Effect of severe renal impairment on the pharmacokinetics of brigatinib.

Background Brigatinib, a next-generation anaplastic lymphoma kinase (ALK) inhibitor, targets activated, mutant forms of ALK and overcomes mechanisms of resistance to the ALK inhibitors crizotinib, ceritinib, and alectinib. Brigatinib is approved in multiple countries for treatment of patients with ALK-positive non-small cell lung cancer. Based on population pharmacokinetic (PK) analyses, no dosage adjustment is required for patients with mild or moderate renal impairment. Methods An open-label, single-dose study was conducted to evaluate the PK of brigatinib (90 mg) in patients with severe renal impairment (estimated glomerular filtration rate < 30 mL/min/1.73 m2; n = 8) and matched healthy volunteers with normal renal function (estimated glomerular filtration rate ≥ 90 mL/min/1.73 m2; n = 8). Plasma and urine were collected for the determination of plasma protein binding and estimation of plasma and urine PK parameters. Results Plasma protein binding of brigatinib was similar between patients with severe renal impairment (92 % bound) and matched healthy volunteers with normal renal function (91 % bound). Unbound brigatinib exposure (area under the plasma concentration-time curve from time zero to infinity) was approximately 92 % higher in patients with severe renal impairment compared with healthy volunteers with normal renal function. The renal clearance of brigatinib in patients with severe renal impairment was approximately 20 % of that observed in volunteers with normal renal function. Conclusions These findings support a brigatinib dosage reduction of approximately 50 % in patients with severe renal impairment.Trial registry: Not applicable.

Absorption, Distribution, Metabolism, and Excretion of Aprocitentan, a Dual Endothelin Receptor Antagonist, in Humans.

BACKGROUND: Aprocitentan is an orally active, dual endothelin receptor antagonist that may offer a new therapeutic option for the treatment of difficult-to-control hypertension. OBJECTIVE: To investigate safety, tolerability, mass balance, absorption, distribution, metabolism, and excretion of aprocitentan. METHODS: In this single-center, open-label study, a single oral dose of 25 mg containing 3.7 MBq of 14C-radiolabeled aprocitentan was administered to 6 healthy male subjects. Metabolites were identified using mass spectrometry and, where possible, confirmed and quantified with reference compounds. RESULTS: Aprocitentan was well tolerated and there were no clinically significant findings for any safety variable. The geometric mean cumulative recovery of radioactivity from urine and feces over 14 days was 77% of the administered radioactive dose, with 52.1% cumulative recovery from urine and 24.8% from feces. Concentrations of total radioactivity in whole blood were markedly lower compared to plasma. In plasma, 94.3% of total radioactivity was aprocitentan. In urine and feces, 5 and 2, respectively (in feces one being aprocitentan) main products were identified. Metabolism data of aprocitentan identified two main elimination pathways, glucosidation to M3 and hydrolysis to M1, representing approximately 25% and 32% of the radioactive dose, respectively. CONCLUSIONS: Based on these metabolism data, aprocitentan can be concomitantly administered without dose adjustment with drugs that are inhibitors or inducers of any metabolizing enzyme, specifically cytochrome P450 enzymes.

Filaggrin Polymorphisms and the Uptake of Chemicals through the Skin-A Human Experimental Study.

BACKGROUND: The filaggrin protein is important for skin barrier structure and function. Loss-of-function (null) mutations in the filaggrin gene FLG may increase dermal absorption of chemicals. OBJECTIVE: The objective of the study was to clarify if dermal absorption of chemicals differs depending on FLG genotype. METHOD: We performed a quantitative real-time polymerase chain reaction (qPCR)-based genetic screen for loss-of-function mutations (FLG null) in 432 volunteers from the general population in southern Sweden and identified 28 FLG null carriers. In a dermal exposure experiment, we exposed 23 FLG null and 31 wild-type (wt) carriers to three organic compounds common in the environment: the polycyclic aromatic hydrocarbon pyrene, the pesticide pyrimethanil, and the ultraviolet-light absorber oxybenzone. We then used liquid-chromatography mass-spectrometry to measure the concentrations of these chemicals or their metabolites in the subjects' urine over 48 h following exposure. Furthermore, we used long-range PCR to measure FLG repeat copy number variants (CNV), and we performed population toxicokinetic analysis. RESULTS: Lag times for the uptake and dermal absorption rate of the chemicals differed significantly between FLG null and wt carriers with low (20-22 repeats) and high FLG CNV (23-24 repeats). We found a dose-dependent effect on chemical absorption with increasing lag times by increasing CNV for both pyrimethanil and pyrene, and decreasing area under the urinary excretion rate curve (AUC(0-40h)) with increasing CNV for pyrimethanil. FLG null carriers excreted 18% and 110% more metabolite (estimated by AUC(0-40h)) for pyrimethanil than wt carriers with low and high CNV, respectively. CONCLUSION: We conclude that FLG genotype influences the dermal absorption of some common chemicals. Overall, FLG null carriers were the most susceptible, with the shortest lag time and highest rate constants for skin absorption, and higher fractions of the applied dose excreted. Furthermore, our results indicate that low FLG CNV resulted in increased dermal absorption of chemicals. https://doi.org/10.1289/EHP7310.

