Population pharmacokinetic characterization of BAY 81-8973, a full-length recombinant factor VIII: lessons learned - importance of including samples with factor VIII levels below the quantitation limit.

INTRODUCTION: The pharmacokinetics (PK), safety and efficacy of BAY 81-8973, a full-length, unmodified, recombinant human factor VIII (FVIII), were evaluated in the LEOPOLD trials. AIM: The aim of this study was to develop a population PK model based on pooled data from the LEOPOLD trials and to investigate the importance of including samples with FVIII levels below the limit of quantitation (BLQ) to estimate half-life. METHODS: The analysis included 1535 PK observations (measured by the chromogenic assay) from 183 male patients with haemophilia A aged 1-61 years from the 3 LEOPOLD trials. The limit of quantitation was 1.5 IU dL-1 for the majority of samples. Population PK models that included or excluded BLQ samples were used for FVIII half-life estimations, and simulations were performed using both estimates to explore the influence on the time below a determined FVIII threshold. RESULTS: In the data set used, approximately 16.5% of samples were BLQ, which is not uncommon for FVIII PK data sets. The structural model to describe the PK of BAY 81-8973 was a two-compartment model similar to that seen for other FVIII products. If BLQ samples were excluded from the model, FVIII half-life estimations were longer compared with a model that included BLQ samples. CONCLUSIONS: It is essential to assess the importance of BLQ samples when performing population PK estimates of half-life for any FVIII product. Exclusion of BLQ data from half-life estimations based on population PK models may result in an overestimation of half-life and underestimation of time under a predetermined FVIII threshold, resulting in potential underdosing of patients.

Safety and efficacy of BAY 81-8973 for surgery in previously treated patients with haemophilia A: results of the LEOPOLD clinical trial programme.

INTRODUCTION: BAY 81-8973 is a recombinant factor VIII (rFVIII) with the same amino acid sequence as Bayer's sucrose-formulated rFVIII (rFVIII-FS) but manufactured with certain more advanced technologies. AIM: To describe surgery outcomes with BAY 81-8973 in the LEOPOLD trials. METHODS: Male patients with severe haemophilia A and no inhibitors aged 12-65 years with ≥150 exposure days (EDs) to FVIII (LEOPOLD I and II), or aged ≤12 years with ≥50 EDs to FVIII (LEOPOLD Kids), received BAY 81-8973 based on dosing recommendations for rFVIII-FS according to surgical requirements. Haemostasis-related complications, investigator/surgeon assessment of haemostasis, blood loss, need for transfusion and use of BAY 81-8973 were determined. RESULTS: In LEOPOLD I and II, 11 patients (mean age, 35.3 years) underwent 13 major surgeries. In LEOPOLD Kids, one patient (aged 6 years) underwent one major surgery. Thirty-two adult and paediatric patients underwent 46 minor surgeries. Haemostasis was rated good or excellent in all major and minor surgeries. Blood loss during surgery did not exceed expected amounts; blood transfusions were required in three of the 14 major surgeries. For major surgeries in LEOPOLD I and II, patients received a presurgical 50-IU kg(-1) dose of BAY 81-8973; median nominal dose on day of surgery was 7000 IU (107.5 IU kg(-1) ). Total BAY 81-8973 dose was 2500 IU (108.7 IU kg(-1) ) on the day of the only major surgery in LEOPOLD Kids. No haemostasis-related complications were reported. CONCLUSIONS: Haemostatic control with BAY 81-8973 during all surgeries in the LEOPOLD trials was good or excellent, with no haemostasis-related complications.

BAY 81-8973, a full-length recombinant factor VIII: results from an International comparative laboratory field study.

