Geometric Coefficient Of Variation Research Articles

Capturing the role of rural consumers in sensitive price indicator through geometric consistency check on urban and rural market prices

This paper focuses on capturing price movement and price stability in rural and urban markets. Pakistan collects prices from both markets, but only for the computation of the Consumer Price Index (CPI), which is calculated on a monthly basis. It is proposed to include rural markets by widening the scope of the Sensitive Price Indicator (SPI), computed by the Pakistan Bureau of Statistics (PBS). The inconsistency in the prices of rural markets is observed on the basis of different measures, including descriptive and inferential statistics. Therefore, it is suggested to include rural markets as well in the SPI computation. Large numbers of head counts make transactions in rural areas, which may be taken into account for capturing the accurate weekly consumption pattern of the consumers. Prices of all SPI items were taken from urban and rural markets and checked for normality through the Kolmogorov-Smirnovand Shapiro-Wilk tests. Further, the normality was checked graphically by the Q-Q plot (Quantile-Quantile plot) and histogram. Due to the skewness of the data, non-parametric methods like the geometric coefficient of variation and the coefficient of mean deviation from the median have been applied to check the consistency of the prices in rural markets. The prices of rural markets for further framing of policy to widen the scope of capturing the movement of prices.

Development and validation of an LC-MS/MS method to quantify ceftaroline in microdialysate samples from plasma and brain: Application to a preclinical pharmacokinetic investigation

A bioanalytical LC–MS/MS method was developed and validated to determine ceftaroline in microdialysate samples from plasma and brain. Ceftaroline was separated using a C18 column and a mobile phase consisting of water and acetonitrile, both with 5 mM of ammonium formate and acid formic 0.1%, eluted as gradient. Ceftaroline was monitored using electrospray ionization operating on positive mode (ESI+) monitoring the transition 604.89 > 209.3 m/z. The method showed linearity in the concentration range of 0.5–500 ng/mL for brain microdialysate and 0.5–2500 ng/mL for plasma microdialysate with coefficients of determination ≥0.997. The inter-and intra-day precision, the accuracy, and the stability of the drug in different conditions were in accordance with the acceptable limits determined by international guidelines. Plasma pharmacokinetics and brain distribution of the drug were carried out after intravenous administration of 20 mg/kg of ceftaroline to male Wistar rats. The estimated geometric mean (geometric coefficient of variation) area under the curve (AUC0-∞) was 4.68 (45.8%) mg·h/L and 1.20 (54.2%) mg·h/L for plasma and brain, respectively, resulting in a brain exposure of about 33% (AUCfree brain/AUCfree plasma). The results indicate that ceftaroline presents good penetration in the brain when considering free plasma and free brain concentrations.

A leucine-rich repeat kinase 2 (LRRK2) pathway biomarker characterization study in patients with Parkinson's disease with and without LRRK2 mutations and healthy controls.

Increased leucine-rich repeat kinase 2 (LRRK2) kinase activity is an established risk factor for Parkinson's disease (PD), and several LRRK2 kinase inhibitors are in clinical development as potential novel disease-modifying therapeutics. This biomarker characterization study explored within- and between-subject variability of multiple LRRK2 pathway biomarkers (total LRRK2 [tLRRK2], phosphorylation of the serine 935 (Ser935) residue on LRRK2 [pS935], phosphorylation of Rab10 [pRab10], and total Rab10 [tRab10]) in different biological sources (whole blood, peripheral blood mononuclear cells [PBMCs], neutrophils) as candidate human target engagement and pharmacodynamic biomarkers for implementation in phase I/II pharmacological studies of LRRK2 inhibitors. PD patients with a LRRK2 mutation (n = 6), idiopathic PD patients (n = 6), and healthy matched control subjects (n = 10) were recruited for repeated blood and cerebrospinal fluid (CSF) sampling split over 2 days. Within-subject variability (geometric coefficient of variation [CV], %) of these biomarkers was lowest in whole blood and neutrophils (range: 12.64%-51.32%) and considerably higher in PBMCs (range: 34.81%-273.88%). Between-subject variability displayed a similar pattern, with relatively lower variability in neutrophils (range: 61.30%-66.26%) and whole blood (range: 44.94%-123.11%), and considerably higher variability in PBMCs (range: 189.60%-415.19%). Group-level differences were observed with elevated mean pRab10 levels in neutrophils and a reduced mean pS935/tLRRK2 ratio in PBMCs in PD LRRK2-mutation carriers compared to healthy controls. These findings suggest that the evaluated biomarkers and assays could be used to verify pharmacological mechanisms of action and help explore the dose-response of LRRK2 inhibitors in early-phase clinical studies. In addition, comparable α-synuclein aggregation in CSF was observed in LRRK2-mutation carriers compared to idiopathic PD patients.

H3N2 influenza hemagglutination inhibition method qualification with data driven statistical methods for human clinical trials.

