Comparative pharmacokinetics of rVIII-SingleChain and octocog alfa (Advate(®) ) in patients with severe haemophilia A.

BACKGROUND: rVIII-SingleChain, a novel recombinant factor VIII (rFVIII), has been designed as a B-domain truncated construct with covalently bonded heavy and light chains, aiming to increase binding affinity to von Willebrand factor (VWF). Preclinical studies confirmed greater affinity for VWF, giving improved pharmacokinetic and pharmacodynamic properties compared with full-length rFVIII. AIM: To investigate the pharmacokinetics of rVIII-SingleChain and compare them against those of full-length rFVIII. METHODS: This study enrolled 27 patients with severe haemophilia A in the AFFINITY clinical trial programme. After a 4-day washout period, all patients received a single infusion of 50 IU kg(-1) octocog alfa (Advate(®) ); after a ≥4-day postinfusion washout period, they received a single infusion of 50 IU kg(-1) rVIII-SingleChain. Blood samples for pharmacokinetic assessments of each product were collected before infusion (predose) and at 0.5, 1, 4, 8, 10, 24, 32, 48 and 72 h postinfusion for both products. RESULTS: rVIII-SingleChain had a longer mean half-life (t1/2 ) (14.5 vs. 13.3 h), lower mean clearance (CL) (2.64 vs. 3.68 mL h(-1) kg(-1) ), higher mean residence time (20.4 vs. 17.1 h) and larger mean AUCinf (2090 vs. 1550 IU?h dL(-1) ) than octocog alfa, respectively. The mean AUCinf after rVIII-SingleChain infusion was ~35% larger than after octocog alfa. A similar pattern was observed for AUC0-last . No serious adverse events or inhibitors were reported. CONCLUSIONS: rVIII-SingleChain has a favourable pharmacokinetic profile compared with octocog alfa and was well tolerated. The prolonged t1/2 , larger AUC and reduced CL of rVIII-SingleChain may permit longer dosing intervals, thereby improving patient adherence to prophylactic treatment.

Efficacy and safety of a new generation von Willebrand factor/factor VIII concentrate (Wilate®) in the management of perioperative haemostasis in von Willebrand disease patients undergoing surgery.

The aim of this study was to assess the efficacy of Wilate®, a new generation, plasma-derived, high-purity, double virus-inactivated von Willebrand factor (VWF) and factor VIII (FVIII) concentrate (ratio close to physiological 1:1) in the perioperative management of haemostasis in von Willebrand disease (VWD). Data for VWD patients who received Wilate® for perioperative management were obtained from four European, prospective, open-label, non-controlled, non-randomised, multicentre phase II or III clinical trials. A total of 57 surgical procedures were performed (major: n = 27; minor n = 30) in 32 patients. The majority of patients (n = 19, 59.4%) had type 3 VWD, 9 (28.1%) had type 2 VWD and four (12.5%) had type 1 VWD. During major surgery, median daily FVIII dose and mean number of infusions were 25 IU•kg-1 FVIII (VWF:RCo ~23 IU•kg-1) and 11.0, respectively. Corresponding values for minor surgery were 35 IU•kg-1 (VWF:RCo ~32 IU•kg-1) and 1.5. The efficacy of Wilate® was rated by the investigator as excellent or good in 51 of 53 (96%) procedures. Tolerability was rated as very good or good in 100% of major surgeries (27 of 27) and minor surgeries (29 of 29). Wilate® is an effective and well-tolerated VWF/FVIII replacement therapy in the perioperative management of haemostasis in patients with VWD. It can be administered at a similar FVIII dose, but at a lower VWF dose, as compared to older generation products. Clinical benefits were shown in a population with a high proportion of type 3 VWD patients.

Recombinant activated factor VII in treatment of bleeding complications following hematopoietic stem cell transplantation.

