Clinical Validation of a Capillary Blood Home-Based Self-Sampling Technique for Monitoring of Infliximab, Vedolizumab, and C-Reactive Protein Concentrations in Patients With Inflammatory Bowel Disease

BACKGROUND

Therapeutic drug monitoring provides important guidance for treatment of patients with inflammatory bowel disease (IBD) and could help to early identify treatment failure. This study aimed to validate a finger prick-based capillary blood sampling technique to measure biological trough levels and C-reactive protein (CRP) and evaluate patient performance and -support.

METHODS

In this prospective cohort study, patients with IBD receiving infliximab (IFX) or vedolizumab (VEDO) therapy performed finger prick-based capillary blood sampling at home. Additionally, blood was collected through routinely performed in-hospital venepuncture prior to biological infusion. IFX, VEDO, and CRP concentrations were measured by enzyme-linked immunosorbent assay. The concordance between methods was statistically evaluated and a survey was conducted to assess practicality and patient support.

RESULTS

In total, 81 patients (46 IFX, 35 VEDO) were enrolled. Mean differences between both methods were 0.42 (95% confidence interval, -1.74 to 2.58) μg/mL for IFX and 0.72 (95% confidence interval, -5.50 to 6.94) μg/mL for VEDO. Passing-Bablok regressions demonstrated no evidence for systematic or proportional biases. Venous and capillary IFX (ρ = 0.96, P < .001) and VEDO (ρ = 0.97, P < .001) levels strongly correlated and showed high intermethod agreement (Cohen's kappa: IFX = 0.82; VEDO = 0.94). Similarly, venous and capillary CRP levels were strongly correlated (ρ = 0.99, P < .001). Most patients (>95%) were able to successfully perform the self-sampling at home without prior instructions.

CONCLUSIONS

This study clinically validated a finger prick-based capillary blood self-sampling technique allowing concomitant home monitoring of biological levels and CRP for patients with IBD, who reported substantial support, tolerability, and practicality.

Validation of an LC-MS/MS assay for rapid and simultaneous quantification of 21 kinase inhibitors in human plasma and serum for therapeutic drug monitoring

Kinase inhibitors have revolutionized cancer treatment in the past 25 years and currently form the cornerstone of many treatments. Due to the increasing evidence for therapeutic drug monitoring (TDM) of kinase inhibitors, the need is growing for new assays to rapidly evaluate kinase inhibitor plasma concentrations. In this study, we developed an LC-MS/MS assay for the rapid and simultaneous quantification of 21 kinase inhibitors. First, a literature search was conducted to ensure that the linear ranges of the analytes were in line with the reported therapeutic windows and/or TDM reference values. Subsequently, the assay was validated according to FDA and EMA guidelines for linearity, selectivity, carry-over, accuracy, precision, dilution integrity, matrix effect, recovery, and stability. The assay was fast, with a short run-time of 2 min per sample. Sample pre-treatment consisted of protein precipitation with methanol enriched with stable isotope-labeled internal standards (SIL-IS), and the mixture was vortexed and centrifuged before sample injection. Separation was achieved using a C18 column (3 μm,50 × 2.1 mm) with a gradient of two mobile phases (ammonium formate buffer pH 3.5 and acetonitrile). Analyte detection was conducted in positive ionization mode using selected reaction monitoring. The assay was accurate and precise in plasma as well as in serum. Extraction recovery ranged between 95.0% and 106.0%, and the matrix effect was 95.7%-105.2%. The stability of the analytes varied at room temperature and in refrigerated conditions. However, all drugs were found to be stable for 7 days in the autosampler. The clinical applicability of the analytical method (486 analyzed samples between 1 July 2022-1 July 2023) as well as external quality control testing results were evaluated. Taken together, the results demonstrate that the analytical method was validated and applicable for routine analyses in clinical practice.

Capsules with Ileocolonic-Targeted Release of Vitamin B2, B3, and C (ColoVit) Intended for Optimization of Gut Health: Development and Validation of the Production Process

The ileocolonic-targeted delivery of vitamins can establish beneficial alterations in gut microbial composition. Here, we describe the development of capsules containing riboflavin, nicotinic acid, and ascorbic acid covered with a pH-sensitive coating (ColoVit) to establish site-specific release in the ileocolon. Ingredient properties (particle size distribution, morphology) relevant for formulation and product quality were determined. Capsule content and the in vitro release behaviour were determined using a HPLC-method. Uncoated and coated validation batches were produced. Release characteristics were evaluated using a gastro-intestinal simulation system. All capsules met the required specifications. The contents of the ingredients were in the 90.0-120.0% range, and uniformity requirements were met. In the dissolution test a lag-time in drug release of 277-283 min was found, which meets requirements for ileocolonic release. The release itself is immediate as shown by dissolution of the vitamins of more than 75% in 1 h. The production process of the ColoVit formulation was validated and reproducible, it was shown that the vitamin blend was stable during the production process and in the finished coated product. The ColoVit is intended as an innovative treatment approach for beneficial microbiome modulation and optimization of gut health.

The Pharmacokinetics and Target Attainment of Antimicrobial Drugs Throughout Pregnancy: Part III Non-penicillin and Non-cephalosporin Drugs

INTRODUCTION

Understanding the pharmacokinetics (PK) of antimicrobial drugs in pregnant women is crucial to provide effective and safe treatment. This study is part of a series that systematically reviews literature on the PK and analyzes if, based on the changed PK, evidence-based dosing regimens have been developed for adequate target attainment in pregnant women. This part focusses on antimicrobials other than penicillins and cephalosporins.

METHODS

A literature search was conducted in PubMed according to the PRISMA guidelines. Search strategy, study selection, and data extraction were independently performed by two investigators. Studies were labeled as relevant when information on the PK of antimicrobial drugs in pregnant women was available. Extracted parameters included bioavailability for oral drugs, volume of distribution (Vd) and clearance (CL), trough and peak drug concentrations, time of maximum concentration, area under the curve and half-life, probability of target attainment, and minimal inhibitory concentration (MIC). In addition, if developed, evidence-based dosing regimens were also extracted.

RESULTS

Of the 62 antimicrobials included in the search strategy, concentrations or PK data during pregnancy of 18 drugs were reported. Twenty-nine studies were included, of which three discussed aminoglycosides, one carbapenem, six quinolones, four glycopeptides, two rifamycines, one sulfonamide, five tuberculostatic drugs, and six others. Eleven out of 29 studies included information on both Vd and CL. For linezolid, gentamicin, tobramycin, and moxifloxacin, altered PK throughout pregnancy, especially in second and third trimester, has been reported. However, no target attainment was studied and no evidence-based dosing developed. On the other hand, the ability to reach adequate targets was assessed for vancomycin, clindamycin, rifampicin, rifapentine, ethambutol, pyrazinamide, and isoniazid. For the first six mentioned drugs, no dosage adaptations during pregnancy seem to be needed. Studies on isoniazid provide contradictory results.

CONCLUSION

This systematic literature review shows that a very limited number of studies have been performed on the PK of antimicrobials drugs-other than cephalosporins and penicillins-in pregnant women.

Pharmacokinetics and Target Attainment of Antimicrobial Drugs Throughout Pregnancy: Part I-Penicillins

BACKGROUND AND OBJECTIVE

Pharmacokinetics (PK) are severely altered in pregnant women due to changes in volume of distribution (Vd) and/or drug clearance (CL), affecting target attainment of antibiotics in pregnant women. This review is part of a series that reviews literature on the description of PK and target attainment of antibiotics in pregnant women with specific focus on penicillins.

METHODS

A systematic literature search was carried out in PubMed. Articles were labelled as relevant when information on PK of penicillins in pregnant women was available.

RESULTS

Thirty-two relevant articles were included, 8 of which discussed amoxicillin (with and without clavulanic acid), 15 ampicillin, 4 benzylpenicillin, 1 phenoxymethylpenicillin, and 4 piperacillin (with and without tazobactam). No studies were found on pheneticillin and flucloxacillin in pregnant women. Ten out of 32 articles included information on both Vd and CL. During the second and third trimester of pregnancy, a higher CL and larger Vd was reported than in non-pregnant women and in pregnant women during first trimester. Reduced target attainment was described in second and third trimester pregnant women. Only 7 studies reported dosing advice, 4 of which were for amoxicillin.

CONCLUSION

The larger Vd and higher CL in second and third trimester pregnant women might warrant a higher dosage or shortening of the dosing interval of penicillins to increase target attainment. Studies frequently fail to provide dosing advice for pregnant women, even if the necessary PK information was available.

