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Pharmacogenetics, one of the cornerstones of personalized medicine, has the potential to change the way in which health care is offered by stratifying patients into various pretreatment categories, such as likely responders, likely non-responders or likely to experience adverse drug reactions. In order to advance drug development and regulatory science, regulatory agencies globally have promulgated guidelines on pharmacogenetics for nearly a decade. The aim of this article is to provide an overview of new guidelines for the implementation of pharmacogenetics in drug development from a multiregional regulatory perspective - encompassing Europe, the United States and Japan - with an emphasis on clinical pharmacokinetics. [ABSTRACT FROM AUTHOR]

A compact, efficient electrical dual-circuit topology for the representation of transient thermal coupling is presented. Based on controlled sources, the method allows an arbitrary level of complexity to be used for each self and coupled response. Two possible variations on the circuit form, and the resulting requirements for model extraction, are developed. The method is applied to the modeling of transient thermal self-heating and coupling data for a pair of thermal sources representative of integrated device structures in semi-infinite homogeneous as well as trench-isolated substrates. [ABSTRACT FROM AUTHOR]

The objective of this phase II and pharmacologic study was to explore the feasibility, toxicity and activity of adaptive intrapatient dose escalation of cisplatin in a dose-intensive weekly schedule using predefined levels of exposure, with the ultimate aim to improve the antitumour activity of the therapy in patients with nonsmall cell lung cancer (NSCLC). Platinum DNA-adduct levels in peripheral white blood cells during treatment were used as the primary parameter for adaptive dosing. If DNA-adduct levels were not available, the area under the concentration-time curve (AUC) of unbound platinum in plasma was used for dose adaptation. Target levels for DNA-adducts and AUC have been defined in a previously performed pharmacologic study. The feasibility of adaptive dosing was tested in 76 patients with stage IIIB and IV NSCLC, who were planned to receive 6 weekly courses of cisplatin at a starting dose of 70 mg m(-2), together with daily low oral dose of 50 mg VP16. In total, 37 patients (49%) who were given more than one course received a dose increase varying from 10 to 55%. The majority of patients reached the defined target levels by a dose increase during course two. Relevant grade 2 neurotoxicity was observed in eight (10%) patients and reversible ototoxicity grade 2 in 14 (18%) patients. The strategy of adaptive intrapatient dose adjustment of cisplatin is practically feasible in a research setting even when results for dose adaptation have to be reported within a short time-period of 1 week. The toxicity appeared to be manageable in this cohort of patients. In some patients, exposure after the standard dose was substantially lower than the defined target level and significant dose escalations of more than 50% had to be applied. The response rate (RR) was relatively high: overall 40% (29 out of 72 patients) partial remission (PR), in patients with stage IIIB the RR was 60% (15 out of 25 patients) and with stage IV 30% (14 out of 47 patients). Randomised studies are needed to determine whether the adaptive dosing strategy results in better efficacy than standard dosing. [ABSTRACT FROM AUTHOR]

In the present study, we addressed the question of a putative relevance of Rho proteins in tumour progression by analysing their expression on protein and mRNA level in breast turnouts. We show that the level of RhoA, RhoB, Racl and Cdc42 protein is largely enhanced in all turnout samples analysed (n=15) as compared to normal tissues originating from the same individual. The same is true for [sup 32]P-ADP-ribosytation of Rho proteins which is catalysed by Clostridium botulinum exoenzyme C3. Also the amount of Rho-GDI and ERK2 as well as the level of overall [sup 32]P-GTP binding activity was turnout-specific elevated, yet to a lower extent than Rho proteins, Although the amount of Rho proteins was enhanced in tumours, most of them did not show changes in rho mRNA expression as compared to the corresponding normal tissue. Thus, elevated gene expression seems not to be the underlying mechanism of tumour-specific overexpression of Rho proteins. Sequence analysis of RhoA, RhoB, RhoC and Racl failed to detect any mutations in both the GTP-binding site and effector binding region, By analysing > 50 tumour samples, the amount of RhoA-like proteins (i,e, RhoA, B, C), but not of Racl, was found to significantly increase with histological grade and proliferation index. Rho protein expression was neither related to p53 nor to HER-2/neu oncogene status. Expression of rho mRNAs did not show a significant increase with histological grade. Overall the data show that (1) Rho proteins are overexpressed in breast tumours (2) overexpression is not regulated on the mRNA level (3) the expression level of RhoA-Iike proteins correlates with malignancy and (4) Rho proteins are not altered by mutation in breast tumours. [ABSTRACT FROM AUTHOR]

