SINGAPORE: A widely available and inexpensive drug used for cancer treatment could potentially be used in the treatment of COVID-19, according to a study by Singapore and US researchers.
They found that the chemotherapeutic drug, called Topotecan, reduced the severity and death rates of infection by the virus that causes COVID-19, by suppressing inflammation in the lungs of laboratory animals.
This has potential implications for COVID-19 treatment in humans, said the National University Cancer Institute, Singapore (NCIS) on Wednesday (Apr 7).
The findings by researchers from NCIS and the Icahn School of Medicine at Mount Sinai in the United States were published online in the scientific journal Cell in March.
The safety and efficacy of the treatment in humans will soon be evaluated at clinical sites around the world, said NCIS, adding that its team has secured a research grant to conduct a Phase 1 clinical trial of Topotecan in COVID-19 patients.
The research is supported by the Singapore Ministry of Health’s National Medical Research Council and the National Research Foundation under the COVID-19 Research Fund, NCIS added.
Co-author of the study, Dr Anand Jeyasekharan, said that a “key finding” from the study is that the cancer drug is able to suppress inflammation induced by the COVID-19 virus at a dose lower than typically used in cancer treatment.
“Topotecan has been used in oncology for over 25 years, with a well-understood safety profile in humans, and importantly is both inexpensive and globally available.
"This research is therefore timely given the lack of universal access to vaccines,” said Dr Jeyasekharan, consultant and assistant director of research (Medical Oncology) at the Department of Haematology-Oncology at NCIS.
Scientists have observed that the virus triggers excess production of chemicals that are normally secreted by cells of the immune system to help fight infection, NCIS said.
“In some patients, an exaggerated immune system response, which characteristically occurs in the lungs, can flood the infected area with white blood cells, resulting in severe inflammation, tissue damage and often death,” a spokesperson said,
“Reduction of the inflammatory state in such patients could therefore improve their clinical outcomes.”
FINDING A SOLUTION TO INFLAMMATION
Associate Professor Ivan Marazzi of the Microbiology Department at the Icahn School of Medicine at Mount Sinai said that so far, in pre-clinical models of COVID-19, there are no therapies shown to reduce SARS-CoV-2 inflammation when administered after more than one day post-infection.
“This is a huge problem because people who have moderate or severe COVID-19 often do not present to hospitals until many days after infection,” he said.
The cancer drug was however found to be able to limit the “hyper-inflammation” in the lungs of infected animals even days after the infection, he added.
The current study, which also has contributions from partners in Hong Kong, the United Kingdom and other global sites, expands on a 2016 research paper by Dr Marazzi’s team, which was also published in a journal.
The earlier research found that inhibiting the activation of inflammatory genes by the cancer drug could help prevent animal deaths from viral and bacterial infections, and suggested this could be a potent strategy against future pandemics, NCIS said.
Dr Jeyasekharan said that repurposing of existing drugs represents a valuable global strategy for treating COVID-19.
However, only a few that show pre-clinical promise have gone on to be efficacious in patients, he said.
“Topotecan is an attractive candidate given that it is safe and inexpensive with generic formulations existing throughout the world,” he added.