Covid-19 treatment hopes as GlaxoSmithKline’s antibody drug moves onto phase 3 trial

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A potential new coronavirus antibody treatment made by a British pharmaceutical giant has moved into late stage trials. 

Brentford-based GlaxoSmithKline (GSK) said its treatment – known as Vir-7831 – could be rolled out by 2021 if its proven to be effective and safe.

The drug uses antibodies – proteins found in people who have survived Covid-19 – that have been genetically modified in a lab. These substances are then injected into patients in the earliest stages of their illness.

This is significant because, currently, there are no drugs on the market that prevent people from falling severely unwell with the disease.

The only medicines scientifically proven to have an effect are steroids that for people already on ventilators or with dangerously low oxygen levels. 

An early trial on 20 patients in the US suggested the new antibody medicine was safe and did not cause any adverse health effects.

Now the study will expand across North America, South America and Europe and aim to recruit nearly 1,500 volunteers to see if the drug can prevent serious illness. 

Brentford-based GlaxoSmithKline (GSK) said its treatment – known as Vir-7831 – could be rolled out by 2021 if its proven to be effective and safe

WHAT IS MONOCLONAL ANTIBODY THERAPY?

Monoclonal antibody therapy is a form of immunotherapy that uses monoclonal antibodies (mAb). 

It’s given as an injection under the skin or through a drip into a vein. 

The treatment works in many different ways. It can work in a vaccine-like way, protecting a patient from severe disease, or can help to stimulate the patient’s immune system to attack antigens. 

Hybridoma technology is one method for producing large numbers of monoclonal antibodies – identical antibodies that are clones of a unique parent cell.

The process starts by injecting an animal, such as a mouse, with an antigen that provokes an immune response.  

B cells produces antibodies that bind to the antigen. These antibody producing B-cells are then harvested and used to culture more antibodies. 

The monoclonal antibodies are screened against their ability to work, with initial experiments in animals. 

Major technological advances have made the discovery and development of mAb therapies quicker and more efficient, deriving the antibodies from humans and not animals. 

Scientists can create a mAb that is specific to almost any antigen, and are working on one for the coronavirus.

The spike protein on the SARS-CoV-2 virus is the primary target being explored for potential Covid-19 monoclonal antibodies.

The aim is that by targeting the spike protein, the antibody will be able to neutralise the SARS-CoV-2 virus, therefore stopping it from infecting healthy cells. 

A particularly interesting avenue is giving them to people who aren’t infected yet as a preventative tool. If the antibodies are potent and long-lasting enough, they could provide sufficient protection for a period of time before a vaccine is found.

Research and development is underway to create antibodies for diseases such as rheumatoid arthritis, multiple sclerosis, Alzheimer’s disease, and different types of cancers.

But many are already in use both in the US and UK. 

Since 2008, 48 new mAbs have been approved, contributing to a total global market of 61 mAbs in clinical use at the end of 2017, according to the US FDA.  

Antibodies are proteins the immune system makes when someone becomes infected with a virus, such as the pathogen that causes Covid-19.

But it can take weeks for them to form after being infected or having a vaccine, which is often too late as the virus has already multiplied in the body.

For some people – particularly the elderly and those with weakened immune systems – their bodies struggle to muster up enough antibodies to fight the disease.

GSK’s treatment uses monoclonal antibodies – which have been engineered in a laboratory and mimic antibodies naturally produced by recovered Covid patients. 

If GSK’s therapy works it could be a way to equip people’s immune systems to fight the coronavirus before their condition deteriorates.

Monoclonal antibodies are already being used to treat tetanus, Ebola and diphtheria. 

The therapy has recently been in the spotlight after it was announced that US President Donald Trump was given an experimental cocktail of the proteins following his Covid-19 diagnosis.

Although not yet approved, the company agreed to supply a single dose for Mr Trump at the request of his physician under ‘compassionate use’ provisions.

GSK and San Francisco-based Vir Biotechnology have been working on their treatment since April after joining forces when the pandemic first took off. 

Dr Hal Barron, chief scientific officer and president of research and design at GSK, said: ‘Given the urgent patient need, I am very pleased that we have progressed Vir-7831 from pre-clinical studies to a phase three trial in only six months since announcing our collaboration with Vir.

‘This neutralising antibody’s high barrier to resistance, notable effector function, and enhanced delivery into the lung, suggest it has best-in-class potential in the fight against this global pandemic.’

George Scangos, chief executive officer of Vir, said: ‘The rapid achievement of this important milestone reflects the urgency with which we’re mobilising our resources in the hope of preventing the worst consequences of this deadly virus.

‘Vir-7831 is an antibody with characteristics that may enable it to prevent hospitalisation or death via multiple mechanisms.

‘We look forward to continuing to collaborate with GSK to accelerate its development.’ 

The Comet-Ice (Covid-19 monoclonal antibody efficacy trial-intent to care early) study is evaluating Vir-7831 for the early treatment of Covid-19 in patients with early stages of the disease.

It aims to recruit 1,300 participants, half of whom will receive the drug while the others are given a placebo. 

GlaxoSmithKline also has a vaccine candidate in human trials, which the UK Government has already struck a multi-million pound deal for 60million doses of.

The Department for Business, Energy and Industrial Strategy penned the deal with GSK and Sanofi Pasteur, who has co-created the jab, on July 29. 

The 60million doses are rumoured to have cost £500million, but Britain will only pay if it turns out to work and be effective.

Human trials began this month and the drugmakers hope to follow them up with phase 3 studies by December.