An Overview of Dolutegravir

Other Names: DTG, GSK1349572, S/GSK1349572
Drug Class: Integrase Inhibitors

What is dolutegravir?

Dolutegravir is an investigational drug for the treatment of HIV infection.

• Dolutegravir is an investigational anti-HIV drug included in the integrase inhibitor drug class.
• Integrase inhibitors prevent HIV from replicating by blocking integrase, an HIV enzyme. By preventing HIV from replicating, integrase inhibitors reduce the amount of HIV in the blood.
• Dolutegravir does not require boosting with an additional drug.

What is an investigational drug?

An investigational drug is one that is under study and is not approved by the U.S. Food and Drug Administration (FDA) for sale in the United States. Medical research studies are conducted to evaluate the safety and effectiveness of an investigational drug. These research studies are also called clinical trials. Once an investigational drug has been proven safe and effective in clinical trials, FDA may approve the drug for sale in the United States.

How are clinical trials of investigational drugs conducted?

Clinical trials are conducted in "phases." Each phase has a different purpose and helps researchers answer different questions.

• Phase I trials: Researchers test an investigational drug in a small group of people (20-;80) for the first time. The purpose is to evaluate its safety and identify side effects.
• Phase II trials: The investigational drug is administered to a larger group of people (100-;300) to determine its effectiveness and to further evaluate its safety.
• Phase III trials: The investigational drug is administered to large groups of people (1,000-;3,000) to confirm its effectiveness, monitor side effects, compare it with standard or equivalent treatments, and collect information that will allow the investigational drug to be used safely.

An investigational drug must be proven safe and effective in a Phase III clinical trial to be considered for traditional approval by the FDA for sale in the United States. Some drugs go through the FDA's accelerated approval process and are approved before a Phase III clinical trial is complete. After a drug is approved by the FDA and made available to the public, researchers track its safety in Phase IV trials to seek more information about the drug's risks, benefits, and optimal use.

In what phase of testing is dolutegravir?

Dolutegravir is currently being studied in several Phase III clinical trials.

What have recent studies shown about dolutegravir?

In a Phase III study, unboosted dolutegravir taken once daily was compared with raltegravir (brand name: Isentress), an FDA-approved non-nucleoside reverse transcriptase inhibitor, taken twice daily in treatment-naive HIV-infected participants. Study participants also received additional anti-HIV drugs as part of their background regimen. (A background regimen is a combination of drugs that are not being studied as the investigational drug[s] in the clinical trial, but are being given to help control a participant's HIV infection.) In HIV treatment-naive adults, dolutegravir proved as effective as raltegravir. In terms of safety, dolutegravir was comparable to raltegravir. The most common side effects that occurred were nausea, headache, common cold, and diarrhea.

In a Phase II study, investigators studied the effectiveness of unboosted dolutegravir taken once daily or twice daily in treatment-experienced adults who have drug resistance to raltegravir (brand name: Isentress). In this study, twice-daily dolutegravir, given in combination with optimized background therapy, proved effective in adults with raltegravir resistance. Dolutegravir was well tolerated in this study, and the most common side effect was diarrhea.

Additional Phase III trials of dolutegravir are under way, including a study of a fixed-dose combination anti-HIV drug containing dolutegravir and abacavir/lamivudine.

More information on Phase I, II, and III testing of dolutegravir is available from these sources:

• Dolutegravir study results presented at the 19th International AIDS Conference, July 22-;27, 2012:
  • Raffi F, Rachlis A, Stellbrink HJ, et al. Once-daily dolutegravir (DTG; S/GSK1349572) is non-inferior to raltegravir (RAL) in antiretroviral-naive adults: 48 week results from SPRING-2 (ING113086)
• Dolutegravir study results presented at the 13th European AIDS Conference, October 12-15, 2011:
  • Soriano V, Cox J, Eron JJ, et al. Dolutegravir (DTG, S/GSK1349572) Treatment of Subjects with Raltegravir (RAL) Resistance: Viral Suppression at Week 24 in the VIKING Study
• PubMed abstract:
  • Katlama C, Murphy R. Dolutegravir for the treatment of HIV. Expert Opin Investig Drugs. 2012 Apr;21(4):523-30. Epub 2012 Mar 2.
• Study of dolutegravir/abacavir/lamivudine fixed-dose combination tablet from ClinicalTrials.gov:
  • Evaluation of the Bioequivalence of a Combined Formulated Tablet

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

More information about dolutegravir-related research studies is available from the AIDSinfo database of ClinicalTrials.gov study summaries. Click on the title of any trial in the list to see the ClinicalTrials.gov trial summary and more information about the study.

I am interested in participating in a clinical trial of dolutegravir. How can I find more information about participating in a clinical trial of an investigational drug?

Clinical trials involve benefits and risks. Before deciding to participate in a clinical trial, talk to your health care provider. For more information on participating in clinical trials, visit NIH Clinical Research Trials and You.