Northfield Labs ( NFLD) late Thursday said the Food and Drug Administration refused to approve the human blood substitute, Polyheme, for use in trauma patients suffering from severe blood loss. The FDA's rejection of Polyheme was widely expected because the blood substitute failed its pivotal clinical trial during which serious concerns were raised about the product's safety. Northfield released excerpts of the FDA's letter, which stated the Polyheme pivotal trial, "... did not meet the pre-specified primary efficacy endpoint," and that "based on the totality of the data in the application, FDA has determined that the data submitted do not support the proposed indication." The FDA also noted that "the safety data of all controlled studies reveal that the administration of PolyHeme places the patients at a higher risk of significant adverse events." Northfield was trying to win a race to get the first human blood substitute approved, a race that other companies like Biopure ( BPUR) and Baxter ( BAX) have failed previously. It's been more than two years since Northfield first announced the failure of the phase III Polyheme study, but recall that the death rate for trauma patients treated with Polyheme was more than 13% compared with a death rate of just under 10% for patients treated with saline and blood. Scarier was the study's safety data, which went against Polyheme in every way measured. Patients treated with Polyheme reported more serious adverse events, more heart attacks and greater risks to the kidneys than the control patients. Northfield said Thursday it was evaluating the FDA response and considering the company's options. Northfield is almost out of money. Northfield shares closed Thursday at 50 cents.