Regeneron has also developed a mAb treatment, and has, like Eli Lilly, stopped its clinical trial in hospitalized patients – in Regeneron’s case, “an independent data monitoring committee warned that the risks might outweigh the benefits for hospitalised patients on high levels of oxygen.” Like Eli Lilly’s drug, Regeneron has reported that its mAB cocktail reduces virus levels in the body and improves symptoms for individuals with COVID-19 who are not hospitalized. Regeneron has also applied to the FDA for an EUA of their mAB therapy, and overall, at least ten COVID-19 antibodies are being tested in clinical trials, with many more under development.
While EUAs can serve to get drugs to patients more rapidly than going through full FDA approval, the use of mAbs outside of clinical trials can make it more difficult to ascertain the therapies’ true effectiveness in different age groups. Furthermore, it could make it harder to enroll volunteers in future clinical trials for alternative therapies, since people may want to take a drug that appears to work, rather than risk possibly getting placebo. Authorizing a low-impact therapeutic could be counterproductive. FDA must take care to only grant EUAs for mAb therapies where the data show they are potent, and clearly delineate the circumstances in which they should be administered to help patients.
Antibodies are expensive and difficult to make, and they are administered at relatively high levels. These factors conspire to limit the number of doses that are produced. By the end of the year, Regeneron is expected to have produced up to 300,000 doses of its cocktail, and Eli Lilly greater than one million. More doses are needed; experts estimate that each day, 10,000 to 15,000 people in the US would be indicated for the drugs based on age and risk factors, even if there’s no further surge of infection.
A major challenge is that manufacturing capacity for monoclonal antibodies is limited, generally actively being used to produce treatments that are needed by patients as therapies for conditions such as cancer, multiple sclerosis, or osteoporosis. Globally, bioreactor capacity for producing mAbs from mammalian cells is spread across 200 facilities, with a total capacity of about 1,500,000 gallons. Constructing new manufacturing capacity requires years, with different types of facilities taking anywhere from 18 months to 7.5 years to come online. Bringing inactive facilities back online is a possibility, but how available such facilities are, and what would be needed to update them for operation, is unclear, and unlikely to happen in the near future. So, COVID-19 mAb manufacturing will need to rely on facilities either in use or in development, at least in the near-term.
Possible roles for government include helping to coordinate the construction of new mAb manufacturing capacity, or the repurposing of existing sites that could serve as bioreactors. Non-traditional mammalian cell lines could be tested to see which produce the highest levels of these mAbs to make the best use of the bioreactor capacity. Also, there are techniques for producing mAb therapies in bacterial or fungal (like brewer’s yeast) cells, in addition to mammalian cells, which could take advantage of existing capacity for microbial fermentation. And regulatory agencies like the Environmental Protection Agency and FDA could help expedite actions like repurposing bioreactor sites or deploying new bioproduction technologies by prioritizing the evaluation of these activities without harming the environment or sacrificing drug safety or efficacy.
Government could also assist with coordination between companies, providing a framework and forum for sharing information about or partnering on manufacturing capacity, or discussing approaches to COVID-19 mAb design that may have already been attempted and that did not pan out. This coordination could even extend to facilitating international collaborations, as COVID-19 mAb development efforts are taking place in countries all around the globe.
Considering COVID-19 is a deadly disease that can also have long-term health impacts for those who survive, the development and deployment of mAb therapies that can be administered soon after infection is detected and reduce the severity of disease are expected to contribute to countering the health effects of the pandemic.
The experts who briefed Congress were Megan Coffee, MD/PhD, Clinical Assistant Professor at New York University; Erica Ollmann Saphire, PhD, Professor at the La Jolla Institute for Immunology and lead of the Coronavirus Immunotherapy Consortium; Jill Horowitz, PhD, Executive Director of the Strategic Operations Laboratory of Molecular Immunology at Rockefeller University; John Cumbers, PhD, CEO of SynBioBeta; Eric Hobbs, PhD, CEO of Berkeley Lights; Jake Glanville, PhD, CEO of Distributed Bio; Mike Fisher, PhD, Senior Fellow at the Federation of American Scientists; and Ali Nouri, PhD, President of the Federation of American Scientists.