Hemagglutination inhibition (HAI) antibody titers to seasonal influenza strains are important surrogates for vaccine-elicited protection. However, HAI assays can be variable across labs, with low sensitivity across diverse viruses due to lack of standardization. Performing qualification of these assays on a strain specific level enables the precise and accurate quantification of HAI titers. Influenza A (H3N2) continues to be a predominant circulating subtype in most countries in Europe and North America since 1968 and is thus a focus of influenza vaccine research. As a part of the National Institutes of Health (NIH)-funded Collaborative Influenza Vaccine Innovation Centers (CIVICs) program, we report on the identification of a robust assay design, rigorous statistical analysis, and complete qualification of an HAI assay using A/Texas/71/2017 as a representative H3N2 strain and guinea pig red blood cells and neuraminidase (NA) inhibitor oseltamivir to prevent NA-mediated agglutination. This qualified HAI assay is precise (calculated by the geometric coefficient of variation (GCV)) for intermediate precision and intra-operator variability, accurate calculated by relative error, perfectly linear (slope of -1, R-Square 1), robust (<25% GCV) and depicts high specificity and sensitivity. This HAI method was successfully qualified for another H3N2 influenza strain A/Singapore/INFIMH-16-0019/2016, meeting all pre-specified acceptance criteria. These results demonstrate that HAI qualification and data generation for new influenza strains can be achieved efficiently with minimal extra testing and development. We report on a qualified and adaptable influenza serology method and analysis strategy to measure quantifiable HAI titers to define correlates of vaccine mediated protection in human clinical trials.

Immune Correlates of Protection from Filovirus Efficacy Studies in Non-Human Primates.

Non-human primate (NHP) efficacy data for several Ebola virus (EBOV) vaccine candidates exist, but definitive correlates of protection (CoP) have not been demonstrated, although antibodies to the filovirus glycoprotein (GP) antigen and other immunological endpoints have been proposed as potential CoPs. Accordingly, studies that could elucidate biomarker(s) that statistically correlate, whether mechanistically or not, with protection are warranted. The primary objective of this study was to evaluate potential CoP for Novavax EBOV GP vaccine candidate administered at different doses to cynomolgus macaques using the combined data from two separate, related studies containing a total of 44 cynomolgus macaques. Neutralizing antibodies measured by pseudovirion neutralization assay (PsVNA) and anti-GP IgG binding antibodies were evaluated as potential CoP using logistic regression models. The predictive ability of these models was assessed using the area under the receiver operating characteristic (ROC) curve (AUC). Fitted models indicated a statistically significant relationship between survival and log base 10 (log10) transformed anti-GP IgG antibodies, with good predictive ability of the model. Neither (log10 transformed) PsVNT50 nor PsVNT80 titers were statistically significant predictors of survival, though predictive ability of both models was good. Predictive ability was not statistically different between any pair of models. Models that included immunization dose in addition to anti-GP IgG antibodies failed to detect statistically significant effects of immunization dose. These results support anti-GP IgG antibodies as a correlate of protection. Total assay variabilities and geometric coefficients of variation (GCVs) based on the study data appeared to be greater for both PsVNA readouts, suggesting the increased assay variability may account for non-significant model results for PsVNA despite the good predictive ability of the models. The statistical approach to evaluating CoP for this EBOV vaccine may prove useful for advancing research for Sudan virus (SUDV) and Marburg virus (MARV) candidate vaccines.

Pharmacokinetics, safety, and tolerability of intravenous brivaracetam in pediatric patients with epilepsy: An open-label trial.

ObjectiveTo evaluate the pharmacokinetics, safety, and tolerability of brivaracetam (BRV) as 15‐min intravenous (IV) infusion and bolus (≤2‐min injection).MethodsEP0065 (ClinicalTrials.gov: NCT03405714) was a Phase 2, multicenter, open‐label trial in patients ≥1 month to <16 years of age with epilepsy. Patients received up to 5 mg/kg/day BRV (not exceeding 200 mg/day). Enrollment was sequential by descending age, depending on safety review. Outcomes included BRV plasma concentrations before and after IV administration, treatment‐emergent adverse events (TEAEs), and discontinuations due to TEAEs.ResultsFifty patients were enrolled, received BRV, and completed the trial. Twenty‐six patients (52.0%) received 15‐min infusions and 24 (48.0%) received bolus injections. Most patients (80.0%) received one IV dose. In the 15‐min infusion group, geometric mean (GeoMean) BRV concentrations 15 (±2) min (n = 21) and 3 h (±15 min) (n = 21) post dose were 1903.0 ng/mL (geometric coefficient of variation [GeoCV]: 60.7%) and 1130.3 ng/mL (58.8%), respectively. In the bolus group, GeoMean BRV concentrations 15 (±2) min (n = 19) and 3 h (±15 min) (n = 21) post dose were 1704.8 ng/mL (GeoCV: 74.5%) and 1383.9 ng/mL (85.0%), respectively. Overall, 14 patients (28.0%) had TEAEs (15‐min infusion: 8 [30.8%]; bolus: 6 [25.0%]), most commonly (≥5% of patients) somnolence (3 [6.0%]). Ten patients (20.0%) had drug‐related TEAEs (15‐min infusion: 6 [23.1%]; bolus: 4 [16.7%]). No patients discontinued due to TEAEs, and no deaths occurred.SignificanceIV BRV (up to 200 mg/day) was well tolerated in patients ≥1 month to <16 years of age, regardless of whether BRV was administered as 15‐min infusion or bolus. No unexpected safety or pharmacokinetic differences were observed between patients receiving 15‐min infusions or bolus, and plasma concentrations were in the expected range. Safety results were consistent with the known safety profile of oral BRV, with no new safety concerns identified.

