Population pharmacokinetics of regorafenib in solid tumours: Exposure in clinical practice considering enterohepatic circulation and food intake.

AIM: Regorafenib is an oral multikinase inhibitor with clinical efficacy in a range of advanced solid tumours. A population pharmacokinetic (PK) model was developed to evaluate the variability of the PK of regorafenib and its pharmacologically active metabolites M-2 and M-5 in solid tumours. METHODS: The model was initially developed using densely sampled phase 1 data and information on food intake to incorporate enterohepatic circulation (EHC) that was identified to considerably contribute to the PK of regorafenib. This was then applied to sparsely sampled data from four phase 3 studies in patients with advanced solid tumours. The need for exact food intake data to estimate individual drug exposure was evaluated. RESULTS: By incorporating EHC, the model adequately described the PK profiles of regorafenib, M-2 and M-5 after single and multiple doses in patients from phase 1 studies. Individual exposure in phase 3 studies was adequately described based on assumptions on the time and frequency of food intake, although exact food intake data are recommended to improve the estimation. Covariate analysis identified sex and body mass index (BMI) as impacting exposure to regorafenib, and sex as strongly impacting exposure to M-2 and M-5 (also influenced by the BMI effect on parent regorafenib in the joint model developed); however, these factors accounted for a small portion of the overall variability in exposure. CONCLUSIONS: The adequate description of regorafenib PK after multiple dosing requires the incorporation of EHC. Neither single nor combined covariates predicted exposures that would warrant a priori regorafenib dose adjustment.

A phase 1b study evaluating the safety and pharmacokinetics of regorafenib in combination with cetuximab in patients with advanced solid tumors.

Regorafenib 160 mg orally once daily (QD) 3 weeks on/1 week off is approved in colorectal cancer, gastrointestinal stromal tumors and hepatocellular carcinoma. We established the safety and pharmacokinetics (PK) of regorafenib combined with cetuximab in advanced refractory solid tumors. This was a phase 1, open-label, dose-escalation study (NCT01973868) in patients with advanced/metastatic solid tumors who progressed after standard therapy. Regorafenib was administered at various dose levels QD continuously or intermittently (3 weeks on/1 week off) combined with intravenous cetuximab 250 mg/m2 weekly. The primary objectives were safety, PK and maximum tolerated dose (MTD). The secondary objective was tumor response. Dose-limiting toxicities (DLTs) were evaluated in Cycle 1. Of 42 treated patients, 31 received regorafenib intermittently (120 mg, n = 8; 160 mg, n = 23) and 11 continuously (60 mg, n = 5; 100 mg, n = 6) plus cetuximab. The continuous arm was terminated due to low tolerable dose. In the intermittent arm, one DLT (grade 3 hand-foot skin reaction) was observed at 120 mg but none at 160 mg, therefore 160 mg/day was declared as the MTD in combination with cetuximab. The most common all-grade treatment-emergent adverse events were fatigue (52%), hypophosphatemia (48%) and diarrhea (40%). One grade 3 cetuximab-related dermatitis acneiform was observed. No clinically relevant drug-drug interactions were observed. Five patients (21%) had a partial response. Regorafenib 160 mg QD (3 weeks on/1 week off) plus standard dose of cetuximab was well tolerated with no unexpected toxicities and promising signs of efficacy.

The effect of gastrectomy on regorafenib exposure and progression-free survival in patients with advanced gastrointestinal stromal tumours.

AIMS: We investigated whether major gastrectomy influences the plasma exposure of regorafenib and treatment outcome. METHODS: Efficacy and pharmacokinetic data from 133 gastrointestinal stromal tumour patients included in a phase III trial were analysed. Patients were subdivided into 2 groups according to the extent of the gastrectomy (no/nonsignificant gastrectomy and major gastrectomy). Progression-free survival (PFS) on regorafenib was measured and regorafenib and its pharmacological active metabolites plasma exposure were measured. RESULTS: A total of 133 patient were included, of whom 27 underwent major gastrectomy. In patients with no/nonsignificant gastrectomy the median PFS was 145 (interquartile range 43-281) days. The PFS in patients with a major gastrectomy was 172 (interquartile range 57-280) days. Regorafenib pharmacokinetic samples were collected in 80 patients of which 19 patients with a major gastrectomy and 61 patients with no/nonsignificant gastric surgery. The average ± standard deviation total concentration of regorafenib including the metabolites M-2 and M-5 was 6.9 ± 1.53 µmol/L and 6.7 ± 1.56 µmol/L in patient with major gastrectomy and no/nonsignificant gastrectomy respectively. CONCLUSION: Our study shows that major gastrectomy did not influence plasma exposure of regorafenib and metabolites. In addition, no difference in PFS between the subgroups was seen.

