Exposure Days (exposure + day)

Distribution by Scientific Domains


Selected Abstracts


Postmarketing surveillance study of KOGENATE® Bayer with Bio-Set® in patients with haemophilia A: evaluation of patients' satisfaction after switch to the new reconstitution system

HAEMOPHILIA, Issue 1 2010
N. VIDOVIC
Summary., KOGENATE® Bayer (rFVIII-FS) with Bio-Set® is designed to prevent patient contact with exposed needles during recombinant factor VIII reconstitution. This postmarketing surveillance study evaluated patient satisfaction before and after switching to the new Bio-Set reconstitution method. Male children and adults with haemophilia A were enrolled from nine European countries. A preference questionnaire was administered to patients after Bio-Set training and at the end of the observation period (,20 exposure days or 3 months). Physician assessments of patient compliance and satisfaction were conducted at the end of the observation period. Patients (N = 306) received a mean ± SD of 28 ± 23 infusions of rFVIII-FS with Bio-Set. A majority of patients (82%) preferred the Bio-Set method, with domain scores for ease of use, safety from needlesticks, and speed of reconstitution being highest after training and at the end of the observation period. The Bio-Set method received higher mean scores than previous reconstitution methods for worry/safety and ease/confidence domains at both time points. Physician-reported patient compliance with the Bio-Set method was similar or greater compared with the previous method for 94% of the patients, with physicians reporting that 92% of the patients were satisfied or very satisfied with Bio-Set. Thirteen adverse events (AEs) occurred in nine patients, and five serious AEs occurred in five patients; none was related to rFVIII-FS. No de novo or recurrent inhibitor development was observed during the observation period. rFVIII-FS with Bio-Set was well tolerated and well accepted by haemophilia A patients, which may improve treatment compliance. [source]


Low-dose immune tolerance induction for paediatric haemophilia patients with factor VIII inhibitors

HAEMOPHILIA, Issue 2 2008
A. UNUVAR
Summary., The development of an inhibitor against factor VIII (FVIII) is a serious complication in children with haemophilia A. Immune tolerance induction (ITI) therapy is generally considered to be the best approach to eradicate the inhibitor. In this paper, the low-dose (,50 IU kg,1 twice or three times weekly with plasma-derived factor concentrates) ITI regimen used in Turkey is discussed. This regimen was given to 21 haemophilia A patients with high titer inhibitors. The median age at the beginning of ITI was 9 years and exposure days were 25. The median pre-ITI historical peak inhibitor titer, and inhibitor titer when ITI started were 80 BU (range 6.0,517), 19.2 BU (range 3.6,515), respectively. Complete immune tolerance was defined as the time at which at least two negative inhibitor assays was obtained with no anamnestic response. Our two cases were not reached in follow-up period. Immune tolerance could be achieved in 5 of 19 (26.3%) patients within a median time of 6 months. Partial tolerance was obtained in 7 patients while treatment failed in spite of significant decreased inhibitor levels in the other patients. A relapse developed in one immune-tolerized patient, one year later. The level of inhibitor titer at the beginning of ITI (,10 BU), the pre-ITI historical peak inhibitor titer (<50 BU), and the time between the first diagnosis inhibitor to starting ITI (<12 months) were main factors in the success (complete or partial tolerance) of ITI. In conclusion, the outcome of low-dose ITI protocol was not satisfactory in this retrospective study. [source]


Safety and efficacy of a plasma-derived monoclonal purified factor VIII concentrate during 10 years of follow-up