INTRODUCTION: BAY 81-8973 is a full-length, unmodified, recombinant human factor VIII (FVIII) with the same primary amino acid sequence as sucrose-formulated recombinant FVIII but produced with certain more advanced manufacturing technologies. AIM: This global laboratory study evaluated variability in measurement of BAY 81-8973 using one-stage and chromogenic assays compared with antihaemophilic factor (recombinant) plasma/albumin-free method (rAHF-PFM; Advate(®) ) under assay conditions routinely used in clinical laboratories. METHODS: BAY 81-8973 or rAHF-PFM was spiked into FVIII-deficient plasma at 0.043 (low), 0.375 (medium) and 0.865 (normal) IU mL(-1) . Participating laboratories analysed blinded samples and normal plasma in triplicate using their routine assay, reagents and standards. Results were analysed for intra- and interlaboratory variability. RESULTS: Forty-one laboratories in 11 countries participated in the study. One-stage assay and chromogenic assays were used by 40 and 10 laboratories, respectively; 9 laboratories used both assays. Intralaboratory variability was <11% for both assays and both products at all concentrations. Interlaboratory variability was highest at the low concentration in the chromogenic and one-stage assay for BAY 81-8973 (60.0% and 33.7%, respectively) and rAHF-PFM (51.0% and 30.8%) and was lowest at the normal concentration (BAY 81-8973, 5.4% and 14.0%; rAHF-PFM, 5.8% and 12.4%), which was similar to the plasma control (6.6% and 10.3%). The chromogenic:one-stage assay ratio ranged from 0.95 (low concentration) to 1.10 (normal concentration) for BAY 81-8973 and 0.96-1.18 for rAHF-PFM. CONCLUSIONS: BAY 81-8973 can be accurately measured in plasma using the one-stage and chromogenic assays routinely used in clinical laboratories without a product-specific standard.

Efficacy and safety of BAY 81-8973, a full-length recombinant factor VIII: results from the LEOPOLD I trial.

INTRODUCTION: BAY 81-8973 (Kovaltry(®) ) is a full-length, unmodified recombinant human factor VIII (FVIII) with the same amino acid sequence as sucrose-formulated recombinant FVIII and is produced using additional advanced manufacturing technologies. AIM: To demonstrate efficacy and safety of BAY 81-8973 for treatment of bleeds and as prophylaxis based on two different potency assignments. METHODS: In LEOPOLD I (ClinicalTrials.gov identifier, NCT01029340), males aged 12-65 years with severe haemophilia A and ≥150 exposure days received BAY 81-8973 20-50 IU kg(-1) two or three times per week for 12 months. Potency was based on chromogenic substrate assay per European Pharmacopoeia and label adjusted to mimic one-stage assay potency. Patients were randomized for potency sequence and crossed over potency groups after 6 months, followed by an optional 12-month extension. Primary efficacy endpoint was annualized bleeding rate (ABR). Patients also received BAY 81-8973 during major surgeries. RESULTS: Sixty-two patients received BAY 81-8973 prophylaxis and were included in the analysis. Median ABR was 1.0 (quartile 1, 0; quartile 3, 5.1) without clinically relevant differences between potency periods. Median ABR was similar for twice-weekly vs. three times-weekly dosing (1.0 vs. 2.0). Haemostasis was maintained during 12 major surgeries. Treatment-related adverse event (AE) incidence was ≤7% overall; no patient developed inhibitors. One patient with risk factors for cardiovascular disease developed a myocardial infarction. CONCLUSIONS: BAY 81-8973 was efficacious in preventing and treating bleeding episodes, irrespective of the potency assignment method, with few treatment-related AEs. Caution should be used when treating older patients with cardiovascular risk factors.

BAY 81-8973 safety and efficacy for prophylaxis and treatment of bleeds in previously treated children with severe haemophilia A: results of the LEOPOLD Kids Trial.

