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.
Adaptavir is an investigational drug that is being studied for its ability to eliminate HIV infection that persists despite treatment with antiretroviral therapy (ART). Currently ART can reduce the level of HIV in the blood to an undetectable level, but it can't eliminate HIV entirely from the body.3,4
Adaptavir is a newer, modified form of an older investigational drug called peptide T. Both adaptavir and peptide T belong to a class (group) of HIV drugs called entry and fusion inhibitors.2 Entry and fusion inhibitors block HIV from getting into and infecting certain cells of the immune system. This prevents HIV from multiplying and can reduce the amount of HIV in the body.
Adaptavir works by attaching to one of two proteins on the surface of the immune cells. These proteins are called the CCR5 and CXCR4 co-receptors. Adaptavir attaches to the CCR5 co-receptor. When adaptavir attaches to the CCR5 co-receptor, certain strains of HIV—called R5-tropic virus—cannot attach to, enter, or infect the cell.5
The main component of adaptavir is peptide T. Peptide T was an investigational drug that was previously studied to test its ability to reduce the amount of HIV in the body and bolster the immune system. The drug’s effect on HIV-associated cognitive impairment was also studied. (Cognitive impairment is when people have trouble remembering, learning new things, concentrating, or making decisions that affect their everyday life.)4,6,7
Clinical trials are conducted in phases. Each phase has a different purpose and helps researchers answer different questions.8
Adaptavir is being studied in Phase II clinical trials.2
Peptide T (base compound of adaptavir)
In a small study of 11 HIV-infected participants, investigators examined the ability of peptide T to reduce HIV viral load (the amount of HIV in the blood), improve immune function, and reduce HIV replication in blood monocytes (a type of white blood cell [WBC] that can be infected by HIV). Before entering the study, participants were either treatment-naïve (had never taken HIV medicines) or treatment-experienced (had taken HIV medicines previously). During the study, some participants received only peptide T, while others received peptide T along with ART. Peptide T was given through the nose (intranasally) three times a day for up to 32 weeks. This study did not include a placebo group. (Participants in a placebo group receive a placebo, an inactive drug that is identical in appearance to the active drug being studied. Placebo groups are used to compare the effectiveness of a study drug with a placebo.)6
In this study, peptide T treatment did not appear to have any effect on viral load levels. CD4 counts in all participants increased from baseline (baseline values are initial measurements used as the basis for future comparison), but this increase was not statistically significant. The CD4 count is a laboratory test that measures the number of CD4 cells in a sample of blood and is an important indicator of immune function. Researchers did note that peptide T was able to significantly reduce HIV replication in blood monocytes, especially in participants who were also receiving ART. In terms of safety, no side effects associated with peptide T use were reported.6
In a Phase II study, peptide T was compared with a placebo to see if either could improve cognitive function in HIV-infected participants.4,7 Study participants’ cognitive function was assessed by various tests, such as tests on verbal fluency, abstract thinking, and memory. Peptide T was given intranasally three times a day for 6 months.7
In this study, peptide T proved no more effective than placebo in improving cognitive function in participants with HIV-associated cognitive impairment. However, in participants who had more severe cognitive impairment or a higher CD4 count at the start of the study, peptide T had some beneficial effects on cognitive impairment when compared to placebo. In terms of safety, there were no significant side effects associated with peptide T.7
Adaptavir (the modified version of peptide T)
A Phase II study was done to examine the ability of adaptavir to eliminate HIV that is resistant to current HIV medicines and remains "resting" in certain immune cells. Although these HIV-infected immune cells may be inactive, they can begin to produce HIV at a later point. Participants in the study were all HIV-infected, treatment-experienced individuals. At the start of the study, participants had to have been on ART for at least 6 months and have suppressed viral loads. During the study, participants were given adaptavir twice daily intranasally. The results of this study are unknown at this time.3
In both studies of peptide T described above, there were no reports of significant side effects associated with peptide T use. Some side effects that occurred during peptide T use were mood disturbances, rash, nasal congestion, abnormal amounts of protein in the urine, and higher than normal amounts of a certain type of WBC.6,7 (A period of time after these studies were done, peptide T was reformulated as adaptavir.)
Because adaptavir is still being studied, information on possible side effects of the drug is not complete. As testing of adaptavir continues, additional information on possible side effects will be gathered.
More information about adaptavir-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.
Participating in a clinical trial can provide benefits. For example, a volunteer participant can benefit from new research treatments before they are widely available. Participants also receive regular and careful medical attention from a research team that includes doctors and other health professionals. However, clinical trials may also involve risks of varying degrees, such as unpleasant, serious, or even life-threatening side effects from the treatment being studied.8
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. Last accessed on March 31, 2014.
2. National Institute of Allergy and Infectious Diseases (NIAID). NIAID ChemDB, HIV Drugs in Development. Last accessed on March 31, 2014.
3. Rapid Laboratories Inc. Safety and Efficacy of ADAPTAVIR's Ability to Eliminate Treatment-Resistant Infectious Virus in the Blood Cellular Reservoir (PBMCs) of HIV Patients With Suppressed Plasma Viral Load. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on July 31, 2009. NLM Identifier: NCT00951743. Last accessed on March 31, 2014.
4. RAPID Pharmaceuticals website. Monomeric DAPTA – the long path to discovery. Last accessed on March 31, 2014.
5. Polianova MT, Ruscetti FW, Pert CB, Ruff MR. Chemokine receptor-5 (CCR5) is a receptor for the HIV entry inhibitor peptide T (DAPTA). Antiviral Res. 2005 Aug;67(2):83-92. Last accessed on March 31, 2014.
6. Polianova MT, Ruscetti FW, Pert CB, et al. Antiviral and immunological benefits in HIV patients receiving intranasal peptide T (DAPTA). Peptides. 2003 Jul;24(7):1093-8. Last accessed on March 31, 2014.
7. Heseltine PN, Goodkin K, Atkinson JH, et al. Randomized Double-blind Placebo-Controlled Trial of Peptide T for HIV-Associated Cognitive Impairment. Arch Neurol. 1998 Jan;55(1):41-51. Last accessed on March 31, 2014.
8. National Institutes of Health (NIH). NIH Clinical Research Trials and You. Last accessed on March 31, 2014.
Last Reviewed: March 31, 2014
Last Updated: January 21, 2015