[Name] PolyHeme [Sponsor] Northfield Laboratories [Description] 
Completed US Phase III Trial, failed FDA approval. PolyHeme is a haemoglobin-based oxygen carrier and, as the only blood substitute to have completed a Phase III trial, represents the leading technology in this field. Developed and manufactured by Chicago-based Northfield Laboratories, Inc., Polyheme originally began as a military project following the Vietnam War, and has since shown great potential for both military and civilian use. PolyHeme uses human haemoglobin as the oxygen-carrying molecule in solution, and the extraction and filtration of this haemoglobin from red blood cells is the first step in production. Then, using a multi-step polymerization process, the purified haemoglobin is associated into tetramers and, as the final step, is incorporated into an electrolyte solution. The polymerization of the haemoglobin represents the critical step in this process because, as demonstrated by failed attempts at blood substitutes, when haemoglobin remains disassociated, it tends to take up nitric oxide, causing vasoconstriction. Also, free haemoglobin can be taken up by the kidney,[22] causing dysfunction and failure, similar to a hemolytic transfusion reaction. Northfield Laboratories came under scrutiny for the Phase III trial they conducted in over 20 level 1 trauma centers across the country. The controversy arose from the fact that the participants in this study were incapable of giving their consent due to the nature of their injuries. Even though this practice is sanctioned by the FDA as necessary emergency research, patients’ rights groups have begun to protest the study. In April 2009, Northfield Laboratories announced receipt of an FDA letter regarding its PolyHeme Biologic License Application (BLA) for the treatment of life-threatening haemoglobin levels when red blood cells may not be available. The BLA was not approved, and the letter stated "in the absence of clinical benefit, the risk:benefit assessment of the product in trauma is unfavorable.” [23] In June 2009, Northfield Laboratories filed Chapter 11 bankruptcy.