Background and Methods: Breast cancer resistance protein (BCRP/MXR/ABCP) is a multidrug-resistance protein that is a member of the adenosine triphosphate-binding cassette family of drug transporters. BCRP can render tumor cells resistant to the anticancer drugs topotecan, mitoxantrone, doxorubicin, and daunorubicin. To investigate the physiologic role of BCRP, we used polarized mammalian cell lines to determine the direction of BCRP drug transport. We also used the BCRP inhibitor GF120918 to assess the role of BCRP in protecting mice against xenobiotic drugs. Bcrp1, the murine homologue of BCRP, was expressed in the polarized mammalian cell lines LLC-PK1 and MDCK-II, and the direction of Bcrp1-mediated transport of topotecan and mitoxantrone was determined. To avoid the confounding drug transport provided by P-glycoprotein (P-gp), the roles of Bcrp1 in the bioavailability of topotecan and the effect of GF120918 were studied in both wild-type and P-gp-deficient mice and their fetuses.Results: Bcrp1 mediated apically directed transport of drugs in polarized cell lines. When both topotecan and GF120918 were administered orally, the bioavailability (i.e., the extent to which a drug becomes available to a target tissue after administration) of topotecan in plasma was dramatically increased in P-gp-deficient mice (greater than sixfold) and wild-type mice (greater than ninefold), compared with the control (i.e., vehicle-treated) mice. Furthermore, treatment with GF120918 decreased plasma clearance and hepatobiliary excretion of topotecan and increased (re-)uptake by the small intestine. In pregnant GF120918-treated, P-gp-deficient mice, relative fetal penetration of topotecan was twofold higher than that in pregnant vehicle-treated mice, suggesting a function for BCRP in the maternal-fetal barrier of the placenta.Conclusions: Bcrp1 mediates apically directed drug transport, appears to reduce drug bioavailability, and protects fetuses against drugs. We propose that strategic application of BCRP inhibitors may thus lead to more effective oral chemotherapy with topotecan or other BCRP substrate drugs. [ABSTRACT FROM AUTHOR]

For the improvement of chemotherapy with platinum (Pt)-containing drugs a sensitive assay to detect the induced Pt-DNA adducts is needed. Therefore, the 32P-postlabelling assay, described by Blommaert and Saris (Nucleic Acids Res., 1995, 23, 1300-1306), to detect the major adducts Pt-GG and Pt-AG has substantially been improved and compared with ELISA and AAS. For the quantification of the adducts, TpT was added as an internal standard immediately after isolation of the Pt-adducts from digested DNA samples. It was found that 32P-labelling of both GpG and ApG, the dinucleotides obtained after deplatination of the adducts, was equally efficient as that of TpT. To isolate the Pt-adducts on basis of a positive charge, the pH of DNA digests was adjusted to approximately 3 prior to separation by strong cation-exchange chromatography. For the subsequent deplatination a volume of only 12 microl of 0.2 M NaCN was used, which did not interfere with the following labelling step. The quantification of the 32P-labelled dinucleotides was performed by phosphorimaging of spots after separation on TLC as well as by 32P-counting of fractions collected after separation by HPLC. The method was used to determine adduct levels in in vitro cisplatin-treated DNA and in DNA isolated from cisplatin-treated cultured cells, tumor xenografts from cisplatin-treated mice, and from white blood cells and (tumor) tissues from cisplatin-treated patients. The results show a significant correlation with the adduct levels as determined with atomic absorption spectroscopy (high levels) or with specific antibodies (low levels). This assay appears to be useful for the determination of low levels of Pt-adducts in small DNA samples as present in clinical specimens such as blood and tumor tissue, but also in buccal mucosal cells and fine needle aspirates. [ABSTRACT FROM PUBLISHER]

