Anti-malarial drug to go on trial in SA and globally to test whether it blocks Covid-19

South African scientists are preparing to join a major international clinical trial to test whether the antimalarial drug chloroquine — similar to the drug which US President Donald Trump claims to be taking, outside of scientific guidelines — can protect healthcare workers from Covid-19 infection.

“The trial among healthcare workers is firstly to determine whether chloroquine prophylaxis does prevent Covid-19 infection, and secondly whether it decreases the severity of the infection. We will be testing three different doses,” the study’s national co-principal investigator, Prof Bruce Biccard, said on Wednesday.

Biccard, in the department of anaesthesia and perioperative medicine at Groote Schuur hospital in Cape Town, said: “The only way we can answer these questions is with a really big trial. The small trials which have been published [to date] are inconclusive, as they are underpowered.

“There are politicians who admit to taking hydroxychloroquine and similar things. Taking a drug with no proven efficacy, when it is not indicated, is irresponsible. It is dangerous and cannot be advocated. It means there is less of the drug available for other diseases where it is indicated and potentially life-saving, such as malaria.”

The Crown Coronation study is a pre-exposure prophylaxis trial that tests the protective benefits of chloroquine. This research is not testing the drug as a treatment for hospitalised patients with severe Covid-19.

As a treatment, chloroquine has proved ineffective in two US studies published to date.

National co-principal investigator Prof Sinéad Delany-Moretlwe, director of research at the Wits Reproductive Health and HIV Institute (RHI) in Johannesburg, said: “Maybe the chloroquine was not enough at that point or it was too late. Before infection or treatment early on may be where it is most effective.”

A small trial in Brazil testing chloroquine for severe Covid-19  was stopped early because of unsafe cardiac side effects, but their doses were extremely high, said Biccard. “Our doses will be nowhere near that,” he added.

“In theory, chloroquine is a great drug to try because it blocks some of the pathways the virus uses to attach to cells and has high concentrations in the lungs, so it’s a win-win.

“It is a cheap drug which is globally accessible and has an established safety profile. And if it shows efficacy, we will rapidly be able to supply it to healthcare workers.”

Clinical researchers in SA hope to recruit participants soon for the study, but are waiting for final ethical and regulatory approvals before they can go ahead.

The trial —led by Washington University in St Louis, Missouri, the University College of London and Wits — has been approved in the UK, Ireland, the US and Zambia so far. The first patient is likely to be recruited in the US next week.

Researchers hope to enrol about 30,000 healthcare workers across the world and SA could provide about half of that target, said Prof Linda-Gail Bekker, deputy director of the Desmond Tutu HIV Centre at UCT’s Institute of Infectious Disease and Molecular Medicine.

“We will go wherever healthcare workers are at risk,” she said, explaining they would be taking an innovative approach with everything going online, including the consent.

“This is new for clinical trials in SA. We will not make any unnecessary physical contact. We may not even eyeball the individuals. We will courier participants the treatment and swabs.”

Bekker said SA’s contribution to the trial included expanding the definition of a healthcare worker to be very broad, including “anyone who may have exposure — a community nurse that does triage at the door or a porter who may not have N95 masks”.

“If you are working in a health facility in a hotspot area, you will be eligible. If you are working in a clinic in Khayelitsha, you could be more at risk than an anaesthetist in the Karoo,” she said.

“We want to keep healthcare workers alive and well and [this will test] if it is as simple as a pill a day.”

Biccard added: “Africa has such limited healthcare resources — way below what is recommended — the implications of losing healthcare workers, even for two weeks, would be catastrophic for the care of patients during a pandemic.”

SA has to protect its healthcare workers or its vital HIV and TB programmes would be set back, said Delany-Moretlwe.

This trial is among several in SA to test possible treatments for Covid-19.

Prof Francois Venter, director of Ezintsha at Wits, said they were doing a much smaller study on both prevention and early treatment of Covid-19, before hospitalisation, with “various combinations of six drugs, including chloroquine”.

“The SA government department of science and innovation and the SA Medical Research Council  have been helping us to get drugs and have been very good at facilitating this,” he said.

They are currently waiting for funding and hope to start in the next few weeks.

“Protecting healthcare workers is an absolute priority - or anyone in contact with Covid-19, like at an old-age home,” said Venter.