Drug information

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Other Names
Elpida, VM-1500, prodrug of VM-1500A
Drug Class
Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs)
Molecular Formula

C24 H17 Br Cl2 F N3 OS

Chemical Name


Phase of Development

Elsulfavirine has been studied in a Phase 2/3 trial for HIV treatment. In June 2017, elsulfavirine received marketing approval in Russia for the treatment of HIV.

(Compound details obtained from ChemIDplus Advanced,1 NIAID Therapeutics Database,2 Viriom press release,3 and ClinicalTrials.gov4)

What is elsulfavirine?What is elsulfavirine?

What is elsulfavirine?

Elsulfavirine is an investigational drug that is being studied to treat HIV infection.5

Elsulfavirine belongs to a group of HIV drugs called non-nucleoside reverse transcriptase inhibitors (NNRTIs).2,6 NNRTIs attach to and block an HIV enzyme called reverse transcriptase. Studies have shown that elsulfavirine appears effective for treating HIV in people who have never taken HIV medicines.6,7 Elsulfavirine may also be effective against certain strains of HIV that can no longer be controlled by Food and Drug Administration (FDA)-approved NNRTIs.8

Elsulfavirine was approved as a daily oral HIV treatment in Russia.3 Researchers are studying long-acting forms of elsulfavirine for treating and preventing HIV. In addition, fixed-dose combination (FDC) drugs containing elsulfavirine are in development.5

To learn about how investigational drugs are tested during clinical trials, read the HIVinfo What is an Investigational HIV Drug? and HIV and AIDS Clinical Trials fact sheets.

Select clinical trials of elsulfavirineSelect clinical trials of elsulfavirine

Select clinical trials of elsulfavirine

Study Name: NCT02485509
Phase: 1b/2a
Status: This study has been completed.
Location: Thailand
Purpose: This study was conducted in two parts. The purpose of Part 1 of the study was to evaluate the safety and drug properties of elsulfavirine in healthy people without HIV. Part 2 was designed to examine the safety, effectiveness, and drug properties of elsulfavirine in people with HIV. In both parts of the study, elsulfavirine was compared to placebo.9
Selected Study Results: Results presented at CROI 2014 showed that elsulfavirine at both the 20 mg and 40 mg doses was effective with minimal side effects. A reduction in viral load and increase in CD4 counts was noted across both dosage groups.7 

Additional Published Material:


Study Name: NCT02489461
Phase: 2/3
Status: This study has been completed.
Location: Russian Federation
Purpose: The purpose of this study was to (1) determine the most effective dose of elsulfavirine, and (2) compare the safety and effectiveness of elsulfavirine to the FDA-approved HIV medicine efavirenz (brand name: Sustiva).4

Selected Study Results: Results presented at CROI 2017 showed that elsulfavirine was safe and effective in people with HIV who never took HIV medicines before. The 48-week study demonstrated equivalent effectiveness of the antiretroviral therapy regimen containing elsulfavirine as compared to the regimen containing efavirenz.6

Additional Published Material:

For more details on the studies listed above, see the Health Professional version of this drug summary.

Additional clinical trials of elsulfavirine have also been conducted, including:

  • NCT05165550: A Phase 1 trial evaluating the safety, tolerability, and pharmacokinetics of single oral ascending doses of elsulfavirine in healthy adults without HIV. This study is currently recruiting participants.10
  • NCT03730311: A Phase 1b trial investigating the safety and pharmacokinetics of once-weekly oral elsulfavirine in healthy adults without HIV. The status of this study is unknown.11
What side effects might elsulfavirine cause?What side effects might elsulfavirine cause?

What side effects might elsulfavirine cause?

One goal of HIV research is to identify new drugs that have fewer side effects. The following side effects were observed in the studies of elsulfavirine listed above.


In Part 2 of this Phase 1b/2a study, reported side effects included mild dry mouth, mild headache, and excessive urination.7,9


In the first part this Phase 2/3 trial, side effects caused by the study drugs occurred more often in participants taking efavirenz than in participants taking elsulfavirine. Brain-related side effects that commonly occurred in participants taking elsulfavirine included headache, unusual dreams, dizziness, problems with sleep, drowsiness, depression, and nightmares. All of these side effects, plus insomnia and memory problems, also occurred in the efavirenz group.4,12

In the second part of this Phase 2/3 trial, the most common side effects reported by participants taking elsulfavirine or efavirenz were headache, dizziness, and sleep disorders. Abnormal dreams, skin rash, and itchiness occurred only in participants taking efavirenz. One participant receiving elsulfavirine and seven participants receiving efavirenz dropped out of the study because of a side effect.6

Because elsulfavirine is still being studied, information on possible side effects of the drug is not complete. As testing of elsulfavirine continues, additional information on possible side effects will be gathered.

Where can I get more information about clinical trials studying elsulfavirine?Where can I get more information about clinical trials studying elsulfavirine?