HAEMOPHILIA, Issue 6 2007
E. P. MAUSER-BUNSCHOTEN
Summary., In 1995, AAFACT®, a new monoclonal purified factor VIII concentrate (FVIII), derived from human plasma, was introduced in the Netherlands. The monoclonal purification based production process includes a viral inactivation step by solvent/detergent treatment. Products manufactured according to this procedure, for example Hemofil M® are used worldwide. The aim of the present study was to assess inhibitor development in a large cohort of previously treated patients (PTPs) who were followed up for 10 years. In addition, efficacy, HIV and hepatitis C virus (HCV) transmission, and allergic reactions were monitored. All 165 patients with severe haemophilia A (FVIII < 1%) known at the van Creveldkliniek who ever used AAFACT® during the period from October 1995 to September 2005 were included. Two of them were previously untreated patients (PUPs) and two others had <50 exposure days. Data on FVIII consumption, number of exposures, bleedings and hospitalization days were collected from start of AAFACT® until last clinical and laboratory evaluation while on this product. At the end of follow-up, 91 patients were still using this plasma-derived FVIII. Median age at start of follow-up was 26 years (range 1,52). None of the patients reported lack of efficacy. Median FVIII consumption per patient during follow-up was 2058 IU kg,1 bodyweight per year, and median number of exposures was 148 per year. During 1029 patient-years of follow-up, one inhibitor was diagnosed in a previously treated patient PTP. This patient developed high titre inhibitor following surgery for which he, during 1 week, had been treated with continuous infusion with recombinant FVIII. No inhibitor occurred during 68 cases of surgery using continuous infusion with AAFACT®. No viral transmissions or other adverse events occurred during 10 years of follow-up; AAFACT® appeared to be an effective and safe FVIII product. [source]


Continuous infusion of factor concentrates in children with haemophilia A in comparison with bolus injections

HAEMOPHILIA, Issue 3 2006
C. BIDLINGMAIER
Summary., Although the concept of continuous infusion (CI) of factor concentrates is well known, prospective paediatric data are rare. We present a prospective open-labelled non-randomized study focusing on safety, efficacy and factor VIII (FVIII) usage compared with bolus injections (BI) in children. In 43 consecutive patients (0.5,17 years; median: 9.6) undergoing different operations, CI was started with an initial FVIII-bolus of 70 IU kg,1 bodyweight, followed by a median infusion rate of 4.4 IU kg,1 h,1 (range: 2.8,9.5) dose adjusted for daily FVIII levels (target: 60,80%). No direct serious adverse events occurred; however, two out of 43 patients, both from the group of four patients with less than 20 exposure days (ED) before starting CI, developed a high-responding inhibitor. Two CI patients showed mild thrombophlebitis or rash. Infusion rates needed to achieve adequate FVIII levels were highly predictable and could be reduced because of decreasing FVIII clearance. Bleeding, requiring additional boli, was observed in eight out of 43 patients. Therapy duration and factor usage of CI were influenced by the procedure, but not by the product used or thrombophilia. Twelve of these CI patients were compared with 12 contemporary consecutive age- and procedure-matched BI patients. Compared with BI patients, CI patients saved 30% FVIII (812.9 vs. 563.2 IU kg,1, P < 0.006). We conclude that CI forms a safe and effective method for perioperative care in children and reduces factor usage. Because of the unknown risk of inhibitor development, we will use CI only in patients beyond 20 ED. [source]


Inhibitor development in patients receiving recombinant factor VIII (Recombinate rAHF/Bioclate®): a prospective pharmacovigilance study

