Safety of Recombinant Human Factor XIII in a Cynomolgus Monkey Model of Extracorporeal Blood Circulation

Abstract

Factor XIII (FXIII) is a thrombin-activated plasma coagulation factor critical for blood clot stabilization and longevity. Administration of exogenous FXIII to replenish depleted stores after major surgery, including cardiopulmonary bypass, may reduce bleeding complications and transfusion requirements. Thus, a model of extracorporeal circulation (ECC) was developed in adult male cynomolgus monkeys (Macaca fascicularis) to evaluate the nonclinical safety of recombinant human FXIII (rFXIII). The hematological and coagulation profile in study animals during and after 2 h of ECC was similar to that reported for humans during and after cardiopulmonary bypass, including observations of anemia, thrombocytopenia, and activation of coagulation and platelets. Intravenous slow bolus injection of 300 U/kg (2.1 mg/kg) or 1000 U/kg (7 mg/kg) rFXIII after 2 h of ECC was well tolerated in study animals, and was associated with a dose-dependent increase in FXIII activity. No clinically significant effects in respiration, ECG, heart rate, blood pressure, body temperature, clinical chemistry, hematology (including platelet counts), or indicators of thrombosis (thrombin:antithrombin complex and D-Dimer) or platelet activation (platelet factor 4 and beta-thromboglobulin) were related to rFXIII administration. Specific examination of brain, heart, lung, liver, and kidney from rFXIII-treated animals provided no evidence of histopathological alterations suggestive of subclinical hemorrhage or thrombosis. Taken as a whole, the results demonstrate the ECC model suitably replicated the clinical presentation reported for humans during and after cardiopulmonary bypass surgery, and do not suggest significant concerns regarding use of rFXIII in replacement therapy after extracorporeal circulation.

Factor XIII Transglutaminase Supports the Resolution of Mucosal Damage in Experimental Colitis

“…The sum of a semi-quantitative intestinal bleeding score, stool consistency score and weight loss score was used to generate a Disease Activity Index (DAI) as follows: bleeding score (0—no bleeding, 1—occult blood only, 2—minimal visible blood in feces, 3—evident blood in stool/rectal bleeding); stool consistency score (0—normal, 1—semi-formed, 2—frank diarrhea); weight loss score (0—no weight change, 1—loss of 1 to 5% of body weight, 2—loss of 5 to 10%, 3—loss of 10–15%, 4—loss of >15% of body weight). Recombinant human FXIII-A (rFXIII) produced by Novo Nordisk has been previously described [ 35 , 36 ]. Mice received either rFXIII (4 mg/kg) or an equal volume of vehicle via an initial intravenous injection the day before DSS challenge followed by an intraperitoneal injection (4 mg/kg) once daily for 14 days starting at the initiation of DSS.…”

Characterization of high molecular weight plasma protein complexes induced by clotting factor rFXIII‐treatment in the cynomolgus monkey

“…Platelet counts, prothrombin time, activated partial thromboplastin time, D‐dimer levels and thrombin–antithrombin complex (TAT) levels were determined by standard methods, as described previously [6,10]. Analysis of plasma FXIII levels was performed using three complementary sandwich ELISAs, measuring total A 2 subunit content, A 2 B 2 tetramer content, and free B 2 subunit content, essentially as described previously [9].…”

“…Factor XIII (FXIII) deficiency in humans is associated with hemorrhagic diathesis, impaired wound healing and miscarriage [1]. Recently, human FXIII has been produced in yeast, to provide a safer alternative to plasma‐derived products [2–8]. However, in cynomolgus monkeys exposed to suprapharmacological levels of recombinant factor XIII (rFXIII) (more than tenfold above expected clinical dose), the dose–toxicity response has been found to be steep, with small increments in rFXIII dose above 22.5 mg kg −1 leading to lethality [9].…”

Treatment and monitoring of coagulation abnormalities in children undergoing heart surgery

“…Human and recombinant factor XIII has been described for use during heart surgery (64–66) and is supported by animal work (67). Factor XIII functions by stabilizing and strengthening bonds in the fibrin polymer and would, therefore, be expected to contribute to clot strength and stability.…”