Bemcentinib
Who makes it?
It’s a tablet developed by the Norwegian company BerGenBio. It’s known as an AXL kinase inhibitor.
What have studies shown?
Bemcentinib is likely to have been chosen because lab tests have shown it has potent anti-viral activity against several enveloped viruses, including Ebola and Zika virus.
Preliminary data suggest bemcentinib is potentially useful for the treatment of early SARS-CoV-2 infection.
How does it work?
Lab studies by the University of Iowa found the pill can boost immune response and switch off AXL receptors, which when turned on, allow the virus to enter and multiply in lung cells.
The number of AXL receptors increases when their environment is stressed, particularly when viruses start multiplying in the body. When AXL receptors are hijacked by invading viruses, the cell’s antiviral powers are switched off and it becomes defenceless to the disease.
Blocking AXL receptors also prompts a type I interferon response, alerting the body to the coronavirus and calls for more immune cells to attack it.
What does it usually treat?
Bemcentinib was being trialled against cancers, including adult acute myeloid leukemia and non-small cell lung cancer (NSCLC). But it is not approved as a treatment in any country.
MEDI3506
Who makes it?
MedImmune, a subsidiary of drug giant AstraZeneca. The anti-inflammatory injection is an interleukin-33 inhibitor.
What have studies shown?
No results from Covid-19 patients have been released yet.
How does it work?
Interleukin-33 (IL-33) is a cytokine involved activating the immune system. It acts as an alarm signal to alert various types of immune cells to trauma.
An IL-33 inhibitor such as Medi3506 acts to dampen down the cytokine storm as a result of the immune system going into overdrive in response to an infection.
What does it usually treat?
It’s being tested for chronic obstructive pulmonary disease (COPD), dermatitis, and diabetic kidney disease.
Acalabrutinib
Who makes it?
Calquence, generic name acalabrutinib, is produced by British company AstraZeneca. It is a Bruton’s tyrosine kinase (BTK) inhibitor.
What have studies shown?
Calquence was given to a small number of COVID-19 patients at the Walter Reed General Hospital in Washington. Experts observed it had ‘some clinical benefit’.
AstraZeneca, headquartered in Cambridge, said ‘clinical benefit was observed in select patients with advanced lung disease’.
How does it work?
COVID-19 can kill when it sparks an aggressive immune response that scars the lungs, making it difficult to breathe.
BTK inhibitors blocks the BTK protein which triggers immune responses. The immune response can go haywire following infection which leads to a so-called cytokine storm. A cytokine storm eventually begins damaging the body itself and, if left unchecked, can be fatal.
By suppressing the exaggerated defence mechanism, it may prevent the virus from damaging the lungs.
Jose Baselga, head of oncology research and development at AstraZeneca, told Forbes: ‘The science of acalabrutinib and, I think more than that, of Bruton’s tyrosine kinase situation, is pretty strong. The mechanism is very clear.’
What does it treat?
It’s a medication used to treat a type of non-Hodgkin lymphoma known as mantle cell lymphoma. It works by blocking BTK that contributes to cancer cell growth and survival.
Zilucoplan
Who makes it?
A drug injected under the skin developed by the Belgian company UCB. The treatment was developed originally by Ra Pharmaceuticals.
What have studies shown?
Nothing has been released for Covid-19 so far.
How does it work?
Zilucoplan is a synthetic molecule designed to bind and inhibit portions of the immune system called the complement system. The complement system is made up of a large group of blood proteins that are involved with the immune system but can kill cells and lead to catastrophic lung and tissue damage.
‘A lot of the damage is focused on the blood cells and the very small blood vessels in the lung,’ Dr Wilkinson said.
By blocking the complement system, zilucoplan may be able to reduce the attack of healthy tissues in the lung, preventing worsening of Covid-19.
What has it been used for?
It has shown to improve myasthenia gravis, a skeleto-muscular disorder, in ongoing clinical trials.
Heparin
Who makes it?
Heparin is an ingredient sold in many different products, marketed as Fragmin, Monoject Prefill Advanced and Innohep.
What have studies shown?
No results have been published yet. It will be given to Covid-19 patients for the first time next month.
How does it work?
Blood clotting problems have emerged in severe and critically-ill COVID-19 patients, affecting the lungs, heart and brain. Some patients are dying from heart attacks or strokes, a complication of the virus.
It’s left doctors considering whether blood thinners should be given to certain patients during their stay and afterwards.
In a number of conditions, heparin has been shown to ‘have a dramatic effect in the lung’ when taken with a nebuliser, said Wilkinson. ‘It is a big sticky molecule which can attach to viruses and stop them from entering cells and secondly it may have an important anti-inflammatory effect,’ he said.
What has it been used for?
Heparin is a blood thinner used to treat and prevent blood clots caused by certain medical conditions. It is also used before surgery to reduce the risk of blood clots.
It is on the World Health Organization’s List of Essential Medicines, the safest and most effective medicines needed in a health system.