Patients back from the brink by reducing immune system

DANGEROUSLY ill coronavirus patients are making “startling recoveries” despite being at “death’s door” after being given drugs that dial down the immune system, experts have said.

Trials are taking place with several drugs that prevent a part of the immune system – called the complement system – from becoming overactivated.

The furthest drug along in trials is called ravulizumab, which is already licensed to treat rare blood diseases, and is currently being tested at hospitals in Cambridge, London, Birmingham and Leeds for use in coronavirus.

The drugs are known as “anti-c5” drugs because they prevent a molecule called C5 activating the complement system response, which helps clear away harmful cells and triggers the production of immune cells known as cytokines, which cause inflammation. But when in overdrive it begins attacking the body itself and is thought to play a role in auto-immune diseases.

Speaking at a coronavirus briefing yesterday on the reasons why Covid-19 is so deadly, Prof Paul Morgan, director of the Systems Immunity Research Institute at Cardiff University, said the drugs were providing a lifeline for some patients who were near death.

Four critically ill patients were treated with eculizumab – an earlier version of ravulizumab – in Italy and recovered within 14 days.

“Switching off C5 can have a big effect,” he said. “We and others have used anti-c5 blocking agents in small scales on very severe Covid patients with very promising results.

“These were people who had reached

‘These drugs are now in large clinical trials and we want to see the outcomes in the not-too-distant future’

the stage where there was no further therapy for them; they were on ventilators, and really at death’s door … [some] have made startling recoveries.

“Of course these are small numbers, but these drugs are now in large-scale clinical trials and we want to see the outcomes of those in the not-too-distant future.”

In its early stages, Covid is believed to switch off the body’s ability to make the antiviral proteins called interferons, which is why patients do not feel unwell even with a lot of virus in their body.

Although antiviral drugs such as remdesivir have not proved as successful as hoped in trials, they may work earlier on to stop the immune system overloading.