Effect of monomer structure of anionic surfactant on voltammetric signals of an anticancer drug: rapid, simple, and sensitive electroanalysis of nilotinib in biological samples.

A rapid, simple, and highly sensitive electroanalytical method was developed for the first time for the detection of ultra-trace amounts of nilotinib in sodium lauryl sulphate media. The electrochemical behavior of nilotinib was investigated on a glassy carbon electrode in the absence and presence of sodium lauryl sulphate media by cyclic voltammetry and adsorptive stripping voltammetric methods. The cyclic voltammograms proved that the electrochemical behavior of nilotinib showed irreversible and diffusion-adsorption-controlled oxidation processes in 0.1 M H2SO4. The effect of surfactant concentration on the first and second peaks of nilotinib was examined. Depending on whether the surfactants had a monomer or monolayer hemimicelle structure, they were attracted to amine moieties at related points in the nilotinib structure through the electrostatic interaction. The sensitivity of the method was markedly enhanced in the presence of surfactants using adsorptive stripping square-wave voltammetry. Under optimum conditions, nilotinib was determined in a concentration range of 2.0 × 10-8 to 2.0 × 10-6 mol L-1, with a limit of detection of 6.33 × 10-9 mol L-1 in 0.1 M H2SO4 containing 2.0 × 10-7 mol L-1 sodium lauryl sulphate. The proposed method can be applied for the sensitive determination of nilotinib in biological samples. Graphical abstract.

Absorption, Metabolism and Excretion of Surufatinib in Rats and Humans.

BACKGROUND: Surufatinib is a potent small-molecule tyrosine kinase inhibitor and exhibited significant efficacy in the treatment of neuroendocrine tumors in clinical trials. OBJECTIVE: The absorption, metabolism and excretion of surufatinib were investigated in rats and human volunteers following a single oral dose of [14C] surufatinib. METHODS: The radioactivity was measured in plasma, urine, feces and bile by liquid scintillation counting, and the metabolites were characterized by liquid chromatography coupled to mass spectrometry. RESULTS: Surufatinib was orally absorbed similarly in rats and human volunteers, with the median Tmax of 4 hours post-dose. The estimated t1/2 appeared longer in humans than in rats (mean t1/2: 3.12 hour for male rats, 6.48 hours for female rats and 23.3 hours for male human volunteers). The excretion of surufatinib was almost complete in rats and human volunteers in the studies, with the total radioactivity recovery of >90% of the dose. Similarly, in rats and humans, fecal excretion predominated (approximately 87% of the dose recovered in feces and only 5% in urine). The parent drug was the major radioactive component detected in the plasma extracts of rats and humans, and no single circulating metabolite accounted for >10% of the total radioactivity. Unchanged drug was a minor radioactive component in the excreta of rats and humans. CONCLUSION: Fecal excretion was the predominant way for the elimination of surufatinib and its metabolites in rats and humans. No disproportionate circulating metabolite was observed in humans.

Pharmacokinetics, mass balance, tissue distribution, metabolism, and excretion of praliciguat, a clinical-stage soluble guanylate cyclase stimulator in rats.