Therapeutic drug monitoring-guided treatment versus standard dosing of voriconazole for invasive aspergillosis in haematological patients: a multicentre, prospective, cluster randomised, crossover clinical trial

OBJECTIVES

Voriconazole therapeutic drug monitoring (TDM) is recommended based on retrospective data and limited prospective studies. This study aimed to investigate whether TDM-guided voriconazole treatment is superior to standard treatment for invasive aspergillosis.

METHODS

A multicentre (n = 10), prospective, cluster randomised, crossover clinical trial was performed in haematological patients aged ≥18 years treated with voriconazole. All patients received standard voriconazole dose at the start of treatment. Blood/serum/plasma was periodically collected after treatment initiation of voriconazole and repeated during treatment in both groups. The TDM group had measured voriconazole concentrations reported back, with dose adjustments made as appropriate, while the non-TDM group had voriconazole concentrations measured only after study completion. The composite primary endpoint included response to treatment and voriconazole treatment discontinuation due to an adverse drug reaction related to voriconazole within 28 days after treatment initiation.

RESULTS

In total, 189 patients were enrolled in the study. For the composite primary endpoint, 74 patients were included in the non-TDM group and 68 patients in the TDM group. Here, no significant difference was found between both groups (P = 0.678). However, more trough concentrations were found within the generally accepted range of 1-6 mg/L for the TDM group (74.0%) compared with the non-TDM group (64.0%) (P < 0.001).

CONCLUSIONS

In this trial, TDM-guided dosing of voriconazole did not show improved treatment outcome compared with standard dosing. We believe that these findings should open up the discussion for an approach to voriconazole TDM that includes drug exposure, pathogen susceptibility and host defence.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov registration no. NCT00893555.

Population pharmacokinetic model and limited sampling strategy for clozapine using plasma and dried blood spot samples

BACKGROUND

To improve efficacy, therapeutic drug monitoring is often used in clozapine therapy. Trough level monitoring is regular, but trough levels provide limited information about the pharmacokinetics of clozapine and exposure in time. The area under the concentration time curve (AUC) is generally valued as better marker of drug exposure in time but calculating AUC needs multiple sampling. An alternative approach is a limited sampling scheme in combination with a population pharmacokinetic model meant for Bayesian forecasting. Furthermore, multiple venepunctions can be a burden for the patient, whereas collecting samples by means of dried blood spot (DBS) sampling can facilitate AUC-monitoring, making it more patient friendly.

OBJECTIVE

Development of a population pharmacokinetic model and limited sampling strategy for estimating AUC_0-12h (a twice-daily dosage regimen) and AUC_0-24h (a once-daily dosage regimen) of clozapine, using a combination of results from venepunctions and DBS sampling.

METHOD

From 15 schizophrenia patients, plasma and DBS samples were obtained before administration and 2, 4, 6, and 8 h after clozapine intake. MwPharm^® pharmacokinetic software was used to parameterize a population pharmacokinetic model and calculate limited sampling schemes.

RESULTS

A three-point sampling strategy with samples at 2, 6, and 8 h after clozapine intake gave the best estimation of the clozapine AUC_0-12h and at 4, 10, and 11 h for the AUC_0-24h. For clinical practice, however, a two-point sampling strategy with sampling points at 2 and 6 h was sufficient to estimate AUC_0-12h and at 4 and 11 h for AUC_0-24h.

CONCLUSION

A pharmacokinetic model with a two-time point limited sampling strategy meant for Bayesian forecasting using DBS sampling gives a better prediction of the clozapine exposure in time, expressed as AUC, compared to trough level monitoring. This limited sampling strategy might therefore provide a more accurate prediction of effectiveness and occurrence of side effects compared to trough level monitoring. The use of DBS samples also makes the collection of clozapine samples easier and wider applicable.

Safe use of radiopharmaceuticals in patients with chronic kidney disease: a systematic review

BACKGROUND

Patients with chronic kidney disease (CKD) may need to have their radiopharmaceutical dosage adjusted to prevent adverse effects and poor outcomes, but there are few recommendations on radiopharmaceutical dosing for this group of patients. The aim of this study is to provide an overview of the available information on radiopharmaceutical dose recommendations for patients with CKD.

METHODS

We performed a systematic literature review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We conducted a literature search in the MEDLINE (PubMed) and Embase databases and screened potentially relevant studies using inclusion and exclusion criteria. We independently assessed the included observational studies' methodologies and extracted relevant data.

RESULTS

Of the 5795 studies first identified, 34 were included in this systematic review. These studies described three radiopharmaceuticals: [131I]sodium iodine, [18F]fludeoxyglucose, and [131I]iobenguane. Twenty-nine studies (85.3%) reported data on patients with CKD stage 5, while only three studies mentioned CKD patients in other stages (8.8%).

CONCLUSION

We found no consistent recommendations for radiopharmaceutical dosing in patients with CKD. Although some studies do mention dosing difficulties in patients with CKD, information is available for only a few radiopharmaceuticals, and recommendations are sometimes contradictory. Further research on radiopharmaceutical dosing in patients with CKD is needed to determine whether these patients require specific dosing, especially for therapeutic radiopharmaceuticals where a non-optimised dose may lead to an increased risk of toxicity for non-targeted organs. Including patients with CKD in studies and providing specific information about dosing in these patients should be a priority for the radiopharmaceutical community.

Treatment outcomes of patients with MDR-TB in Nepal on a current programmatic standardised regimen: retrospective single-centre study

Objectives

The objectives of this study were to evaluate treatment in patients on current programmatic multidrug-resistant tuberculosis (MDR-TB) regimen and verify eligibility for the 9-month regimen and therapeutic drug monitoring (TDM).

Methods

We performed a retrospective chart review of patients with MDR-TB receiving standardised regimen at the German Nepal TB Project Clinic, Nepal, between 2014 and 2016. Eligibility for the 9-month regimen and indications for TDM were evaluated.

Results

Out of 107 available patients’ medical records, 98 were included. In this centre, the MDR-TB treatment success rates were 69.0% in 2015, 86.6% in 2016 and 86.5% in 2017. The median time to sputum smear conversion was 60 days (60–90 IQR) and culture conversion was 60 days (60–90 IQR). Observed side effects did not impact treatment outcomes. No difference in treatment success rates was observed between patients with predisposing risk factors and those without. Only 49% (36/74) of patients were eligible for the 9-month regimen and 23 patients for TDM according to American Thoracic Society guideline criteria.

Conclusions

Nepalese patients with MDR-TB on ambulatory care had good treatment outcome after programmatic treatment. Implementation of the new WHO oral MDR-TB treatment regimen may further improve treatment results. The 9-month regimen and TDM should be considered as part of programmatic care.

Patient-Reported Adverse Events of Radiopharmaceuticals: A Prospective Study of 1002 Patients

INTRODUCTION

Adverse events of radiopharmaceuticals may be underreported or remain undetected. Patients can provide information about these adverse events to enable healthcare professionals to detect, understand, and manage them more efficiently.

OBJECTIVE

In this study, we aimed to (a) determine the type, causality, and frequency of patient-reported adverse events of radiopharmaceuticals and to (b) assess the onset, outcome, and follow-up of these adverse events from the patient's perspective.

METHODS

We performed a prospective cohort study of 1002 patients who underwent a nuclear medicine examination. Using a validated questionnaire, we collected patient-reported information on adverse events that occurred immediately after administration of the radiopharmaceutical as well as those that occurred later. Adverse events were analysed, coded and assessed for causality by two independent researchers.

RESULTS

A total of 187 (18.7%) patients reported 379 adverse events. Most patient-reported adverse events of radiopharmaceuticals belonged to the 'general disorder and administration site conditions' (42.0%) and 'nervous system disorders' (16.9%) system organ classes. Of the patient-reported adverse events, 43.0% were possibly or probably causally related to radiopharmaceuticals. We found the frequency of patient-reported adverse drug reactions to diagnostic radiopharmaceuticals to be 2.8%. No important medical events were related to the administrations of diagnostic radiopharmaceuticals. Most adverse events (80.0%) occurred shortly after administration of the radiopharmaceutical and were resolved within a few hours. Some events (20.0%) emerged after patients had left the nuclear medicine department, took longer to resolve, and sometimes prompted the patient to consult a healthcare professional.

CONCLUSION

Adverse reactions to diagnostic radiopharmaceuticals can occur, and the frequency reported by patients was found to be 2.8%, which is higher than reported in the existing literature. We hope that the results of this study increase awareness of these adverse reactions among patients and healthcare professionals.

Improving the aseptic transfer procedures in hospital pharmacies part A: methods for the determination of the surface bioburden on ampoules and vials

OBJECTIVES

To develop methods for surface bioburden determination of ampoules and vials to be used in the validation of the disinfection procedures and in routine monitoring of ampoules and vials.

METHODS

The surface bioburdens of ampoules and vials are determined before and after disinfection by contact plates and total immersion.

