Effects of Omeprazole and Verapamil on the Pharmacokinetics, Safety, and Tolerability of Mavacamten: Two Drug-Drug Interaction Studies in Healthy Participants

Two open-label, Phase 1 studies assessed the effects of omeprazole (a weak to moderate cytochrome P450 [CYP] 2C19 inhibitor) and verapamil (a moderate CYP3A4 inhibitor) on the pharmacokinetics, safety, and tolerability of mavacamten. In the omeprazole study, healthy participants received mavacamten 15 mg alone or with a 31-day course of omeprazole 20 mg once daily. In the verapamil study, healthy participants received mavacamten 25 mg alone or with a 28-day course of verapamil 240 mg once daily. In the omeprazole study, 27 of 29 randomized participants completed the study. Nine participants receiving mavacamten alone were normal metabolizers (NMs) of CYP2C19 substrates, and 6 were rapid metabolizers; 8 NMs and 6 rapid metabolizers received mavacamten + omeprazole. In both studies, mavacamten showed no safety signals and was generally well tolerated. Overall mavacamten exposure (area under the plasma concentration-time curve) increased by approximately 50% with omeprazole coadministration; maximum observed concentration (Cmax ), time to Cmax , and elimination half-life were not affected appreciably. In the verapamil study, 25 of 26 randomized participants received the study drug(s) and were included in the pharmacokinetic analyses; 24 completed the study. In the pharmacokinetic population, 12 participants received mavacamten alone (11 NMs, 1 poor metabolizer) and 13 received mavacamten + verapamil (7 NMs, 4 intermediate metabolizers, 2 poor metabolizers). Following verapamil coadministration in NMs and intermediate metabolizers, mavacamten area under the plasma concentration-time curve was minimally increased (by less than 20%), and Cmax was modestly increased (by 52%). These results suggest that mavacamten can be coadministered with weak CYP2C19 and moderate CYP3A4 inhibitors.

Physiologically Based Pharmacokinetic Modeling and Simulation of Mavacamten Exposure with Drug-Drug Interactions from CYP Inducers and Inhibitors by CYP2C19 Phenotype

Mavacamten is a first-in-class, oral, selective, allosteric, reversible cardiac myosin inhibitor approved by the US Food and Drug Administration for the treatment of adults with symptomatic New York Heart Association functional class II-III obstructive hypertrophic cardiomyopathy. Mavacamten is metabolized in the liver, predominantly via cytochrome P450 (CYP) enzymes CYP2C19 (74%), CYP3A4 (18%), and CYP2C9 (8%). A physiologically-based pharmacokinetic (PBPK) model was developed using Simcyp version 19 (Certara, Princeton, NJ). Following model verification, the PBPK model was used to explore the effects of strong CYP3A4 and CYP2C19 inducers, and strong, moderate, and weak CYP2C19 and CYP3A4 inhibitors on mavacamten pharmacokinetics (PK) in a healthy population, with the effect of CYP2C19 phenotype predicted for poor, intermediate, normal, and ultrarapid metabolizers. The PBPK model met the acceptance criteria for all verification simulations (> 80% of model-predicted PK parameters within 2-fold of those observed clinically). A weak induction effect was predicted when mavacamten was administered with a strong CYP3A4 inducer in poor metabolizers. Moderate reductions in mavacamten exposure were predicted with a strong CYP2C19/CYP3A4 inducer in all CYP2C19 phenotypes. Except for the effect of strong CYP2C19 inhibitors on ultrarapid metabolizers, steady-state area under plasma concentration-time curve and maximum plasma concentration values were weakly affected (< 2-fold) or not affected (< 1.25-fold), regardless of CYP2C19 phenotype. In conclusion, a fit-for-purpose PBPK model was developed and verified, which accurately predicted the available clinical data and was used to simulate the potential impact of CYP induction and inhibition on mavacamten PKs, stratified by CYP2C19 phenotype.