An international collaborative study to assign value for Total Factor XIII‐B Subunit Antigen to the WHO 1st International Standard for Factor XIII Plasma, (02/206): Communication from the ISTH SSC Subcommittee on Factor XIII and Fibrinogen

BackgroundFactor XIII (FXIII)‐B subunit measurements are required for the diagnosis and characterization of the type of FXIII deficiency. Furthermore, therapy for FXIII‐A deficiency with recombinant FXIII (rFXIII‐A) relies on available FXIII‐B. ObjectiveTo carry out a collaborative study to calibrate and assign value to the current WHO 1st International Standard (IS) FXIII Plasma for Total FXIII‐B subunit, relative to locally collected normal plasma pools. MethodsLaboratories were instructed to use a validated method (specific ELISA antibodies provided) for assessment of Total FXIII‐B subunit antigen potency. All laboratories used this method with one laboratory using an additional in‐house method. Nine data sets were received from seven laboratories (37 assays in total), which provided a total of 35 valid estimates for this new assignment. Total FXIII‐B subunit estimates were calculated relative to locally collected normal plasma pools, using an arbitrary value of 1.00 unit of Total FXIII‐B subunit per ml, for each pool. ResultsCombination of results produced an overall mean of 0.98 units/mL with an inter‐laboratory variability (geometric coefficients of variation – GCV%) of 18.3% [95% confidence interval: 0.86–1.11]. Real‐time and bench stability studies indicated good stability and preservation of the FXIII‐B subunit analyte in the WHO 1st IS FXIII Plasma (02/206). ConclusionFollowing agreement by study participants, ISTH/SSC Experts, WHO‐ISTH Liaison Group and the SSC Board, the WHO/ECBS established the current WHO 1st IS Factor XIII plasma (NIBSC code 02/206) by additionally assigning it with a Total FXIII‐B subunit antigen value of 0.98 IU/ampoule, in October 2019.

International collaborative study to evaluate and calibrate two recombinant L chain Ferritin preparations for use as a WHO International Standard.

To evaluate and calibrate two candidate preparations for the 4th International Standard for Ferritin (Human, Recombinant) (codes: 19/118 and 19/162) against the 3rd International Standard for Ferritin (Human, Recombinant) (code: 94/572), and three serum commutability samples in an international collaborative study involving 12 laboratories in nine countries. Eleven of the 12 participating laboratories performed Ferritin quantitation using automated assay platforms and one laboratory used a manual ELISA kit. There was better overall agreement between all laboratories and between assay methods for the potency of preparation 19/118 than for preparation 19/162. The overall geometric mean potency (from all methods) of the candidate 4th International Standard, 19/118, was 10.5 µg/ampoule, with inter-laboratory variability, expressed as % geometric coefficient of variation (GCV), of 4.7%. Accelerated stability studies have predicted both 19/118 and 19/162 to be very stable for long term storage at-20°C. The candidate 4th International Standard for Ferritin (Human, Recombinant) (19/118) has been shown to be immunologically similar to the 3rd International Standard for Ferritin (Human, Recombinant) (94/572). It was recommended to and accepted by the WHO Expert Committee on Biological Standardization that 19/118 be established as the 4th International Standard for Ferritin (Human, Recombinant) with an assigned potency of 10.5µg/ampoule and expanded uncertainty limits 10.2-10.8µg/ampoule (95% confidence; k=2.23).

Single- and Multiple-Dose Pharmacokinetics and Safety of Vilaprisan in Healthy Postmenopausal Japanese Women: A Randomized Clinical Trial.

