.2% and 95.5% vs 67.3%, respectively; P < .001 for both comparisons).
• Among patients with symptomatic infections, the cure rate was 85.7% with moxifloxacin vs 56.8% with azithromycin (relative risk, 1.51; P = .015).
• Exposure to doxycycline did not significantly improve microbiologic cure rates compared with no exposure.
• Immune suppression also did not affect treatment response, with a success rate of 81.0% in patients with immunosuppression vs 74.7% in those with normal immune status.

IN PRACTICE:

"Our results suggest that a 10-day course of moxifloxacin 400 mg daily could be used as a first-line regimen to treat MG infections in settings where assessment of resistance-associated mutations is not feasible or pending implementation, achieving satisfactory success rates," the authors wrote. 

SOURCE:

The study was led by Roberto Rossotti, MD, University of Verona, Verona, Italy. It was published online on May 17, 2026, in Clinical Infectious Diseases.

LIMITATIONS:

The monocentric design may have limited the study's generalisability. The subgroup analyses were based on small sample sizes and did not meet the superiority margin. Researchers did not collect data on treatment adherence or adverse events.

DISCLOSURES:

The study received no specific funding support. The authors disclosed having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.