Sequential protein and peptide immunoaffinity capture for mass spectrometry-based quantification of total human ß-nerve growth factor.

Nerve growth factor (NGF) is a neurotrophin that is implicated in the modulation of pain perception. Tanezumab, a humanized monoclonal antibody (mAb) specific for NGF, is highly potent in sequestering NGF and has demonstrated efficacy for treatment of chronic pain in clinical trials. We describe a novel, sensitive immunoaffinity liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for quantitative determination of human serum NGF levels at baseline and after tanezumab treatment. The assay combines magnetic bead-based NGF immunoaffinity enrichment using a non-neutralizing polyclonal antibody followed by digestion and quantitation of a NGF-derived tryptic peptide via high-flow peptide immunoaffinity enrichment and nanoflow LC-MS/MS. Following validation, the assay was employed to measure total NGF concentrations in samples from clinical studies. The assay had a <10% interassay relative error and <15% interassay coefficient of variation across a range from 7.03 to 450 pg/mL human NGF. Generally, human basal serum NGF concentrations were between 20 and 30 pg/mL which, upon treatment with tanezumab, elevated in a dose-dependent manner into the high pg/mL to low ng/mL range. This is the first report of clinical trial implementation of a MS-based assay that uses sequential protein and peptide immunoaffinity capture for protein target quantitation. The use of robotic sample preparation and a robust chromatography configuration enabled this technology to advance into the routine clinical analysis and now provides a bioanalytical platform for the development of similar assays for other protein targets.

Predicted heart rate effect of inhaled PF-00610355, a long acting ß-adrenoceptor agonist, in volunteers and patients with chronic obstructive pulmonary disease.

AIM: To assess the cardiovascular effects of a new inhaled long-acting ß-adrenoceptor agonist PF-00610355 in COPD patients. METHODS: Thirteen thousand and sixty-two heart rate measurements collected in 10 clinical studies from 579 healthy volunteers, asthma and COPD patients were analyzed. The relationship between heart rate profiles and predicted plasma concentration profiles, patient status, demographics and concomitant medication was evaluated using non-linear mixed-effects models. The median heart rate increase in COPD patients for doses of PF-00610355 up to 280 µg once daily was simulated with the final pharmacokinetic/pharmacodynamic (PKPD) model. RESULTS: An Emax model accounting for delayed on-and off-set of the PF-00610355-induced change in heart rate was developed. The predicted potency in COPD patients was three-fold lower compared with healthy volunteers, while no difference in maximum drug effect was identified. Simulations suggested a maximum placebo-corrected increase of 2.7 (0.90-4.82) beats min(-1) in COPD patients for a PF-00610355 dose of 280 µg once daily, with 19% subjects experiencing a heart rate increase of more than 20 beats min(-1) compared with 8% in the placebo group. CONCLUSIONS: This PKPD analysis supports the clinical observation that no relevant effects of PF-00610355 on heart rate in COPD patients should be expected for doses up to 280 µg once daily.

Longitudinal FEV1 dose-response model for inhaled PF-00610355 and salmeterol in patients with chronic obstructive pulmonary disease.