As the prevalence of some gynecological conditions depends on patient characteristics such as race/ethnicity, it is important to study therapies for these conditions in diverse populations. The study described in this article was conducted to investigate the safety, tolerability, and pharmacokinetics of vilaprisan, a selective progesterone receptor modulator, in Japanese women in Japan. It supplements two comparable studies that were conducted in healthy postmenopausal European and Chinese women, respectively. In this exploratory randomized, placebo-controlled, double-blind, ascending-dose study, five groups of healthy postmenopausal Japanese women received vilaprisan as immediate-release tablets (1, 5, or 15 mg as a single dose or 1 or 5 mg/day for 28 days) or placebo tablets (single dosing: 8 subjects/dose step, thereof 2 subjects randomized to placebo; multiple dosing: 12subjects/dose step, thereof 4 subjects randomized to placebo). Blood samples for pharmacokinetic profiles were collected over 14-19 days. Safety assessments were based on adverse event data, vital signs, electrocardiograms, clinical laboratory tests, and transvaginal ultrasound examinations. 48 participants were randomized, treated, and analyzed. Vilaprisan was rapidly absorbed, reaching maximum plasma concentrations (Cmax) between 1and 3 h post dose. Post maximum, plasma concentrations rapidly declined, indicating pronounced distribution into tissues. The exposure of vilaprisan increased roughly dose-proportionally: The geometric mean(geometric coefficients of variation) areas under the concentration time curves from time zero to infinity (AUC∞) after single administration of 1, 5, or 15mg vilaprisan were 67µg·h/l (34%), 249µg·h/l (15%), and 788µg·h/l (37%), respectively. The AUC in the dosing interval after multiple administrations (AUC24,md) of 1mg/day was 76µg·h/l (59%), and the AUC24,md after 5 mg/day was 311 µg·h/l (20%). Geometric mean Cmax values also increased roughly dose-proportionally: They amounted to 6µg/l (22%), 16µg/l (33%), and 52 µg/l (27%) after single administration and to 8µg/l (28%) and 31µg/l (22%) after multiple administrations of the above doses. Mild adverse events were observed, similar to those observed in other clinical studies of vilaprisan. Overall, vilaprisan was safe and well tolerated. The exposure in Japanese women was similar to that observed in European and Chinese women in separate studies. 15 Nov 2011 (no registration number assigned).

Preparation and qualification of internal rabies reference standards for use in the rabies rapid fluorescent focus inhibition test

The World Health Organization (WHO) international standard rabies immune globulins (SRIGs) allow the standardisation of the cell-based rapid fluorescent-focus inhibition test (RFFIT) for rabies virus neutralising antibody measurement. SRIG stocks have been depleted. We describe the preparation and qualification of two internal rabies reference standards (IRRSs), calibrated against WHO SRIGs. Candidate IRRSs IMORAB2, from human rabies immunoglobulin; and GCIRAB1, from pooled serum samples from healthy adults immunised with licensed rabies vaccine, were generated. IRRSs were qualified for use in RFFIT based on pre-determined acceptance criteria. Unitage (IU/mL) was assigned using WHO-1 and WHO-2 SRIGs as calibrators. Geometric mean concentrations (GMCs) (% geometric coefficient of variation), calibrated against WHO-1 and WHO-2 SRIGs, were: 1.8 IU/mL (18.7%) and 1.5 IU/mL (17.8%) for IMORAB2; and 2.9 IU/mL (17.5%) and 2.5 IU/mL (16.7%), respectively, for GCIRAB1. We demonstrated IRRS specificity in competition studies using homologous (inactivated Pitman Moore rabies virus) and heterologous (inactivated vesicular stomatitis virus) antigens and acceptable accuracy/linearity of WHO SRIGs using IRRSs as calibrators. Concordance between IRRS and the WHO-1 SRIG was demonstrated using (non-)clinical human serum samples. The candidate reference standards are suitable for use as IRRS in the in-house rabies RFFIT. Funding:Sanofi Pasteur.

Mediators of the effects of canagliflozin on kidney protection in patients with type 2 diabetes

Canagliflozin reduced kidney disease progression in participants with type 2 diabetes in the CANagliflozin cardioVascular Assessment Study (CANVAS) Program. This analysis explored potential mediators of the effects of canagliflozin on kidney outcomes. The percent mediating effect of 18 biomarkers indicative of disease was determined by comparing the hazard ratios for the effect of randomized treatment from an unadjusted model and from a model adjusting for the average post-randomization level of each biomarker. Multivariable analyses assessed the joint effects of biomarkers that mediated most strongly in univariable analyses. The kidney outcome was defined as a composite of 40% estimated glomerular filtration rate decline, end-stage kidney disease, or death due to kidney disease. Nine biomarkers (systolic blood pressure [8.9% of effect explained], urinary albumin:creatinine ratio [UACR; 23.9%], gamma glutamyltransferase [4.1%], hematocrit [51.1%], hemoglobin [41.3%], serum albumin [19.5%], erythrocytes [56.7%], serum urate [35.4%], and urine pH [7.5%]) individually mediated the effect of canagliflozin on the kidney outcome. In a parsimonious multivariable model, erythrocyte concentration, serum urate, and systolic blood pressure maximized cumulative mediation (115%). Mediating effects of UACR, but not other mediators, were highly dependent upon the baseline level of UACR: UACR mediated 42% and 7% of the effect in those with baseline UACR 30 mg/g or more and under 30 mg/g, respectively. The identified mediators support existing hypothesized mechanisms for the prevention of kidney outcomes with sodium glucose co-transporter 2 inhibitors. Thus, the disparity in mediating effects across baseline UACR subgroups suggests that the mechanism for kidney protection with canagliflozin may vary across patient subgroups.

