Treatment of bleeding in patients with platelet disorders: is there a place for recombinant factor VIIa?

Efficacy of recombinant factor VIIa for severe bleeding complicated by platelet transfusion refractoriness in patients with hematologic malignancies

INTRODUCTION

Severe bleeding with platelet transfusion refractoriness (PTR) is a common complication associated with reduced survival in patients with hematologic malignancies. The present study aimed to evaluate the efficacy of recombinant factor VIIa (rFVIIa) for severe bleeding complicated by PTR.

MATERIALS AND METHODS

Sixty-four patients suffering from severe bleeding with PTR hospitalized in our center between September 2012 and December 2016 were enrolled in this study. Thirty-two patients received rFVIIa (rFVIIa group) and other conventional hemostatic treatments, while the other 32 patients received conventional hemostatic treatments other than rFVIIa (control group).

RESULTS

The baseline parameters of patients before treatment were similar in both groups. The total response rates to hemostatic treatment at 24h and 48h were significantly higher in the rFVIIa group compared with the control group (p=0.014, p=0.020, respectively). Significantly more patients in the rFVIIa group achieved complete responses (CR) at 24h (p=0.031), 48h (p=0.039), and 72h (p=0.021) compared with the control group. The bleeding score (p=0.029), time to control bleeding (p=0.034), and activated partial thromboplastin time (p=0.021) after hemostatic treatment were significantly lower in the rFVIIa group compared with the control group. Patients who achieved a CR to rFVIIa had a significant survival advantage compared with those with a partial response/no response (p=0.020). No complications with venous or arterial thromboembolism were observed during treatment.

CONCLUSIONS

rFVIIa may provide effective and safe hemostasis in patients suffering from severe bleeding and PTR.

Proteases as therapeutics

Proteases are an expanding class of drugs that hold great promise. The U.S. FDA (Food and Drug Administration) has approved 12 protease therapies, and a number of next generation or completely new proteases are in clinical development. Although they are a well-recognized class of targets for inhibitors, proteases themselves have not typically been considered as a drug class despite their application in the clinic over the last several decades; initially as plasma fractions and later as purified products. Although the predominant use of proteases has been in treating cardiovascular disease, they are also emerging as useful agents in the treatment of sepsis, digestive disorders, inflammation, cystic fibrosis, retinal disorders, psoriasis and other diseases. In the present review, we outline the history of proteases as therapeutics, provide an overview of their current clinical application, and describe several approaches to improve and expand their clinical application. Undoubtedly, our ability to harness proteolysis for disease treatment will increase with our understanding of protease biology and the molecular mechanisms responsible. New technologies for rationally engineering proteases, as well as improved delivery options, will expand greatly the potential applications of these enzymes. The recognition that proteases are, in fact, an established class of safe and efficacious drugs will stimulate investigation of additional therapeutic applications for these enzymes. Proteases therefore have a bright future as a distinct therapeutic class with diverse clinical applications.

Recombinant activated factor VII for intractable bleeding post splenectomy in a patient with myeloproliferative disorder

Recombinant activated factor VII has been Food and Drug Administration approved to treat hemorrhages in hemophiliac patients with inhibitors and in acquired hemophilia patients. Recombinant activated factor VII use has also been considered for the management of uncontrolled bleeding in a number of congenital and acquired hemostatic abnormalities. The myeloproliferative disorders are a group of clonal hematologic diseases where, frequently, abnormal platelet function is considered a hallmark. This is the first case report addressing the clinical benefit of off-label use of recombinant activated factor VII in an attempt to control intractable bleeding in a patient with a myeloproliferative disorder after splenectomy.

Recombinant activated factor VII combined with desmopressin in preventing bleeding from dental extraction in a patient with Glanzmann's thrombasthenia

The case of a 41-year-old woman with Glanzmann's thrombasthenia who underwent double dental extraction is presented. In the past, treatments with desmopressin (DDAVP) and tranexamic acid had often unsuccessful efficacy to stop or decrease bleeding. After ineffective DDAVP administration, the removal was performed successfully with recombinant activated factor VII (rFVIIa) infusion. rFVIIa infusion after DDAVP administration could be useful in patients with Glanzmann's thrombasthenia in which DDAVP and tranexamic acid weren't always effective.