The objective of this work was to characterize the dose-response relationship between two inhaled long-acting beta agonists (PF-00610355 and salmeterol) and the forced expiratory volume in one second (FEV1) in order to inform dosing recommendations for future clinical trials in patients with chronic obstructive pulmonary disease (COPD). This meta-analysis of four studies included 8,513 FEV1 measurements from 690 patients with moderate COPD. A longitudinal kinetic-pharmacodynamic (K-PD) model was developed and adequately described changes in FEV1 measurements over time, including circadian patterns within a day, as well as changes in FEV1 measurements elicited from administration of PF-00610355 or salmeterol. The fine-particle dose, the amount of drug present in particles small enough for lung delivery, was used as the exposure measure for PF-00610355. Greater reversibility following administration of a short-acting beta agonist during run-in was associated with increased FEV1 response to long-acting beta agonists (through an increased maximal response, E(max)). Simulations were conducted to better understand the response to PF-00610355 relative to placebo and salmeterol. The results of the simulations show that once daily fine-particle doses of 28.1 µg versus placebo have a moderate probability of providing an average improvement above 100 mL at trough. The 50 µg fine-particle dose, on the other hand, has a greater than 0.78 probability of achieving a 120 mL improvement versus placebo at trough. From an efficacy perspective and assuming a fine-particle fraction of 25 % for the Phase 3 formulation; 100 and 200 µg once daily nominal doses would be of interest to investigate in future Phase 3 trials.

Bioequivalence Evaluation Between Acarbose and Metformin Fixed-Dose Combination and Corresponding Individual Components in Healthy Chinese Male and Female Subjects.

Acarbose and metformin have been recommended both as monotherapy and add-on therapy in type 2 diabetes mellitus. A novel fixed-dose combination (FDC) of acarbose and metformin has been developed to improve compliance and patient adherence to therapy. The current study investigated the bioequivalence (BE) between acarbose/metformin FDC (50 mg/500 mg) with corresponding loose combination of individual components under fasting conditions in healthy Chinese male and female subjects, using a randomized, 2-period, 2-way crossover study design. Pharmacodynamic parameters of serum glucose ratio between treatment day and baseline (ratio of maximum concentration [Cmax ], day 1/Cmax , day -1 and ratio of area under the concentration-time curve [AUC] from time 0 to 4 hours, day 1/AUC from time 0 to 4 hours, day -1) were used as the primary variables to evaluate BE of acarbose. Pharmacokinetic parameters Cmax , AUC from time 0 to the last data point greater than the lower limit of quantification, and AUC were used to evaluate BE of metformin. The results showed that the 90% confidence intervals of the ratios of all primary target variables including ratio of Cmax , day 1/Cmax , day -1 and ratio of AUC from time 0 to 4 hours, day 1/AUC from time 0 to 4 hours, day -1 for acarbose, and Cmax , AUC from time 0 to the last data point greater than the lower limit of quantification, and AUC for metformin all fell within the acceptance limits of 0.8 to 1.25. Thus, BE between 50-mg acarbose and 500-mg metformin as an FDC and loose combination was established. Furthermore, different kinds of exploratory pharmacodynamic parameters (based on either serum glucose or insulin) including several newly proposed parameters were also investigated for acarbose BE evaluation in this study, and inconsistent results were observed.

A time scaling approach to develop an in vitro-in vivo correlation (IVIVC) model using a convolution-based technique.

In vitro-in vivo correlation (IVIVC) models prove very useful during drug formulation development, the setting of dissolution specifications and bio-waiver applications following post approval changes. A convolution-based population approach for developing an IVIVC has recently been proposed as an alternative to traditional deconvolution based methods, which pose some statistical concerns. Our aim in this study was to use a time-scaling approach using a convolution-based technique to successfully develop an IVIVC model for a drug with quite different in vitro and in vivo time scales. The in vitro and the in vivo data were longitudinal in nature with considerable between subject variation in the in vivo data. The model was successfully developed and fitted to the data using the NONMEM package. Model utility was assessed by comparing model-predicted plasma concentration-time profiles with the observed in vivo profiles. This comparison met validation criteria for both internal and external predictability as set out by the regulatory authorities. This study demonstrates that a time-scaling approach may prove useful when attempting to develop an IVIVC for data with the aforementioned properties. It also demonstrates that the convolution-based population approach is quite versatile and that it is capable of producing an IVIVC model with a big difference between the in vitro and in vivo time scales.

