Other Names: GSK1265744
Drug Class: Integrase Inhibitors

What is S/GSK1265744?

S/GSK1265744 is an investigational drug for the treatment of HIV infection.

• S/GSK1265744 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.
• S/GSK1265744 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 S/GSK1265744?

S/GSK1265744 is currently being studied in Phase II clinical trials.

What have recent studies shown about S/GSK1265744?

In a Phase I-II study, different strengths of unboosted S/GSK1265744 taken orally (by mouth) were compared with placebo in both healthy participants and HIV-infected participants who were integrase inhibitor-naive (had not taken an integrase inhibitor in the past). HIV-infected study participants did not receive additional anti-HIV drugs; they received only the investigational study drug, S/GSK1265744.

This study indicated that S/GSK1265744 may be given once daily without boosting. In HIV-infected adults, S/GSK1265744 was effective in reducing viral load. In terms of safety, S/GSK1265744 was well tolerated and most side effects were considered mild. The most common side effect that occurred was headache. More studies are needed to determine safety and efficacy of S/GSK1265744.

Additional Phase I and II studies of S/GSK1265744 are under way, including a study of long-acting injectable formulations.

More information on Phase I and II testing of S/GSK1265744 is available from these sources:

• S/GSK1265744 study results presented at the 49th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), September 12-15, 2009:
  • Min S, DeJesus E, McCurdy L, et al. Pharmacokinetics (PK) and Safety in Healthy and HIV-Infected Subjects and Short-Term Antiviral Efficacy of S/GSK1265744, a Next Generation Once Daily HIV Integrase Inhibitor
• S/GSK1265744 study results presented at the 18th International AIDS Conference, July 18-23, 2010:
  • Underwood M, St Clair M, Johns B, et al. S/GSK1265744: a next generation integrase inhibitor (INI) with activity against raltegravir-resistant clinical isolates
• Study of Long-Acting GSK1265744 (intramuscular and subcutaneous injection) from ClinicalTrials.gov:
  • A Study to Investigate the Safety, Tolerability and Pharmacokinetics of Repeat Dose Administration of Long-Acting GSK1265744 and Long-Acting TMC278 Intramuscular and Subcutaneous Injections in Healthy Adult Subjects

Where can I get more information about clinical trials studying S/GSK1265744?

More information about S/GSK1265744-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 S/GSK1265744. 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.