Merck & Co. has agreed to buy Maryland-based OncoImmune for $425 million, marking its third COVID-19-related acquisition in 2020.
OncoImmune’s lead therapy is an engineered protein called CD24Fc. It is in clinical trials to combat cytokine storm, the often-deadly overreaction of the human immune system that can occur with COVID-19.
CD24Fc has two parts. The CD24 chunk recognizes molecular patterns on the surfaces of microbes and injured cells. It also recognizes a protein on the surface of human cells that tamps down the early immune response. The second chunk is the bit of an antibody that can attach to human cells. Put together, the two pieces soak up invasive microbes and turn down the early immune response, OncoImmune says on its website.
OncoImmune scientists decided to test the treatment for COVID-19 after its success in other clinical trials preventing stem cell rejection in people with leukemia and in preclinical work in primates infected with simian immunodeficiency virus, in which the treatment reduced pneumonia.
“CD24Fc may be a prime candidate for non-antiviral biological modifier for COVID-19 therapy,” the company says on its clinical trials web page.
In interim data from 203 people in a Phase 3 trial of CD24Fc, one dose of the treatment reduced the risk of death or respiratory failure by 50% in people with severe COVID-19 who needed oxygen treatment, according to a Merck press release.
Compared to some of its big pharma peers, Merck is a latecomer to COVID-19 therapy development. In June, the company bought Themis and its measles-vector-based vaccine candidate. In July, Merck agreed to develop EIDD-2801, an antiviral created at Emory University and developed by Ridgeback Biotherapeutics.