The cytotoxicity of cisplatin alone and in combination with topotecan (TPT) or SN-38, two novel topoisomerase I (topo I) inhibitors, was determined in a panel of eight well-characterized human solid-tumor cell lines. Interactions between cisplatin and these topo I inhibitors were investigated using three different administration schedules: (1) simultaneous incubation (C + T and C + S), (2) cisplatin followed by TPT or SN-38 (C --> T and C --> S), and (3) TPT or SN-38 followed by cisplatin (T --> C and S --> C). Median-effect analysis revealed synergistic cytotoxicity in seven of the eight cell lines used. In addition, a significant schedule-dependent synergistic cytotoxicity was found in three of the cell lines used, with C --> T (or C --> S) being the most active schedule. The formation and repair of total cisplatin-DNA adducts in the IGROV-1 ovarian cancer cell line and its cisplatin-resistant subline IGROV(CDDP) was not significantly affected by TPT on simultaneous incubation. In contrast, the number of cisplatin-DNA interstrand cross-links detected in the IGROV-1 and IGROV(CDDP) lines at certain time points was significantly lower after coincubation of the cells with TPT. Assessment of the cell-cycle distribution revealed an accumulation of cells in the G2/M phase after exposure to cisplatin. After exposure to TPT a different pattern was observed that was cell-type-specific and dependent upon the TPT concentration. Although up to 4-fold differences in topo I activity were observed in this panel of cell lines, these differences did not appear to be related to the synergy observed between cisplatin and TPT or SN-38. The observed synergy may at least partly be explained by the increased retention of cisplatin-DNA interstrand cross-links in the presence of topo I inhibitors. [ABSTRACT FROM AUTHOR]