RESULTS

The mean surface bioburdens of non-disinfected ampoules and vials taken straight from the original boxes are 2.4 and 5.01 cfu (total immersion; n = 20), and 0.97 and 0.94 cfu (contact plates; n = 60). The mean surface bioburdens of ampules and vials after disinfection by wiping are 1.15 and 7.50 cfu (total immersion; n = 20), and 0.12 and 0.10 cfu (contact plates; n = 60). The high number of cfu on vials (total immersion) indicate hidden cfu around the neck not removable by wiping and not detected by contact plates. Total immersion needs special laboratory facilities and is expensive (about €50 a sample). Therefore, it is less appropriate for use in routine monitoring. However, because of the high recovery, it is the method of choice for the validation of the disinfection procedure. Surface bioburden determination by contact plates is relatively simple. Non-flat surfaces cannot be reached, but the recovery from the touched flat part of the surface is high (around 50%). The recovery from swabs is low (around 10%). Another disadvantage of swabs is the laboratory work after sampling. We therefore advise contact plates for routine monitoring. To get a reliable value of the mean surface bioburden at least 30 samples need to be examined.

CONCLUSION

Total immersion is the method of choice for the determination of the effectiveness of a disinfection procedure for ampoules and vials. Contact plate is the method of choice for routine monitoring of the surfaces of ampoules and vials.

First-in-Human Phase I Clinical Trial of an SFV-Based RNA Replicon Cancer Vaccine against HPV-Induced Cancers

A first-in-human phase I trial of Vvax001, an alphavirus-based therapeutic cancer vaccine against human papillomavirus (HPV)-induced cancers was performed assessing immunological activity, safety, and tolerability. Vvax001 consists of replication-incompetent Semliki Forest virus replicon particles encoding HPV16-derived antigens E6 and E7. Twelve participants with a history of cervical intraepithelial neoplasia were included. Four cohorts of three participants were treated per dose level, ranging from 5 × 10⁵ to 2.5 × 10⁸ infectious particles per immunization. The participants received three immunizations with a 3-week interval. For immune monitoring, blood was drawn before immunization and 1 week after the second and third immunization. Immunization with Vvax001 was safe and well tolerated, with only mild injection site reactions, and resulted in both CD4⁺ and CD8⁺ T cell responses against E6 and E7 antigens. Even the lowest dose of 5 × 10⁵ infectious particles elicited E6/E7-specific interferon (IFN)-γ responses in all three participants in this cohort. Overall, immunization resulted in positive vaccine-induced immune responses in 12 of 12 participants in one or more assays performed. In conclusion, Vvax001 was safe and induced immune responses in all participants. These data strongly support further clinical evaluation of Vvax001 as a therapeutic vaccine in patients with HPV-related malignancies.

Discontinuation of metformin to prevent metformin-induced high colonic FDG uptake: is 48 h sufficient?

Objective

In this retrospective, single-center observational study, we investigated whether discontinuing metformin for at least 48 h prevents metformin-induced [¹⁸F]fluorodeoxyglucose (FDG) uptake in all segments of the colon.

Methods

Patients with type 2 diabetes who were using metformin before undergoing an FDG PET/CT scan were included. Two groups were created: patients who discontinued metformin for less than 48 h (< 48 h group) and patients who discontinued metformin for between 48 and 72 h (≥ 48 h group). A control group comprised non-diabetic patients who were not using metformin before undergoing an FDG PET/CT. We visually scored the uptake of FDG in four segments of the colon—the ascendens, transversum, descendens, and rectosigmoid—using a four-point scale (1–4) and considered scores of 3 or 4 to be clinically significant.

Results

Colonic FDG uptake in the ≥ 48 h group (n = 23) was higher than uptake in the control group (n = 96) in the colon descendens [odds ratio (OR) 14.0; 95% confidence interval (CI) 4.8–40.9; p value: 0.001] and rectosigmoid (OR 11.3; 95% CI 4.0–31.9; p value: 0.001), and there was no difference in the colon ascendens and transversum. Colonic FDG uptake in the < 48 h group (n = 25) was higher than uptake in the ≥ 48 h group (n = 23) in the colon transversum (OR 4.8; 95% CI 1.3–18.5; p value: 0.022) and rectosigmoid (p value: 0.023), and there was no difference in the colon ascendens and descendens.

Conclusions

Discontinuing metformin for 48 h before undergoing an FDG PET/CT still gives a high uptake in the distal parts of the colon when compared with non-diabetic patients who are not using metformin. Discontinuing metformin for 48 h seems to be useful for scanning the more proximal segments of the colon.

Association between 8 P-glycoprotein (MDR1/ABCB1) gene polymorphisms and antipsychotic drug-induced hyperprolactinaemia

Introduction

Hyperprolactinaemia, a common adverse effect of antipsychotic drugs, is primarily linked to blockade of dopamine D2 receptors in the pituitary gland. Certain antipsychotic drugs, such as, for example risperidone and paliperidone, are more likely to induce hyperprolactinaemia compared to others. This effect is probably caused by a relatively high blood/brain concentration ratio, a consequence of being a substrate of P‐glycoprotein. Genetic variants of P‐glycoprotein with changed functional activity might influence the potential of risperidone and paliperidone to cause hyperprolactinaemia as the altered blood/brain concentration ratio would lead to a reduced therapeutic drug level within essential brain areas making dose adaptations necessary. This increases exposure of dopamine D2 receptors within the pituitary gland.

Aims

To investigate possible associations between MDR1/ABCB1 gene polymorphisms and antipsychotic drug‐induced hyperprolactinaemia in Russian patients with schizophrenia and to determine possible differences between risperidone/paliperidone and other antipsychotics.

Methods

In total, 446 patients with schizophrenia were included from 3 psychiatric hospitals in Siberia. Blood samples were obtained in a cross‐sectional study design for DNA extraction and prolactin measurement. Associations between hyperprolactinaemia and 8 MDR1/ABCB1 gene‐polymorphisms were assessed using logistic regression analysis accounting for covariates. The analysis was repeated in a patient subgroup using risperidone or paliperidone.

Results

We did not observe an association between any of the 8 single nucleotide polymorphisms and the prevalence of antipsychotic‐induced hyperprolactinaemia in the total patient population. However, in the risperidone/paliperidone subgroup, the single nucleotide polymorphism rs2032582 (G2677T) was found to be negatively associated with risperidone/paliperidone‐induced hyperprolactinaemia.

Conclusion

This study revealed a significant association between the ABCB1 gene polymorphism rs2032582 (G2677T) and risperidone/paliperidone‐induced hyperprolactinaemia.

Patient-Reported Adverse Events of Radiopharmaceuticals: Development and Validation of a Questionnaire

Introduction

Radiopharmaceuticals may cause adverse events. Knowledge about adverse events from a patient’s perspective could help healthcare professionals to detect, understand, and manage adverse events more efficiently when using radiopharmaceuticals. Researchers need a validated questionnaire that can be used in patients to assess adverse events with radiopharmaceuticals.

Objective

The aim of this study was to develop, validate the content of, and perform initial testing of a questionnaire assessing patient-reported adverse events of radiopharmaceuticals.

Methods

Based on existing literature, six professionals drafted and evaluated a first version of the questionnaire. Further content validation was performed using cognitive interviews with six patients undergoing a nuclear medicine examination. After adaptations, the questionnaire was developed into a web-based questionnaire. One hundred patients undergoing nuclear examination tested this version, and the results were used to assess its acceptability and evaluate reported adverse events.

Results

Questions and answer options were revised in the initial questionnaire to improve clarity. In addition, some questions were removed. The final version consisted of 18 questions. In the test phase, the acceptability of the questionnaire was demonstrated (e.g. 79% of the patients who received the questionnaire completed it, and the median time to complete the questionnaire was 12 min for patients who reported an adverse event). Of the 100 patients (53% men, median age 64 years), 12 reported a total of 22 adverse events. One of these adverse events had a high causal association.

Conclusion

After validation and testing, the developed questionnaire to study patient-reported adverse events of radiopharmaceuticals is a suitable and valid instrument which can be used in future research.

Electronic supplementary material

The online version of this article (10.1007/s40264-019-00895-2) contains supplementary material, which is available to authorized users.

