Phase 2 Dose Finding Trial of Prophylactic Darbepoetin Alfa to Improve Outcomes From Ischemic Complications of Surgery

Numerous neuroprotectants have been effective when given prior to ischemic stroke in animals, yet they have all have failed when given after ischemic stroke in humans. A novel approach to ischemic neuroprotection is needed. Many patients who undergo cardiac, vascular, and neurosurgical procedures develop ischemic central nervous system (CNS) complications. These high risk surgeries present a unique opportunity to administer neuroprotectant medication prior to the injury, greatly increasing the likelihood that it will have a positive impact on outcomes. Patients undergoing descending thoracic aortic (DTA) and thoracoabdominal aortic (TAA) surgery have a particularly high rate of both brain and spine ischemia. In addition, these surgeries require placement of a lumbar cerebrospinal fluid (CSF) drain, allowing access to CSF in order to monitor markers of injury and penetration of medication into the CNS. We performed a pilot dose finding trial of prophylactic darbepoetin alfa, a long-acting erythropoiesis medication with putative neuroprotectant properties, in patients undergoing DTA and TAA surgery. This dose finding trial was stopped early after 9 patients were enrolled at the request of the FDA after an unrelated trial of erythropoietin in acute stroke performed in Germany was negative and showed possible harm in those patients who received intravenous tissue plasminogen activaor (tPA). We then enrolled 9 additional patients who did not receive any intervention in order to compare them to the patients who received darbepoetin.