227Th-Labeled Anti-CD22 Antibody (BAY 1862864) in Relapsed/Refractory CD22-Positive Non-Hodgkin Lymphoma: A First-in-Human, Phase I Study.

Background: BAY 1862864 is an α-particle emitting 227Th-labeled CD22-targeting antibody. This first-in-human dose-escalation phase I study evaluated BAY 1862864 in patients with CD22-positive relapsed/refractory B cell non-Hodgkin lymphoma (R/R-NHL). Materials and Methods: BAY 1862864 intravenous injections were administered at the starting 227Th radioactivity dose of 1.5 MBq (2 or 10 mg antibody), and the radioactivity dose escalated in ∼1.5 MBq increments (10 mg antibody) until the maximum tolerated dose (MTD) was reported. The primary objective was to determine the safety, tolerability, and MTD. Results: Twenty-one patients received BAY 1862864. Two dose-limiting toxicities (grade 3 febrile neutropenia and grade 4 thrombocytopenia) were reported in one patient in the 4.6 MBq (10 mg antibody) cohort. The MTD was not reached. Ten (48%) patients reported grade ≥3 treatment-emergent adverse events, with the most common being neutropenia, thrombocytopenia, and leukopenia, each occurring in 3 (14%) patients. Pharmacokinetics demonstrated the dose proportionality and stability of BAY 1862864 in the blood. The objective response rate (ORR) was 25% (5/21 patients) according to the LUGANO 2014 criteria, including 1 complete and 4 partial responses. The ORR was 11% (1/9) and 30% (3/10) in patients with relapsed high- and low-grade lymphomas, respectively. Conclusions: BAY 1862864 was safe and tolerated in patients with R/R-NHL. Clinical Trial Registration numbers: NCT02581878 and EudraCT 2014-004140-36.

Phase 1 dose-escalation and pharmacokinetic study of regorafenib in paediatric patients with recurrent or refractory solid malignancies.

BACKGROUND: This phase 1 study evaluated safety, pharmacokinetics (PK), maximum tolerated dose (MTD), and antitumour activity of regorafenib in paediatric patients with solid tumours. PATIENTS AND METHODS: Patients (aged 6 months to <18 years) with recurrent/refractory solid tumours received oral regorafenib once daily for 3 weeks on/1 week off. The starting dose (60 mg/m2) was derived from an adult physiology-based PK model and scaled to children; dose escalation was followed by safety expansion of the MTD cohort. Treatment-emergent adverse events (TEAEs) were evaluated using National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Regorafenib PK was evaluated using a population PK model. RESULTS: Forty-one patients (median age 13 years) received regorafenib (four cohorts: 60-93 mg/m2). Five of 23 evaluable patients experienced dose-limiting toxicities (Grade 4 thrombocytopenia, Grade 3 maculopapular rash, pyrexia, hypertension, and exfoliative dermatitis [each n = 1]). The MTD was defined as 82 mg/m2. The most common Grade ≥3 drug-related TEAE was thrombocytopenia (10%). The incidence and severity of hypertension, diarrhoea, fatigue, hypothyroidism, and hand-foot skin reaction were lower than reported in adults. Regorafenib exposure increased with dose, with substantial overlap because of moderate-to-high interpatient variability. One patient with rhabdomyosarcoma experienced an unconfirmed partial response; 15 patients had stable disease, five for >16 weeks. CONCLUSIONS: The recommended phase 2 dose of single-agent regorafenib in paediatric patients with solid malignancies is 82 mg/m2. Regorafenib demonstrated acceptable tolerability and preliminary antitumour activity, supporting further investigation in paediatric patients. CLINICAL TRIAL NUMBER: NCT02085148.

Feasibility of Thorium-227/Radium-223 Gamma-Camera Imaging During Radionuclide Therapy.