Historically, dose selection of anticancer drugs has mainly been based on establishing the maximum tolerated dose in phase 1 clinical trials with a traditional 3 plus 3 design. In the era of targeted therapies and immune-modulating agents, this approach does not necessarily lead to selection of the most favourable dose. This strategy can introduce potentially avoidable toxicity or inconvenience for patients. Multiple changes in drug development could lead to more rational dose selection, such as use of better predictive preclinical models, adaptive and randomised trial design, evaluation of multiple dose levels in late-phase development, assessment of target activity and saturation, and early biomarker use for efficacy and safety evaluation. In this Review, we evaluate the rationale and validation of dose selection in each phase of drug development for anticancer drugs approved by the European Medicines Agency and US Food and Drug Administration from Jan 1, 2020, to June 30, 2023, and give recommendations for dose optimisation to improve safety and patient convenience. In our evaluation, we classified 20 (65%) of the 31 recently registered anticancer agents as potential candidates for dose optimisation, which could be achieved either by reducing the dose (n=10 [32%]) or adjusting the dosage regimen (n=10 [32%]). Dose selection seemed to be adequately justified for nine (29%) of the drugs, whereas the reviewed data were inconclusive for formulating a recommendation on dose optimisation for two (6%) of the drugs., Competing Interests: Declaration of interests NPvE has received research grants from Astellas and Ipsen. NM received consultancy fees from Janssen-Cilag, Bayer, Astellas Pharma, AstraZeneca, Pfizer, and Merck Sharp and Dohme, and research funding (all paid to the institution) from Janssen-Cilag, Astellas Pharma, AstraZeneca/Merck, and Bristol Myers Squibb Foundation. KB received consultancy fees (all paid to the institution) from Merck Sharp and Dohme and Pierre Fabre. HG's institution has received research grants or compensation for patients in studies from Bayer, Boehringer Ingelheim, Deciphera, AmmaxBio, Abbisko, Springworks, Amgen, Pfizer, Novartis, and Servier. GSS received research support (all paid to the institution) from Agendia, AstraZeneca, Merck Sharp and Dohme, Novartis, Roche, and Seagen, and serves on advisory boards for Biovica and Seagen. AJdL reports financial interests and institutional research grants from Bristol Myers Squibb, Merck Sharp and Dohme, Boehringer Ingelheim, and AstraZeneca; and non-financial interests from Merck Serono and Roche. NWCJvdD has received research support (all paid to the institution) from Janssen Pharmaceuticals, Amgen, Celgene, Novartis, Cellectis, and Bristol Myers Squibb; and serves on advisory boards for Janssen Pharmaceuticals, AMGEN, Celgene, Bristol Myers Squibb, Sanofi, Takeda, Roche, Novartis, Bayer, Adaptive, Pfizer, AbbVie, and Servier. JJWMJ has received research support (all paid to the institution) from Novartis and Bristol Myers Squibb; serves as president for Apps for Care and Science, a non-profit foundation supported by AbbVie, Alexion, Amgen, Astellas, AstraZeneca, Bristol Myers Squibb, Daiichi-Sankyo, Janssen-Cilag, Novartis, Olympus, Incyte, Sanofi Genzyme, Servier, Jazz, and Takeda; and has received honoraria (all paid to the institution) from AbbVie, Novartis, Pfizer, and Incyte. MCM has received research support (all paid to the institution) from Beigene, consultancy fees (all paid to the institution) from Janssen-Cilag, CDR-life, BMC, and GlaxoSmithKline; fees for speakers bureau (all paid to the institution) from Siemens and Janssen-Cilag; and hospitality from Janssen-Cilag. All other authors declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Patients are often switched between generic formulations of the same drug, but in some cases generic interchangeability is questioned. For generic drugs to be approved, bioequivalence with the innovator drug should be demonstrated, but evidence of bioequivalence is not required in the intended patient population or relative to other approved generics., Aim: We aim to identify pathophysiological pharmacokinetic subpopulations for whom there is a difference in comparative bioavailability compared to a healthy population., Methods: We used simulated exposures from a nonparametric model of multiple generics and the originator gabapentin. Exposure was simulated for virtual populations with pharmacokinetic characteristics beyond those of healthy subjects with regard to rate of absorption, volume of distribution and reduced renal function. Virtual parallel design bioequivalence studies were performed using a random sample of 24 simulated subjects, with standard acceptance criteria., Results: Results indicated increased pharmacokinetic variability for patient populations with a lower rate of absorption or a reduced renal function, but no change in the average comparable bioavailability ratio. This increased variability results in a reduced likelihood of demonstrating bioequivalence. Observations were similar for comparisons between all different formulations, as well as between subjects who received the identical formulation in a repeated fashion. No relevant effect was observed for simulations with increased volume of distribution., Conclusion: Our simulations indicate that the reduced likelihood of demonstrating bioequivalence for subjects with altered pharmacokinetics is not influenced by a formulation switch, nor does the average comparable bioavailability ratio change, therefore these results support generic interchangeability and current approval requirements for generics., (© 2022 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Background: Knowledge of quality-of-life after cytoreductive surgery is important to counsel patients with advanced-stage epithelial ovarian cancer prior to surgery. The aim of this study was to determine whether the use of the PlasmaJet Surgical device during cytoreductive surgery has an effect on the quality-of-life of patients with advanced epithelial ovarian cancer., Methods: Data included in this prospective observational study were derived from the PlaComOv study, in which patients with advanced epithelial ovarian cancer were randomly assigned to have cytoreductive surgery with or without adjuvant use of the PlasmaJet. Quality-of-life was measured before surgery and one, six, 12, and 24 months after surgery with three questionnaires: the EORTC QLQ-C30, QLQ-OV28, and EQ-5D-5L., Results: Between 2018 and 2020, 326 patients were enrolled in the trial. The overall response rate was high, with the lowest response rate at 24 months of 77%. At 6 months, quality-of-life was higher in the intervention group (95%CI 0.009; 0.081, p = 0.045). At 12 months, quality-of-life was higher in the intervention group with fewer symptoms of fatigue, appetite loss, and diarrhea (95%CI 0.6; 10,0, p = 0.027); similarly, patients in the intervention group reported a better body image (95%CI -14.2; -3.0, p = 0.003) and a higher score on the visual analog scale (95%CI 1.99; 11.15, p = 0.005). At 24 months postoperatively, no further difference was found between the two groups except for pain (95%CI -12.9; -0.8, p = 0.027) and body image (95%CI -13.808; -0.733, p = 0.029). A higher quality-of-life in the intervention group was partially explained by the mediator 'surgery outcome'., Conclusions: This study demonstrated knowledge of patients' quality-of-life until two years after cytoreductive surgery. The use of the PlasmaJet Surgical device during cytoreductive surgery leads to a higher quality-of-life than conventional surgery with electrocoagulation alone. Even after adjustment for the mediator of surgical outcome, a higher quality-of-life was seen in patients who had surgery with the use of the PlasmaJet device.