The pharmacokinetics (PK), metabolism, excretion, mass balance, and tissue distribution of [14 C]praliciguat were evaluated following oral administration of a 3-mg/kg dose in Sprague-Dawley rats and in a quantitative whole-body autoradiography (QWBA) study conducted in male Long-Evans rats. Plasma Tmax was 1 hour and the t1/2 of total plasma radioactivity was 23.7 hours. Unchanged praliciguat accounted for 87.4%, and a minor metabolite (N-dealkylated-praliciguat) accounted for 7.6% of the total radioactivity in plasma through 48 hours (AUC0-48 ). Tissues with the highest exposure ratios relative to plasma were liver, intestines, adrenal gland, and adipose, and those with the lowest values were seminal vesicle, blood, CNS tissues, lens of the eye, and bone. Most of the [14 C]praliciguat-derived radioactivity was excreted within 48 hours after oral administration. Mean cumulative recovery of the administered radioactivity in urine and feces over 168 hours was 3.7% and 95.7%, respectively. Unchanged praliciguat was not quantifiable in urine or bile of cannulated rats; however, based on the total radioactivity in these fluids, a minimum of approximately 82% of the orally administered dose was absorbed. [14 C]Praliciguat was metabolized via oxidative and glucuronidation pathways and the most abundant metabolites recovered in bile were praliciguat-glucuronide and hydroxy-praliciguat-glucuronide. These results indicate that praliciguat had rapid absorption, high bioavailability, extensive tissue distribution, and elimination primarily via hepatic metabolism.

Open-label, single-center, phase I trial to investigate the mass balance and absolute bioavailability of the highly selective oral MET inhibitor tepotinib in healthy volunteers.

Tepotinib (MSC2156119J) is an oral, potent, highly selective MET inhibitor. This open-label, phase I study in healthy volunteers (EudraCT 2013-003226-86) investigated its mass balance (part A) and absolute bioavailability (part B). In part A, six participants received tepotinib orally (498 mg spiked with 2.67 MBq [14C]-tepotinib). Blood, plasma, urine, and feces were collected up to day 25 or until excretion of radioactivity was <1% of the administered dose. In part B, six participants received 500 mg tepotinib orally as a film-coated tablet, followed by an intravenous [14C]-tepotinib tracer dose (53-54 kBq) 4 h later. Blood samples were collected until day 14. In part A, a median of 92.5% (range, 87.1-96.9%) of the [14C]-tepotinib dose was recovered in excreta. Radioactivity was mainly excreted via feces (median, 78.7%; range, 69.4-82.5%). Urinary excretion was a minor route of elimination (median, 14.4% [8.8-17.7%]). Parent compound was the main constituent in excreta (45% [feces] and 7% [urine] of the radioactive dose). M506 was the only major metabolite. In part B, absolute bioavailability was 72% (range, 62-81%) after oral administration of 500 mg tablets (the dose and formulation used in phase II trials). In conclusion, tepotinib and its metabolites are mainly excreted via feces; parent drug is the major eliminated constituent. Oral bioavailability of tepotinib is high, supporting the use of the current tablet formulation in clinical trials. Tepotinib was well tolerated in this study with healthy volunteers.

First-in-Human Pharmacokinetics and Safety Study of GSK3008356, a Selective DGAT1 Inhibitor, in Healthy Volunteers.

Diacylglycerol acyltransferase (DGAT) enzymes are involved in triglyceride (TG) biosynthesis. GSK3008356 is a potent and selective DGAT1 inhibitor that was administered orally in a 2-part study as double-blind, randomized, placebo-controlled single doses (SDs) and repeat doses (RDs) in healthy subjects to investigate its pharmacokinetics, pharmacodynamics, and safety/tolerability. Gastrointestinal adverse events were considered drug related and increased with dose and when given as multiple doses. In the SD part (n = 80), GSK3008356 was dosed from 5 to 200 mg as single or multiple doses per day. In the RD part (n = 24), GSK3008356 was dosed twice daily at 1, 3, and 10 mg for 14 days. GSK3008356 was generally well tolerated in the SD and RD parts. With single doses, absorption was rapid (median tmax , 0.5-1.5 hours), whereas single-day divided dosing resulted in higher tmax . Following 14-day RD oral administration, GSK3008356 was also rapidly absorbed, with median tmax ranging from 0.5 to 0.75 hours on days 1 and 14. Estimated mean half-life ranged from 1.5 to 4.6 hours with SDs and 1.3 to 2.1 hours with RDs. Exposure of GSK3008356 was largely dose proportional after RDs. At higher doses, there was a trend toward lower absolute postprandial TG level in some subjects.

