Israel has just reported a potent monoclonal antibody (mAb) against SARS CoV-2. Firms in South Korea, the US are leading mAb trials.
Israel’s new monoclonal antibody against SARS-CoV-2, isolated by the country’s premier public sector biological research organisation, the Israel Institute of Biological Research (IIBR), joins a line of monoclonal antibodies being proposed against the pathogen. Celltrion, a South Korean pharma company, had announced mid-April that it had identified 14 neutralising monoclonal antibodies (mAbs) in partnership with the Korea Centers for Disease Control and Prevention, from a pool of 300 antibodies that bind to SARS-CoV-2’s surface proteins.
The company is eyeing human trials in July, and has said that it is also on track for the development of an ‘antibody cocktail’. It is important to mention here that South Korea has a high recovery rate, of 86% as on May 4; such a large pool of recovered people could facilitate a wide assessment of convalescent antibody-led lines of treatment, mAbs trials.
Monoclonal antibodies are generated from a single recovered parent-cell in laboratory conditions through the use of genetically modified mice, and are reformatted for use in humans after they show efficacy in beating a pathogen. These are particularly potent, since they target one epitope (site of engagement with the pathogen on its surface) and prevent its entry into a healthy cell. The fact that these engage with a unique epitope means that the pathogen targeted is overwhelmed with very little time for it to develop a mutation against the mAb.
The Israeli authorities—the IIBR reports directly to the prime minister—however haven’t shared any scientific literature on the development or information on laboratory evaluation of their isolated mAb. While, as per news reports, the IIBR researchers are looking to apply for a patent and enter into a commercial partnership with an international pharma company, that will need regulatory approvals for human use after the results of clinical trials are assessed. Human trials will be an important milestone in the progress of an mAb line of therapy, since mAbs, though they mimic antibodies produced by the human body, could have significant side-effects.
Trials of gimsilumab, an mAb developed by Roivant Sciences, was rolled out on April 16 on Covid-19 patients with lung injury or showing signs of Acute Respiratory Distress Syndrome, with the Temple University Hospital in Philadelphia being the primary site of trial. The primary endpoint being considered for the trial is mortality by day 43, with the secondary endpoints being incidence and duration of mechanical ventilation use, number of ICU days and inpatient hospitalisation days. Considering the primary endpoint for the trial, the results should be available by the end of this month.
Researchers at the Utrecht University in the Netherlands have also reported the development of an mAb (named 47D11), in the journal Nature Communications. The mAb neutralised SARS-CoV-2 in in vitro conditions by binding to the Spike surface protein of the virus. The researchers believe the mAb may also have therapeutic use in another coronavirus (SARS-CoV, the pathogen behind SARS), if it passes the clinical trial stage. This would make the Utrecht mAb a bi-specific one, i.e., with efficacy against two pathogens.
Apart from these instances of mAb research targeting Covid-19, American biotech major Regeneron Pharmaceuticals and British-Swedish pharma major AstraZeneca are working on mAb solutions, too. The US’s Darpa is also playing a seminal role in mAb research with many partner biotech firms.