Patients treated for vulvar carcinoma may experience losses in mobility and physical activity. In this study, we assess the prevalence and severity of mobility problems using patient-reported outcomes of three questionnaires: EQ-5D-5L to estimate QoL and perceived health; SQUASH to estimate habitual physical activity; and a problem-specific questionnaire on bicycling. Patients treated for vulvar carcinoma between 2018 and 2021 were recruited, and 84 (62.7%) responded. The mean age was 68 ± 12 years (mean ± standard deviation). Self-reported QoL and perceived health were 0.832 ± 0.224 and 75.6 ± 20.0, respectively. Dutch physical activity guidelines were met by 34.2% of participants. Compared to baseline values, the times spent walking, bicycling, and participating in sports were all reduced. During bicycling, patients experienced moderate or severe pain in the skin of the vulva (24.5%), pain in the sit bones (23.2%), chafing (25.5%), or itching (8.9%). Overall, 40.3% experienced moderate or severe bicycling problems or could not bicycle, 34.9% felt that their vulva impeded bicycling, and 57.1% wished to make more or longer bicycling journeys. To conclude, vulvar carcinoma and its treatment reduce self-reported health, mobility, and physical activity. This motivates us to investigate ways to reduce discomfort during physical activities, and help women regain their mobility and self-reliance.

Protein kinase inhibitors (PKIs) used in oncology can induce severe and even fatal hepatotoxicity. Several PKIs are registered within a certain class to target a specific kinase. No systematic comparison of the reported hepatotoxicity and clinical guidance for monitoring and management of hepatotoxic events between the various PKI summaries of product characteristics (SmPC) is yet available. A systematic analysis of data on 21 hepatotoxicity parameters obtained from the SmPCs and European public assessment reports (EPARs) of European Medicines Agency-approved antineoplastic PKIs (n = 55) has been conducted. The median reported incidence (range) of all grades of aspartate aminotransferase (AST) elevations was 16.9% (2.0%-86.4%) for PKI monotherapy, with 2.1% (0.0%-10.3%) being grade 3/4 and for all grades alanine aminotransferase (ALT) elevations 17.6% (2.0%-85.5%), with 3.0% (0.0%-25.0%) being grade 3/4. Fatalities due to hepatotoxicity were reported for 22 out of 47 PKIs (monotherapy) and for 5 out of 8 PKIs (combination therapy). A maximum grade of grade 4 and grade 3 hepatotoxicity was reported for 45% (n = 25) and 6% (n = 3), respectively. Liver parameter monitoring recommendations were present in 47 of the 55 SmPCs. Dose reductions were recommended for 18 PKIs. Discontinuation was recommended for patients meeting Hy's law criteria (16 out of 55 SmPCs). Severe hepatotoxic events are reported in approximately 50% of the analyzed SmPCs and EPARs. Differences in the degree of hepatotoxicity are apparent. Although liver parameter monitoring recommendations are present in the vast majority of the analyzed PKI SmPCs, the clinical guidance for hepatotoxicity was not standardized., (© 2023 The Authors. Pharmacology Research & Perspectives published by British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics and John Wiley & Sons Ltd.)