INTRODUCTION: BAY 81-8973, a full-length, unmodified, recombinant factor VIII (FVIII) in development for treatment of haemophilia A, has the same primary amino acid sequence as Bayer's sucrose-formulated recombinant FVIII but is produced with more advanced manufacturing technologies. AIM: To demonstrate safety and efficacy of BAY 81-8973 for prophylaxis and treatment of bleeds in previously treated children. METHODS: In this phase III, multicentre, open-label, nonrandomized study, boys aged ≤12 years with severe haemophilia A and ≥50 exposure days (EDs) to FVIII products received prophylaxis with BAY 81-8973 25-50 IU kg(-1) ≥2 times weekly for ≥50 EDs. The efficacy endpoint was annualized number of total bleeds. Adverse events (AEs) and immunogenicity were assessed. RESULTS: Fifty-one patients were treated (age: <6 years, n = 25; 6-<12 years, n = 26) with a 2× per week (43%) or >2× per week (57%) regimen at study start. Median [quartile 1; quartile 3 (Q1; Q3)] annualized number of bleeds for the combined age groups was 1.90 (0; 6.02) for total bleeds, 0 (0; 2.01) for joint bleeds and 0 (0; 0) for spontaneous bleeds. Median (Q1; Q3) annualized number of total bleeds within 48 h of previous prophylaxis infusion was 1.88 (0; 3.97) for children aged <6 years and 0 (0; 1.96) for children aged 6-<12 years. No drug-related serious AEs or inhibitors were reported. CONCLUSIONS: Prophylaxis with BAY 81-8973 using individualized prophylaxis regimens of 2× per week, 3× per week and every-other-day infusions was efficacious in prevention and treatment of bleeds in children with severe haemophilia A. Treatment with BAY 81-8973 was well tolerated.

Chromogenic assay for BAY 81-8973 potency assignment has no impact on clinical outcome or monitoring in patient samples.

UNLABELLED: Essentials Discrepancies can exist in factor VIII activity measured by the one-stage or chromogenic assays. LEOPOLD trial data were used to assess clinical impact of BAY 81-8973 potency assignment assay. Efficacy was not affected by the assay used for potency assignment and dosing of BAY 81-8973. Either assay may be used to measure factor VIII activity after BAY 81-8973 infusion. SUMMARY: Background Product-specific discrepancies have been reported for factor VIII (FVIII) activity determined with one-stage or chromogenic assays. Objective To assess the clinical impact of potency assignment of BAY 81-8973, a full-length, unmodified, recombinant human FVIII, by use of the chromogenic assay or chromogenic assay adjusted to mimic results obtained with the one-stage assay Patients/methods Patients aged 12-65 years with severe hemophilia A received BAY 81-8973 in LEOPOLD I (20-50 IU kg(-1) two or three times weekly [investigator decision]) and LEOPOLD II (randomized to 20-30 IU kg(-1) twice weekly, 30-40 IU kg(-1) three times weekly, or on-demand treatment). Both trials included two 6-month crossover periods in which potency labeling was determined with the chromogenic substrate assay as per the European Pharmacopoeia (CS/EP) or the chromogenic substrate assay adjusted to mimic results obtained with the one-stage assay (CS/ADJ). The annualized bleeding rate (ABR) and FVIII incremental recovery were assessed by the use of pooled data. Results The analysis was perfomed on 121 patients. Median (quartile [Q] 1; Q3) ABRs during the CS/EP and CS/ADJ periods were 1.98 (0; 5.92) and 1.98 (0; 7.34), respectively. The mean incremental recovery was > 2 IU dL(-1) per IU kg(-1) in both periods with the use of either assay for postinfusion FVIII measurements. The median (Q1; Q3) chromogenic/one-stage assay recovery ratio was 1.054 (0.892; 1.150) for the CS/EP period when a plasma standard was used for calibration. Conclusions No impact on the ABR was observed with chromogenic-based as compared with one-stage assay-based potency and dosing. Either assay may be used to determine FVIII plasma activity after infusion of BAY 81-8973 without the need for a product-specific standard.

Prophylaxis vs. on-demand treatment with BAY 81-8973, a full-length plasma protein-free recombinant factor VIII product: results from a randomized trial (LEOPOLD II).