Recombinant factor VIIa is an effective therapy for abdominal surgery and severe thrombocytopenia: a case report

A 50-year-old woman was admitted to the emergency room. An appendectomy was done. On the sixth day the patient's general state deteriorated and she became somnolent with jaundice due to distal obstructive choledocholithiasis. The results of laboratory tests were platelets 12 x 10(9)/L, prothrombin time 13 seconds, international normalized ratio 1.19, activated partial thromboplastin time 31.8 seconds, and fibrinogen 8.78 g/L. There was no evidence of disseminated intravascular coagulation. In view of the patient's clinical condition, surgery was considered to be indicated. Because it was a life-threatening situation and at the time there was no platelet concentrate available for immediate transfusion, she was treated with a single dose of recombinant factor VIIa (rFVIIa) (60 microg/kg). The dose of 60 microg/kg was selected on the basis of experience with rFVIIa in the treatment of hemophilic patients. In this case, use of rFVIIa was a valid alternative to control the bleeding in a patient with thrombocytopenia. However, despite the efficacy of the treatment, it should not be forgotten that it was used because of the unavailability of platelets and that we were dealing with a life-threatening situation. Clinical trials should be carried out to verify the safety, effectiveness, and efficiency of rFVIIa in these cases.

The use of recombinant factor VIIa for severe intractable bleeding during spine surgery

STUDY DESIGN

A report on the use of recombinant activated factor VII in 4 patients who developed severe intractable bleeding and coagulopathy during spine surgery.

OBJECTIVE

To describe the role of recombinant activated factor VII for hemostasis during spine surgery.

SUMMARY OF BACKGROUND DATA

Recombinant activated factor VII is indicated for the treatment of bleeding episodes and the prevention of bleeding during surgery in patients with hemophilia with inhibitors. However, its use in adults undergoing spine surgery has not yet been reported.

METHODS

Four patients who underwent multilevel spine surgery through an anterior approach incurred massive bleeding and subsequently became coagulopathic. Standard hemostatic techniques were performed and blood products were transfused. Persistence of the bleeding prompted the use of recombinant activated factor VII.

RESULTS

Treatment with recombinant activated factor VII led to an improvement in prothrombin time and partial thromboplastin time and brought about cessation in gross, nonsurgical bleeding intraoperatively. No clinically relevant thrombotic complications related to the drug were noted.

CONCLUSIONS

Recombinant activated factor VII is promising as an adjunctive hemostatic agent for patients with perioperative bleeding problems during spine surgery. Efficacy is seen even at low doses.

Platelet function in term and preterm neonates

Platelet dysfunction likely contributes to the pathophysiology of catastrophic hemorrhages in preterm neonates. In vitro studies have demonstrated that platelets of both term and preterm neonates are hyporesponsive to a variety of agonists. In contrast,template bleeding times of term neonates are shorter than those from adults. Very little is known about this and other tests of primary hemostasis in premature and sick neonates in the neonatal intensive care unit (NICU). This article covers the current knowledge of platelet function in preterm and term neonates and review show new agents (such as recombinant thrombopoietin and recombinant factor VIIa) may enhance neonatal platelet function.

Inherited thrombocytopenias: toward a molecular understanding of disorders of platelet production

PURPOSE OF REVIEW

To review the defined syndromes of inherited thrombocytopenia and discuss new genetic data for several disorders that shed light on the process of megakaryopoiesis.

RECENT FINDINGS

The genes responsible for several inherited thrombocytopenias have been recently discovered, including congenital amegakaryocytic leukemia, amegakaryocytic thrombocytopenia with radio-ulnar synostosis, familial platelet syndrome with predisposition to acute myelogenous leukemia, Paris-Trousseau, Wiskott-Aldrich syndrome, and the May-Hegglin, Sebastian, Epstein, and Fechner syndromes. These clinical syndromes, combined with studies in mouse and in vitro models, reveal the importance of these genes for normal hematopoiesis.

SUMMARY

Although inherited syndromes of thrombocytopenia are rare, characterization of mutations in these disorders has contributed greatly to our understanding of megakaryocyte and platelet development. A systematic registry of congenitally thrombocytopenic individuals would almost certainly lead to new genetic discoveries.