- Scientists are trying to develop antigen therapies over the next few months
- Two are already in clinical trials; more are likely to reach this stage in a few weeks
- Used to develop immunity injections from blood of recovered COVID-19 patients
- Mass manufacturing is an issue, but can act as temporary vaccine
While vaccines that can permanently halt spread of COVID-19 are months away, scientists are pinning hopes on a temporary therapy by the end of the year - injecting antigens from cured patients, to arrest spread of the virus in human body. While two such therapies have entered the human clinical trial phase, more are expected in the coming weeks.
From the first week of June, the US multinational drug maker Eli Lilly and its Canadian biotech partner AbCellera started the first phase of clinical trials of lead COVID-19 antibody treatment candidate, LY-CoV555, in 30 patients at medical centers in the US such as the New York University Grossman School of Medicine and Cedars-Sinai in Los Angeles. The scientists developed an investigational candidate within three months from the blood of COVID-19 recovered patients.
In this therapy, scientists use a cured COVID-19 patient's successful immune response to develop a drug and neutralise the viruses. Such drugs are not vaccines, but can temporarily give weeks or months of protection, especially to healthcare workers. But its limitations can't be ignored. The drugs for antigen therapy, used in development of many biologics, are complex to make. The technology for mass production is not available as it is for vaccines and these drugs may make sick people sicker, as scientists are yet to master the genetic constitution of the six-seven months old COVID-19 virus.
A couple of days ago, Eli Lilly and its Chinese partner Junshi Biosciences of Shanghai, began the phase I clinical trial for a second COVID-19 antibody therapy. Lilly and Junshi Biosciences are jointly developing this candidate therapy, JS016. Lilly has exclusive rights for the therapy for the rest of the world. Another US biotech Regeneron is also planning to test its antibody cocktails in three different clinical programs starting from this month.
The US based Vir Biotechnology is developing two treatments -- VIR-7831 and VIR-7832 -- in collaboration with GlaxoSmithKline, which bought a stake in Vir for $250 million to access its COVID-19 biologics under development. The partners have a commercial supply arrangement for antibodies with Biogen and is hoping to push the candidates into trials soon. AstraZeneca, which licensed six neutralising antibodies from Vanderbilt University in the US, is also readying to test a combination of monoclonal antibodies within next few weeks. Berkeley Lights, GenScrip etc are some other biotech companies trying to develop antigen therapies.