Clinical and genetic analysis of 7 Chinese patients with ß-ureidopropionase deficiency.

ß-Ureidopropionase (ßUP) deficiency is an autosomal recessive disease caused by abnormal changes in the pyrimidine-degradation pathway. This study aimed to investigate the mutation of ß-ureidopropionase gene (UPB1) gene and clinical features of 7 Chinese patients with ßUP deficiency.We reported 7 Chinese patients with ßUP deficiency who were admitted at Tianjin Children's Hospital. Urine metabolomics was detected by gas chromatography-mass spectrometry (GC-MS). Then genetic testing of UPB1 was conducted by polymerase chain reaction (PCR) method.The patients presented with developmental delay, seizures, autism, abnormal magnetic resonance imaging, and significantly elevated levels of N-carbamyl-ß-alanine and N-carbamyl-ß-aminoisobutyric acid in urine. Subsequent analysis of UPB1 mutation revealed 2 novel missense mutations (c.851G>T and c.853G>A), 3 previously reported mutations including 2 missense mutations (c.977G>A and c.91G>A) and 1 splice site mutation (c.917-1 G>A).The results suggested that the UPB1 mutation may contribute to ßUP deficiency. The c.977G>A is the most common mutation in Chinese population.

A case of dihydropyrimidinase deficiency incidentally detected by urine metabolome analysis.

Dihydropyrimidinase deficiency is a rare autosomal recessive disease affecting the second step of pyrimidine degradation. It is caused by mutations in the DPYS gene. Only approximately 30 cases have been reported to date, with a phenotypical variability ranging from asymptomatic to severe neurological illness. We report a case of dihydropyrimidinase deficiency incidentally detected by urine metabolome analysis. Gas chromatography-mass spectrometry-based urine metabolomics demonstrated significant elevations of dihydrouracil and dihydrothymine, which were subsequently confirmed by a quantitative analysis using liquid chromatography-tandem mass spectrometry. Genetic testing of the DPYS gene revealed two mutations: a novel mutation (c.175G > T) and a previously reported mutation (c.1469G > A). Dihydropyrimidinase deficiency is probably underdiagnosed, considering its wide phenotypical variability, nonspecific neurological presentations, and an estimated prevalence of 2/20,000. As severe 5-fluorouracil-associated toxicity has been reported in patients and carriers of congenital pyrimidine metabolic disorders, urinary pyrimidine analysis should be considered for those who will undergo 5-fluorouracil treatment.

Biomarkers of Exposure to Pyrimethanil After Controlled Human Experiments.

Pyrimethanil (PYM) is a fungicide used pre- and post-harvest on many crops. It has a low acute toxicity but is of toxicological concern because of its antiandrogenic properties. The aim of the current work was to investigate some metabolism and estimate elimination kinetics of PYM in humans after experimental oral and dermal exposure. A liquid chromatography triple quadrupole mass spectrometry (LC-MS-MS) method was developed and validated for the analysis of PYM and its metabolite 4-hydroxypyrimethanil (OH-PYM) in human urine. The method was applied to analyze urine obtained from two volunteers experimentally exposed to PYM. The elimination of OH-PYM seemed to follow first-order kinetics and a two-phase excretion. After the oral exposure, the elimination half-life of OH-PYM in the rapid phase was 5 and 3 h for the female and male volunteer, respectively. In the slower phase, it was 15 h in both volunteers. After the dermal exposure, the half-life in the rapid phase was 8 h in both volunteers. In the slower phase, it was 30 and 20 h, respectively. About 80% of the oral dose was recovered as urinary OH-PYM in both volunteers. The dermal dose recovered as urinary OH-PYM was 9.4% and 19%, in the female and male volunteer, respectively. OH-PYM was mainly found as a conjugate of sulfonate and glucuronic acid. No free PYM was found. The analytical method showed good within-run, between-run and between-batch precision with a coefficient of variation between 6% and 12%. A limit of detection of 0.1 ng/mL and a limit of quantification of 0.4 ng/mL were achieved for both the analytes. The method was applied to biomonitor PYM exposure in populations in Sweden. OH-PYM was detected in nearly 50% and 96% of samples from the environmentally and occupationally exposed populations, respectively.