BACKGROUND: Bleeding is a common complication following hematopoietic stem cell transplantation (HSCT) and standard hemostatic treatment is often ineffective. We conducted a multicentre, randomized trial of the efficacy and safety of activated recombinant factor VII (rFVIIa, NovoSeven) in the treatment of bleeding following HSCT. METHODS: 100 patients with moderate or severe bleeding (52 gastrointestinal; 26 hemorrhagic cystitis; seven pulmonary; one cerebral; 14 other) were included from days +2 to +180 post-transplant (97 allogeneic; three autologous) to receive seven doses of rFVIIa (40, 80 or 160 microg kg(-1)) or placebo every 6 h. The primary efficacy endpoint was the change in bleeding score between the first administration and 38 h. RESULTS: No significant effect of increasing rFVIIa dose was observed on the primary endpoint. A post hoc analysis comparing each rFVIIa dose with placebo showed that 80 microg kg(-1) rFVIIa improved the bleeding score at the 38 h time point (81% vs. 57%, P = 0.021). This effect was not seen at 160 microg kg(-1). There were no differences in transfusion requirements across dose groups. There was no trend in the type or number of severe adverse events observed. Six thromboembolic events were observed in the active treatment groups: three during, and three following the 96-h observation period. CONCLUSIONS: Despite no overall effect of rFVIIa treatment on primary endpoint, post hoc analysis showed an improvement in the control of bleeding for 80 microg kg(-1) rFVIIa vs. standard hemostatic treatment. The heterogeneity of the population may have contributed to the lack of an increasing effect with increased dose. Further trials should focus upon identifying the patient populations that may benefit from treatment with rFVIIa.

[Blood coagulation disorders in oncological patients]. / Hämostasestörungen bei onkologischen Patienten.

Patients with malignancies often experience acute disorders of coagulation. They may manifest as thromboembolism, disseminated intravascular coagulation or a tendency to bleed. Either disorder carries a high rate of complications and a difficult task in diagnosing and treating them. Some complications typical for patients with malignancies are discussed. Among these are tumor associated thrombophilia, acquired von Willebrand's disease, and thrombocytopenia.

Treatment patterns and cost-of-illness of severe haemophilia in patients with inhibitors in Germany.

To evaluate current treatment patterns and resource utilization as well as related cost in the management of severe haemophilia patients with inhibitors in Germany, a cost-of-illness study was conducted. Generally, data were generated by structured literature search. Missing data were collected by expert interviews. All data were validated by a panel of German experts in haemophilia care. In Germany, immune tolerance therapy (ITT) is first-line therapy in inhibitor management for children in the initial year after inhibitor development, particularly for high responders (HR). In adult HR patients ITT is applied but to a remarkably lower extent than in children. To treat bleeding episodes, factor VIII (FVIII) is first-line therapy in low responders (LR). For paediatric HR patients, bleeds are mainly treated with recombinant FVIIa (rFVIIa). In adult HR patients, activated prothrombin complex concentrate (aPCC) and rFVIIa are more equally distributed as treatment options. Treatment costs were calculated for paediatric patients (15 kg) and adult patients (75 kg) from third party payers' perspective. Cost for ITT ranges from Euro 70,290 (2 months; LR) to Euro 3 812,400 (24 months; with aPCC; HR) in a paediatric patient. For an adult patient ITT cost ranges from Euro 287,500 (6 months; LR) to Euro 17,253,000 (36 months; HR). For on average 12.5 acute bleeds, average annual treatment costs amount to Euro 77,000 for a child and Euro 354,000 for an adult. Assessing the results it has been taken into consideration that ITT can last longer and annual number of bleeds can be extremely higher than on average 12.5 episodes. This indicates more health care resource consumption in some patients.

[Acquired haemophilia due to autoantibodies against factor VIII]. / Erworbene Hämophilie infolge Antikörperbildung gegen Faktor VIII.