HAEMOPHILIA, Issue 5 2004
B. M. Ewenstein
Summary., Clinical trials to date have not been adequately powered to assess comparatively infrequent events such as inhibitor development in previously treated patients (PTPs). Comprehensive large-scale pharmacovigilance studies can be useful for this purpose. We prospectively collected inhibitor development reports worldwide among recipients of Recombinate rAHF recombinant factor VIII (rFVIII), also formerly distributed under the product name Bioclate®, for the entire postlicensure period from 1993 through 2002. To determine level of exposure to rFVIII we also compiled the Recombinate rAHF/Bioclate International Units (IU) distributed annually. To estimate inhibitor incidence separately for previously untreated or minimally treated patients (PUPs) with 1,50 exposure days and PTPs with >50 exposure days, we used haemophilia A incidence and prevalence data and pooled mean annual rFVIII consumption per PUP and PTP from international multicentre prospective clinical trials. Documented inhibitor cases totalled 89, and the total quantity of Recombinate rAHF/Bioclate rFVIII distributed was 6.48 ×109 IU. No lot association or other clustering of inhibitor events was evident in PTPs. The incidence of all reported inhibitors, expressed as a percentage of patients treated, was 11.9% (CI: 5.05,28.0%) for PUPs when compared with 0.123% (CI: 0.030,0.512%) for PTPs. The rates for high-titre inhibitors (>5 BU) only were 5.96% (CI: 3.00,11.8%) for PUPs and 0.0554% (CI: 0.0113,0.271%) for PTPs. Thus, incidence rates for both all inhibitors and high-titre inhibitors in PTPs were 1% of the corresponding rates in PUPs. Data from prospective PUP clinical trials involving intensive active monitoring suggest that true inhibitor incidence may be approximately twice that estimated in this pharmacovigilance study. Nevertheless, inhibitor development in PTPs receiving Recombinate rAHF/Bioclate is infrequent. [source]


European data of a clinical trial with a sucrose formulated recombinant factor VIII in previously treated haemophilia A patients

HAEMOPHILIA, Issue 2002
C. Rothschild
Summary., To increase the safety of antihaemophilic treatment, the production process of full-length recombinant factor VIII (FVIII) KOGENATE® Bayer (Kogenate®FS)has been modified. Human albumin is no longer added as stabilizer during purification and in final formulation. Instead, the new KOGENATE® Bayer production process uses sucrose as a stabilizer in the formulation and adds solvent/detergent virus inactivation step. An European clinical trial was carried out in Germany and France in previously treated patients with severe haemophilia A who had more than 100 exposure days to exogenous FVIII. Pharmacokinetic data was analysed according to one-stage and chromogenic assays. Efficacy and safety during home therapy and in surgical procedures were evaluated; inhibitor formation was carefully monitored. Safety and efficacy were evaluated in 33 European patients for 24 months. Patients received more than 13 million IU KOGENATE® Bayer. Over 75% of patients accrued more than 100 exposure days with the new product. Of 875 bleeding episodes, 90.7% were treated with 1 or 2 infusions and 75.8% of responses to treatment were rated as ,excellent' or ,good'. Prophylactic treatment was the most common mode of therapy (60.7% of infusions). The product was well-tolerated and FVIII recovery studies were consistent throughout the study period. Only 0.26% of adverse events were reported to be drug related. No evidence of de novo inhibitor formation was observed. Overall, KOGENATE® Bayer was efficacious, safe and well-tolerated for the treatment of haemophilia A in multitransfused patients. [source]


Schedule of Passive Ethanol Exposure Affects Subsequent Intragastric Ethanol Self-Infusion

ALCOHOLISM, Issue 11 2009
Tara L. Fidler
Background:, Many studies have shown that chronic ethanol exposure can enhance later self-administration of ethanol, but only a few studies have identified critical parameters for such exposure. The present studies examined temporal and other parameters of chronic ethanol exposure on subsequent intragastric (IG) self-infusion of ethanol. Methods:, Sprague,Dawley rats implanted with IG catheters were passively infused with ethanol for 5 to 6 days and then allowed to self-infuse ethanol or water using a procedure in which infusions were contingent upon licking fruit-flavored solutions. Experiment 1 examined the time interval between consecutive periods of passive infusion (Massed Group: 12 hours vs. Spaced Group: 36 hours). Experiment 2 studied the interval between the final passive infusion and onset of self-infusion (12 vs. 36 hours). Finally, Experiment 3 tested the effect of inserting self-infusion days within the passive infusion phase. Results:, Passive ethanol exposure on consecutive days induced relatively large amounts of ethanol self-infusion (4.1 to 7.9 g/kg/d). Increasing the duration of the ethanol-free interval between periods of passive exposure to 36 hours significantly reduced ethanol self-infusion (2.2 g/kg/d; Exp. 1). The time delay between the last passive ethanol exposure and onset of self-infusion had no effect on self-infusion (Exp. 2). Moreover, inserting no-choice self-infusion days between the last few passive exposure days did not increase self-infusion (Exp. 3). Conclusions:, Measurement of withdrawal signs indicated that Massed passive exposure produced stronger dependence than Spaced passive exposure, suggesting that enhanced ethanol self-infusion in Massed Groups might be explained by the opportunity for greater negative reinforcement by ethanol. Although enhanced negative reinforcement might also explain why the Massed Group showed a weaker aversion for the ethanol-paired flavor than the Spaced Group, this observation could also be explained by the development of greater tolerance to ethanol's aversive pharmacological effects in the Massed Group. [source]