Thorium-227 (227Th) is a long-lived (T1/2 = 18.7 d) α-emitter that has emerged as candidate for radioimmunotherapy. Imaging of patients treated with thorium-227 conjugates is challenging due to the low activity administered and to photon emissions with low yields. In addition, the radioactive daughter radium-223 (223Ra) have photon emissions in the same energy range as 227Th. The long half-life of 223Ra (T1/2 = 11.4 d) and the possibility of redistribution motivates efforts to separate 227Th and 223Ra. The aim of this study was to investigate the feasibility of imaging of patients treated with 227Th-labeled-monoclonal antibody (mAb) and to determine acquisition and image processing parameters to enable discrimination between 227Th and 223Ra. Imaging was performed with a GE Discovery 670 NM/CT γ-camera. Radionuclide separation with different energy windows (EW) and collimators was studied in images of vials with either 227Th or 223Ra. Phantom acquisitions with clinically relevant activities were performed to assess image quality and the usefulness of background subtraction and spatial filtering. Two patients treated with 227Th-labeled-mAb were imaged. Imaging of vials showed that 223Ra can be distinguished from 227Th using multiple energy windows. Medium- and high-energy collimators showed similar performance of sensitivity and spatial resolution, whereas the low-energy collimator had higher sensitivity but poor resolution due to collimator penetration. Visually, the image quality was improved with background subtraction and spatial filtering. The patient images exhibited the expected image quality and a possibility to separate 227Th and 223Ra. γ-Camera imaging of patients treated with 227Th-mAb is feasible and 223Ra can be distinguished from 227Th. Image quality is substantially improved using background subtraction and a spatial smoothing filter. Acquisition settings recommended for planar images are: high-energy general purpose or medium-energy general purpose collimator, 40 min acquisition time and energy windows: (1) 70-100 keV (227Th and 223Ra); (2) 215-260 keV (227Th); (3) 260-290 keV (223Ra); (4) 350-420 keV (223Ra).

Quantitative Dual-Isotope Planar Imaging of Thorium-227 and Radium-223 Using Defined Energy Windows.

Introduction: Thorium-227 is an alpha-emitting radioisotope with potential therapeutic applications in targeted alpha therapy. Thorium-227 decays to Radium-223, which may have an independent biodistribution to that of the parent Thorium-227 radiopharmaceutical. Quantitative in vivo imaging with sodium iodide (NaI) detectors is challenging due to cross-talk between neighboring γ-photopeaks as well as scattered γ-photons. The aim of this work was to validate the use of a spectral analysis technique to estimate the activity of each isotope within a region of interest applied to a pair of conjugate view planar acquisitions, acquired at multiple energy windows. Methods: Energy spectra per unit activity arising from unscattered Thorium-227 photons and Radium-223 photons as well as from scattered photons were modeled. These spectra were scaled until the combination of these component spectra resulted in the closest match to the measured data in four energy windows. Results: Measured estimates of activity followed the known decay curves in phantoms representative of a human torso. The mean errors in estimating Thorium-227 and Radium-223 were 5.1% (range -8.0% to 40.0%) and 3.4% (range -50.0% to 48.7%), respectively. The differences between the integrals of the theoretical and estimated time activity curve were <10% for both Thorium-227 and Radium-223. Conclusion: γ-camera quantification of Thorium-227 and Radium-223 can be achieved by using multiple energy window acquisitions.

No pharmacokinetic interaction between paliperidone extended-release tablets and trimethoprim in healthy subjects.

OBJECTIVE: The effect of trimethoprim, a potent organic cation transport inhibitor, on the pharmacokinetics (PK) of paliperidone extended-release tablets (paliperidone ER), an organic cation mainly eliminated via renal excretion, was assessed. METHODS: Open-label, two-period, randomized, crossover study in 30 healthy males. Single dose of paliperidone ER 6 mg was administered either alone on day 1 or day 5 during an 8-day treatment period of trimethoprim 200 mg twice daily. Serial blood and urine samples were collected for PK and plasma protein binding of paliperidone and its enantiomers. The 90% confidence interval (CI) of ratios with/without trimethoprim for PK parameters of paliperidone and its enantiomers calculated. RESULTS: Creatinine clearance decreased from 119 to 102 mL min(-1) with trimethoprim. Addition of trimethoprim increased unbound fraction of paliperidone by 16%, renal clearance by 13%, AUC(infinity) by 9%, and t((1/2)) by 19%. The 90% CIs for ratios with/without trimethoprim were within the 80-125% range for C(max), AUC(last), and renal clearance. For AUC(infinity), 90% CI was 79.37-101.51, marginally below the lower bound of the acceptance range. Paliperidone did not affect steady-state plasma concentrations of trimethoprim. CONCLUSIONS: No clinically important drug interactions are expected when paliperidone ER is administered with organic cation transport inhibitors.