Adverse Events of Diagnostic Radiopharmaceuticals: A Systematic Review

Diagnostic radiopharmaceuticals used in nuclear medicine can cause adverse events. Information on these adverse events is available in case reports and databases but may not be readily accessible to healthcare professionals. This systematic review provides an overview of adverse events of diagnostical radiopharmaceuticals and their characteristics. A median frequency for adverse events in diagnostical radiopharmaceuticals of 1.63 (interquartile range: 1.09-2.29) per 100,000 is reported. Most common are skin and subcutaneous tissue disorders, and general disorders and administration site conditions. Many adverse events reported are minor in severity, although 6.7% can be classified as important. In rare cases, adverse events are serious and potentially life-threatening. With the introduction of new radiopharmaceuticals and the increasing use of positron emission tomography-computed tomography, previously unknown adverse events may be detected in daily practice. Future work should cover the experience of the patient with adverse events from diagnostic radiopharmaceuticals.

Improving the aseptic transfer procedures in hospital pharmacies. Part B: evaluation of disinfection methods for materials with a non-sterile surface

Objectives

To improve the disinfection methods for materials with a non-sterile surface to be used in aseptic handling.

Methods

The surface bioburden on ampoules (A) and injection vials (IV) is determined by contact plates and total immersion. The occurrence of spore-forming bacteria is determined by strain colouring and matrix-assisted laser desorption ionisation-time of flight mass spectrometry. The disinfection procedures of non-sterile materials in 10 hospital pharmacies are judged by observing.

Results

After wiping according to local disinfection methods, the mean surface bioburden determined by contact plates in 10 hospital pharmacies is 0.36 (plastic A), 0.50 (glass A) and 0.29 colony-forming unit (cfu) (IV). The observers found great differences in accuracy of wiping and degree of wetting the sterile gauzes.

After improved wiping with commercially available alcohol impregnated sterile wipes and a two-towel technique (one-step TT disinfection), the mean surface bioburden determined by contact plates is 0.03 (plastic A), 0.2 (glass A) and 0.13 cfu (IV). Further improvement can be reached by submerging A and IV in ethanol 70% followed by improved wiping (two-step TT disinfection), but still micro-organisms will remain (mean surface bioburden determined by total immersion is 0 (plastic A) and 0.3 cfu (IV); glass A not determined). Two-step TT disinfection is more labour intensive. Spilling of alcohol is another disadvantage. However, we presume one-step TT disinfection is effective enough in daily practice. Routine surface bioburden determinations have to prove this.

The effectiveness of the combination of spray and wipe is not examined because we observed a quick disappearance of alcohols from vertical as well as horizontal surfaces, which shortens the contact time to far below the advised 2 min.

Spore-forming bacteria disappear as quickly as other micro-organisms during disinfection by alcohols.

Conclusion

Local disinfection procedures can be improved. Complete removal of micro-organisms from materials with a non-sterile surface, even after two-step TT disinfection, is impossible. Routine surface bioburden determinations have to prove if one-step TT disinfection is effective enough.

Towards the Oral Treatment of Ileo-Colonic Inflammatory Bowel Disease with Infliximab Tablets: Development and Validation of the Production Process

Infliximab (IFX) is an intravenously administered monoclonal antibody antagonizing the effects of tumor necrosis factor-alpha (TNF) systemically and is efficacious in the treatment of inflammatory bowel disease (IBD). However, studies suggest that the anti-inflammatory effects result from local immunomodulation in the inflamed regions. Furthermore, topical inhibition of TNF in IBD ameliorates inflammation. We therefore hypothesized that orally administered IFX targeted to the ileo-colonic region in IBD may be an efficacious new treatment option. This study describes the development and validation of the production process of ileo-colonic-targeted 5 mg IFX tablets (ColoPulse-IFX) intended for the oral treatment of IBD by means of producing three consecutive validation batches (VAL1, VAL2, and VAL3, respectively). UV-VIS spectroscopy, HPLC-SEC analysis (content, fragments, aggregates), fluorescence spectroscopy (tertiary protein structure), and ELISA (potency) showed no noticeable deviations of IFX compounded to ColoPulse-IFX compared to fresh IFX stock. The average ± SD (n = 10) IFX content of VAL1, VAL2, and VAL3 was 96 ± 2%, 97 ± 3%, and 96 ± 2%, respectively, and complied with the European Pharmacopeia (Ph. Eur.) requirements for Content Uniformity. The average ± SD (n = 3) ColoPulse-IFX potency was 105 ± 4%, 96 ± 4%, and 97 ± 5%, respectively, compared to fresh IFX stock. The IFX release profile from the tablet core was complete (≥85%) after 10 min in simulated ileum medium. The in vitro coating performance of ColoPulse-IFX showed that the formulation was targeted to the simulated ileo-colonic region. Stability data showed that ColoPulse-IFX was stable for up to 6 months stored at 25 °C/60% RH. Based on these results, the production process can be considered validated and its application is discussed in light of the rationale and available evidence for the topical treatment of IBD with IFX.

Dried Blood Spot Analysis for Therapeutic Drug Monitoring of Clozapine

BACKGROUND

Schizophrenia is a psychiatric disorder that affects approximately 0.4%-1% of the population worldwide. Diagnosis of schizophrenia is based primarily on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria. Clozapine is an antipsychotic drug that is mainly used in the treatment of schizophrenia patients who are refractory or intolerant to at least 2 other antipsychotics. Due to the high variability in pharmacokinetics of clozapine, therapeutic drug monitoring (TDM) is highly recommended for clozapine therapy.

OBJECTIVE

To develop and clinically validate a novel sampling method using dried blood spot (DBS) to support TDM of clozapine and norclozapine.

METHODS

From June 2014 to September 2014, 15 schizophrenia patients (18-55 years) treated with clozapine were included. Plasma, DBS samples made from venous samples (VDBS), and finger prick DBS (DBS) samples were obtained before administration and 2, 4, 6, and 8 hours after clozapine intake. The study was repeated in 6 Russian patients for external validation. Passing-Bablok regression and Bland-Altman analysis were used to compare the DBS, VDBS, and plasma results for clozapine and norclozapine.

RESULTS

The DBS validation results showed good linearity over the concentration time curve measured for clozapine and norclozapine. The accuracy and between- and within-day precision variation values were within accepted ranges. Different blood spot volumes and hematocrit values had no significant influence on the results. The DBS samples were stable at 20°C and 37°C for 2 weeks and at -20°C for 2 years. The mean clozapine and norclozapine DBS/plasma ratios were, respectively, 0.80 (95% CI, 0.76 to 0.85) and 1.063 (95% CI, 1.027 to 1.099) in Dutch patients. The mean clozapine DBS/DPS ratio in Russian patients was 0.70 (95% CI, 0.64 to 0.76).

CONCLUSION

DBS analysis is a reliable tool for blood sampling and performing TDM of clozapine and norclozapine in daily practice and substantially extends the opportunities for TDM of clozapine.

Development of novel zero-order release budesonide tablets for the treatment of ileo-colonic inflammatory bowel disease and comparison with formulations currently used in clinical practice

Up to 50% of Crohn's disease and ulcerative colitis patients suffer from ileo-colonic inflammation. Topically delivered budesonide is an effective treatment but in vitro as well as clinical data suggest that oral formulations currently used in clinical practice are not optimal to treat the ileo-colon. The aim of this in vitro study was to develop ileo-colonic-targeted zero-order sustained-release tablets containing 3 mg or 9 mg budesonide. Targeted delivery was achieved by coating the tablets with the ColoPulse technology (ColoPulse 3 mg or ColoPulse 9 mg, respectively). Tablets were tested in a 10-h gastrointestinal simulation system for site-specific release, zero-order release kinetics (R² ≥ 0.950), release rate, and completeness of release (≥80%). Release profiles of the novel formulations were compared with Entocort, Budenofalk, and Cortiment (budesonide MMX). ColoPulse 3 mg and 9 mg were targeted to the simulated ileo-colon, budesonide release was complete and in a sustained zero-order manner, and both formulations complied with a 6-month accelerated stability study. None of the formulations currently used in clinical practice targeted the ileo-colon. These in vitro results are discussed in light of clinical data. ColoPulse 3 mg and 9 mg are novel interesting formulations for the treatment of the entire ileo-colon in inflammatory bowel disease.

Influence of protein properties and protein modification on biodistribution and tumor uptake of anticancer antibodies, antibody derivatives, and non-Ig scaffolds

Newly developed protein drugs that target tumor-associated antigens are often modified in order to increase their therapeutic effect, tumor exposure, and safety profile. During the development of protein drugs, molecular imaging is increasingly used to provide additional information on their in vivo behavior. As a result, there are increasing numbers of studies that demonstrate the effect of protein modification on whole body distribution and tumor uptake of protein drugs. However, much still remains unclear about how to interpret obtained biodistribution data correctly. Consequently, there is a need for more insight in the correct way of interpreting preclinical and clinical imaging data. Summarizing the knowledge gained to date may facilitate this interpretation. This review therefore provides an overview of specific protein properties and modifications that can affect biodistribution and tumor uptake of anticancer antibodies, antibody fragments, and nonimmunoglobulin scaffolds. Protein properties that are discussed in this review are molecular size, target interaction, FcRn binding, and charge. Protein modifications that are discussed are radiolabeling, fluorescent labeling drug conjugation, glycosylation, humanization, albumin binding, and polyethylene glycolation.