Mass balance, routes of excretion, and pharmacokinetics of investigational oral [14C]-alisertib (MLN8237), an Aurora A kinase inhibitor in patients with advanced solid tumors.

Aims This two-part, phase I study evaluated the mass balance, excretion, pharmacokinetics and safety of the investigational aurora A kinase inhibitor, alisertib, in three patients with advanced malignancies. Methods Part A; patients received a single 35-mg dose of [14C]-alisertib oral solution (~80 µCi total radioactivity [TRA]). Serial blood, urine, and fecal samples were collected up to 336 h post-dose for alisertib mass balance and pharmacokinetics in plasma and urine by liquid chromatography-tandem mass spectrometry, and mass balance/recovery of [14C]-radioactivity in urine and feces by liquid scintillation counting. Part B; patients received non-radiolabeled alisertib 50 mg as enteric-coated tablets twice-daily for 7 days in 21-day cycles. Results In part A, absorption was fast (median plasma Tmax, 1 h) for alisertib and TRA. Mean plasma t1/2 for alisertib and TRA were 23.4 and 42.0 h, respectively. Mean plasma alisertib/TRA AUC0-inf ratio was 0.45, indicating presence of alisertib metabolites in circulation. Mean TRA blood/plasma AUC0-last ratio was 0.60, indicating preferential distribution of drug-related material in plasma. On average, 87.8% and 2.7% of administered radioactivity was recovered in feces and urine, respectively (total recovery, 90.5% by 14 days post-dose). In part B, patients received a median 3 cycles of alisertib. The most common any-grade adverse events were fatigue and alopecia. Conclusions Findings suggest that alisertib is eliminated mainly via feces, consistent with hepatic metabolism and biliary excretion of drug-related material. Further investigation of alisertib pharmacokinetics in patients with moderate-severe hepatic impairment is warranted to inform dosing recommendations in these patient populations.

Accurate and sensitive determination of sildenafil, tadalafil, vardenafil, and avanafil in illicit erectile dysfunction medications and human urine by LC with quadrupole-TOF-MS/MS and their behaviors in simulated gastric conditions.

The widespread use of phosphodiesterase-5 inhibitors has attracted broad attention of counterfeiters to develop illicit erectile products with inaccurate amounts, unknown toxicity, and purity of active ingredients. Correspondingly, intake of these products endangers consumer health and needs to be screened for precautionary actions to reduce this risk. Therefore, in this study, a sensitive and rapid analytical method has been developed for simultaneous determination of selected phosphodiesterase-5 inhibitors present in illicit erectile medications and human urine. Quantification of the analytes was performed by liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry system. The chromatographic separation was successfully achieved with a run period of 8 min. Low detection limits were obtained in the range of 1.63-9.81 ng/g with relative standard deviations below 7.72% obtained using the replicate measurements of lowest concentration in calibration plots. The analytical performance of the proposed method proved good linearity, low detection limits, good accuracy and precision with high percent recoveries for human urine samples. Developed method was successfully applied to real samples including four different brands of illicit erectile medications. The results obtained revealed the presence of high levels of sildenafil in analyzed samples. The behaviors of selected phosphodiesterase-5 inhibitors were also studied in simulated gastric conditions.

19F-NMR-based determination of the absorption, metabolism and excretion of the oral phosphatidylinositol-3-kinase (PI3K) delta inhibitor leniolisib (CDZ173) in healthy volunteers.

1. Leniolisib is a novel oral phosphatidylinositol-3-kinase (PI3K) delta inhibitor, currently in clinical development for the treatment of inflammatory and autoimmune diseases. 2. We investigated the absorption, metabolism, and excretion of leniolisib in healthy subjects after a single oral 400 mg dose as part of a first-in-human clinical study. The parent drug and metabolites were quantified by 19F-NMR in plasma, urine and faeces after liquid chromatography separation, and structures were determined by liquid chromatography coupled to tandem mass spectrometry. 3. Drug-related material was mainly excreted as oxidative metabolites in urine and faeces, providing evidence that elimination occurs mainly by metabolism. No metabolites were abundant in plasma relative to the parent drug. An average mass balance of 66% was obtained, demonstrating that relatively extensive elimination/excretion data can be obtained by 19F-NMR in a first in human clinical study without the use of a radiolabeled drug.