Establishment of the national reference standard for tetanus toxoid in Thailand

The use of reference materials is the basis of standardization and quality control of biologicals such as vaccines produced by different manufacturers and lot-to-lot consistency. The aim of this study was to establish a secondary local and national reference standard of adsorbed tetanus toxoid that can be used for tetanus toxoid vaccine potency testing. Concentrated bulk of tetanus toxoid was adjuvanted and aliquoted before lyophilization. Lyophilized product was tested for biological and physicochemical qualities, including moisture content, identity, appearance, antigen content, degree of adsorption, and sterility. The potency of the candidate reference material was calibrated against the 4th World Health Organization International Standard (WHO IS) for tetanus toxoid by two independent laboratories (BioNet-Asia and Thai National Control Laboratory) using the WHO mouse challenge test. A total of 839 vials with lyophilized tetanus toxoid reference material were produced. Potency was estimated at 115 IU/vial [intra-laboratory geometric coefficient of variation (GCV) of 7 tests was 16.5%] and 112 IU/vial (intra-laboratory GCV of 5 tests was 38.6%) at the two laboratories, with an inter-laboratory GCV of 25.5%. The potency of the candidate standard was assigned a value of 114 IU/vial. The candidate reference standard was approved by The Thai National Central Laboratory (NCL) as the Thai national tetanus toxoid reference standard.

Pharmacokinetic study of two extended-release formulations of cilostazol in healthy Korean subjects: A randomized, open-label, multiple-dose, two-period crossover study .

The aim of this study was to compare the pharmacokinetic characteristics and safety of two extended-release formulations of cilostazol after multiple oral doses in healthy Korean subjects. A randomized, open-label, multiple-dose, two-period, crossover study was conducted in 30 healthy male subjects. In each treatment period, subjects received oral doses of 200 mg cilostazol SR (Pletaal SR Cap.) or cilostazol CR (Cilostan CR Tab.) once daily for 5 consecutive days, with a washout period of 9 days. Plasma concentrations of cilostazol and its metabolites were determined using a validated liquid chromatography-tandem mass spectrometry method. 24 subjects completed the study. The maximum plasma concentrations (Cmax,ss, geometric mean (geometric coefficient of variation, CV%)) of cilostazol after cilostazol SR and cilostazol CR regimens were 1,532.7 (43.2%) ng/mL and 548.3 (58.9%) ng/mL, respectively, and the areas under the plasma concentration-time curves within dosing intervals (AUCτ, geometric mean (CV%)) were 17,060.7 (39.2%) h×ng/mL and 7,485.7 (55.0%) h×ng/mL, respectively. The geometric mean ratios (cilostazol SR/cilostazol CR) of the Cmax,ss and AUCτ values were 2.7954 (90% confidence interval: 2.3561 - 3.3166) and 2.2791 (90% confidence interval: 1.9770-2.6273), respectively. Both cilostazol SR and cilostazol CR were well tolerated in all subjects, and no serious adverse events occurred. The total incidence of headache, which is the most common adverse drug reaction, was significantly higher with cilostazol SR (63.0%) than cilostazol CR (25.9%). Cilostazol SR showed significantly higher Cmax and AUCτ of cilostazol than cilostazol CR after 5 days of multiple dosing of extended-release formulations of cilostazol.

Towards international standardization of immunoassays for Müllerian inhibiting substance/anti-Müllerian hormone.

Research questionIs formulated and lyophilized, recombinant human Müllerian inhibiting substance, also known as anti-Müllerian hormone (AMH), suitable for the preparation of a WHO international standard to calibrate AMH immunoassays?DesignThe AMH content of a trial preparation, coded SS-581, was determined by five laboratories using seven immunoassay methods. Participants were requested to report the content of the preparation in terms of their method calibrators through the measurement of a minimum of five concentrations in the linear part of the dose-response curve. Participants were also asked to measure, concomitantly, a panel of six serum samples containing AMH at concentrations of 0.1–13.0 ng/ml.ResultsAcross all assays, including two automated assays in development, the geometric mean content was 361.76 ng/ampoule with a geometric coefficient of variation (GCV%) of 39.95%. When measured by immunoassays that were commercially available at the time of the study, the mean content was 423.08 ng/ampoule, with a GCV% of 26.67%. The inter-method geometric means of five serum samples with an AMH concentration >0.3 ng/ml and measured concomitantly with dilutions of SS-581 varied with a range of GCV% of 14.90–22.35%, which may reflect the use of serum sample value transfer to calibrate current immunoassays, some of which use non-human AMH calibrators. The AMH in trial preparation SS-581 was shown to be biologically active in the Müllerian duct regression assay.ConclusionsA reference material prepared using human recombinant AMH is a promising candidate for the preparation of an international standard for AMH for immunoassays calibrated to recombinant human AMH.

Establishment of the World Health Organization First International Standard for Factor XII, Plasma, Human.