UNLABELLED: The acquired haemophilia is caused by formation of autoantibodies which are most frequently directed against factor VIII (FVIII). This disease associated with considerable morbidity as well as mortality occurs preferentially in the elderly. The antibodies lead to a loss of FVIII activity resulting in bleeds especially of soft or subcutaneous tissue or in muscles. DIAGNOSIS: aPTT prolongation and the reduction of the factor activity are of diagnostic importance. However, with respect to bleeding tendency basal activity and inhibitor titre are less meaningful than in inherited haemophilia complicated by inhibitor formation. Therapy is subdivided into treatment of acute bleeds and long-term eradication of the inhibitor. Administration of recombinant FVIIa, high dosed FVIII or activated prothrombin complex concentrates represent approved treatment options of bleeding episodes. Immunosuppressive agents occasionally combined with FVIII administration or immunoadsorption may lead to long-term inhibitor eradication. As CD4(+) T cells as well as anti-idiotypic antibodies appear to be increasingly pathogenetically meaningful new immunomodulating agents might improve the treatment of acquired haemophilia.

Quantification and facilitated comparison of von Willebrand factor multimer patterns by densitometry.

The analysis of von Willebrand factor (vWF) multimers is an important laboratory tool for distinguishing among the numerous subtypes of von Willebrand disease (vWD). Comparability and reproducibility of this method are insufficient; standardization and external references are pending. Interlaboratory comparison of results therefore may be difficult. We applied densitometry to obtain a reproducible quantification of vWF multimer patterns in healthy donors, patients with vWD variants, and factor VIII/vWF concentrates to improve the reproducibility and comparability of vWF multimer analysis. Multimers were separated and visualized luminographically on x-ray films. Films were scanned and evaluated by densitometry. The variation inherent in vWF multimer analysis and the range of the normal could be quantified. In vWD variants and factor VIII/vWF concentrates, densitometry could quantify and visualize alterations of vWF multimer patterns and facilitate their comparison. Densitometry permits a precise quantitative comparison of sample patterns to a reference plasma. It could be a valuable tool offering reproducible quantification and additional visualization of normal and pathologic vWF multimer patterns, facilitating their comparison and contributing to a standardization of vWF multimer analysis.

Anticoagulant prophylaxis and therapy in patients with cancer.

Due to the various reported mechanisms by which tumours may alter haemostasis directly or indirectly, a close relationship between tumour and thrombosis is convincing. As patients with cancer represent a diverse group, the establishment of general treatment guidelines concerning antithrombotic prophylaxis and therapy requires more data than are present to date. However, in cancer patients who are candidates for surgery, chemotherapy, indwelling central venous line, or prolonged immobility, primary prophylaxis is recommended. Patients with manifest thromboembolism should receive immediate treatment and a secondary prophylaxis for more than 3 months or at least as long as the cancer is active. In patients inappropriate for oral anticoagulation, the administration of LMWH is a suitable alternative. More prospective, randomized and larger studies are required to determine the optimally tailored primary prophylaxis, the best time to start and to stop treatment, to determine the best route, dosage and pharmacological antithrombotic, and to define the role of newer anticoagulants as hirudins in the anticoagulative prophylaxis and treatment of patients with cancer.

[Activated protein C resistance and venous thrombophilia: molecular genetic prevalence study in the German population]. / APC-Resistenz und venöse Thrombophilie: Molekulargenetische Prävalenzstudie in der deutschen Bevölkerung.

