Recombinant Human Coagulation Factor VIIa Research Articles

Thromboembolic Adverse Events After Use of Recombinant Human Coagulation Factor VIIa

The US Food and Drug Administration (FDA) licensed recombinant human coagulation factor VIIa (rFVIIa) on March 25, 1999, for bleeding in patients with hemophilia A or B and inhibitors to factors VIII or IX. Use in patients without hemophilia has been increasing since licensure. To review serious thromboembolic adverse events (AEs) reported to the FDA's Adverse Event Reporting System (AERS). The AERS database was reviewed from March 25, 1999, through December 31, 2004, for thromboembolic AE reports with rFVIIa. The AERS database includes US and non-US spontaneous AE reports from both approved (specific indications for patients with hemophilia) and unlabeled uses. It also includes serious AEs in patients enrolled in postlicensure clinical trials who received rFVIIa. Manufacturer reporting to FDA is mandatory, but primary notification from clinicians and others to FDA or manufacturers is voluntary for spontaneous reports; therefore, AERS underrepresents actual event occurrences. Reported thromboembolic events occurring in patients administered rFVIIa. A total of 431 AE reports for rFVIIa were found, of which 168 reports described 185 thromboembolic events. Seventeen events occurred in patients with hemophilia and 59 occurred in patients enrolled in postlicensure trials. Unlabeled indications accounted for 151 of the reports, most with active bleeding (n = 115). Reported AEs were thromboembolic cerebrovascular accident (n = 39), acute myocardial infarction (n = 34), other arterial thromboses (n = 26), pulmonary embolism (n = 32), other venous thromboses (including deep vein thrombosis) (n = 42), and clotted devices (n = 10). In 36 (72%) of 50 reported deaths, the probable cause of death was the thromboembolic event. In 144 patients with timing information, 73 events (52%) occurred in the first 24 hours after the last dose (30 events within 2 hours). Sixty-four reports (38%) noted concomitant use of hemostatic agents. Most reports lacked sufficient information to evaluate potential dosage associations. Most reported thromboembolic AEs followed the use of rFVIIa for unlabeled indications and occurred in arterial and venous systems, often resulting in serious morbidity and mortality. Analysis of the relationship between AEs and rFVIIa is hindered by concomitant medications, preexisting medical conditions, confounding by indication, and inherent limitations of passive surveillance. Randomized controlled trials are needed to establish the safety and efficacy of rFVIIa in patients without hemophilia.

Recombinant Human Coagulation Factor VIIa in Jehovah's Witness Patients Undergoing Liver Transplantation

Indisputably, liver transplantation is among the most technically challenging operations in current practice and is compounded by significant coagulopathy and portal hypertension. Recombinant human coagulation factor VIIa (rFVIIa) is a new product that was initially described to treat bleeding in hemophilia patients. We present in this paper 10 liver transplants in Jehovah's Witness patients using this novel product at University of Southern California-University Hospital. The subject population included nine males and one female with an average age of 50 years. Six patients underwent cadaveric and four live donor liver transplantation. Surgeries were conducted following our established protocol for transfusion-free liver transplantation, which includes preoperative blood augmentation, intraoperative blood salvage, acute normovolemic hemodilution, and postoperative blood conservation. Factor rFVIIa was used at a dose of 80 microg/kg intravenously just prior to the incision in all patients, and a second intraoperative dose was used in 3 patients. All living donor liver transplantation (LDLT) recipients did well and were discharged uneventfully with normal liver functions. Two of the six cadaveric recipients died. One patient died intraoperatively from acute primary graft nonfunction, and the other died 38 hours postoperatively from severe anemia. This report suggests factor rFVIIa might have a much broader application in surgery in the control of bleeding associated with coagulopathy.

Posttranslational N-glycosylation takes place during the normal processing of human coagulation factor VII

N-glycosylation is normally a cotranslational process that occurs during translocation of the nascent protein to the endoplasmic reticulum. In the present study, however, we demonstrate posttranslational N-glycosylation of recombinant human coagulation factor VII (FVII) in CHO-K1 and 293A cells. Human FVII has two N-glycosylation sites (N145 and N322). Pulse-chase labeled intracellular FVII migrated as two bands corresponding to FVII with one and two N-glycans, respectively. N-glycosidase treatment converted both of these band into a single band, which comigrated with mutated FVII without N-glycans. Immediately after pulse, most labeled intracellular FVII had one N-glycan, but during a 1-h chase, the vast majority was processed into FVII with two N-glycans, demonstrating posttranslational N-glycosylation of FVII. Pulse-chase analysis of N-glycosylation site knockout mutants demonstrated cotranslational glycosylation of N145 but primarily or exclusively posttranslational glycosylation of N322. The posttranslational N-glycosylation appeared to take place in the same time frame as the folding of nascent FVII into a secretion-competent conformation, indicating a link between the two processes. We propose that the cotranslational conformation(s) of FVII are unfavorable for glycosylation at N332, whereas a more favorable conformation is obtained during the posttranslational folding. This is the first documentation of posttranslational N-glycosylation of a non-modified protein in mammalian cells with an intact N-glycosylation machinery. Thus, the present study demonstrates that posttranslational N-glycosylation can be a part of the normal processing of glycoproteins.

