Silva Zupančić-Šalek

Recombinant factor VIIa analog in the management of hemophilia with inhibitors: results from a multicenter, randomized, controlled trial of vatreptacog alfa

Vatreptacog alfa, a recombinant factor VIIa (rFVIIa) analog with three amino acid substitutions and 99% identity to native FVIIa, was developed to improve the treatment of hemophilic patients with inhibitors.

Successful reversal of anticoagulant effect of superwarfarin poisoning with recombinant activated factor VII.

The use of second-generation anticoagulants termed ‘superwarfarins’ as rodenticides, although widespread, is poorly controlled. Products containing superwarfarin have been marketed in over-the-counter rodenticides and can be easily purchased. Poor control potentiates the risk of accidental or intentional poisoning, but clinicians may underestimate the incidence of superwarfarin toxicity. Therefore, when cases of unexplained acquired coagulopathy and selective deficiency of vitamin K-dependent clotting factors occur in patients in the absence of liver disease or inhibitors, physicians should consider the possibility of superwarfarin poisoning as a cause. According to our own experience, recombinant activated factor VII (NovoSeven®; Novo Nordisk, Bagsvaerd, Denmark) appears to be a safe and effective therapy for acute bleeding caused by superwarfarin poisoning. Due to the extended half-life of the second-generation rodenticides, follow-up therapy with oral vitamin K1 should be of long-term duration.

Changes in the amino acid sequence of the recombinant human factor VIIa analog, vatreptacog alfa, are associated with clinical immunogenicity.

Vatreptacog alfa, a recombinant human factor VIIa (rFVIIa) analog developed to improve the treatment of bleeds in hemophilia patients with inhibitors, differs from native FVIIa by three amino acid substitutions. In a randomized, double‐blind, crossover, confirmatory phase III trial (adept™2), 8/72 (11%) hemophilia A or B patients with inhibitors treated for acute bleeds developed anti‐drug antibodies (ADAs) to vatreptacog alfa.

Clinical evaluation of glycoPEGylated recombinant FVIII: Efficacy and safety in severe haemophilia A

Turoctocog alfa pegol (N8-GP) is a novel glycoPEGylated extended half-life recombinant factor VIII (FVIII) product developed for prophylaxis and treatment of bleeds in patients with haemophilia A, to enable higher activity levels with less frequent injections compared with standard FVIII products. This phase III (NCT01480180), multinational, open-label, non-randomised trial evaluated the safety and clinical efficacy of N8-GP when administered for treatment of bleeds and for prophylaxis, in previously treated patients aged ≥12 years with severe haemophilia A. Patients were allocated to receive N8-GP for prophylaxis or on-demand treatment for up to 1.8 years. Patients on prophylaxis were administered one dose of 50 IU/kg of N8-GP every fourth day. Bleeds were treated with doses of 20-75 IU/kg. Total exposure to N8-GP in the trial was 14,114 exposure days (159 patient-years). For the prophylaxis arm (n=175), the median annualised bleeding rate (ABR) was 1.33 (interquartile range, 0.00-4.61), the mean ABR was 3.70 (95 % confidence interval 2.94-4.66) and 70 (40 %) patients had no bleeds during the trial. Across treatment arms, 83.6 % of bleeds resolved with one injection and 95.5 % with up to two injections. N8-GP had a favourable safety profile and was well tolerated. The frequency and types of adverse events reported were as expected in this population. One patient developed inhibitory antibodies against FVIII (≥0.6 Bethesda units [BU]) after 93 N8-GP exposure days. No clinically significant safety concerns were identified and N8-GP was effective for prophylaxis and treatment of bleeds in previously treated patients.

