LEXINGTON, Ky. – A treatment for coronavirus could be growing on the sides of Kentucky's roads.

Researchers at the University of Kentucky are conducting clinical trials on an extract from the leaves of the Artemisia annua L plant, also known as sweet wormwood, that is active against SARS-CoV-2, the virus behind the COVID-19 pandemic. The extract being used as a potential coronavirus treatment has been added to UK’s clinical trial for experimental COVID-19 therapies, which was launched this past May by leaders from the school’s Markey Cancer Center, College of Medicine, and College of Pharmacy and is the only such trial in the United States. The new arms of the clinical trial will test the effectiveness of Artemisia annua extract as well as artesunate, a derivative of the plant that is a standard treatment for malaria in many parts of the world.

The new trial arm is supported by ArtemiLife, which recently collaborated with UK on a clinical study using Artemisia annua grown in Kentucky to test for the anti-cancer activity of its extract and to determine the recommended dose of Artemisia annua for future clinical trials.

Researchers at the University of Kentucky are conducting clinical trials to determine the benefit of extract from the sweet wormwood plant in the treatment of coronavirus. (Photo courtesy of the University of Kentucky)

The current project, which has moved from laboratory trials to human trials, actually began in 2017 when UK researchers were asked by members of the Max Planck in Germany to evaluate tobacco-style sweet wormwood cultivation to meet the needs for prediction of malaria medication.

“As time went on, the goals not only pursued malaria medicine but started getting into cancer therapeutics as well,” said Patrick Perry, research coordinator at UK’s Tobacco Research and Development Center. “Then came 2020 and the coronavirus, and previous literature had highlighted the leaf extract from the Artemesia annua plant could be effective against the SARS virus back in 2008, which is a close relative of the coronavirus. From there, they started laboratory trials of the use of Artemisia annua leaf extracts and also whole-leaf blends with coffee and tea to see their efficacy against the coronavirus, and then the laboratory the results were very positive.”

The positive lab results prompted the Markey Cancer Center and the Drug Discovery Program at the university to launch human clinical trials using the Artemesia annua leaf extract with coffee and tea as a possible treatment for the coronavirus, and those clinical trials are ongoing. ArtemiFlow, the Potsdam, Germany-based company behind the research has also started clinical trials in several different research hospitals in Meso-America and in Europe. 

“We're very hopeful that the results from the human clinical trials will correlate with those laboratory trials,” Perry said. “Maybe we'll be able to have Kentucky farmers be a part of the solution by growing this crop.”

The ongoing trial has a “pick-the-winner” design, which will allow UK researchers to rapidly understand what potential therapies appear to be effective, guiding patients to treatments that work and researchers to promising drugs that warrant further investigation, according to a press release from UK.

“While there is no standard treatment for COVID-19, this trial gives us the ability to test multiple therapies rapidly in order to identify the most promising agents,” Dr. Susanne Arnold, a medical oncologist and associate director of clinical translation at the UK Markey Cancer Center, who is co-leading the trial said in the press release. “This rapid assessment means that the trial can quickly include and test new therapies such as Artemisia annua.”

Each treatment is selected by a multidisciplinary committee of medical experts from across the university as some of the most unique and promising compounds that can be studied at the moment. The drugs are also attractive candidates for repurposing for treatment of COVID-19 considering they have excellent safety profiles and are readily available, rapidly scalable, and relatively inexpensive.

UK’s clinical trial is reserved for high-risk patients both at home and in the hospital who have tested positive for COVID-19, or who have COVID-19 symptoms but have not developed severe symptoms that would require intensive care unit treatment. Patients with COVID-19 who choose to enroll in the trial will be randomly assigned to one of four treatment groups including Artemisia annua.    

“The human trials identify individuals who have tested positive for Coronavirus and provide those individuals with coffee and tea with Artemisia annua leaf blended in,” Perry said. “Then those individuals will be evaluated intermittently over the course of a couple of weeks and then after the course of the human clock trial study, all that data will be collected and analyzed and then we'll be able to be reported on at the conclusion of the study.”

The sweet wormwood plant is plentiful in Kentucky. (Photo courtesy of the University of Kentucky)

Successful trials could be a boom for Kentucky farmers as well. There is currently no commercial cultivation of Artemisia annua on any surmountable scale in North America. It is traditionally found in ornamental nurseries and Perry said positive results from the clinical trials would immediately create an obvious huge demand for more plant material, which is relatively scarce globally.  

“This particular species originated in Southeast Asia but has been acclimated to several intercontinental regions, Perry said. “It can be found just growing on the side of the road somewhere, but the varieties that we're using for commercial production are hybrids that have been bred specifically for the purpose of commercial production for several decades. The lines that our producers are growing currently are called elite commercial hybrids, so that creates a need Kentucky producers can fulfill and fits in their production model quite well.” 

Kentucky farmers have been successful in growing sweet wormwood, consistently beating worldwide average yields. Farms in Georgetown and Lancaster are currently growing sweet wormwood for the trials.

“It grows very well here and farmers are very happy to grow it, Perry said. “They already have the expertise to know how it's grown – just as tobacco or commercial industrial hemp would be grown. The equipment, expertise, and know-how is already there. It's just putting another plant through the system. Kentucky producers are very prepared.” 

The infrastructure to immediately scale up production of sweet wormwood is already in place, Perry said, and the plant could be used not only for the immediate treatment of the coronavirus but as treatments for things such as ovarian cancer, which has clinical trials starting later this year, and as a treatment for childhood acute myeloma lymphoma, for which a clinical trial is planned to launch in the spring of 2021. 

“Not only can our Kentucky producers address the immediate need for coronavirus treatment, but in the long term, this could be a huge impact long term on the healthcare community as far as cancers are concerned,” Perry said. “The material that's been tested for each one of these has been grown right here in Kentucky by Kentucky producers. We’re really at the forefront of being the production hubs in the future if the need were to arise.”