Until recently, the role of factor XII (FXII) in hemostasis was not considered to be important since patients with FXII deficiency do not present with bleeding. The activation of FXII by agents including mast cells and platelet polyphosphates suggests that it may have a role in thrombogenesis. The inhibition of FXII therefore presents an option for antithrombotic therapy, and antibodies and inhibitors are already in development. Assays for FXII will be required to support these technologies, and an international standard (IS) for FXII would be useful for the development of these methods and for the clinical monitoring of patients. The purpose of this study was to develop an IS for FXII, with values for functional activity (FXII:C) and antigen (FXII:Ag). Double-spun normal plasma was pooled, filled into siliconized glass ampoules, and freeze-dried to prepare the candidate material. Data from 20 laboratories using the one-stage clotting assay were used to assign the functional activity value in units (u). The antigen value was calculated using data from eight laboratories that carried out antigen assays. Each laboratory was requested to collect two local normal plasma pools. Units of activity and antigen were calculated relative to these pools, as is usual for new coagulation factor analytes. The amount of activity or antigen in 1 ml of normal plasma from each pool was taken to be 1 unit. A total of 566 donors were used across the pools for the FXII:C study and 216 donors for the FXII:Ag study. The overall geometric mean per ampoule for FXII:C was 0.86 u and for FXII:Ag was 0.80 u. The inter-laboratory variation was 10 and 11%, respectively (expressed as the geometric coefficient of variation). Based on these data, the candidate was deemed suitable for use as an IS for FXII. In 2017, the candidate was established by the World Health Organization (WHO) Expert Committee on Biological Standardization as the WHO first IS for blood coagulation FXII, Plasma (National Institute for Biological Standards and Control code 15/180). The values assigned were 0.86 international units (IU) of functional activity (FXII:C) per ampoule and 0.80 IU/ampoule of antigen (FXII:Ag).

A Dual-Administration Microtracer Technique to Characterize the Absorption, Distribution, Metabolism, and Excretion of [14 C]Seletalisib (UCB5857) in Healthy Subjects.

Phosphoinositide 3 kinases are targets for development of small-molecule inhibitors to disrupt progression of immune-inflammatory diseases. This phase 1 open-label study (Eudract 2014-005353-39) evaluated the safety and relative bioavailability of 2 new seletalisib (UCB5857) formulations (A and B) compared with a reference formulation. Absolute bioavailability (period 1a, n = 6) and disposition and metabolism (period 1b, n = 6) of the reference formulation were evaluated: healthy subjects received 30 mg orally plus ∼20 μg of a 14 C-labeled microtracer (intravenously in 1a, orally in 1b). New formulations were evaluated: subjects from periods 1a and 1b were pooled and randomly distributed to receive a single oral dose (30 mg) of formulation A (n = 6) or B (n = 6) in periods 2 and 3, using a crossover design. Absolute oral bioavailability of seletalisib was 97% (90% confidence interval 87, 107). Unchanged [14 C]seletalisib was the predominant radioactive component in plasma (94.8%). After oral dosing, the radioactive dose was primarily recovered in feces (74.6%, geometric coefficient of variation [GeoCV] 18.1%), mostly as metabolites. Seletalisib demonstrated a 24-hour terminal half-life, volume of distribution of 60.9 L (GeoCV 23.8%), and a total plasma clearance of 1.7L/h (GeoCV 35.4%). Formulations A and B displayed similar or even higher exposure compared with reference seletalisib (areas under the concentration-time curves 19 337 [GeoCV 30.8%], 20 380 [GeoCV 37.7%], and 15 932 [GeoCV 36.4%]h·ng/mL, respectively). New formulations A and B were bioequivalent with each other, and all 3 formulations showed acceptable safety profiles. This radiolabeled microtracer approach successfully informed on the absorption, distribution, metabolism, and excretion of seletalisib and further guided the mechanistic pharmacokinetic modeling.

Establishment of the World Health Organization 2nd International Standard for Factor XI, Plasma, Human.

The 1st International Standard (IS) for blood coagulation factor XI (FXI), plasma, has been successfully used for potency labeling of FXI therapeutics and for diagnosis of FXI deficiency in patients. With stocks of the 1st IS near depletion, a replacement is required. In addition to the functional activity value, assignment of an antigen value to the 2nd IS would allow harmonization of antigen assay methods and differentiation of patients who have low functional activity but normal antigen FXI levels from patients who have both low functional and antigen FXI levels. The aims of this study were, therefore, to assign FXI functional activity to the 2nd IS for FXI, plasma, and to additionally assign a new analyte, FXI antigen, to the same International Standard. The candidate material was prepared from double-spun, virology negative, normal plasma, which was pooled and filled into siliconized glass ampoules and subsequently freeze-dried. Assignment of the functional activity (FXI:C) value in International Units (IUs) was performed by one-stage clotting assay by 29 laboratories, relative to the 1st IS. The overall geometric mean (GM) was 0.71 IU/amp with extremely low inter-laboratory variability (expressed as geometric coefficient of variation) of 1.8%. The antigen value assignment was performed by 11 laboratories and was calculated relative to normal plasma pools, as is customary with new coagulation factor analytes. The amount of antigen present in 1 ml of normal plasma was taken to be 1 U. The overall GM for the antigen assays was 0.78 IU/amp with an inter-laboratory variation of 10%. The candidate (National Institute for Biological Standards and Control code, 15/180) was established by the World Health Organization (WHO) Expert Committee on Biological Standardization in 2016 as the WHO 2nd IS for blood coagulation FXI, plasma, with a functional activity value (FXI:C) of 0.71 IU/amp and an antigen value (FXI:Ag) of 0.78 IU/amp.