With the implementation of the new EU regulation on in vitro diagnostics (IVDR) in May 2022, notified bodies will be required to assess Companion Diagnostics (CDx). The EMA and national medicines agencies will be consulted on the performance and safety of CDx. In this paper, we report on our systematic review on how the EMA has dealt with CDx in dossiers for marketing authorization procedures, in 2017-2019, and in scientific advice procedures in 2016-2020, prior to the implementation of the new IVDR. Out of 167 medicines approved or refused by the EMA, CDx played a role for 20 medicines during assessment. Both European public assessment reports (EPARs) and the internal day 80 and day 120 assessment reports (ARs) of the EMA centralized marketing authorization procedures for these 20 medicines were analyzed in detail to determine how CDx were assessed. Likewise, in 46 of 159 cases in which scientific advice was provided, CDx were mentioned in the question-and-answer section of the scientific advice, and these were analyzed in an analogous manner. Our analysis indicates that clinical performance and analytical performance of the CDx were the most-discussed topics, being discussed 11 and seven times in the 20 EPARs and 59 and 29 times in the ARs, respectively. For scientific advice, clinical and analytical performance was discussed 65 and 22 times in the 46 retrieved mentions of scientific advice. Other aspects in relation to CDx were discussed as well, although at a lower frequency, in assessment reports and scientific advice. Overall, our analysis demonstrates that, despite the absence of an obligation from a legal point of view, EMA has gained experience on the assessment of CDx, most notably regarding its analytical and clinical performance. This experience may be useful in situations in which the EMA and national agencies of EU member states will formally be consulted by notified bodies regarding the performance and safety of CDx. In addition, the issues raised in the EPARs, ARs and scientific advice reports provide insight for applicants on aspects of CDx that need careful consideration., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Maliepaard, Nibi, Nibi and Pasmooij.)

Objectives: The In Vitro Diagnostics Regulation 2017/746 (IVDR) coming into force from May 2022, creates the first European regulatory recognition for biomarker tests linked to medicinal products, so-called companion diagnostics (CDx). Since the introduction of the IVDR is associated with uncertainties about its impact on hospital practice, it is urgent and valuable to investigate how and why CDx are currently used in hospital practice, which factors influence the choice for applying in-house or commercial CDx, and what the expectations are about how the IVDR may affect current practice., Methods: We investigated these questions using an interview-based approach and focused on 15 hospital laboratories in the Netherlands, including 7 academic and 8 general hospitals. All types of CDx were considered relevant for this research, including both genetic and protein-based biomarkers., Results: Factors found included: costs and convenience, complexity of application, and compatibility with existing workflows. Next to in-house and commercial CDx, hospital laboratories addressed compatibility by tweaking existing CDx., Conclusion: Although increased quality of CDx is welcomed, worries toward increased costs and administrative work, and decreased quality were expressed. Further, the IVDR might also hinder using optimized in-house and tweaked CDx. Additionally, increased administrative burden could decrease innovativeness toward CDx.

There appears to be a mismatch between the assumed therapeutic equivalence of generic drugs, their interchangeability, and reported clinical discomfort following generic drug use and drug switches. In this article, we describe why we are of the opinion that the current regulatory approach to the evaluation of generic drugs based on average bioequivalence is sufficient to expect therapeutic equivalence in the clinical setting. This has often been debated, specifically as adverse drug reactions related to generic drug switches are regularly reported. We agree that clinical discomfort during a bioequivalent drug switch may indeed be caused by different exposures to the active substance. However, this difference in exposure is not a result of the characteristics or quality of generic drugs; it is caused by the pharmacokinetic within-subject variability of the active substance, i.e., the variability on the bioavailability of the active substance, when comparing two occasions of administration of the same drug product, to the same patient. Therefore, reported clinical discomfort following generic drug use and drug switches does not warrant a change in the regulatory approach to the evaluation of the bioequivalence of generic drugs. Switching from a brand-name drug to currently approved generic drugs, or between different generic drugs, will in principle result in comparable exposure, within boundaries determined by the within-subject variability of the pharmacokinetics of the active substance involved.