The use of recombinant factor VIIa in a primigravida with Glanzmann’s thrombasthenia during delivery

Glanzmann's thrombasthenia is an inherited hemorrhagic disorder characterized by a severe reduction in, or absence of, platelet aggregation in response to multiple physiologic agonists due to qualitative or quantitative abnormalities of platelet glycoprotein IIb-IIIa. Glanzmann's thrombasthenia is characterized by potentially major mucocutaneous bleeding and prolonged bleeding time. Platelet counts, platelet morphology, prothrombin, and activated thromboplastin times are all within normal ranges in patients with Glanzmann's thrombasthenia. Pregnancy and delivery are rare in Glanzmann thrombasthenia patients and have been associated with immediate postpartum hemorrhage. We describe the peripartum management of a 31-year-old primipara with Glanzmann's thrombasthenia who underwent spontaneous vaginal delivery. Four units of single-donor platelets, two units of packed red blood cells, 36 microg/kg recombinant human coagulation Factor VIIa (rFVIIa) were given during peripartum management.

Failure of recombinant FVIIa as treatment for abdominal bleeding in acquired hemophilia

American Journal of HematologyVolume 66, Issue 1 p. 67-68 Letters and CorrespondenceFree Access Failure of recombinant FVIIa as treatment for abdominal bleeding in acquired hemophilia M. Makris, M. Makris Sheffield Haemophilia and Thrombosis Centre, Royal Hallamshire Hospital, Glossop Road, Sheffield, United KingdomSearch for more papers by this authorK.K. Hampton, K.K. Hampton Sheffield Haemophilia and Thrombosis Centre, Royal Hallamshire Hospital, Glossop Road, Sheffield, United KingdomSearch for more papers by this authorE.E. Preston, E.E. Preston Sheffield Haemophilia and Thrombosis Centre, Royal Hallamshire Hospital, Glossop Road, Sheffield, United KingdomSearch for more papers by this author M. Makris, M. Makris Sheffield Haemophilia and Thrombosis Centre, Royal Hallamshire Hospital, Glossop Road, Sheffield, United KingdomSearch for more papers by this authorK.K. Hampton, K.K. Hampton Sheffield Haemophilia and Thrombosis Centre, Royal Hallamshire Hospital, Glossop Road, Sheffield, United KingdomSearch for more papers by this authorE.E. Preston, E.E. Preston Sheffield Haemophilia and Thrombosis Centre, Royal Hallamshire Hospital, Glossop Road, Sheffield, United KingdomSearch for more papers by this author First published: 11 December 2000 https://doi.org/10.1002/1096-8652(200101)66:1<67::AID-AJH1015>3.0.CO;2-MCitations: 4AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat REFERENCES 1Liebman HA, Chediak J, Fink KI, Galvez AG, Shah PC, Sham RL. Activated recombinant human coagulation factor VII (rFVIIa) therapy for abdominal bleeding in patients with inhibitory antibodies to factor VIII. Am J Hematol 2000; 63: 109 Citing Literature Volume66, Issue1January 2001Pages 67-68 ReferencesRelatedInformation

Local application of recombinant active-site inhibited human clotting factor VIIa reduces thrombus weight and improves patency in a rabbit venous thrombosis model

To study whether locally administered recombinant inactivated human coagulation factor VIIa (FFR-rFVIIa) would reduce the thrombus formation and improve patency in an experimental venous thrombosis model without inducing systemic changes in the coagulation. Experimental double-dummy randomised study. In 20 healthy New Zealand White rabbits both jugular veins were exposed under general anaesthesia. The thrombi were induced in a 10 mm long jugular vein segment with a combination of chemical destruction of the intima and a restriction of the bloodflow. Each segment was treated with either FFR-rFVIIa or placebo injected directly into the vein. 1.5 mg topically applied FFR-rFVIIa significantly reduced the thrombus weight (p < 0.001). The 30 and the 120 min patency tests were significantly improved (p < 0.05 and p < 0.001, respectively) Plasma analyses (APTT, dilute-TF time, FVII protein) were evaluated as baseline, 3 min after declamping and at sacrifice. No prolongation of the clotting times were seen. FFR-rFVIIa protein was detected in minute amounts (ng/ml); however, this was not enough to prolong the dilute-TF time. Local application of recombinant active-site inhibited human FVIIa reduced both thrombus weight and improved patency significantly in an experimental venous thrombosis model without affecting the systemic clotting times.