Gemcitabine in the treatment of relapsed and refractory Hodgkin´s disease

Background: Patients with refractory Hodgkin’s disease or relapsing after high-dose therapy and autografting have a poor prognosis. Here, we present our experiences with gemcitabine in this setting. Patients and Methods: We treated 14 patients with relapsed or refractory Hodgkin’s disease with gemcitabine. The treatment was given on a compassionate use basis, off-label and not according to a study protocol. Patients were 17-46 years of age. 1 patient had stage IA disease, 2 patients had stage IIIB disease and 11 patients had stage IVB disease. 9 patients had received radiotherapy. 8 patients had been autografted and 1 patient auto- and allografted. Gemcitabine was administered at a starting dose of 1 g/m2 on days 1 and 8 every 3 weeks in combination with steroids. Results: The median follow-up period was 10 months. Hematological toxicity grade 3-4 occurred in 12 patients leading to dose reductions. 1 patient died of neutropenic sepsis. No other non-hematological toxicities were observed. The response rate was 64% with 6 patients achieving complete remission (CR) and 3 patients partial remission (PR). The median time to treatment failure was 9 months, and survival was 11 months. Responses were seen in previously transplanted patients and in patients refractory to previous treatment. The so far longest responder has been in CR for over 68 months. Conclusion: Gemcitabine is an effective treatment for Hodgkin’s disease. Heavily pretreated patients often require dose reductions.

Once‐weekly prophylactic treatment vs. on‐demand treatment with nonacog alfa in patients with moderately severe to severe haemophilia B

Limited data are available on optimal prophylaxis regimens of factor IX (FIX) replacements for patients with haemophilia B.

Practical aspects of extended half-life products for the treatment of haemophilia

Haemophilia A and haemophilia B are congenital X-linked bleeding disorders caused by deficiency of coagulation factor VIII (FVIII) and IX (FIX), respectively. The preferred treatment option for patients with haemophilia is replacement therapy. For patients with severe disease, prophylactic replacement of coagulation factor is the treatment of choice; this has been shown to reduce arthropathy significantly, reduce the frequency of bleeds and improve patients’ quality of life. Prophylaxis with standard recombinant factor requires regular intravenous infusion at least two (FIX) to three (FVIII) times a week. Recombinant FVIII and FIX products with an extended half-life are in development, or have been recently licensed. With reported mean half-life extensions of 1.5–1.8 times that of standard products for FVIII and 3–5 times that of standard products for FIX, these products have the potential to address many of the unmet needs of patients currently treated with standard factor concentrates. For example, they may encourage patients to switch from on-demand treatment to prophylaxis and improve the quality of life of patients receiving prophylaxis. Indeed, extended half-life products have the potential to reduce the burden of frequent intravenous injections, reducing the need for central venous lines in children, promote adherence, improve outcomes, potentially allow for more active lifestyles and, depending on the dosing regimen, increase factor trough levels. Members of the Zürich Haemophilia Forum convened for their 19th meeting to discuss the practicalities of incorporating new treatments into the management of people with haemophilia. This review of extended half-life products considers their introduction in haemophilia treatment, including the appropriate dose and schedule of infusions, laboratory monitoring, patient selection, safety considerations, and the economic aspects of care.

A case report of acute inferior myocardial infarction in a patient with severe hemophilia A after recombinant factor VIII infusion

Rationale: The extent of protective effects of hemophilia against thrombotic events such as myocardial infarction (MI) and other acute coronary syndromes remains to be determined, as major risk factors for cardiovascular disease exist despite factor VIII (FVIII) deficiency. We present a case report of a 41-year-old male with severe hemophilia A and several cardiovascular risk factors. Patient concerns: This morbidly obese patient developed chest pressure, followed by chest pain and difficulty in breathing shortly after receiving on-demand treatment with intravenous recombinant FVIII (rFVIII) (turoctocog alfa) dosed per body weight. Diagnoses: An electrocardiogram revealed a diagnosis of inferior ST-segment elevation MI. Interventions: The patient underwent an urgent coronary angiography using a radial artery approach. During the next 12 months, he received dual antiplatelet treatment, acetylsalicylic acid 100 mg, and clopidogrel 75 mg daily. His treatment for severe hemophilia A was changed to plasma-derived FVIII replacement therapy. Outcomes: During this 12-month period, he experienced several small bleeds in his elbows. Conclusions: The temporal relationship between rFVIII infusion and onset of the MI suggests a possible association; however, apart from obesity, the patient also had other major risk factors for arterial thrombosis, such as hypertension and smoking. Furthermore, atherosclerotic disease and underlying atherosclerotic changes could not be excluded with certainty. This case highlights the importance of studies assessing the impact of excess body weight on rFVIII dosing.