Where can I get more information about clinical trials studying elsulfavirine?

More information about elsulfavirine-related research studies is available from ClinicalTrials.gov. (The ClinicalTrials.gov search can be modified so that you can get results that better match your interests. To learn more about the ClinicalTrials.gov search features, please see How to Search.)

Some clinical trials may be looking for volunteer participants. Your health care provider can help you decide whether participating in a clinical trial is right for you. For more information, visit NIH Clinical Research Trials and You.



  1. United States National Library of Medicine. ChemIDplus Advanced: Elsulfavirine. https://chem.nlm.nih.gov/chemidplus/rn/868046-19-9. Accessed July 20, 2022
  2. National Institute of Allergy and Infectious Diseases (NIAID). NIAID ChemDB, HIV Drugs in Development. https://chemdb.niaid.nih.gov/DrugDevelopmentHIV.aspx. Accessed July 20, 2022
  3. Viriom. Press release, dated July 25, 2017. Viriom obtains first market approval of elsulfavirine (Elpida®) for treatment of HIV-1 infection in Russia. https://web.archive.org/web/20190418144705/https://www.viriom.com/news/2017/11/30/viriom-obtains-first-market-approval-of-elsulfavirine-elpida-for-treatment-of-hiv-1-infection-in-russia. Accessed July 20, 2022
  4. Viriom. International, multicenter, randomized, partially blind clinical study to evaluate efficacy, safety and selection of the optimal dose for VM-1500 in comparison to efavirenz in combination with two NRTIs in treatment-naive, HIV-1 infected patients. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on June 18, 2015. NLM Identifier: NCT02489461. https://www.clinicaltrials.gov/ct2/show/NCT02489461. Accessed July 20, 2022
  5. Viriom, Inc. website. Pipeline. https://www.viriom.com/pipeline/. Accessed July 20, 2022
  6. Murphy RL, Kravchenko AV, Orlova-Morozova EA, et al. Elsulfavirine as compared to efavirenz in combination with TDF/FTC: 48-week study. Poster presented at: Conference on Retroviruses and Opportunistic Infections (CROI); February 13-16, 2017; Seattle, Washington. Poster 452LB. https://www.croiconference.org/wp-content/uploads/sites/2/posters/2017/452LB_Murphy.pdf. Accessed July 20, 2022
  7. Ratanasuwan W, Werarak P, Murphy RL, Bichko V. A randomized, placebo-controlled, double-blind study of VM-1500 in HIV-naive patients. Abstract presented at: Conference on Retroviruses and Opportunistic Infections (CROI); March 3-6, 2014; Boston, Massachusetts. Abstract 544LB. https://www.croiconference.org/abstract/randomized-placebo-controlled-double-blind-study-vm-1500-hiv-naive-patients/. Accessed July 20, 2022
  8. Viriom, Inc.: Press Release, dated November 20, 2013. Viriom expands global licensing agreement with Roche for innovative compound development for HIV treatment. https://www.biospace.com/article/releases/viriom-expands-global-licensing-agreement-with-roche-for-innovative-compound-development-for-hiv-treatment-/. Accessed July 20, 2022
  9. Viriom. Phase Ib/IIa, single-centre, placebo-controlled randomized study of safety and pharmacokinetics in healthy volunteers and safety, tolerability and antiviral activity of VM-1500 in patients with human immunodeficiency virus-1 infection. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on June 18, 2015. NLM Identifier: NCT02485509. https://clinicaltrials.gov/ct2/show/NCT02485509. Accessed July 20, 2022
  10. Viriom. A Phase 1, double-blind, placebo-controlled study of single ascending doses of elsulfavirine to evaluate the safety, tolerability, and pharmacokinetics of elsulfavirine and its active metabolite VM-1500A in healthy subjects. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on December 7, 2021. NLM Identifier: NCT05165550. https://clinicaltrials.gov/ct2/show/NCT05165550. Accessed July 20, 2022
  11. Viriom. Phase Ib, single-centre, placebo-controlled randomised study of safety, tolerability and pharmacokinetics of Elpida in healthy HIV-uninfected volunteers. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on November 1, 2018. NLM Identifier: NCT03730311. https://clinicaltrials.gov/ct2/show/NCT03730311. Accessed July 20, 2022
  12. Kravchenko AV, Orlova-Morozova EA, Nagimova FI, et al. Safety and antiviral effect of Elpida (VM-1500), a novel NNRTI (+Truvada) in treatment-naive HIV-1 infected patients. Poster presented at: European AIDS Conference (EAC); October 21-24, 2015; Barcelona, Spain. Poster PE7/4. https://static1.squarespace.com/static/5a20396b90bade9e464cc7a1/t/5a32f83d9140b721ac85d24f/1513289792907/2.+barcelona2015.pdf. Accessed July 20, 2022

Last Reviewed: July 20, 2022