A drug taken by many people to control intestinal conditions appears to also combat HIV.
Doctor Anthony Fauci from the National Institutes of Allergy and Infectious Diseases found that the drug controlled HIV in monkeys.
The drug, vedolizumab, is made by Japan's Takeda Pharmaceutical Company and it suppressed HIV to almost undetectable levels in eight monkeys for two years.
The company do not research HIV and are focused on cancer, gastroenterology and the central nervous system, but are supporting this study and providing the drug.
The drug will now go into early-stage human trials. It is hoped it patients could use the drug instead of daily antiretroviral therapy (ART).
ART is a difficult treatment, causing fatigue nausea and nerve problems short term, whilst in the long term it can cause many problems including insulin resistance.
Fauci said meaningful results from the study of vedolizumab are not expected until late 2017 or early 2018, but even a partial success would be a huge breakthrough.