Co-medication and interference testing in bioanalysis: a European Bioanalysis Forum recommendation.

Interference testing of co-medication in bioanalytical method validation has become an area of debate in view of the increased specificity offered by current state-of-the-art technology in both LC-MS/MS and ligand-binding assay platforms. In view of this, and considering the extensive experience within the European Bioanalysis Forum member companies, we evaluated the impact of co-medication on the performance of hundreds of bioanalytical methods with the aim of providing a science-based recommendation on how to evaluate and document potential interference from co-medication on the PK parameters in clinical studies in patients and volunteers.

European Bioanalysis Forum: recommendation for dealing with internal standard variability.

Adequate monitoring of internal standard (IS) response across an analytical run and identification of anomalies is now a common expectation. However, the means to conduct this assessment in an appropriate manner is unclear and differs widely between laboratories. A European Bioanalysis Forum (EBF) topic team was formed to survey current practices within European Bioanalysis Forum member companies and to recommend a best practice approach for dealing with IS response variability.

Small molecule specific run acceptance, specific assay operation, and chromatographic run quality assessment: recommendation for best practices and harmonization from the global bioanalysis consortium harmonization teams.

Consensus practices and regulatory guidance for liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) assays of small molecules are more aligned globally than for any of the other bioanalytical techniques addressed by the Global Bioanalysis Consortium. The three Global Bioanalysis Consortium Harmonization Teams provide recommendations and best practices for areas not yet addressed fully by guidances and consensus for small molecule bioanalysis. Recommendations from all three teams are combined in this report for chromatographic run quality, validation, and sample analysis run acceptance.

Reduced exposure variability of the CYP3A substrate simvastatin by dose individualization to CYP3A activity.

This study aimed to demonstrate that the dose of a CYP3A substrate (simvastatin) can be adapted individually on the basis of CYP3A activity as assessed by midazolam metabolic clearance. In 18 healthy participants individual CYP3A activity was quantified using midazolam metabolic clearance both alone and during CYP3A inhibition with 40 mg ritonavir. Thereafter, simvastatin acid exposure was determined after a simvastatin standard dose (40 mg) and doses adapted to individual CYP3A activity at baseline and during CYP3A inhibition. Interindividual variability of CYP3A activity and simvastatin acid AUC0-24 was large and both correlated (r(2) = 0.745, P < .001). The adapted simvastatin doses ranged from 25 to 80 mg and their administration reduced simvastatin variability fivefold. Despite the low adapted simvastatin dose of 12 mg during CYP3A inhibition with ritonavir, exposure increased (point estimate of 4.2 [90% CI: 3.15-5.61]) probably caused by additional OATP1B1 inhibition. CYP3A activity-based dose adaptation can be used to reduce interindividual variability in simvastatin exposure.

A novel double-tracer technique to characterize absorption, distribution, metabolism and excretion (ADME) of [14C]tofogliflozin after oral administration and concomitant intravenous microdose administration of [13C]tofogliflozin in humans.

BACKGROUND: Human mass balance studies and the assessment of absolute oral bioavailability (F) are usually assessed in separate studies. Intravenous microdose administration of an isotope tracer concomitant to an unlabeled oral dose is an emerging technique to assess F. We report a novel double-tracer approach implemented for tofogliflozin combining oral administration of a radiolabel tracer with concomitant intravenous administration of a stable isotope tracer. Tofogliflozin is a potent and selective sodium/glucose cotransporter 2 inhibitor for the treatment of type 2 diabetes mellitus currently in clinical development. OBJECTIVES: The objectives of the present study were to assess the systemic exposure of major circulating metabolites, excretion balance, F and contribution of renal clearance (CLR) to total clearance (CL) of tofogliflozin in healthy subjects within one study applying a novel double-tracer technique. METHODS: Six healthy male subjects received 20 mg [(12)C/(14)C]tofogliflozin (3.73 MBq) orally and a concomitant microdose of 0.1 mg [(13)C]tofogliflozin intravenously. Pharmacokinetics of tofogliflozin were determined for the oral and intravenous route; the pharmacokinetics of the metabolites M1 and M5 were determined for the oral route. Quantification of [(12)C]tofogliflozin in plasma and urine and [(13)C]tofogliflozin in plasma was performed by selective LC-MS/MS methods. For the pre-selected metabolites of tofogliflozin, M1 and M5, a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) was applied to plasma and urine samples. Total radioactivity was assessed in plasma, urine and feces. Pharmacokinetic analysis was conducted by non-compartmental methods. RESULTS: The pharmacokinetics of tofogliflozin in healthy subjects were characterized by an F of 97.5 ± 12.3 %, CL of 10.0 ± 1.3 l/h and volume of distribution at steady-state (V(ss)) of 50.6 ± 6.7 l. The main route of elimination of total drug-related material was by excretion into urine (77.0 ± 4.1 % of the dose). The observed CL(R) of 25.7 ± 5.0 ml/min was higher than the product of the estimated glomerular filtration rate (eGFR) and fraction unbound in plasma (f(u)) (eGFR × f(u) 15 ml/min), indicating the presence of net active tubular secretion in the renal elimination of tofogliflozin. However, CLR contributed only 15.5 % to the CL of tofogliflozin, suggesting that reductions in CLR by renal impairment won't significantly affect systemic exposure to tofogliflozin. Tofogliflozin and its metabolite M1 were the only major circulating entities accounting for 46 ± 8.6 and 50 ± 8.2 %, respectively, of total circulating drug-related material, while the metabolite M5 was a minor circulating metabolite accounting for 3.0 ± 0.3 % of total circulating drug-related material. Both the M1 and M5 metabolites were excreted into urine and the major metabolite M1 did not exhibit active tubular secretion. CONCLUSIONS: These results demonstrate the utility of the double-tracer approach to provide essential pharmacokinetic data and excretion data for drug-related material in one study at the same dosing occasion. The data obtained allowed the characterization of absorption, distribution, metabolism and excretion of tofogliflozin. Tofogliflozin exhibited highly favorable pharmacokinetic properties as demonstrated by its high F, low CL and a low V(ss. The presence of only one major circulating metabolite of tofogliflozin was unambiguously demonstrated. As a drug targeting the kidney, luminal exposure of the kidney is achieved by renal filtration and active tubular secretion.