Exposure to di-2-ethylhexyl terephthalate in the U.S. general population from the 2015-2016 National Health and Nutrition Examination Survey.

BACKGROUND: Di-2-ethylhexyl terephthalate (DEHTP) is used as a replacement plasticizer for other phthalates, including di-2-ethylhexyl phthalate (DEHP). Use of consumer products containing DEHTP may result in human exposure to DEHTP. OBJECTIVE: To assess exposure to DEHTP in a nationally representative sample of the U.S. general population 3 years and older from the 2015-2016 National Health and Nutrition Examination Survey (NHANES). METHOD: We quantified two DEHTP metabolites, mono-2-ethyl-5-hydroxyhexyl terephthalate (MEHHTP) and mono-2-ethyl-5-carboxypentyl terephthalate (MECPTP) in 2970 urine samples by using online solid-phase extraction coupled with isotope dilution-high-performance liquid chromatography-tandem mass spectrometry. We used linear regression to examine associations between MEHHTP and MECTPP and several parameters including age, sex, race/ethnicity, and household income. We also compared the MEHHTP and MECPTP results to those of their corresponding DEHP metabolite analogs, namely mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP) and mono-2-ethyl-5-carboxypentyl phthalate (MECPP). RESULTS: The weighted detection frequencies were 96% (MEHHTP) and 99.9% (MECPTP); urinary concentrations of the two metabolites correlated significantly (Pearson correlation coefficient = 0.89, p < 0.0001). MECPTP concentrations were higher than MEHHTP in all age, sex, race/ethnicity groups examined. Furthermore, MECPTP adjusted geometric mean (GM) concentrations were significantly higher in samples collected in the evening than in the morning or afternoon. Females had significantly higher adjusted GM concentrations of MEHHTP and MECPTP than males. We observed no significant associations between the adjusted GM concentrations of the metabolites and race/ethnicity. Both metabolite adjusted GM concentrations increased significantly with household income, and decreased significantly with age. Only household income was significantly associated with the concentrations of MECPP, but not of MEHHP, the two DEHP metabolites. The adjusted GM of the [MEHHTP]:[MECPTP] molar concentrations ratio increased with age, and was significantly higher in samples collected in the morning than in those collected in the afternoon or evening. CONCLUSIONS: Exposure to DEHTP is widespread in the U.S. general population 3 years and older. These data represent the first U.S. population-based representative background exposure to DEHTP.

Pharmacokinetics of the Oral Selective CXCR2 Antagonist AZD5069: A Summary of Eight Phase I Studies in Healthy Volunteers.

OBJECTIVE: The aim of this study was to summarise the pharmacokinetic findings from eight phase I studies in healthy volunteers given oral AZD5069, a selective small-molecule CXCR2 antagonist. METHODS: 240 healthy volunteers across eight phase I studies received single (0.1-200 mg) or multiple once- or twice-daily (10-120 mg) oral AZD5069 as solution, suspension, capsules or tablets. Pharmacokinetics were evaluated using non-compartmental analysis methods. RESULTS: AZD5069 was rapidly absorbed (time to maximum concentration ~ 2 h) under fasting conditions. A high-fat, high-calorie meal delayed and reduced the peak plasma AZD5069 concentration (Cmax) by 50%, but total exposure (AUC) was unchanged (fed:fasting geometric mean ratio 90% confidence interval within 0.80-1.25). The plasma concentration of AZD5069 declined with an initial half-life of 4 h and terminal half-life of 11 h. Steady-state plasma concentrations were achieved within 2-3 days and accumulation was ~ 1.1-fold with twice-daily dosing. Systemic exposure was approximately proportional to dose. Intra- and inter-subject variability in AUC was 3-11 and 29-64%, respectively. Less than 5% of the AZD5069 dose was excreted as parent drug in the urine. Elderly subjects had 39% higher AZD5069 AUC and 21% higher Cmax than younger adults. Japanese subjects had similar or slightly higher exposure to AZD5069 than Caucasian subjects. Co-administration with ketoconazole resulted in 2.1-fold higher AUC and 1.6-fold higher Cmax. All formulations had similar bioavailability. CONCLUSIONS: AZD5069 demonstrated predictive linear pharmacokinetics with low intra- and moderate inter-subject variability and no major influences from ethnicity, age, food or formulation. Half-life data indicated suitability for twice-daily dosing. CLINICALTRIALS. GOV IDENTIFIERS: NCT00953888, NCT01051505, NCT01083238, NCT01100047, NCT01332903, NCT01480739, NCT01735240, NCT01989520.

