When I reported last month that San Diego-based Sangart had raised $50 million in additional venture funding, CEO Brian O’Callaghan was eager to discuss how the biopharmaceutical has progressed in a field where others ran aground. But O’Callaghan, who is every bit as Irish as his name sounds, was unavailable at the time. So I met with him recently after touring Sangart’s impressive manufacturing facility, where the company now makes an oxygen-carrying compound from donated blood that has outlived its 45-day expiration date. But don’t call Sangart’s MP4 compound a blood substitute, even though it represents the latest effort in a decades-long scientific quest for a such a substance.
“This product has been designed to have the exact molecular size, viscosity, oxygen affinity and diffusion rate as human hemoglobin,” O’Callaghan said. “What that really means is that this product carries oxygen very well, and can transport it into oxygen-starved tissue. It can get into the micro-vasculature, opens it back up, and it releases the oxygen there.”
But Sangart does not describe its compound as a blood substitute. Rather, it is a biological product the company calls an oxygen therapeutic. MP4 is an oxygen-carrying molecule that Sangart makes by chemically modifying human hemoglobin purified from donated blood. The molecule also is pegylated (i.e. treated with polyethylene glycol) which allows the MP4 compound to reach oxygen-starved tissue before releasing its oxygen molecules.
“The entire concept of a blood substitute is incorrect,” said Dr. Howard Levy, who became Sangart’s chief scientific officer in December. Blood consists of more than red blood cells, Levy explains. It is the river that also carries immune cells, clotting factors, and nutrients throughout the body. “The ideal of having a fluid that you could just hang [in an IV bag] and have it as a substitute for blood just doesn’t exist.”
In addition to overseeing clinical trials of Sangart’s MP4 oxygen therapeutic, Levy also bears the task—along with O’Callaghan—of carrying on where Sangart’s founder, the late Robert M. Winslow, left off. Winslow, who founded Sangart in 1998 and headed the company until last year, died on Feb. 2 after battling brain cancer. He came