BACKGROUND: BAY 81-8973 is a new full-length human recombinant factor VIII product manufactured with technologies to improve consistency in glycosylation and expression to optimize clinical performance. OBJECTIVES: To demonstrate superiority of prophylaxis vs. on demand therapy with BAY 81-8973 in patients with severe hemophilia A. PATIENTS/METHODS: In this multinational,randomized, open-label crossover study (LEOPOLD II;ClinicalTrials.gov identifier: NCT01233258), males aged 12­65 years with severe hemophilia A were randomized to twice-weekly prophylaxis (20-30 IU kg(-1)), 3-times-weekly prophylaxis (30-40 IU kg(-1)), or on-demand treatment with BAY 81-8973. Potency labeling for BAY 81-8973 was based on the chromogenic substrate assay or adjusted to the one-stage assay. Primary efficacy endpoint was annualized number of all bleeds (ABR). Adverse events (AEs)and immunogenicity were also assessed. RESULTS: Eighty patients (on demand, n = 21; twice-weekly prophylaxis, n = 28; 3-times-weekly prophylaxis, n = 31) were treated and analyzed. Mean ± SD ABR was significantly lower with prophylaxis (twice-weekly, 5.7 ± 7.2; 3-times-weekly, 4.3 ± 6.5; combined, 4.9 ± 6.8) vs. on-demand treatment (57.7 ± 24.6; P < 0.0001, ANOVA). Median ABR was reduced by 97% with prophylaxis (twice-weekly, 4.0;3-times-weekly, 2.0; combined, 2.0) vs. on-demand treatment (60.0). Median ABR was higher with twice-weekly vs. 3-times-weekly prophylaxis during the first 6-month treatment period (4.1 vs. 2.0) but was comparable in the second 6-month period (1.1 vs. 2.0). Few patients reported treatment-related AEs (4%); no treatment-related serious AEs or inhibitors were reported. CONCLUSIONS: Twice weekly or 3-times-weekly prophylaxis with BAY 81-8973 reduced median ABR by 97% compared with on-demand therapy, confirming the superiority of prophylaxis. Treatment with BAY 81-8973 was well tolerated.

Intravenous immunoglobulin in relapsing-remitting multiple sclerosis: a dose-finding trial.

OBJECTIVE: Several studies have reported a reduction of relapses after the long-term administration of IV immunoglobulin (IVIG) to patients with relapsing-remitting multiple sclerosis (RRMS), but they were mostly small and differed in terms of predefined outcome variables and treatment regimen. We therefore set out to test two different doses of a new formulation of immunoglobulin termed IGIV-C 10% for suppression of both clinical and MRI disease activity as well as safety. METHODS: One hundred twenty-seven patients with RRMS participated in this multicenter, randomized, double-blind, placebo-controlled trial. Forty-four and 42 patients received treatment with 0.2 and 0.4 g/kg of IGIV-C 10%, and 41 patients received an equal volume of placebo (0.1% albumin) every 4 weeks for 48 weeks. The primary endpoint was the proportion of relapse-free patients. The main secondary endpoint was lesion activity assessed by 6-weekly MRI. RESULTS: Baseline variables were similar in IVIG- and placebo-treated groups. After 1 year, the proportion of relapse-free patients did not differ statistically according to treatment (IVIG 0.2 g/kg: 57%; IVIG 0.4 g/kg: 60%; placebo: 68%), and there was no difference regarding the cumulative number of unique newly active MRI lesions (median numbers: IVIG 0.2 g/kg: 8.0; IVIG 0.4 g/kg: 5.0; placebo: 7.2) after 48 weeks. There were no significant between-group differences in the rates of adverse events. CONCLUSION: Although IV immunoglobulin (IVIG) treatment was well tolerated, this study did not substantiate a beneficial effect of IVIG in doses ranging from 0.2 to 0.4 g/kg. This result seriously questions the utility of IVIG for the treatment of relapsing-remitting multiple sclerosis.

No effect of intravenous immunoglobulins on cytokine-producing lymphocytes in secondary progressive multiple sclerosis.

Intravenous immunoglobulins (IVIG) have been effective in reducing multiple sclerosis (MS) disease activity and improving disability scores. However, the mechanism by which this beneficial effect is achieved remains unclear. An effect of IVIG on pro- and anti-inflammatory cytokines which are thought to play a role in the disease process - has been postulated in a number of animal and ex vivo studies. Hence, we performed a study on 34 patients with secondary progressive (SP) MS being treated with monthly IVIG or placebo for two years according to the protocol of the ESIMS study. Clinical outcome measures and cytokine production (interferon gamma, tumour necrosis factor alpha, interleukin-4 and -10) were recorded in all patients and compared with respect to the treatment group. Against our expectations, IVIG did not reduce the relapse rate or the progression of disability or cytokine production. Our data argue against an enduring immunomodulating effect of IVIG, at least in SPMS.

