What is Regeneron’s antibody cocktail?
The human body creates Y-shaped proteins called antibodies whenever there is a foreign pathogen that enters. These antibodies signal other chemicals in the immune system to eliminate the pathogen.
B cells, a type of white blood cell, adapt the antibodies to prepare an immune response to a foreign pathogen. The arrangement made by B cells may or may not be useful to defend against a virus and other threats. If the B cell encounters the pathogen under the right circumstances, the body will start a clonal expansion to produce more defensive cells to defeat the pathogen.
Regeneron created an antibody combination of 2 monoclonal antibodies: REGN10933 and REGN10987. They designed them to target the spike protein before it can harm the ACE2 receptor.
The antibody cocktail lowered the SARS-CoV-2 viral loads and disease in trials of golden hamsters and rhesus macaques. More trials are necessary to prove safety and efficacy in human patients.
Alexandra Bowie of Regeneron commented on this experimental therapy:
“Like many biopharma companies that conduct scientific research (see Pfizer, J&J, for instance), we have a general position statement on stem cell use,” Bowie said. “We share this and other similar statements in the interest of transparency and to help educate people on the steps we take to conduct our business responsibly.”
It seems Regeneron used fetal-derived cells from their early research to develop this therapy. It is an outlier from industry practice given most pharma and biotech research teams would use adult stem cells, which everyone has in their bodies during their lifetime.
Cell division produces more living cells regularly. Organs and tissues hold stem cells in reserve to replace our cells. There is a clear difference between an adult stem cell that may be derived from the bone marrow of an adult patient with consent and a fetal stem cell.
A paper published in Science mentioned HEK293T cells. These are considered an epithelial cell group derived from embryonic kidney cells. Bowie indicated that HEK293T cells were applied and stem cells were not.
“This particular discovery program (REGN-COV2) did not involve human stem cells or ESCs,” she wrote. “The 293T cell line was originally derived from human embryonic kidney cells but is an immortalized epithelial cell – so not a stem cell. These cells were transfected and used in production of a ‘pseudoparticle’ that mimics the virus’ Spike protein and allowed us to test neutralization ability of our antibodies against the virus.”