This study aimed to determine to which extent data on potential pharmacogenetic-pharmacokinetic (PG-PK) interactions are provided to, and assessed by, the European Medicines Agency (EMA) in novel drug marketing authorization applications (MAAs), and whether regulatory assessment of PG-PK interactions is adequate or could be optimized. For this purpose, we retrospectively analyzed MAAs of small molecule drugs assessed by the EMA between January 2014 and December 2017. As per two key requirements in the EMA's guideline, we analyzed cases where (i) a single functionally polymorphic drug metabolizing enzyme (DME) metabolizes > 25% of the drug, or (ii) the drug's PK shows high interindividual variability not explained by other factors than PG. Results showed that, of 113 drugs analyzed, 53 (47%) had ≥ 1 functionally polymorphic DME accounting for > 25% of the drug's metabolism, yielding 55 gene-drug pairs. For 36 of 53 (68%) of the products, CYP3A4 was the major DME. Compliance with European Union (EU) guidance on PG-PK issues in drug development was notably different for CYP3A4 substrates vs. non-CYP3A4 substrates. Adequate PG-PK data were provided during registration in 89% (16/18) of cases concerning non-CYP3A4 substrates, compared with 32% (12/37) of cases concerning CYP3A4 substrates. Concluding, PG-PK interactions related to non-CYP3A4 substrate drugs were, in general, addressed adequately in EU MAAs. PG-PK information on CYP3A4 substrates was available less frequently, despite some available evidence on the functional relevance of CYP3A4 polymorphisms. A more harmonized approach toward assessment of PG-PK issues in EU MAAs seems warranted, and a discussion on the relevance of CYP3A4 polymorphisms, such as CYP3A4*22, is recommended., (© 2020 Medicines Evaluation Board. Clinical Pharmacology & Therapeutics published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Background: For a patient, drug switches are not desirable (either between a brand-name drug and a generic drug, or between two generic drugs of the same active substance). Research into the causes of drug switches, and related adverse drug reactions, is hampered by the absence of quantitative data on drug switches., Methods: We describe the frequency of drug switches in the Netherlands for a selection of active substances. A retrospective cohort study was conducted using the Drug Information System of the National Health Care Institute in the Netherlands. We studied the Dutch patient population from mid-2009 to 2016. The selection of active substances (n = 20) was made based on a report by Lareb, the Netherlands Pharmacovigilance Centre, on adverse drug reactions related to drug switching, and we used qualitative and quantitative descriptive analyses. A drug switch is defined as the replacement of a patient's prescribed drug with a similar drug from a different manufacturer., Results: We identified 23.8 million drug switches on a total of 206 million (11.6%) similar drug dispenses. The frequency of drug switches demonstrated a yearly peak in the period from January to March. In some months, for atorvastatin, losartan, pantoprazole, and irbesartan, more than 60% of similar drug dispenses were drug switches. Most drug switches (80.3%) were between two generic drugs, and 0.12% of these involved a drug from a European parallel import. The proportion of drug switches between two brand-name drugs decreased from 14.5 to 5.53% during our study period, and of these, 86.5% involved a drug from a European parallel import., Conclusions: Drug switching is common in the Netherlands, and most of the drug switches we studied are between generic drugs. The observed annual peak of drug switches is most likely explained by a specific Dutch reimbursement policy. Not only are the data valuable as is, but they also serve as a first step towards elucidating the reasons for the occurrence of these drug switches. In addition, these data can be used to put into perspective the adverse drug reactions associated with drug switching.

