Evaluation of the HIV-1 drug resistance to elsulfavirine and the effectiveness of it among Russian treatment-naïve patients
Authors: Kirichenko A. A. , Kireev D. E. , Kravchenko A. V. , Pokrovskaya A. V. , Kuimova U. A. , Sizova N. V. , Mayorova S. O. , Gusev D. A. , Pokrovsky V. V. 
Published: January 2021

The aim of the study: to analyze the prevalence of resistance mutations to elsulfavirine and to evaluate the effectiveness of it among HIV-infected treatment-naïve patients in real clinical practice.

Materials and methods. The study included 578 patients with HIV infection, which divided into 3 groups. The first group is 354 HIV-infected treatment-naïve patients for whom HIV-1 nucleotide sequences were obtained as part of routine drug resistance testing. The second study group included 111 HIV-infected treatment-naïve patients, tested for drug resistance before the antiretroviral therapy containing elsulfavirine. The third study group included 113 HIV-infected treatment-naïve patients, each of whom was assigned a treatment regimen containing elsulfavirine without prior drug resistance testing. The observation period for patients of the second and third groups who received treatment was 24 weeks. To assess the effectiveness of antiretroviral therapy in patients, viral load, CD4+ T-cell counts, and adherence to therapy were assessed. HIV-1 subtypes and drug resistance mutations were determined using the Stanford HIV Resistance Database (v. 8.9-1). To clarify the results of subtyping, phylogenetic analysis of nucleotide sequences was carried out using the MEGA program (v. 6.0).

Results. The prevalence of mutations associated with decreased susceptibility to elsulfavirine among HIV-infected treatment-naïve patients was 1.7% and 4.5% for the first and second groups of patients, respectively. All of the patients have only single resistance mutations which, according to the results of preclinical studies, cannot cause drug resistance. The use of elsulfavirine in real clinical practice among treatment-naïve patients has demonstrated good virological and immunological efficacy of the drug. As a result of 24 weeks of therapy in patients of the second group, no treatment ineffectiveness, and the development of drug resistance were observed. Among the patients of the third group, 6 patients (5.3%) have the virological failure of therapy associated with the resistance to the used drugs. All patients with virological failure had a resistance mutation profile associated with a high level of drug resistance to one of the drugs in the treatment regimen, lamivudine. Additionally, 1 patient had a combination of mutations that reduce susceptibility to elsulfavirine, and 4 patients had mutations that can reduce susceptibility to elsulfavirine in combination with other mutations.

Conclusion. The low prevalence of mutations associated with a decrease in susceptibility to elsulfavirine and the absence of combinations of mutations make it possible to predict the successful use of this drug for Russian treatment-naïve patients. Reported cases of virological failure of antiretroviral therapy are difficult to interpret in the context of elsulfavirine due to the lack of an exact list of mutations and their combinations, and associations with the degree of resistance to it. This study describes for the first time the mutation profiles in patients with virological failure of therapy containing elsulfavirine and demonstrates the necessity of the further study of drug resistance profile to drug in vitro and in vivo.