Risk factors contributing to a low darunavir plasma concentration

Darunavir is an efficacious drug; however, pharmacokinetic variability has been reported. The objective of this study was to find predisposing factors for low darunavir plasma concentrations in patients starting the once‐ or twice‐daily dosage. Darunavir plasma concentrations from January 2010 till December 2014 of human immunodeficiency virus‐infected individuals treated in the outpatient clinic of the University Medical Center Groningen were retrospectively reviewed. The first darunavir plasma concentration of patients within 8 weeks after initiation of darunavir therapy was selected. A dichotomous logistic regression analysis was conducted to select the set of variables best predicting a darunavir concentration below median population pharmacokinetic curve. In total 113 patients were included. The variables best predicting a darunavir concentration besides food intake included age together with estimated glomerular filtration rate (Hosmer–Lemeshow test P = 0.945, Nagelkerke R² = 0.284). Systematic evaluation of therapeutic drug monitoring results may help to identify patients at risk for low drug exposure.

Food intake and darunavir plasma concentrations in people living with HIV in an outpatient setting

Aims

Patients receiving darunavir are advised to take it concomitantly with food. The objectives of the present cross‐sectional study were to evaluate the actual concomitant food intake of patients visiting an HIV outpatient clinic.

Methods

Sixty participants treated with darunavir/ritonavir once daily were subjected to a food recall questionnaire concerning their last concomitant food intake with darunavir. Darunavir trough concentrations were calculated.

Results

The median food intake was 507 (0–2707) kcal; protein intake, 20 (0–221)g; carbohydrate intake, 62 (0–267)g; fat intake: 14 (0–143)g; and dietary fibre: 4 (0–30)g. Twenty‐five patients (42%) ingested their drug with between‐meal snacks. No relationship was found between food intake and trough concentrations.

Conclusions

Clear advice on the optimal caloric intake is needed, to avoid high caloric intake in patients who already have an increased risk of cardiovascular disease due to their HIV infection.

Target attainment with continuous dosing of piperacillin/tazobactam in critical illness: a prospective observational study

Optimal dosing of β-lactam antibiotics in critically ill patients is a challenge given the unpredictable pharmacokinetic profile of this patient population. Several studies have shown intermittent dosing to often yield inadequate drug concentrations. Continuous dosing is an attractive alternative from a pharmacodynamic point of view. This study evaluated whether, during continuous dosing, piperacillin concentrations reached and maintained a pre-defined target in critically ill patients. Adult patients treated with piperacillin by continuous dosing in the intensive care unit of a university medical centre in The Netherlands were prospectively studied. Total and unbound piperacillin concentrations drawn at fixed time points throughout the entire treatment course were determined by liquid chromatography-tandem mass spectrometry. A pharmacokinetic combined target of a piperacillin concentration ≥80 mg/L, reached within 1 h of starting study treatment and maintained throughout the treatment course, was set. Eighteen patients were analysed. The median duration of monitored piperacillin treatment was 60 h (interquartile range, 33-96 h). Of the 18 patients, 5 (27.8%) reached the combined target; 15 (83.3%) reached and maintained a less strict target of >16 mg/L. In this patient cohort, this dosing schedule was insufficient to reach the pre-defined target. Depending on which target is to be met, a larger initial cumulative dose is desirable, combined with therapeutic drug monitoring.

Human Epidermal Growth Factor Receptor 3-Specific Tumor Uptake and Biodistribution of 89Zr-MSB0010853 Visualized by Real-Time and Noninvasive PET Imaging

The human epidermal growth factor receptor 3 (HER3) is an interesting target for antitumor therapy. For optimal HER3 signaling inhibition, a biparatopic Nanobody construct (MSB0010853) was developed that binds 2 different HER3 epitopes. In addition, MSB0010853 contains a third HER3 epitope that binds albumin to extend its circulation time. MSB0010853 is cross-reactive with HER3 and albumin of mouse origin. We aimed to gain insight into MSB0010853 biodistribution and tumor uptake by radiolabeling the Nanobody construct with ⁸⁹Zr. Methods: MSB0010853 was radiolabeled with ⁸⁹Zr. Dose- and time-dependent tumor uptake was studied in nude BALB/c mice bearing a subcutaneous HER3 overexpressing H441 non-small cell lung cancer xenograft. Dose-dependent biodistribution of ⁸⁹Zr-MSB0010853 was assessed ex vivo at 24 h after intravenous injection. Protein doses of 5, 10, 25, 100, and 1,000 μg were used. Time-dependent biodistribution of MSB0010853 was analyzed ex vivo at 3, 6, 24, and 96 h after intravenous administration of 25 μg of ⁸⁹Zr-MSB0010853. PET imaging and biodistribution were performed 24 h after administration of 25 μg of ⁸⁹Zr-MSB0010853 to mice bearing human H441, FaDu (high HER3 expression), or Calu-1 (no HER3 expression) tumor xenografts. Results: Radiolabeling of MSB0010853 with ⁸⁹Zr was performed with a radiochemical purity of greater than 95%. Ex vivo biodistribution showed protein dose- and time-dependent distribution of ⁸⁹Zr-MSB0010853 in all organs. Uptake of ⁸⁹Zr-MSB0010853 in H441 tumors was only time-dependent. Tumor could be visualized up to at least 96 h after injection. The highest mean SUV of 0.6 ± 0.2 was observed at 24 h after injection of 25 μg of ⁸⁹Zr-MSB0010853. ⁸⁹Zr-MSB0010853 tumor uptake correlated with HER3 expression and was highest in H441 (6.2 ± 1.1 percentage injected dose per gram [%ID/g]) and lowest in Calu-1 (2.3 ± 0.3 %ID/g) xenografts. Conclusion:⁸⁹Zr-MSB0010853 organ distribution and tumor uptake in mice are time-dependent, and tumor uptake correlates with HER3 expression. In contrast to tumor uptake except for kidney uptake, organ distribution of ⁸⁹Zr-MSB0010853 is protein dose-dependent for the tested doses. ⁸⁹Zr-MSB0010853 PET imaging gives insight into the in vivo behavior of MSB0010853.

Bioavailability of voriconazole in hospitalised patients

An important element in antimicrobial stewardship programmes is early switch from intravenous (i.v.) to oral antimicrobial treatment, especially for highly bioavailable drugs. The antifungal agent voriconazole is available both in i.v. and oral formulations and bioavailability is estimated to be >90% in healthy volunteers, making this drug a suitable candidate for such a transition. Recently, two studies have shown that the bioavailability of voriconazole is substantially lower in patients. However, for both studies various factors that could influence the voriconazole serum concentration, such as inflammation, concomitant intake of food with oral voriconazole, and gastrointestinal complications, were not included in the evaluation. Therefore, in this study a retrospective chart review was performed in adult patients treated with both oral and i.v. voriconazole at the same dose and within a limited (≤5 days) time interval in order to evaluate the effect of switching the route of administration on voriconazole serum concentrations. A total of 13 patients were included. The mean voriconazole trough concentration was 2.28 mg/L [95% confidence interval (CI) 1.29-3.26 mg/L] for i.v. voriconazole administration and 2.04 mg/L (95% CI 0.78-3.30 mg/L) for oral administration. No significant difference was found in the mean oral and i.v. trough concentrations of voriconazole (P = 0.390). The mean bioavailability was 83.0% (95% CI 59.0-107.0%). These findings suggest that factors other than bioavailability may cause the observed difference in voriconazole trough concentrations between oral and i.v. administration in the earlier studies and stress the need for an antimicrobial stewardship team to guide voriconazole dosing.

Predictors of Prolonged TB Treatment in a Dutch Outpatient Setting

Introduction

Standard treatment duration for drug-susceptible tuberculosis (TB) treatment is 6 months. Treatment duration is often extended—and for various different reasons. The aim of this study was to determine the prevalence and to assess risk factors associated with extended TB treatment.

Methods

A cross-sectional study was conducted. Data including demographic, clinical, radiological and microbiological information from the Netherlands TB Register (NTR) of 90 patients with smear and culture positive pulmonary TB of the region Haaglanden, The Netherlands, was eligible for analysis.

Results

Treatment was extended to ≥ 200 days by 46 (51%) patients. Extended TB treatment was associated with a higher frequency of symptoms, presumed to be due to adverse drug reactions (ADR; OR 2.39 95% CI: 1.01–5.69), drug-induced liver injury (DILI) (OR: 13.51; 95% CI: 1.66–109.82) and longer than 2 month smear and culture conversion rate (OR: 11.00; 95% CI: 1.24–97.96 and OR: 8.56; 95% CI: 1.53–47.96). In the multivariable logistic analysis, development of DILI emerged as the single statistically strong risk factor necessitating extension of TB treatment.