Intravenous immunoglobulins in the treatment of relapsing remitting multiple sclerosis--results of a retrospective multicenter observational study over five years.

Use of intravenous immunoglobulins (IVIG) has been recommended for treatment of RRMS if first line therapy with beta-interferon or glatiramer acetate is not tolerated, or if contraindications exist. This consensus recommendation is based on the demonstration of efficacy and tolerability of IVIG in four randomized controlled trials (RCTs). The impact of non-randomized observational trials on evidence-based recommendations for treatment is still under discussion. In order to evaluate the transferability of study results derived from RCTs into a routine practice setting, we carried out a retrospective data analysis on patients with RRMS who had been treated with IVIG during the last five years. Data sets from 308 out of 1122 screened patients were available for analysis. Treatment with IVIG resulted in a 69% reduction of the mean annual relapse rate (ARR) (calculated over two years) from 1.74+/-1.15 before IVIG treatment to 0.53+/-0.61 after start of IVIG treatment. Mean expanded disability status scale (EDSS) values remained stable throughout the observation period. The results of this observational study were similar to the results of previous RCTs with IVIG.

ESIMS--an ongoing clinical trial in secondary progressive multiple sclerosis.

The design of a double-blind, placebo-controlled, European-Canadian Study on IVIG treatment in multiple sclerosis-ESIMS- is described. Three hundred and eighteen multiple sclerosis patients with a secondary progressive course, are treated with monthly infusions of immunoglobulin 10% 1 g/kg bodyweight or with 0.1 g albumin/vial for 27 months. The primary efficacy parameter is the percentage of patients with a confirmed treatment failure in the EDSS scale and/or the Nine Hole Peg Test Secondary outcome measures are MRI T2 lesion load, Magnetization Transfer Imaging, and MRI brainatrophy measures. Documentation of health resource utilisation and ability to work will cover socio-economic aspects. Recruitment of patients was completed in October 1998. The clinical part of the trial will be completed in April 2001.

[Anti-rubella IgM and IgG antibodies in congenital cardiopathy]. / Anticuerpos IgM e IgG antirubéola en cardiopatía congénita.

In utero infection by rubella virus is a well known cause of congenital heart disease. We look for prevalence of anti-rubella antibodies of IgM (primary response) or IgG (anamnestic response) classes in sera of 32 children with congenital heart disease and in 12 normal children of the same socioeconomic background. Only in a patient with a full congenital rubella syndrome we found high titers of IgG anti-rubella antibodies, there was no difference in prevalence of IgM nor IgG anti-rubella antibodies between normals and cardiac patients. There is no reason to look for anti-rubella antibodies in the isolated congenital heart disease.

[Immunologic studies in active rheumatic fever and infectious endocarditis]. / Estudios inmunológicos en fiebre reumática activa y endocarditis infecciosa.

We compared clinical and immunological characteristics of acute rheumatic fever (19 cases) and infectious endocarditis (7 cases), because these two diseases can be confused easily with each other and their differential diagnosis is not simple. In this small series we had cases of acute rheumatic fever with splenomegaly and/or vasculitis, as well as infectious endocarditis with subcutaneous nodules, which exemplifies the diagnostic problem. Using laboratory tests we were able to point out differences which are statistically significant, such as: rheumatoid factor by passive agglutination of IgG sensitized latex particles (X2 4.27 p less than 0M05), and tests which reflects the presence of circulating immune complexes, hemolytic capacity of antigammaglobulin antibodies (X2 3.79 p less than 0.05) and the presence of circulating C3 degradation products (X2 5.92 p less than 0.01), which occurs preferentially or exclusively in infectious endocarditis. Although in the standard patient the clinical assessment is usually sufficient to establish a diagnosis, when differentiation between acute rheumatic fever and infectious endocarditis is not clear, immunologic tests are helpful.

