Prevalence of Drug-resistant Hiv-1 Strains in Patients Experiencing Virologic Failure. (MULTIVIR2025)

Detailed Description:

This is a cross-sectional, national and multicenter study with retrospective and prospective data collection. The study will be conducted in all French virology laboratories that participated in the last quality control for HIV genotypic resistance testing conducted by the ANRS MIE network (n = 42).

Study population All patients treated with antiretrovirals and experiencing virological failure (defined as two consecutive viral loads, at least two weeks apart, greater than 50 copies/mL) can be included in this study.

The study will run for twelve months, with a planned start in 2025. During six months, virologists will be asked to identify all patients meeting the inclusion criteria until they reach 20 patients (for centers following less than 2000 PLWHA) or 40 patients (for centers following more than 2000 PLWHA). Genotypic resistance testing will be performed for all these patients, as recommended by French guidelines. Genotypic resistance testing will always include the amplification of the reverse transcriptase (RT), protease (PR) and integrase (INT), whereas the amplification of gp120, gp41 and/or capsid will only be performed in patients receiving maraviroc, enfuvirtide or lenacapavir, respectively.

Genotypic resistance testing will be performed in each local laboratory, using Sanger or high-throughput sequencing.

Sample size It is estimated that the proportion of patients with multi-drug resistant viruses is between 1 and 5% in this population. Thus, the aim is to include at least 500 patients, which would allow to determine the proportion of multi-drug resistant viruses with an accuracy of 1 to 2%.

With at least 30 participating centers, an expected number of 800 patients should be included. Given the threshold used to define virological failure (50 copies/mL), it is expected that genotypic resistance testing will not be successful in a number of cases. Assuming that all patients with virological failure have viral loads between 51 and 200 copies/mL, and that the success rate for genotypic resistance testing is 63%, the number of patients for whom we would have genotypic data would be 504.

Data collection The virology laboratories will send the list of eligible patients to the associated clinical centers, according to their usual data transfer procedure, so that clinicians can inform the participants and obtain their informed consent. An information form will also be distributed to participants.

A unique identification code will be assigned to each patient that have agreed to this study. An electronic case report form will be used to collect genotypic, clinical and demographic data.

Data analysis Identification of drug resistance-associated mutations will be performed using two different algorithms: Stanford HIVDB (version 9.7, November 2024) and HIV French Resistance (version 35, April 2024).