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.
To learn more about investigational drugs, read the AIDSinfo What is an Investigational HIV Drug? fact sheet.
Tucaresol is an investigational drug that is categorized as an immune modulator.2 Immune modulators (also called immunomodulators) are substances that modify (activate, enhance, or suppress) the immune response or the functioning of the immune system.
Tucaresol was studied for its ability to help restore or boost the immune systems of HIV-infected individuals. The drug may help to repair damage that HIV has done to the immune system and to protect the long-term health of HIV-infected individuals.3
Clinical trials are conducted in phases. Each phase has a different purpose and helps researchers answer different questions.4
In most cases, an investigational drug must be proven effective and must show continued safety in a Phase III clinical trial to be considered for approval by FDA for sale in the United States. Some drugs go through FDA’s accelerated approval process and are approved before a Phase III clinical trial is complete. After a drug is approved by 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.4
Tucaresol has been studied in a Phase II clinical trial.2
Study Name: Not available
Participants: Four groups of HIV-infected participants were studied.
Purpose: The purpose of this study was to look at the safety and immune-modulating effects of tucaresol in different groups of HIV-infected participants. In terms of immune-modulating effects, the study looked at whether tucaresol could increase the number and activity of certain cells of the immune system.3,5,6For more details on the study, see the Health Professional version.
In the Phase I/II study discussed under the previous question, the most common side effects that occurred in the treatment-experienced participants taking ART and tucaresol were low-grade fever and other mild constitutional symptoms. (Constitutional symptoms are symptoms affecting the whole body, such as fever and weight loss.)3
Information on possible side effects of tucaresol is not complete. As testing of tucaresol continues, additional information on possible side effects will be gathered.
More information about tucaresol-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.4
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.
Last Reviewed: June 24, 2016