Prolonged Response to Regorafenib in a Patient with Iodine Refractory Thyroid Cancer.

Thyroid cancer is the most common type of endocrine malignancy. Cornerstones of thyroid cancer treatment include surgery, radioactive iodine ablation, and thyroid stimulating hormone suppression. The National Comprehensive Cancer Network guidelines recommend two tyrosine kinase inhibitors for thyroid cancer patients who are non-responsive to iodine: sorafenib and lenvatinib. Another oral kinase inhibitor, regorafenib, is not considered standard of care treatment for differentiated thyroid cancer. The chemical structures of regorafenib and sorafenib differ by a single fluorine atom. Given the significant improvement in progression-free survival (PFS) of sorafenib compared to placebo demonstrated in the phase 3 DECISION trial, we report on a patient with iodine-refractory follicular thyroid cancer treated with regorafenib as part of a phase 1 clinical trial. A 75 year old woman was diagnosed with follicular thyroid carcinoma in 2006 and initiated on treatment with regorafenib in 2011. She has completed 76 cycles with stable disease and pulmonary metastases 34% smaller than baseline.

Absorption, metabolism, and excretion of paliperidone, a new monoaminergic antagonist, in humans.

Absorption, metabolism, and excretion of paliperidone, an atypical antipsychotic, was studied in five healthy male subjects after a single dose of 1 mg of [(14)C]paliperidone oral solution ( approximately 16 microCi/subject). One week after dosing, 88.4 to 93.8% (mean 91.1%) of the administered radioactivity was excreted: 77.1 to 87.1% (mean 79.6%) in urine and 6.8 to 14.4% (mean 11.4%) in the feces. Paliperidone was the major circulating compound (97% of the area under the plasma concentration-time curve at 24 h). No metabolites could be detected in plasma. Renal excretion was the major route of elimination with 59% of the dose excreted unchanged in urine. About half of the renal excretion occurred by active secretion. Unchanged drug was not detected in feces. Four metabolic pathways were identified as being involved in the elimination of paliperidone, each of which accounted for up to a maximum of 6.5% of the biotransformation of the total dose. Biotransformation of the drug occurred through oxidative N-dealkylation (formation of the acid metabolite M1), monohydroxylation of the alicyclic ring (M9), alcohol dehydrogenation (formation of the ketone metabolite M12), and benzisoxazole scission (formation of M11), the latter in combination with glucuronidation (M16) or alicyclic hydroxylation (M10). Unchanged drug, M1, M9, M12, and M16 were detected in urine; M10 and M11 were detected in feces. The monohydroxylated metabolite M9 was solely present in urine samples of extensive CYP2D6 metabolizers, whereas M10, another metabolite monohydroxylated at the alicyclic ring system, was present in feces of poor metabolizers as well. In conclusion, paliperidone is not metabolized extensively and is primarily renally excreted.

Mass balance, metabolic disposition, and pharmacokinetics of a single oral dose of regorafenib in healthy human subjects.