Pharmacokinetics (PK) and Pharmacodynamics (PD), Safety and Tolerability of a Single-Dose Oral Solution of Dabigatran Etexilate Given after Standard Anticoagulant Therapy in Children from Birth to Less Than One Year Old, with Venous Thromboembolism

Background: Venous thromboembolism (VTE) events are more frequent in neonates than in children of other age groups. The standard of care for pediatric anticoagulation includes unfractionated or low-molecular-weight heparin, or vitamin K antagonists. However, these treatments have limitations in terms of practicality of use in infants, such as parenteral administration, frequent monitoring and drug interactions. Alternative oral agents that address these shortcomings may improve compliance, efficacy and safety. The safety and efficacy of dabigatran etexilate (DE), a direct thrombin inhibitor, are established in adults; pharmacokinetic/pharmacodynamic (PK/PD) studies indicate linear PK. There is a relationship between dabigatran plasma concentration (PK) and its PD effects, resulting in reproducible dose-dependent prolongation in clotting times with rapid onset and offset of effect, which is consistent across populations. Although phase IIa studies suggest a similar PK/PD relationship of dabigatran in children and adults, the hemostatic system in infants differs from older children and adults, which may lead to a different PK/PD effect.Objective: To demonstrate comparable PK/PD relationship of DE oral liquid formulation (OLF) between infants and older children and adults, and to assess safety and tolerability.Methods: Open-label, multicenter, single-dose, single-arm, phase IIa pediatric study. Infants aged < 1 year diagnosed with VTE who completed standard anticoagulant treatment for VTE were enrolled. Exclusion criteria included < 37 weeks gestational age at birth, weight < 3 kg, major bleed with standard anticoagulant and swallowing abnormalities. Patients received DE OLF (based on age- and weight-adjusted nomogram) and were followed up for 30 (+7) days. The primary endpoints were PK/PD related, measured at 2 hrs and 12 (±2) hrs after DE administration. The PK endpoint was plasma concentration of total dabigatran, and PD endpoints were activated partial thromboplastin time (aPTT), ecarin clotting time (ECT) and diluted thrombin time (dTT). Secondary endpoints included incidence of all bleeding events and adverse events (AEs), acceptability and tolerability. Descriptive statistics were applied to the endpoints. PK/PD relationship was analyzed using a simple linear regression model and nonlinear Emax model to confirm whether models used in previous studies were consistent with the pediatric data of this study.Results: Ten patients were screened and 8 entered the study (mean age [SD]: 89 [52] days; range: 41-169 days). Patients received a single dose of DE OLF. The geometric mean (gMean) total dabigatran plasma concentrations 2 hrs post dose (around peak concentrations) was 120 ng/mL with geometric coefficient of variation (gCV) of 62.1%, which indicated moderate variability. The gMean at 12 hrs post dosing was 60.4 ng/mL (gCV 30%), which indicated low variability. The projected steady-state dabigatran trough concentrations were largely comparable to those observed in adults with VTE (Table).A linear PK/PD relationship was observed for ECT (ECT ratio) and dTT (dTT ratio) (Figure). The relationship between total dabigatran concentration and aPTT (aPTT ratio) was nonlinear. The observed PK/PD relationships were similar to those in adult and adolescent patients with VTE, except for patients aged < 2 months, in whom a slight upward shift of aPTT of 10-20% (average) and ECT by 10-15% was observed relative to adults. There were no AEs, deaths or treatment discontinuations during the treatment period. None of the treated patients had any bleeding events or thromboembolic events during the study. One patient had a serious AE (aortic stenosis) during the post-treatment period, which was not considered treatment related by the investigator. There were no clinically relevant or unexpected laboratory findings. The majority of patients were assessed with good tolerability (six patients, 75%), and one patient each (12.5%) was evaluated with satisfactory or bad tolerability.Conclusion:In this small population of infants (aged < 1 year), DE OLF was well tolerated without any treatment-related AEs, thromboembolic or bleeding events. The observed PK/PD relationships were consistent with the established profile in adult and adolescent patients with VTE. [Display omitted] [Display omitted] DisclosuresHalton:Boehringer Ingelheim: Other: Pediatric Expert Working Group for Boehringer Ingelheim. Picard:Boehringer Ingelheim: Employment. Harper:Boehringer Ingelheim: Employment. Huang:Boehringer Ingelheim: Employment. Brueckmann:Boehringer Ingelheim: Employment. Gropper:Boehringer Ingelheim: Employment. Maas:Boehringer Ingelheim: Employment. Tartakovsky:Boehringer Ingelheim: Employment. Nurmeev:Boehringer Ingelheim: Other: Investigator fees. Mitchell:Boehringer Ingelheim: Consultancy; Pfizer: Consultancy; Bristol Myers Squibb: Consultancy. Albisetti:Boehringer Ingelheim: Other: Pediatric Expert Working Group.

