May 29, 2013
Other Names: CVC, TAK-652, TBR-652
Drug Class: Entry and Fusion Inhibitors
Molecular Formula: C41 H52 N4 O4 S
Registry Number: 497223-25-3 (CAS)
Chemical Name: (5E)-8-[4-(2-butoxyethoxy)phenyl]-1-isobutyl-N-[4-[(S)-(3-propylimidazol-4-yl)methylsulfinyl]phenyl]-3,4-dihydro-2H-1-benzazocine-5-carboxamide
Chemical Class: Benzazepines
Company: Takeda; Tobira Therapeutics
Phase of Development: Phase II
Molecular Weight: 696.9518
(Compound details obtained from ChemIDplus Advanced1 and NIAID Therapeutics Database2)
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.
Cenicriviroc is an investigational drug that is being studied for the treatment of HIV infection.
Cenicriviroc belongs 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.
Cenicriviroc works by attaching to one of two proteins on the surface of the immune cells. These proteins are called the CCR5 and CXCR4 coreceptors. Cenicriviroc attaches to the CCR5 coreceptor. When cenicriviroc attaches to the CCR5 coreceptor, certain strains of HIV -- called R5-tropic virus -- cannot attach to, enter, or infect the cell.3
Cenicriviroc also appears to block another receptor known as CCR2. The CCR2 receptor is associated with inflammatory diseases. The potential benefits of blocking the CCR2 receptor in people with HIV are being studied.4,5
Clinical trials are conducted in "phases." Each phase has a different purpose and helps researchers answer different questions.6
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.6
In most cases, an investigational drug must be proven safe and effective in a Phase III clinical trial to be considered for 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.6
Cenicriviroc is currently being studied in Phase II clinical trials.2
In a 10-day Phase I/II study, several different strengths of cenicriviroc taken once daily were compared to placebo in HIV-infected participants who had been taking HIV medicines before entering the study (treatment-experienced). (A placebo is an inactive drug that is identical in appearance to the active drug being studied.) Study participants did not receive additional HIV medicines as part of a 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 given to help control a participant's HIV infection.)4,7,8
In the adults who had been taking HIV medicines before entering the study and who had not been previously treated with a CCR5 antagonist, cenicriviroc at all strengths was effective in reducing HIV viral load (the amount of HIV in the blood). Cenicriviroc was also shown to have anti-inflammatory activity. In terms of safety, no serious side effects occurred. The most common side effects were headache, nausea, constipation, diarrhea, and sinus infection/inflammation (sinusitis).4,7,8
Additional Phase II studies of cenicriviroc in HIV-infected adults who have not taken HIV medicines before are under way.9
In the 10-day Phase I/II study discussed under the previous question, the most common side effects reported were the following: headache, nausea, constipation, diarrhea, and sinus infection/inflammation (sinusitis). Overall, side effects occurring in this study were considered mild.4,7
Because cenicriviroc is still being studied, information on possible side effects of the drug is not complete. As testing of cenicriviroc continues, additional information on possible side effects will be gathered.
More information about cenicriviroc-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.6
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.