BACKGROUND AND OBJECTIVE: Resistance against activated protein C (APC), caused by factor V R506Q mutation (factor V Leiden mutation), is among the most important hereditary clotting defects that are associated with an increased risk of venous thrombosis. As there are hardly any data for Germany regarding APC resistance that have been validated by genetic analysis, this study was undertaken to determine the prevalence of factor V Leiden (fVL) mutations in a sizeable group of patients in Germany with venous thromboembolism (VTE) and a control group of healthy persons. PATIENTS AND METHODS: 1200 consecutive patients (689 females, 511 males) from various regions of Germany were examined who, at an age between 0.1 and 45 years, had developed primary deep vein thrombosis (DVT) and/or pulmonary embolism (PE), as confirmed by imaging tests. The control group consisted of 740 healthy persons (332 females and 408 males; median age 33 years) for whom there was no evidence in their personal or family history of TE. Analysis of the fV-1691 genotype was by Mnll-restriction analysis of genomic fV DNA fragments, amplified by polymerase chain reaction. RESULTS: The prevalence in the control group was 7.5% the for heterozygotic fV:Q506 mutant (25 females, 30 males). For the patients the prevalence of the fV R506Q mutation was 27.2% (32.1% heterozygotes [165 females, 112 males]; 4.1% homozygotes [33 females, 16 males], i.e. significantly higher than in the healthy controls (P < 0.0001). In 81.3% of the patients with fV:Q506 DVT in the leg-pelvic vein region was found as the first manifestation, thrombosis in an atypical site in 14.4% and isolated PE in 4.3%. The first manifestation had occurred spontaneously in 36% of patients with the fV:Q506 mutant (44 females, 75 males), in 53.1% of homozygotes and in 33.5% of heterozygotic carriers of the mutation. CONCLUSION: The fV Leiden mutation due to APC resistance is the most common cause of venous thrombosis and apparently one of the most common inherited diseases.

Clinical relevance of genetic risk factors for thrombosis in paediatric oncology patients with central venous catheters.

UNLABELLED: We prospectively evaluated the clinical relevance of genetic risk factors of thrombosis in 137 paediatric patients with solid tumours or leukaemia/lymphoma. The factor V G1691A (FV-L), the prothrombin G20210A (FII-L) and the homozygous MTHFR variant were examined. In addition, protein C, protein S and antithrombin (AT) deficiency were evaluated in patients with ALL or thrombosis. The inter-group incidence of risk factors and thrombotic events was compared. 73 of the 137 patients had ALL and 64 another form of leukaemia, lymphoma or a solid tumour. They were treated according to the established paediatric tumour protocols ALL-BFM, NHL-BFM, COSS, CWS and others. All patients had central venous lines. No patient received heparin or any other anticoagulant. Endpoints of the study were thrombosis, regular completion of chemotherapy or death. Incidence of mutations in the whole group: FV-L (7.3% heterozygous, 0.7% homozygous); FII-L (2.9% heterozygous, no homozygotes); MTHFR (51.8% heterozygous, 10.9% homozygous). Ten patients (7.3%), 6 with ALL and 4 with solid tumours, developed thrombosis. 4 of the 6 patients with ALL and thrombosis (67%) but only 21% of ALL patients without thrombosis had a genetic risk factor (P < 0.013, chi2). No genetic defect was found in the 4 patients with other malignancies and thrombosis. However, besides a tumour, these patients had additional exogenous risk factors including diabetes insipidus and hemiparesis. CONCLUSION: Genetic mutations appear to be additional risk factors for the development of thrombosis in patients with ALL. In contrast, these mutations do not appear to be relevant risk factors for thrombosis in the small number of children with other malignant diseases reported here. This difference may be due to asparaginase and corticosteroids being used in ALL but not in solid tumour protocols.

Hepatitis C plasma viral load is associated with HCV genotype but not with HIV coinfection.