In non-severe hemophilia A the risk of inhibitor after intensive factor treatment is greater in older patients: a case,control study

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 10 2010
C. L. KEMPTON
Summary.,Background:,Twenty-five percent of new anti-factor VIII (FVIII) antibodies (inhibitors) that complicate hemophilia A occur in those with mild and moderate disease. Although intensive FVIII treatment has long been considered a risk factor for inhibitor development in those with non-severe disease, its strength of association and the influence of other factors have remained undefined. Objective:,To evaluate risk factors for inhibitor development in patients with non-severe hemophilia A. Methods:,Information on clinical and demographic variables and FVIII genotype was collected on 36 subjects with mild or moderate hemophilia A and an inhibitor and 62 controls also with mild or moderate hemophilia A but without an inhibitor. Results:,Treatment with FVIII for six or more consecutive days during the prior year was more strongly associated with inhibitor development in those , 30 years of age compared with those < 30 years of age [adjusted odds ratio (OR) 12.62; 95% confidence interval (CI), 2.76,57.81 vs. OR 2.54; 95% CI, 0.61,10.68]. Having previously received < 50 days of FVIII was also not statistically associated with inhibitor development on univariate or multivariate analysis. Conclusions:,These findings suggest that inhibitor development in mild and moderate hemophilia A varies with age, but does not vary significantly with lifetime FVIII exposure days: two features distinct from severe hemophilia A. [source]


Incidence of inhibitors in a cohort of 838 males with hemophilia A previously treated with factor VIII concentrates

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 12 2006
C. L. KEMPTON
Summary.,Background:,Development of an inhibitory antibody to factor VIII is currently the most serious complication of hemophilia A treatment. The rate of inhibitor development in those that have been previously treated with factor concentrates is poorly defined. Understanding the baseline rate of inhibitor development in the population of previously treated patients (PTPs) is important when evaluating the effect of exposure to new factor replacement products on inhibitor formation. Objectives:,To determine the rate of inhibitor development in PTPs with hemophilia A. Methods:,A cohort of males with hemophilia A who had data collected on four or more occasions prior to 30 March 2003, as part of the Center for Disease Control and Prevention's Universal Data Collection Project, were eligible for inclusion in the cohort. Patients were included in the cohort if they had at least two Bethesda assay measurements and did not have an inhibitor prior to or at the start of the study period. The overall incidence rate was estimated as the number of verified incident inhibitor cases divided by the total follow-up time in years multiplied by 1000 (cases per 1000 person-years). Results:,A total of 838 patients were included in the study. The overall incidence rate was calculated to be 2.14 cases per 1000 person years. All incident cases had more than 50 exposure days prior to inhibitor development. Conclusions:,Given the low rate of inhibitor development in PTPs with hemophilia A, small, non-randomized studies are inadequate to determine the rate of inhibitor development after exposure to novel products. Ongoing, standardized, postmarketing surveillance is needed to determine if novel factor products pose an increased risk of inhibitor development. [source]