Evaluation of cAMS for 14C microtracer ADME studies: opportunities to change the current drug development paradigm.

AIM: Although regulatory guidances require human metabolism information of drug candidates early in the development process, the human mass balance study (or hADME study), is performed relatively late. hADME studies typically involve the administration of a 14C-radiolabelled drug where biological samples are measured by conventional scintillation counting analysis. Another approach is the administration of therapeutic doses containing a 14C-microtracer followed by accelerator mass spectrometry (AMS) analysis, enabling hADME studies completion much earlier. Consequently, there is an opportunity to change the current drug development paradigm. MATERIALS & METHODS: To evaluate the applicability of the MICADAS-cAMS method, we successfully performed: the validation of MICADAS-cAMS for radioactivity quantification in biomatrices and, a rat ADME study, where the conventional methodology was assessed against a microtracer MICADAS-cAMS approach. RESULTS & DISCUSSION: Combustion AMS (cAMS) technology is applicable to microtracer studies. A favorable opinion from EMA to complete the hADME in a Phase I setting was received, opening the possibilities to change drug development.

Interspecies scaling of urinary excretory amounts of nine drugs belonging to different therapeutic areas with diverse chemical structures - accurate prediction of the human urinary excretory amounts.

1. The human urinary excretory amounts of total drug (parent + metabolites) were predicted for nine drugs with diverse chemical structures using simple allometry. The drugs used for scaling were cephapirin, olanzapine, labetolol, carisbamate, voriconazole, tofacitinib, nevirapine, ropinirole, and cyclindole. 2. The traditional allometric scaling was attempted using Y = aWb relationship. The corresponding predicted urinary amounts were converted into % recovery by using appropriate human dose. Appropriate statistical tests comprising of fold-difference (predicted/observed values) and error calculations (MAE and RMSE) were performed. 3. The interspecies scaling of all nine drugs tested showed excellent correlation (r > 0.9672). The predictions for eight out of nine drugs (exception was cephaphirin) were contained within 0.80-1.25 fold-differences. The MAE and RMSE were within ± 18% and 14.64%, respectively. 4. The present work supported the potential application of prospective allometry scaling to predict the urinary excretory amounts of the total drug and gauge any issues for the renal handling of the total drug.

Impact of chemotherapy on medium-term physical function and activity of older breast cancer survivors, and associated biomarkers.

OBJECTIVE: Chemotherapy is less often prescribed in older individuals due to concerns about post-treatment morbidity and quality of life. We evaluated the physical performance of breast cancer survivors treated with and without adjuvant chemotherapy. MATERIALS AND METHODS: We conducted a case-control study in 56 estrogen receptor positive breast cancer survivors (BCS) on adjuvant aromatase inhibitors 1-2years after definitive surgery. Cases had received adjuvant chemotherapy (n=27; age 70.5±3.6years) versus age-matched controls who had not (n=29; age 70.0±4.3years). Measures of grip strength, physical activity and performance, walking speed, fatigue, and self-reported physical function were collected. Biological correlates of inflammation, frailty and markers of DNA and RNA oxidation were compared. RESULTS: Grip strength (controls: 21±7.4 vs. CASES: 29.7±5.0kg, p=0.20), physical activity (5403±3204 vs. 6801±9320steps/day, p=0.45), physical performance (short physical performance battery score: 10.1±1.8 vs. 10.4±1.1, p=0.52) and long-distance walking speed (1.2±0.21 vs. 1.3±0.41m/s, p=0.17) were similar between the two groups. Self-reported physical function was marginally lower in cases than controls (controls: 72±24 vs. CASES: 57±34AU, p=0.07). Fatigue disruptiveness was not different between groups (controls: 11.1±13.0 vs. CASES: 15.7±16.2AU, p=0.24). Similarly, the inflammation, oxidation, and frailty markers did not present a significant difference between groups, except for vitamin D levels (p=0.04). CONCLUSION: Older women who received chemotherapy reported having slightly lower physical function, but a similar physical performance compared to women who did not. These data suggest that older BCS treated with chemotherapy recover to an extent similar to survivors who only received hormonal therapy.