Conclusion

This finding will need further confirmation in a prospective study, exploring the possible mutual role of pharmacokinetic and pharmacogenetic determinants of DILI among TB patients.

Imaging the distribution of an antibody-drug conjugate constituent targeting mesothelin with ⁸⁹Zr and IRDye 800CW in mice bearing human pancreatic tumor xenografts

Mesothelin is a tumor differentiation antigen expressed by epithelial tumors, including pancreatic cancer. Currently, mesothelin is being targeted with an antibody-drug conjugate (ADC) consisting of a mesothelin-specific antibody coupled to a highly potent chemotherapeutic drug. Considering the toxicity of the ADC and reduced accessibility of pancreatic tumors, non-invasive imaging could provide necessary information. We therefore developed a zirconium-89 (⁸⁹Zr) labeled anti-mesothelin antibody (⁸⁹Zr-AMA) to study its biodistribution in human pancreatic tumor bearing mice. Biodistribution and dose-finding of ⁸⁹Zr-AMA were studied 144 h after tracer injection in mice with subcutaneously xenografted HPAC. MicroPET imaging was performed 24, 72 and 144 h after tracer injection in mice bearing HPAC or Capan-2. Tumor uptake and organ distribution of ⁸⁹Zr-AMA were compared with nonspecific ¹¹¹In-IgG. Biodistribution analyses revealed a dose-dependent ⁸⁹Zr-AMA tumor uptake. Tumor uptake of ⁸⁹Zr-AMA was higher than ¹¹¹In-IgG using the lowest tracer dose. MicroPET showed increased tumor uptake over 6 days, whereas activity in blood pool and other tissues decreased. Immunohistochemistry showed that mesothelin was expressed by the HPAC and CAPAN-2 tumors and fluorescence microscopy revealed that AMA-800CW was present in tumor cell cytoplasm. ⁸⁹Zr-AMA tumor uptake is antigen-specific in mesothelin-expressing tumors. ⁸⁹Zr-AMA PET provides non-invasive, real-time information about AMA distribution and tumor targeting.

Voriconazole metabolism is influenced by severe inflammation: a prospective study

BACKGROUND

During an infection or inflammation, several drug-metabolizing enzymes in the liver are down-regulated, including cytochrome P450 iso-enzymes. Since voriconazole is extensively metabolized by cytochrome P450 iso-enzymes, the metabolism of voriconazole can be influenced during inflammation via reduced clearance of the drug, resulting in higher voriconazole trough concentrations.

OBJECTIVE

To investigate prospectively the influence of inflammation on voriconazole metabolism and voriconazole trough concentrations.

METHODS

A prospective observational study was performed at the University Medical Center Groningen. Patients were eligible for inclusion if they were ≥18 years old and treated with voriconazole. Voriconazole and voriconazole-N-oxide concentrations were determined in discarded blood samples. To determine the degree of inflammation, C-reactive protein (CRP) concentrations were used. Subsequently, a longitudinal data analysis was performed to assess the effect of inflammation on the metabolic ratio and voriconazole trough concentration.

RESULTS

Thirty-four patients were included. In total 489 voriconazole trough concentrations were included in the longitudinal data analysis. This analysis showed that inflammation, reflected by CRP concentrations, significantly influenced the metabolic ratio, voriconazole trough concentration and voriconazole-N-oxide concentration (all P < 0.001), when corrected for other factors that could influence voriconazole metabolism. The metabolic ratio was decreased by 0.99229^N and the voriconazole-N-oxide concentration by 0.99775^N, while the voriconazole trough concentration was increased by 1.005321^N, where N is the difference in CRP units (in mg/L).

CONCLUSIONS

This study shows that voriconazole metabolism is decreased during inflammation, resulting in higher voriconazole trough concentrations. Therefore, frequent monitoring of voriconazole serum concentrations is recommended during and following severe inflammation.

Development, preclinical safety, formulation, and stability of clinical grade bevacizumab-800CW, a new near infrared fluorescent imaging agent for first in human use

There is a dire need for better visualization of cancer and analysis of specific targets in vivo. Molecular imaging with fluorescence is gaining more and more attention, as it allows detection of these targets and has advantages over radioactivity, such as no radiation dose, and lower costs. A key challenge in optical imaging however, is translation of the newly developed tracers from pre-clinical phase to clinical application. We describe the development and safety testing of clinical grade bevacizumab-800CW, an antibody-based targeted agent for non-invasive imaging of vascular endothelial growth factor A (VEGF-A). Development included implementing the manufacturing process and analytical methods according to current Good Manufacturing Practice (cGMP), formulation studies, extended characterization and stability testing. For safety pharmacology an extended single dose toxicity study in mice was performed. Bevacizumab-800CW was formulated in isotonic phosphate buffered sodium chloride solution at pH 7. The production was robust and showed a reproducible labeling efficiency, and no impurities. The binding affinity to VEGF-A remained intact. The optimized product meets all release specifications, is stable up to at least 3months and its characteristics did not significantly differ from the unlabeled bevacizumab. Toxicity testing in mice showed no remarkable findings. In conclusion, sterile bevacizumab-800CW (6mg=6ml) can be produced in stock according to current Good Manufacturing Practice. It is ready for first-in-human use.

Development of a zero-order sustained-release tablet containing mesalazine and budesonide intended to treat the distal gastrointestinal tract in inflammatory bowel disease

Ulcerative colitis (UC) and Crohn's disease (CD) are diseases affecting the gastrointestinal tract. Treatment depends on the severity of the disease, site of inflammation, and patient's response. The aim of this study was to develop a zero-order sustained-release tablet containing both the anti-inflammatory drugs mesalazine and budesonide as a new treatment option for ileo-colonic CD and UC. Tablets were attained by wet granulation with hydroxypropyl methylcellulose and direct compression. Our newly developed tablet core was coated with different ColoPulse® coating thicknesses and the mesalazine and budesonide release profiles were investigated in a 600-min gastrointestinal simulation system (GISS) experiment, together with commercially available MMX®-mesalazine and MMX®-budesonide. Lag-time, release rate (k0), completeness of release, and zero-order correlation coefficient (R(2)0) could be manipulated by varying ColoPulse® coating thickness. Our newly developed combination preparation (C[4.92]) complied with all conducted European Pharmacopoeia tests as well as an accelerated 6-month stability test and had a lag-time of 250min (simulated ileum targeted), a linear release profile (mesalazine R(2)0=0.9002; budesonide R(2)0=0.9481), and drug release of 100% mesalazine and 77% budesonide. Like C[4.92], MMX®-mesalazine had a linear (R(2)0=0.9883) and complete release profile (96%). However, C[4.92] lag-time was longer (250 vs. 210min), assuring simulated ileum specificity. Remarkably, MMX®-budesonide lag-time was 480min and release was only 7% with a linear character (R(2)0=0.9906). The in vitro results suggest that MMX®-budesonide effectiveness may be improved if budesonide release in the aqueous phase would be increased and that C[4.92] is a potential, new treatment option for ileo-colonic CD and UC.

Biodistribution and PET Imaging of Labeled Bispecific T Cell-Engaging Antibody Targeting EpCAM

AMG 110, a bispecific T cell engager (BiTE) antibody construct, induces T cell-mediated cancer cell death by cross-linking epithelial cell adhesion molecule (EpCAM) on tumor cells with a cluster of differentiation 3 ε (CD3ε) on T cells. We labeled AMG 110 with (89)Zr or near-infrared fluorescent dye (IRDye) 800CW to study its tumor targeting and tissue distribution.

METHODS

Biodistribution and tumor uptake of (89)Zr-AMG 110 was studied up to 6 d after intravenous administration to nude BALB/c mice bearing high EpCAM-expressing HT-29 colorectal cancer xenografts. Tumor uptake of (89)Zr-AMG 110 was compared with uptake in head and neck squamous cell cancer FaDu (intermediate EpCAM) and promyelocytic leukemia HL60 (EpCAM-negative) xenografts. Intratumoral distribution in HT-29 tumors was studied using 800CW-AMG 110.

RESULTS

Tumor uptake of (89)Zr-AMG 110 can be clearly visualized using small-animal PET imaging up to 72 h after injection. The highest tumor uptake of (89)Zr-AMG 110 at the 40-μg dose level was observed at 6 and 24 h (respectively, 5.35 ± 0.22 and 5.30 ± 0.20 percentage injected dose per gram; n = 3 and 4). Tumor uptake of (89)Zr-AMG 110 was EpCAM-specific and correlated with EpCAM expression. 800CW-AMG 110 accumulated at the tumor cell surface in viable EpCAM-expressing tumor tissue.