PURPOSE: To evaluate the mass balance, metabolic disposition, and pharmacokinetics of a single dose of regorafenib in healthy volunteers. In addition, in vitro metabolism of regorafenib in human hepatocytes was investigated. METHODS: Four healthy male subjects received one 120 mg oral dose of regorafenib containing approximately 100 µCi (3.7 MBq) [14C]regorafenib. Plasma concentrations of parent drug were derived from HPLC-MS/MS analysis and total radioactivity from liquid scintillation counting (LSC). Radiocarbon analyses used HPLC with fraction collection followed by LSC for all urine samples, plasma, and fecal homogenate extracts. For the in vitro study, [14C]regorafenib was incubated with human hepatocytes and analyzed using HPLC-LSC and HPLC-HRMS/MS. RESULTS: Regorafenib was the major component in plasma, while metabolite M-2 (pyridine N-oxide) was the most prominent metabolite. Metabolites M-5 (demethylated pyridine N-oxide) and M-7 (N-glucuronide) were identified as minor plasma components. The mean concentration of total radioactivity in plasma/whole blood appeared to plateau at 1-4 h and again at 6-24 h post-dose. In total, 90.5% of administered radioactivity was recovered in the excreta within a collection interval of 12 days, most of which (71.2%) was eliminated in feces, while excretion via urine accounted for 19.3%. Regorafenib (47.2%) was the most prominent component in feces and was not excreted into urine. Excreted metabolites resulted from oxidative metabolism and glucuronidation. CONCLUSIONS: Regorafenib was eliminated predominantly in feces as well as by hepatic biotransformation. The multiple biotransformation pathways of regorafenib decrease the risk of pharmacokinetic drug-drug interactions.

A double-blind, placebo-controlled, randomized study evaluating the effect of paliperidone extended-release tablets on sleep architecture in patients with schizophrenia.

The effects of paliperidone extended-release on sleep architecture in patients with schizophrenia-related insomnia were evaluated in this multicenter, double-blind, randomized, placebo-controlled study. Patients received paliperidone extended-release 9 mg/day or matching placebo during the 14-day double-blind phase. Sleep architecture and sleep continuity were evaluated using polysomnograms. Subjective sleep measures were evaluated daily using the Leeds Sleep Evaluation Questionnaire. Efficacy and safety were also assessed. Thirty-six patients (17 on paliperidone extended-release, 19 on placebo; mean age 32.2 years) completed the study. Paliperidone extended-release treatment vs. placebo resulted in clinically and statistically significant differences in sleep measurements from baseline to endpoint including a reduction in: persistent sleep latency (41 min), sleep onset latency (35 min), number of awakenings after sleep onset (7), time awake in bed (50 min), and stage 1 sleep duration (12 min); prolongation in: total sleep time (53 min), sleep period time (42 min), stage 2 sleep duration (51 min), and rapid eye movement sleep duration (18 min); and an increase in sleep efficiency index (11%). Paliperidone extended-release, compared with placebo, did not exacerbate daytime somnolence and improved symptoms of schizophrenia. Paliperidone extended-release was well tolerated and improved sleep architecture and sleep continuity in patients diagnosed with schizophrenia and concomitant insomnia.

Pharmacokinetics of the Inhaled Selective Glucocorticoid Receptor Modulator AZD5423 Following Inhalation Using Different Devices.

AZD5423 is a non-steroidal glucocorticoid receptor modulator, with low aqueous solubility, developed for treatment of asthma and COPD. In this work, we aim to evaluate and compare the absorption pharmacokinetics (PK) of AZD5423 after inhalation via four devices, (Spira®, I-neb®, Turbuhaler® and a new dry powder inhaler (new DPI)) with two formulations using differently sized primary particles, and to compare the pulmonary bioavailability with the predicted lung deposited dose. Plasma concentration-time data after intravenous, oral and inhaled administration via four devices were available from two clinical studies in healthy and asthmatic subjects. A population PK modelling approach was taken to sequentially incorporate each route of administration, assuming parallel absorption compartments for inhaled AZD5423. A non-compartmental analysis for derivation of PK parameters was performed for comparison. Pulmonary bioavailability varied between devices, with the lowest estimates for I-neb (27%) and Turbuhaler (30%) and the highest for the new DPI (46%) and Spira (35-49%). The pulmonary bioavailability was substantially lower than the predicted lung deposited dose (range 59-90%). Lung absorption was separated into a faster and a slower process in the model. The half-life of the faster absorption appeared formulation-dependent, while the slower absorption (half-life of 0.59-0.78 h) appeared independent of formulation. The large difference in the estimated pulmonary bioavailability and the predicted lung deposited dose for AZD5423 implies an impact of mucociliary clearance. The lung absorption half-life indicates that AZD5423 is retained in the lung for a relatively short time.

Exposure-response relationship of regorafenib efficacy in patients with hepatocellular carcinoma.