Olaratumab and doxorubicin versus doxorubicin alone for treatment of soft-tissue sarcoma: an open-label phase 1b and randomised phase 2 trial

Treatment with doxorubicin is a present standard of care for patients with metastatic soft-tissue sarcoma and median overall survival for those treated is 12-16 months, but few, if any, novel treatments or chemotherapy combinations have been able to improve these poor outcomes. Olaratumab is a human antiplatelet-derived growth factor receptor α monoclonal antibody that has antitumour activity in human sarcoma xenografts. We aimed to assess the efficacy of olaratumab plus doxorubicin in patients with advanced or metastatic soft-tissue sarcoma. We did an open-label phase 1b and randomised phase 2 study of doxorubicin plus olaratumab treatment in patients with unresectable or metastatic soft-tissue sarcoma at 16 clinical sites in the USA. For both the phase 1b and phase 2 parts of the study, eligible patients were aged 18 years or older and had a histologically confirmed diagnosis of locally advanced or metastatic soft-tissue sarcoma not previously treated with an anthracycline, an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, and available tumour tissue to determine PDGFRα expression by immunohistochemistry. In the phase 2 part of the study, patients were randomly assigned in a 1:1 ratio to receive either olaratumab (15 mg/kg) intravenously on day 1 and day 8 plus doxorubicin (75 mg/m(2)) or doxorubicin alone (75 mg/m(2)) on day 1 of each 21-day cycle for up to eight cycles. Randomisation was dynamic and used the minimisation randomisation technique. The phase 1b primary endpoint was safety and the phase 2 primary endpoint was progression-free survival using a two-sided α level of 0.2 and statistical power of 0.8. This study was registered with ClinicalTrials.gov, number NCT01185964. 15 patients were enrolled and treated with olaratumab plus doxorubicin in the phase 1b study, and 133 patients were randomised (66 to olaratumab plus doxorubicin; 67 to doxorubicin alone) in the phase 2 trial, 129 (97%) of whom received at least one dose of study treatment (64 received olaratumab plus doxorubicin, 65 received doxorubicin). Median progression-free survival in phase 2 was 6.6 months (95% CI 4.1-8.3) with olaratumab plus doxorubicin and 4.1 months (2.8-5.4) with doxorubicin (stratified hazard ratio [HR] 0.67; 0.44-1.02, p=0.0615). Median overall survival was 26.5 months (20.9-31.7) with olaratumab plus doxorubicin and 14.7 months (9.2-17.1) with doxorubicin (stratified HR 0.46, 0.30-0.71, p=0.0003). The objective response rate was 18.2% (9.8-29.6) with olaratumab plus doxorubicin and 11.9% (5.3-22.2) with doxorubicin (p=0.3421). Steady state olaratumab serum concentrations were reached during cycle 3 with mean maximum and trough concentrations ranging from 419 μg/mL (geometric coefficient of variation in percentage [CV%] 26.2) to 487 μg/mL (CV% 33.0) and from 123 μg/mL (CV% 31.2) to 156 μg/mL (CV% 38.0), respectively. Adverse events that were more frequent with olaratumab plus doxorubicin versus doxorubicin alone included neutropenia (37 [58%] vs 23 [35%]), mucositis (34 [53%] vs 23 [35%]), nausea (47 [73%] vs 34 [52%]), vomiting (29 [45%] vs 12 [18%]), and diarrhoea (22 [34%] vs 15 [23%]). Febrile neutropenia of grade 3 or higher was similar in both groups (olaratumab plus doxorubicin: eight [13%] of 64 patients vs doxorubicin: nine [14%] of 65 patients). This study of olaratumab with doxorubicin in patients with advanced soft-tissue sarcoma met its predefined primary endpoint for progression-free survival and achieved a highly significant improvement of 11.8 months in median overall survival, suggesting a potential shift in the treatment of soft-tissue sarcoma. Eli Lilly and Company.

An International Standard for holotranscobalamin (holoTC): international collaborative study to assign a holoTC value to the International Standard for vitamin B12 and serum folate.

Investigation of possible B12 and folate deficiencies requires measurement of these vitamins in serum. There is evidence that holotranscobalamin (holoTC), the active portion of B12 available to cells, is a more specific marker of early B12 deficiency than total B12. The availability of immunoassays for holoTC prompted an international collaborative study to assign a holoTC value to the World Health Organization (WHO) 1st International Standard (IS) for vitamin B12 and serum folate, 03/178. The IS, 03/178, and three serum samples with different holoTC levels were assayed by 12 laboratories in eight countries using manual and automated immunoassays for holoTC; one laboratory additionally performed an in-house assay. Fourteen sets of data were analysed. Overall, the IS, 03/178, and the three serum samples demonstrated assay linearity and parallelism. An overall geometric mean (GM) holoTC value of 106.8 pmol/L was obtained for 03/178, with an inter-laboratory geometric coefficient of variation (GCV) of 10.5%. There was a reduction in inter-laboratory variability when the holoTC levels in the serum samples were determined relative to the IS with an assigned holoTC value rather than to the assays' calibration. Accelerated degradation studies showed that 03/178 was sufficiently stable to serve as an IS for holoTC. The WHO Expert Committee on Biological Standardization endorsed the proposal to assign a holoTC value of 107 pmol/L to 03/178, corresponding to 0.107 pmol per ampoule, for use as the 1st IS for vitamin B12, serum folate, and holoTC.