CONCLUSION

PET and fluorescent imaging provided real-time information about AMG 110 distribution and tumor uptake in vivo. Our data support using (89)Zr and IRDye 800CW to evaluate tumor and tissue uptake kinetics of bispecific T cell engager antibody constructs in preclinical and clinical settings.

Impact of food on the pharmacokinetics of first-line anti-TB drugs in treatment-naive TB patients: a randomized cross-over trial

OBJECTIVES

Concomitant food intake influences pharmacokinetics of first-line anti-TB drugs in healthy volunteers. However, in treatment-naive TB patients who are starting with drug treatment, data on the influence of food intake on the pharmacokinetics are absent. This study aimed to quantify the influence of food on the pharmacokinetics of isoniazid, rifampicin, ethambutol and pyrazinamide in TB patients starting anti-TB treatment.

METHODS

A prospective randomized cross-over pharmacokinetic study was conducted in treatment-naive adults with drug-susceptible TB. They received isoniazid, rifampicin and ethambutol intravenously and oral pyrazinamide on day 1, followed by oral administration of these drugs under fasted and fed conditions on two consecutive days. Primary outcome was the bioavailability while fasting and with concomitant food intake. This study was registered with clinicaltrials.gov identifier NCT02121314.

RESULTS

Twenty subjects completed the study protocol. Absolute bioavailability in the fasted state and the fed state was 93% and 78% for isoniazid, 87% and 71% for rifampicin and 87% and 82% for ethambutol. Food decreased absolute bioavailability of isoniazid and rifampicin by 15% and 16%, respectively. Pyrazinamide AUC0-24 was comparable for the fasted state (481 mg·h/L) and the fed state (468 mg·h/L). Food lowered the maximum concentrations of isoniazid, rifampicin and pyrazinamide by 42%, 22% and 10%, respectively. Time to maximum concentration was delayed for isoniazid, rifampicin and pyrazinamide. The pharmacokinetics of ethambutol were unaffected by food.

CONCLUSIONS

Food decreased absolute bioavailability and maximum concentration of isoniazid and rifampicin, but not of ethambutol or pyrazinamide, in treatment-naive TB patients. In patients prone to low drug exposure, this may further compromise treatment efficacy and increase the risk of acquired drug resistance.

Decision support at the point of prescribing to increase formulary adherence

PURPOSE

Study results demonstrating the effectiveness of order-entry clinical decision support (CDS) alerts as a tool for enforcing therapeutic interchange are presented.

METHODS

A retrospective observational study was conducted at an academic medical center to evaluate formulary nonadherence before and after implementation of a fully electronic medical record with computerized prescriber order-entry (CPOE) technology configured to display therapeutic interchange alerts immediately on entry of orders for nonformulary agents. Formulary nonadherence (defined as the proportion of pharmacist-verified nonformulary orders to total verified orders) within eight medication classes was assessed during a six-month baseline period and two consecutive six-month periods after implementation.

RESULTS

In the 12 months after implementation of the therapeutic interchange alerts, the overall rate of formulary nonadherence decreased by 65%, from 3.5% at baseline to 1.2% during the second 6-month postintervention period (p < 0.001). The total number of verified nonformulary orders decreased from 300 at baseline to 102 during the second postintervention period. The largest decreases in formulary nonadherence were observed in the intranasal steroid drug class (the rate of nonadherent orders declined by a total of 12 percentage points) and the nonbarbiturate sedatives and hypnotics class (a 5-point decline), with significant 6- and 12-month declines also documented in four of the remaining six drug classes.

CONCLUSION

The incorporation of hard-stop CDS alerts into the CPOE system improved the overall rate of prescriber adherence to institutional therapeutic interchange protocols.

Population pharmacokinetics of infliximab in patients with inflammatory bowel disease: potential implications for dosing in clinical practice

BACKGROUND

Infliximab (IFX) is effective in the treatment of inflammatory bowel diseases (IBD). Currently, IFX is administered at fixed doses and intervals; however, costs are high and optimisation is necessary. Several publications indicate that IFX should be dosed on trough levels ≥3.0 mg/L. For optimising IFX dosing, the use of a pharmacokinetic model is important. Population pharmacokinetics of IFX have been described earlier; however, these models were not used for dose optimising.

AIMS

To develop a pharmacokinetic model for IFX in IBD patients that can be used for dose-optimisation of IFX and to predict serum trough levels in this population.

METHODS

An observational retrospective study was performed in 42 IFX-treated IBD patients. Serum samples were drawn before infusion at T = 0, 2, 6, 14, 22 and 54 weeks and analysed for IFX and antibodies against IFX (ATI). Relevant covariates were recorded and a population pharmacokinetic model was developed.

RESULTS

Individual plots created using the final model showed good correspondence between observed and model predicted values. Serum levels were influenced by ATI, disease activity, sex and albumin. Our results show that in patients without ATI target trough levels ≥3.0 mg/L can be achieved by increasing dosing intervals from 8 to 12 weeks combined with a dose increase. This results in a reduction of 33% in concomitant costs.

CONCLUSIONS

In IBD patients without ATI, trough level dosing based on longer intervals can reduce IFX therapy-related visits to the hospital with one-third. Trough level based dose intensification should always be justified by disease activity parameters.

Drug-drug interaction checking assisted by clinical decision support: a return on investment analysis

BACKGROUND

Drug-drug interactions (DDIs) are very prevalent in hospitalized patients.

OBJECTIVES

To determine the number of DDI alerts, time saved, and time invested after suppressing clinically irrelevant alerts and adding clinical-decision support to relevant alerts.

MATERIALS AND METHODS

The most frequently occurring DDIs were evaluated for clinical relevance by a multidisciplinary expert panel. Pharmacist evaluation of relevant DDIs was facilitated using computerized decision support systems (CDSS). During Phase 1, only CDSS-assisted DDI checking was implemented. During Phase 2, CDSS-assisted DDI checking remained in place, and clinically irrelevant DDIs were suppressed. In each phase, the number of alerts and duration of pharmacist DDI checking were compared to conventional DDI checking. In addition, the time invested to implement and configure the CDSS was compared to the time saved using CDSS-assisted DDI checking.

RESULTS

CDSS-assisted DDI checking resulted in a daily decrease of DDI checking alerts from 65 to 47 alerts in Phase 1 (P = .03) and from 73 to 33 alerts in Phase 2 (P = .003). DDI checking duration decreased from 15 to 11 minutes (P = .044) and from 15½ to 8½ minutes (P = .001) in Phases 1 and 2, respectively. Almost 298 of the 392 hours required for implementation were invested by pharmacists. An annual timesaving of 30 hours yielded a return on investment of 9.8 years.

CONCLUSION

CDSS-assisted DDI checking resulted in a 55% reduction of the number of alerts and a 45% reduction in time spent on DDI checking, yielding a return on investment of almost 10 years. Our approach can be used to refine other drug safety checking modules, increasing the efficiency of checking for drug safety without the need to add more staff pharmacists.

Insufficient fluconazole exposure in pediatric cancer patients and the need for therapeutic drug monitoring in critically ill children

BACKGROUND

Fluconazole is recommended as first-line treatment in invasive candidiasis in children and infants. Although timely achievement of adequate exposure of fluconazole improves outcome, therapeutic drug monitoring is currently not recommended.

METHODS

We conducted a retrospective study of critically ill children treated with fluconazole from January 2007 to October 2013 and for whom fluconazole concentrations were available. We collected demographic, clinical, and treatment data through review of the medical records and determined the correlation of clinical variables with the fluconazole concentration. Additionally, we assessed the relation between the fluconazole concentration and the time to culture conversion in patients with proven invasive candidiasis.

RESULTS

In total, 99 pediatric patients met the inclusion criteria. The fluconazole concentration was considered subtherapeutic in 40% of the patients. Multiple linear regression analysis showed a significant, independent, and positive association of the fluconazole trough concentration with the fluconazole dose (P <.001), weight (P = .009), and the serum urea concentration (P = .003), and a significant, independent, and negative association with age (P = .004) and cancer as an underlying condition (P = .003). A higher fluconazole concentration was associated with a shorter time to culture conversion (hazard ratio = 1.076 [95% confidence interval, 1.017-1.138]; P = .011).

CONCLUSIONS

The fluconazole concentration is not sufficient in pediatric cancer patients with the currently recommended dose regimen, and a higher fluconazole dose is required to achieve adequate drug exposure. Therapeutic drug monitoring of fluconazole can be a valuable tool to detect possible underexposure in critically ill children.