[Procoagulant activity associated with mononuclear cells in active rheumatic fever]. / Actividad procoagulante asociada a células mononucleares en fiebre reumática activa.

Acute rheumatic fever (ARF) is associated with disseminated inflammation and tissue lesions with heavy fibrin deposition, specially in heart valves and myocardium. The immune pathogenesis of ARF has been suspected, but not satisfactorily proven. An active cellular immune reaction generates cell activators (lymphokines) from T cells, which are able to induce a procoagulant activity (PCA) in mononuclear cells. We studied PCA in peripheral blood mononuclear cells isolated form ARF patients as well as normal controls. The PCA from ARF was 1.5 to 15 times higher than the PCA from controls. This activity was associated with the presence of C-reactive protein and other acute phase markers. The PCA from mononuclear cells in ARF may be one of the mechanisms responsible for fibrin deposition.

[Ebstein's anomaly in infants]. / Anomalía de Ebstein en el lactante.

Ebstein's disease is a congenital malformation of the tricuspid valve that causes various hemodynamic alterations depending on the anatomic changes in the valve, presence or absence of atrial septal defect and reduction in the ventricular function. We present 19 patients with Ebstein's malformation of the tricuspid valve younger than 2 years of age. The long-term follow-up was from 1 week to 16 years with a mean of 40 months. Eight children died, 6 were lost in the follow-up and 5 survived. Early cyanosis with associated lesions give a bad prognosis. If the child survives the first year of life he has a better long term prognosis.

[Isolated double-chamber right ventricle. Report of 2 cases]. / Doble cámara ventricular derecha aislada. Informe de dos casos.

Two cases of double-chambered right ventricle without ventricular septal defect are presented. Both were diagnosed with the hemodynamic study and underwent successful surgical repair. We discuss the probable embryologic development and the diagnostic procedures of this malformation.

[Difficulties in controlled inhalation of alpha 1-protease inhibitor]. / Neue Strategien zur kontrollierten Inhalation von alpha 1-Antitrypsin.

In this paper a number of studies will be summarized which were designed to improve the inhalation of alpha 1 -protease inhibitor in patients with alpha 1-protease inhibitor deficiency. A pilot study has shown that the high inter-individual variability of drug deposition in the lungs is due to heterogeneous breathing patterns of the patients. Controlling the breathing pattern led to a significantly decreased variability. Then it was studied which particle size and breathing pattern resulted in highest peripheral lung deposition in patients with emphysema. It was found that for 3 - 4 microm particles and slow inhalation flow rate the peripheral deposition increases with increasing inhalation volume. After the development of an inhalation device which allows to perform controlled inhalations in clinical practice it was shown that this device, in combination with a breathing pattern individually normalized to the patients lung function, allows to deposit nearly 60 % of the drug into the patients lung periphery.

Peripheral deposition of alpha1-protease inhibitor using commercial inhalation devices.

Patients with hereditary alpha1-proteinase inhibitor (alpha1-PI) deficiency are at risk of developing lung emphysema. To prevent the development of this disease, alpha1-PI replacement therapy via inhalation may be a more convenient and effective therapy than the intravenous administration of the drug. In order to optimise this treatment approach, lung deposition of inhaled radiolabelled alpha1-PI (Prolastin) was studied using four different commercial inhalation devices (PARI-LC Star, HaloLite, and AKITA system in combination with LC Star and Sidestream) in six patients with alpha1-PI deficiency and mild-to-severe chronic obstructive pulmonary disease. The time required to deposit 50 mg of the Prolastin (5% solution) in the lung periphery was used as a measure for the efficiency of delivery. The time was calculated from measurements of total and peripheral lung deposition of the radiolabelled alpha1-PI. This time was shortest for the AKITA system (18-24 min) and significantly higher for the PARI-LC Star (44 min) and the HaloLite (100 min). The higher efficiency of drug delivery using the AKITA system is due to the fact that this device controls breathing patterns, which are optimised for each patient individually.