Efficacy of 7-Day Oral Doxycycline for Asymptomatic Anal Lymphogranuloma Venereum Infection: Multicentre Study

The primary objective is to assess the efficacy of a 7-day oral course of doxycycline 200 mg daily in asymptomatic anal lymphogranuloma venereum, measured by the microbiological cure rate four weeks after treatment initiation. This endpoint is clinically relevant because it determines whether the regimen achieves eradication of infection. The secondary objectives are to characterize C. trachomatis genotype distribution in baseline LGV-positive anal specimens, identify genotypes in week 4 C. trachomatis-positive specimens to distinguish reinfection from treatment failure, estimate bacterial load at baseline and week 4, investigate molecular mechanisms associated with doxycycline resistance, evaluate adherence to doxycycline, and assess safety through adverse events and serious adverse events.

The sponsor did not provide the total number of participants or detailed information on the study population. The trial population consisted of male patients aged 18 years and older with asymptomatic anal LGV infection. Participants were selected based on a positive anal specimen screening result by nucleic acid amplification test, absence of anorectal symptoms, and availability for follow-up over four weeks. Additional inclusion criteria included written informed consent, a screening-to-inclusion interval of no more than 12 days, prior intake of doxycycline for at least two days but not more than seven days at 200 mg per day, and affiliation or entitlement to a social security scheme. No lifestyle considerations were provided.

This multicentre phase 4, low-interventional study evaluates the efficacy of a 7-day course of doxycycline in asymptomatic anal lymphogranuloma venereum. The trial is not described as randomized, double-blind, or controlled in the source data. Participants undergo a screening visit to confirm eligibility, including age criteria, informed consent, anal specimen testing by nucleic acid amplification test, treatment exposure requirements, absence of anorectal symptoms, and availability for follow-up. Eligible participants then continue the prescribed oral treatment and are followed for four weeks after treatment initiation. A follow-up assessment at week 4 includes collection of an anal specimen for microbiological evaluation and related molecular analyses, as well as review of adherence and recording of adverse events and serious adverse events. The end-of-study visit occurs at the four-week assessment. Expected participant involvement is four weeks. Early termination may occur if eligibility criteria are not met, if the required treatment exposure conditions are not satisfied, if follow-up cannot be completed, or if withdrawal of consent or other protocol-defined discontinuation conditions arise.

Doxycycline was administered as DOXYCYCLINE SANDOZ 100 mg, a tablet for oral use containing doxycycline monohydrate. The dose was 200 mg daily by mouth for 7 days. Administration was conducted as part of the experimental treatment regimen in the clinical trial evaluating treatment of asymptomatic anal lymphogranuloma venereum.

No non-experimental treatment, placebo, or comparator treatment was specified in the source data. The dosing schedule consisted of a 7-day course, and treatment efficacy was assessed four weeks after treatment initiation. No additional information on compliance monitoring was provided in the source data.

Efficacy will be assessed by the microbiological cure rate. Microbiological cure is defined as a LGV-negative NAAT result in an anal specimen four weeks after treatment initiation among participants with a LGV-positive NAAT result at baseline. The C. trachomatis genotypes in LGV-positive anal specimens collected at baseline will be studied by sequencing the ompA gene. Treatment failure will be defined by an identical ompA genotype in anal swabs collected at baseline and at four weeks after treatment initiation, or by inability to determine the ompA genotype in individuals reporting no anal sexual intercourse after treatment or consistent condom use between inclusion and visit at week 4. Reinfection will be defined by a different ompA genotype in anal swabs collected at baseline and at four weeks after treatment initiation, or by inability to determine the ompA genotype in individuals reporting unprotected anal sexual intercourse with an untreated or new sexual partner between inclusion and visit at week 4.

The C. trachomatis load will be assessed at baseline and four weeks after treatment initiation using quantitative real-time PCR and reported as the number of DNA copies per microliter. Molecular mechanisms for doxycycline resistance will be studied by sequencing the target genes in all LGV-positive specimens at baseline and four weeks after treatment initiation. Adherence to doxycycline will be evaluated using a diary.