Visualising dual downregulation of insulin-like growth factor receptor-1 and vascular endothelial growth factor-A by heat shock protein 90 inhibition effect in triple negative breast cancer

PURPOSE

Triple negative breast cancer (TNBC) is biologically characterised by heterogeneous presence of molecular pathways underlying it. Insulin-like growth factor receptor-1 (IGF-1R) expression and vascular endothelial growth factor-A (VEGF-A) have been identified as key factors in these pathways in TNBC. In this study, we aimed at in vivo PET imaging the effect of heat shock protein (Hsp) 90 inhibition by means of NVP-AUY922 on these pathways, with zirconium-89 ((89)Zr) labelled antibodies targeting IGF-1R and VEGF-A.

MATERIALS AND METHODS

In vitro NVP-AUY922 effects on cellular IGF-1R expression and VEGF-A secretion were determined in MCF-7 and MDA-MB-231 cell lines. Moreover human TNBC bearing MDA-MB-231 mice received 50mg/kg NVP-AUY922 or vehicle q3d intraperitoneally for 21days. PET scans with (89)Zr-MAB391 and (89)Zr-bevacizumab for visualisation of IGF-1R and VEGF-A were performed before and during treatment. Ex vivo biodistribution and correlative tissue analyses were performed.

RESULTS

NVP-AUY922 treatment reduced IGF-1R expression and VEGF-A excretion in both cell lines. Hsp90 inhibition lowered tumour uptake on (89)Zr-MAB391-PET by 37.3% (P<0.01) and on (89)Zr-bevacizumab-PET by 44.4% (P<0.01). This was confirmed by ex vivo biodistribution with a reduction of 41.3% injected dose (ID)/g for (89)Zr-MAB391 and 37.8% ID/g for (89)Zr-bevacizumab, while no differences were observed for other tissues. This coincided with reduced IGF-1R expression and mean vessel density in the NVP-AUY922 treated tumours.

CONCLUSION

(89)Zr-MAB391 and (89)Zr-bevacizumab PET reflect effect of Hsp90 inhibitors and can therefore potentially be used to monitor therapeutic effects of Hsp90 inhibitor therapy in TNBC.

Cost-effectiveness of an electronic medication ordering system (CPOE/CDSS) in hospitalized patients

INTRODUCTION

Prescribing medication is an important aspect of almost all in-hospital treatment regimes. Besides their obviously beneficial effects, medicines can also cause adverse drug events (ADE), which increase morbidity, mortality and health care costs. Partially, these ADEs arise from medication errors, e.g. at the prescribing stage. ADEs caused by medication errors are preventable ADEs. Until now, medication ordering was primarily a paper-based process and consequently, it was error prone. Computerized Physician Order Entry, combined with basic Clinical Decision Support System (CPOE/CDSS) is considered to enhance patient safety. Limited information is available on the balance between the health gains and the costs that need to be invested in order to achieve these positive effects. Aim of this study was to study the balance between the effects and costs of CPOE/CDSS compared to the traditional paper-based medication ordering.

METHODS

The economic evaluation was performed alongside a clinical study (interrupted time series design) on the effectiveness of CPOE/CDSS, including a cost minimization and a cost-effectiveness analysis. Data collection took place between 2005 and 2008. Analyses were performed from a hospital perspective. The study was performed in a general teaching hospital and a University Medical Centre on general internal medicine, gastroenterology and geriatric wards. Computerized Physician Order Entry, combined with basic Clinical Decision Support System (CPOE/CDSS) was compared to a traditional paper based system. All costs of both medication ordering systems are based on resources used and time invested. Prices were expressed in Euros (price level 2009). Effectiveness outcomes were medication errors and preventable adverse drug events.

RESULTS

During the paper-based prescribing period 592 patients were included, and during the CPOE/CDSS period 603. Total costs of the paper-based system and CPOE/CDSS amounted to €12.37 and €14.91 per patient/day respectively. The Incremental Cost-Effectiveness Ratio (ICER) for medication errors was 3.54 and for preventable adverse drug events 322.70, indicating the extra amount (€) that has to be invested in order to prevent one medication error or one pADE.

CONCLUSIONS

CPOE with basic CDSS contributes to a decreased risk of preventable harm. Overall, the extra costs of CPOE/CDSS needed to prevent one ME or one pADE seem to be acceptable.

ImmunoPET and biodistribution with human epidermal growth factor receptor 3 targeting antibody ⁸⁹Zr-RG7116

The humanized monoclonal antibody with high affinity for the human epidermal growth factor receptor (HER) 3, RG7116, is a glycoengineered, IgG1 class antibody. By labeling RG7116 with zirconium-89 ((89)Zr) we aimed to visualize in vivo HER3 expression and study the biodistribution of this antibody in human tumor-bearing mice. Biodistribution of (89)Zr-RG7116 was studied in subcutaneously xenografted FaDu tumor cells (HER3-positive). Dose-dependency of (89)Zr-RG7116 organ distribution and specific tumor uptake was assessed by administering doses ranging from 0.05 to 10 mg/kg RG7116 to SCID/Beige mice. Biodistribution was analyzed at 24 and 144 h after injection. MicroPET imaging was performed at 1, 3, and 6 days after injection of 1.0 mg/kg (89)Zr-RG7116 in the FaDu, H441, QG-56 and Calu-1 xenografts with varying HER3 expression. The excised tumors were analyzed for HER3 expression. Biodistribution analyses showed a dose- and time-dependent (89)Zr-RG7116 tumor uptake in FaDu tumors. The highest tumor uptake of (89)Zr-RG7116 was observed in the 0.05 mg/kg dose group with 27.5%ID/g at 144 h after tracer injection. MicroPET imaging revealed specific tumor uptake of (89)Zr-RG7116 in FaDu and H441 models with an increase in tumor uptake over time. Biodistribution data was consistent with the microPET findings in FaDu, H441, QG56 and Calu-1 xenografts, which correlated with HER3 expression levels. In conclusion, (89)Zr-RG7116 specifically accumulates in HER3 expressing tumors. PET imaging with this tracer provides real-time non-invasive information about RG7116 distribution, tumor targeting and tumor HER3 expression levels.

ColoPulse tablets perform comparably in healthy volunteers and Crohn's patients and show no influence of food and time of food intake on bioavailability

ColoPulse tablets are an innovative development in the field of oral drug delivery and are characterized by a colon-specific release. Until now ColoPulse dosage forms (only capsules) have been studied in healthy volunteers having a standardized breakfast three hours after administration but not in specific patient groups and not with a shorter interval between administration and breakfast. Information on bioavailability and release characteristics of ColoPulse tablets in Crohn's patients and the influence of food and time of food intake is a prerequisite to properly design future clinical studies with active substances in these patients. In the current cross-over study bioavailability and drug release characteristics of ColoPulse tablets were compared in healthy volunteers and in Crohn's patients in remission. Furthermore the influence of food and time of food intake on the in vivo drug release behavior of ColoPulse tablets was investigated. In this study the dual label isotope strategy was used which means that a ColoPulse tablet containing (13)C-urea and an uncoated, immediate release tablet containing (15)N2-urea were taken simultaneously. Breath and urine samples were collected during the test day for isotope analysis. The appearance of the stable isotopes in breath and/or urine provides information on the site of release from the dosage form, release characteristics and bioavailability. Both tablets were administered on two different days in a cross-over design: the first day with a breakfast (non-standardized) one hour after administration and the second day with a standardized breakfast three hours after administration of the tablets. There was no difference in instructions for administration between both days. Results of 16 healthy volunteers and 14 Crohn's patients were evaluated. At least 86% (51 out of 59) of all ColoPulse tablets administered in this study released their contents at the desired intestinal region. There was no significant difference in bioavailability between healthy volunteers and Crohn's patients on both days (day 1 75.8% vs 90.2%, p=0.070 and day 2 83.4% vs 91.4%, p=0.265). There was also no significant influence of food and time of food intake on bioavailability in healthy volunteers (75.8% and 83.4%, p=0.077) and in Crohn's patients (90.2% and 91.4%, p=0.618) when day 1 and day 2 were compared. Release characteristics did not significantly differ between healthy volunteers and Crohn's patients. However, food and time of food intake had some, clinically non-relevant, influence on the release characteristics within both groups which is in line with the fact that food affects gastro-intestinal transit times. This study shows that ColoPulse tablets enable the site-specific delivery of drugs or other compounds (e.g. diagnostics) deep in the ileo-colonic region of the intestine of Crohn's patients in a comparable amount and rate as in healthy volunteers. Food and time of food intake had no relevant influence on bioavailability. In conclusion ColoPulse delivery systems are promising and deserve further research for local therapy with immunosuppressive drugs in Crohn's patients in the near future.