'Large Meets Small': connecting the bioanalytical community around peptide and protein bioanalysis with LC-MS(/MS).

This conference report provides an overview of the discussions at the 2nd European Bioanalysis Forum (EBF) Focus Meeting 'Large Meets Small' held on 20 and 21 June 2011 in Brussels. The meeting discussed scientific progress in the bioanalysis of peptides and proteins with MS-based techniques. Bioanalytical experts in ligand-binding assays (LBAs) and MS from industry and academia presented at the meeting or joined the discussion. The conference hosted sessions on technology developments, validation requirements, cutting edge (bio)analytical approaches for both proteins and peptides and discussions on the analytical challenge presented by the metabolism of peptides or proteins. The engagement of the scientists as well as the bioanalytical challenges identified were real: by shifting peptide or protein analysis from the LBAs laboratory into the LC-MS laboratory, the bioanalytical scientist is moving into partially uncharted territory. The conference delegates strongly shared the feeling that success in overcoming the challenges of peptide and protein bioanalysis will require further integration of the expertise of LBAs and LC-MS/MS experts.

From challenges to solutions. European Bioanalysis Forum 3rd Annual Open Symposium, Hesperia Towers, Barcelona, Spain, 1-3 December 2010.

The European Bioanalysis Forum is a bioanalytical nonprofit organization comprised of European pharmaceutical companies (27 members to date) and currently expanding to include CROs as well. The European Bioanalysis Forum provides a broad European bioanalytical network for the discussion of scientific, technological and regulatory topics of bioanalytical interest. The 3rd Annual Open Symposium was again much anticipated after the two previous successful meetings. The symposium included sessions on thinking outside the 'commodity' box, bioanalytical challenges with blood, global harmonization, assay platforms, dried blood spots, immunogenicity, matrix effects, anomalous results, biomarkers and two plenary technology sessions hosted by the Platinum sponsors. Experts and key opinion leaders were invited as guest speakers. A total of 424 delegates registered from 113 companies representing a large percentage of the European bioanalytical community. In addition to 48 oral presentations, 88 posters were presented and there was a vendor exposition of 40 companies.

Workshop/conference report on EMA draft guideline on validation of bioanalytical methods.

This is a summary report of the workshop on the EMA Draft Guideline on Validation of Bioanalytical Methods held April 15-16th 2010 in Brussels (Belgium) and jointly organised by the European Bioanalysis Forum (EBF) and the European Federation for Pharmaceutical Sciences (EUFEPS). Aim of the workshop was to discuss the current scientific knowledge in the area of bioanalysis, the regulatory requirements with special focus on the new Draft Guideline and their subsequent implementation to the work in bioanalytical laboratories. Comments on the Draft Guideline were presented and discussed with representatives from regulatory authorities in Europe. The workshop started with discussions on the scope of the Guideline and the need for implementation of GLP. A special focus was set on method validation of chromatographic procedures and subsequent study sample analysis. In addition, requirements for ligand-binding assays were briefly addressed. Intention of this Conference Report is to summarise important aspects of the discussions in order to draw certain conclusions, and to identify points which remain open and may require clarification at a later stage.

Incurred sample reproducibility: views and recommendations by the European Bioanalysis Forum.

Following intensive discussions, review, alignment of procedures and multiple surveys among their member companies, the European Bioanalysis Forum (EBF) is providing a recommendation on how to integrate incurred sample reproducibility (ISR) in the bioanalytical process. The recommendation aims to provide guidance throughout the lifecycle of a validated method, including the application of the method in study support. In its recommendation, the EBF considers both the internal discussions with EBF member companies, as well as the input provided in international meetings where ISR was discussed. The ultimate goal of the EBF recommendation is to ensure that bioanalytical methods can provide accurate and reproducible concentration data for pharmacokinetic and/or toxicokinetic evaluation, without any compromise, while safeguarding the optimal use of laboratory resources.