PURPOSE: To explore the relationship between regorafenib exposure and efficacy in patients with hepatocellular carcinoma (HCC) who had disease progression during sorafenib treatment (RESORCE). METHODS: Exposure-response (ER) analyses for regorafenib were performed using data from a phase 3, randomized, placebo-controlled trial (RESORCE). Patients received 160mg regorafenib or placebo once daily (3weeks on/1week off in a 4-week cycle) with best supportive care until disease progression, death, or unacceptable toxicity. Kaplan-Meier analyses for overall survival (OS) and time-to-progression (TTP) were performed in which regorafenib-treated patients were grouped into four categories according to their estimated average exposure over 4weeks in cycle 1. While this analysis primarily focused on efficacy, a potential correlation between exposure and treatment-emergent adverse events (TEAEs) was also evaluated. If any differences were observed between Kaplan-Meier plots, the ER analysis continued with a multivariate Cox regression analysis to evaluate the correlation between exposure quartile categories and the efficacy and safety parameters while taking into consideration the effect of the predefined clinically relevant demographic and baseline covariates. The functional form of the ER relationship within the regorafenib treatment group was subsequently evaluated. RESULTS: Based on visual assessment of the Kaplan-Meier plots, no meaningful relationship between the exposure categories and TEAEs were observed, although median OS and TTP tended to be longer in the higher exposure categories. Further ER analyses, which considered the effects of predefined covariates and the different shapes of the ER relationship, focused on efficacy. The baseline risk factors Eastern Cooperative Oncology Group (ECOG) performance status ≥1, alpha-fetoprotein levels ≥400ng/ml, and aspartate transaminase or alanine transaminase levels >3×upper limit of normal were significantly associated with OS (P<0.01) and age was associated with TTP. A statistically significant difference was found for OS and TTP between patients receiving regorafenib compared with those receiving placebo in the multivariate ER analysis (P<0.01) in favor of regorafenib. However, within the group of regorafenib-treated patients, the effect of regorafenib exposure on efficacy, either by estimating four effect sizes for each quartile, or by including a continuous linear or nonlinear relationship between individual exposure and efficacy, was not significant (P>0.01) and relatively flat. This suggests that increasing regorafenib exposure would not result in a meaningful increase in OS or TTP. CONCLUSION: After considering the baseline risk factors: ECOG performance status, alpha-fetoprotein levels, and hepatic function for OS and age for TTP, the ER analysis in regorafenib-treated patients showed similar efficacy over the entire predicted exposure range in RESORCE. This supports the selected regorafenib dose of 160mg once daily (3weeks on/1week off in a 4-week cycle) in patients with intermediate or advanced HCC who have experienced disease progression on sorafenib.

Pharmacokinetic profile after multiple deltoid or gluteal intramuscular injections of paliperidone palmitate in patients with schizophrenia.

Paliperidone palmitate (PP) is a once-monthly long-acting injectable antipsychotic approved for the treatment of schizophrenia in many countries. To evaluate the different injection-site options, we compared the pharmacokinetic profile of paliperidone after multiple injections of PP 100 mg eq. (156 mg of PP, equivalent to 100 mg of paliperidone) on days 1, 8, 36, and 64 into the deltoid (n = 24) or gluteal muscle (n = 25) in patients with schizophrenia. After four injections in the deltoid muscle, paliperidone exposure was higher for AUCτ and Cmax , compared with the gluteal muscle (geometric mean AUCτ -based ratio: 120% [90% CI: 93.1-154.7%], and geometric mean Cmax -based ratio: 130% [90% CI: 100.6-168.9%]). The mean [SD] fluctuation index was higher, with a larger interpatient variability, after deltoid-injections (75.9% [30.9%]) than gluteal-injections (58.5% [14.3%]). The median tmax was similar for both sites. PP was generally tolerable in patients, with more favorable local-site tolerability for gluteal-injection. In conclusion, to achieve therapeutic-concentrations quickly, the first-two injections of PP are best administered into the deltoid muscle, whereas thereafter maintenance-injections can be administered either in the deltoid or gluteal muscle.