We performed a retrospective cohort study in the Dutch patient population to identify active substances with a relatively high number of adverse drug reactions (ADRs) potentially related to drug switching. For this, we analyzed drug switches and reported ADRs related to switching between June 1, 2009, and December 31, 2016, for a selection of 20 active substances. We also compared pharmacovigilance analyses based on the absolute, switch-corrected, and user-corrected numbers of ADRs. In total, 1,348 reported ADRs and over 23.8 million drug switches were obtained from the National Health Care Institute in The Netherlands and from Lareb, which is The Netherlands Pharmacovigilance Centre. There was no correlation between the number of ADRs and the number of switches, but, on average, we found 5.7 reported ADRs per 100,000 switches. The number was relatively high for rivastigmine, levothyroxine, methylphenidate, and salbutamol, with 74.9, 50.9, 47.6, and 26.1 ADRs per 100,000 switches, respectively. When comparing analyses using the absolute number and the switch-corrected number of ADRs, we demonstrate that different active substances would be identified as having a relatively high number of ADRs, and different time periods of increased numbers of ADRs would be observed. We also demonstrate similar results when using the user-corrected number of ADRs instead of the switch-corrected number of ADRs, allowing for a more feasible approach in pharmacovigilance practice. This study demonstrates that pharmacovigilance analyses of switch-related ADRs leads to different results when the number of reported ADRs is corrected for the actual number of drug switches., (© 2020 The Authors. Clinical and Translational Science published by Wiley Periodicals, Inc. on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Background: Information on drug safety in different ethnic populations reported in public documents such as the European Public Assessment Reports (EPARs), European Summary of Product Characteristics (SmPCs) or Singapore Package Inserts (SGPIs) generally appears limited., Objective: This study aimed to clarify the extent of drug safety data in ethnic populations that is available in drug registration dossiers used for registration in the European Union (EU) and Singapore, and how much of this information is then included in the EPARs and SmPCs or SGPIs., Methods: For this purpose, drug registration dossiers and these public documents for a selection of 25 drugs authorized both in the EU and Singapore were compared (note, the number of available full registration dossiers was only 24 due to a technical issue)., Results: Detailed safety data in ethnic groups were present in 23/24 (96%) of the drug registration dossiers, but was only present in 12/25 (48%) of the EPARs, 8/25 (32%) of the SmPCs, and 9/25 (36%) of the SGPIs. Furthermore, in many cases where ethnicity-specific safety information was provided in the SmPC or SGPIs, details on the ethnic subpopulations was not provided., Conclusions: Despite the fact that safety data analyzed with respect to ethnic populations are available in almost all screened registration dossiers, this information is often unknown to patients or prescribers as it was often not included in the EPARs, EU SmPCs or SGPIs. In order to increase the availability of such potentially important safety information, it is recommended to at least provide ethnic populations and group size in these public documents. In this way, trust in the registered drugs in different ethnic populations may be increased, and more robust treatment decisions may be obtained in clinical practice.

The simultaneous intake of food and drugs can have a strong impact on drug release, absorption, distribution, metabolism and/or elimination and consequently, on the efficacy and safety of pharmacotherapy. As such, food-drug interactions are one of the main challenges in oral drug administration. Whereas pharmacokinetic (PK) food-drug interactions can have a variety of causes, pharmacodynamic (PD) food-drug interactions occur due to specific pharmacological interactions between a drug and particular drinks or food. In recent years, extensive efforts were made to elucidate the mechanisms that drive pharmacokinetic food-drug interactions. Their occurrence depends mainly on the properties of the drug substance, the formulation and a multitude of physiological factors. Every intake of food or drink changes the physiological conditions in the human gastrointestinal tract. Therefore, a precise understanding of how different foods and drinks affect the processes of drug absorption, distribution, metabolism and/or elimination as well as formulation performance is important in order to be able to predict and avoid such interactions. Furthermore, it must be considered that beverages such as milk, grapefruit juice and alcohol can also lead to specific food-drug interactions. In this regard, the growing use of food supplements and functional food requires urgent attention in oral pharmacotherapy. Recently, a new consortium in Understanding Gastrointestinal Absorption-related Processes (UNGAP) was established through COST, a funding organisation of the European Union supporting translational research across Europe. In this review of the UNGAP Working group "Food-Drug Interface", the different mechanisms that can lead to pharmacokinetic food-drug interactions are discussed and summarised from different expert perspectives., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)