Activated Recombinant Human Coagulation Factor VII Therapy for Intracranial Hemorrhage in Patients with Hemophilia A or B with Inhibitors

Activated recombinant human coagulation factor VII (rFVIIa) is a promising new therapeutic agent for patients with hemophilia A or B with inhibitors who experience serious bleeding episodes or who need coverage during surgical procedures. This open-label, uncontrolled, emergency-use study evaluated the efficacy and safety of rFVIIa in 11 hemophiliac patients and 1 FVII-deficient patient with life-threatening intracranial hemorrhage previously unresponsive to one or more alternative therapies. rFVIIa effectively controlled intracranial hemorrhage in 10 of the 12 patients. Patients with hemophilia A or B received an average of 96.9 rFVIIa injections over 14.7 days with a mean total administration of 153.3 mg, corresponding to 8.1 mg/kg. Most reported adverse events were considered to be unrelated to rFVIIa therapy. These findings suggest that rFVIIa is an effective and well-tolerated therapeutic option in the management of central nervous system bleeding in patients with hemophilia A or B with inhibitors.

Internalization and Degradation of Recombinant Human Coagulation Factor VIIa by the Human Hepatoma Cell Line HuH7

Previous studies demonstrated that several normal and transformed cultured human cell lines specifically bind human coagulation factors VII and VIIa via tissue factor. In the present study, we show that 125I-radiolabeled recombinant human factor VIIa (125I-rFVIIa) binds to a human hepatoma cell line (HuH7). In the presence of rabbit polyclonal anti-human tissue factor apoprotein IgG, binding of 125I-rFVIIa to the HuH7 cells was decreased approximately 60%, suggesting of tissue factor-independent binding sites for 125I-rFVIIa on these cells. The binding isotherm of 125I-rFVIIa for the HuH7 cells in the presence of anti-tissue factor IgG exhibited a hyperbolic profile and was time-, temperature- and calcium-dependent. Furthermore, binding at 4 degrees C was specific, dose-dependent and saturable. Scatchard analysis of the binding data demonstrated a single class of binding sites with a dissociation constant (Kd) of 3.2 nM and 27,000 binding sites per cell. At 4 degrees C, 125I-rFVIIa bound to, and eluted from, the cell was indistinguishable from offered 125I-rFVIIa as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by autoradiography. The molecular properties of the tissue factor-independent binding protein were studied by using the cleavable cross-linking agent 3,3'-dithiobis(sulfosuccinimidylpropionate). A cross-linking product of 125I-rFVIIa and a cell surface protein with an apparent M(r) approximately 100,000 was observed. The cross-linking reaction was strongly inhibited by a 100-fold molar excess of unlabeled rFVIIa, but not by rabbit polyclonal anti-human tissue factor apoprotein IgG, indicating that cross-linking does not involve the extracellular domain of tissue factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of Recombinant Human Blood Coagulation Factor VIIa Amidolytic and Proteolytic Activity by Zinc Ions

Although it is well established that calcium is an essential cofactor in blood coagulation, recent experimental evidence suggests that zinc may also play an important role in hemostasis. In the present study, we have examined the effect of zinc ions on the amidolytic and proteolytic activity of recombinant factor VIIa in the presence of physiological levels of calcium ions. The amidolytic activity of factor VIIa was inhibited half-maximally by 20 microM zinc. The amidolytic activity of a derivative of factor VIIa lacking the gamma-carboxyglutamic acid domain was also inhibited half-maximally by 20 microM zinc, suggesting that the mechanism of zinc inhibition of factor VIIa amidolytic activity did not involve its gamma-carboxyglutamic acid residues. The amidolytic activity of a complex of recombinant tissue factor and factor VIIa was inhibited half-maximally by 70 microM zinc. In contrast to the results obtained with factor VIIa, the amidolytic activities of other human vitamin K-dependent coagulation proteases including factor Xa, thrombin and activated protein C were not appreciably affected by 50-100 microM zinc. The proteolytic activation of factor X by a complex of factor VIIa and relipidated tissue factor apoprotein was inhibited half-maximally by 40 microM zinc, whereas activation of factor IX in this system was inhibited half-maximally by 70 microM zinc ions. Considerably higher levels of zinc (approximately 100 microM) were required to inhibit half-maximally the rate of factor X activation by a complex of factor VIIa and functional tissue factor on the surface of either a human bladder carcinoma cell line, J82, or stimulated human umbilical vein endothelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)