The influence of human immunodeficiency virus (HIV) coinfection and hepatitis C virus (HCV) genotype distribution on HCV viral load and alanine amino transferase (ALT) levels in chronically infected patients remains unclear. In the present study, serum samples from a group of haemophiliac patients were investigated retrospectively. HCV geno- and subtyping was carried out using the Inno line probe assay (Inno LIPA, Innogenetics, Zwijnaarde, Belgium) in 87 patients positive by HCV RT PCR. Of these patients, 31 (35.6%) were HIV coinfected. HCV RNA was quantified with the HCV Monitor kit (Roche, Basel, Switzerland) in 43 patients (22 HIV-negatives, 21 HIV-positives). The most prevalent genotypes were 1 (n = 52) and 3a (n = 16) followed by genotype 2 (n = 9) and 4 (n = 3). Mixed infections were detected in 7 patients. Of genotype 1 positive samples, 24 and 23 were classified as subtype a and b, respectively. Five samples could not be subtyped. Although higher mean values of ALT were observed in genotype 1 infected patients, there was no statistically significant association between HCV genotype or subtype and liver enzymes (P > 0.05). On the other hand, statistically significant higher HCV RNA titres were observed in haemophiliacs infected with HCV genotype 1 in comparison to those infected with other genotypes (P < 0.01). No relationship was found between the presence of HIV coinfection and viral load of HCV RNA. There was no evidence that HCV infection had a more severe outcome in HIV-positive patients who had been infected with HIV and HCV more than ten years ago, even in those with very low CD4+ cell counts. No clear association between high ALT levels and large amounts of viral RNA was observed. In conclusion, a large viral load is associated with HCV genotype 1 infection; HIV coinfection has no clear effect on the intensity of HCV replication. An ongoing prospective study will evaluate the respective role of viral load, genotype, HIV coinfection and ALT level in the response to interferon therapy.

Effects of systemic interferon-alpha (IFN-alpha) on the antigenic phenotype of melanoma metastases. EORTC melanoma group cooperative study No. 18852.

In order to investigate the effects of in vivo treatment with interferon-alpha (IFN-alpha) on melanoma antigens, a clinical EORTC trial (No. 18852) was accompanied by an immunohistological study. Twenty patients with melanoma metastases of skin and soft tissues, eventually also of the lung, who were treated with systemic IFN-alpha, were evaluated for a comparison of metastases before (40) and during (42) treatment. Representative cryostat sections were studied immunohistologically with a panel of monoclonal antibodies against differentiation antigens (HMW-MAA, K-1-2, NKI-beteb, M-2-10-15), progression markers (transferrin receptor, ICAM-1, VLA-2), histocompatibility antigens (HLA-A, B, C, HLA-DR) and the proliferation-associated nuclear antigen Ki67. We found an overall reduction of the proliferation-associated antigen Ki-67 (p < 0.01), and an increase in expression of HLA-DR (p < 0.05) and ICAM-1 (trend) during treatment. The intensity of expression of HLA-A, B and C antigens as well as pigmentation (p < 0.01) was found to be increased. Early progression (< or = 8 weeks after onset of treatment) was associated with a lack of phenotypic changes. The data suggest an independent modulation of proliferation, pigmentation, and antigen expression by systemic treatment of metastatic melanoma with IFN-alpha.

Heterogeneity of the T-cell and macrophage infiltrate in cutaneous and subcutaneous metastases of melanoma patients.

To examine the intra-individual heterogeneity of the local inflammatory infiltrate in metastases of untreated melanoma patients we analysed 42 skin and subcutaneous metastases from 11 patients. Metastases were excised on the same date (10 patients) or consecutively (six patients), and processed in a two-step immunoperoxidase technique using monoclonal antibodies directed against T-cells (CD3, CD25) and two macrophage subpopulations (RM 3/1, 27E10). The number of positively stained T-cells and macrophages were counted for each lesion in representative high power fields. The mean values were calculated. We observed limited heterogeneity among T-cells (CD3+) and activated T-cells (CD25+) in simultaneously excised metastases. Contrary to this, markedly heterogeneous CD3+ infiltrates were found in metastases taken on different dates, even if there was a time difference of only 1 day between excisions, suggesting spontaneous variations. However, activated T-cells in follow-up biopsies showed only limited heterogeneity. In spite of inter-individual variations, metastases taken simultaneously, as well as consecutively, showed little intra-individual heterogeneity with respect to macrophages. Our findings should be taken into account for comparative studies of the infiltrate in metastatic melanoma during immunotherapy.