Safety, Pharmacokinetics, and Antifibrotic Activity of CC-90001 (BMS-986360), a c-Jun N-Terminal Kinase Inhibitor, in Pulmonary Fibrosis

Approved treatments for idiopathic pulmonary fibrosis have tolerability concerns and limited efficacy. CC-90001, a c-Jun N-terminal kinase inhibitor, is under investigation as a therapy for fibrotic diseases. A Phase 1b safety, pharmacokinetics, and pharmacodynamics study of oral CC-90001 (100, 200, or 400 mg) administered once daily for 12 weeks was conducted in patients with pulmonary fibrosis (NCT02510937). Sixteen patients with a mean age of 68 years were studied. The most common treatment-emergent adverse events were nausea and headache; all events were of mild or moderate intensity. Pharmacokinetic profiles were similar between the patients in this trial and healthy adults in previous studies. Forced vital capacity increased in the 200- and 400-mg cohorts from baseline to Week 12, and dose-dependent reductions in fibrosis biomarkers were observed. Antifibrotic activity of CC-90001 was also evaluated in vitro in transforming growth factor beta 1 (TGF-β1)-stimulated cells. CC-90001 reduced in vitro profibrotic gene expression in both lung epithelial cells and fibroblasts, supporting a potential direct antifibrotic action of c-Jun N-terminal kinase inhibition in either or both cell types. Overall, CC-90001 was generally safe and well tolerated, and treatment was associated with forced vital capacity improvement and reductions in profibrotic biomarkers.

Optical characterization of the impact of 100 keV protons on the optical properties of ZrO2 films prepared by ALD on fused silica substrates

Atomic layer deposition (ALD)-grown zirconia films underwent irradiation by 100 keV protons at fluences ranging from 1⋅10¹² p ⁺/c m ² through 5⋅10¹⁴ p ⁺/c m ². The induced structural damage was modeled using the stopping and range of ions in matter (SRIM) and compared with the change of the optical properties characterized by ellipsometry, spectrophotometry, and x-ray reflectometry. Proton-induced contamination of the optical surface due to deposition of a carbon-rich layer was determined. Correct estimation of the substrate damage was shown to be critical for reliable evaluation of the optical constants of the irradiated films. The ellipsometric angle Δ is shown to be sensitive to both the presence of the buried damaged zone in the irradiated substrate and the contamination layer on the surface of the samples. The complex chemistry in carbon-doped zirconia accommodating over-stoichiometric oxygen is discussed, along with the impact of the film composition change on the refractive index of the irradiated films.

Safety, Pharmacokinetics, and Pharmacodynamics of CC-90001 (BMS-986360), a c-Jun N-terminal Kinase Inhibitor, in Phase 1 Studies in Healthy Participants

CC-90001 selectively inhibits c-Jun N-terminal kinase (JNK), a stress-activated protein implicated in fibrosis. In 3 phase 1 trials evaluating CC-90001 pharmacokinetics, pharmacodynamics, and safety, healthy adults (N = 184) received oral CC-90001 in a single dose (10-720 mg) or multiple doses (30-480 mg once daily for 7-18 days) or placebo. CC-90001 was rapidly absorbed (median time to maximum concentration, 1-4 hours) and eliminated with a mean terminal elimination half-life of 12-28 hours. Steady state was reached on day 5, with a mean accumulation ratio of 1.5- to 2-fold following daily dosing. Exposure was similar in fed versus fasted participants and in Japanese versus non-Japanese participants. CC-90001 demonstrated dose- and exposure-dependent inhibition of JNK as determined by histopathological analysis of c-Jun phosphorylation in ultraviolet-irradiated skin. The most common treatment-emergent adverse events were nausea and headache; all were mild or moderate in intensity. Based on exposure-response analysis using high-quality electrocardiogram data, no clinically relevant QT prolongation liability for CC-90001 was observed. Overall, single- and multiple-dose CC-90001 were generally safe and well tolerated at the tested doses and demonstrated JNK pathway engagement. These results support further clinical evaluation of CC-90001.

CC-99677, a novel, oral, selective covalent MK2 inhibitor, sustainably reduces pro-inflammatory cytokine production

Background

Mitogen-activated protein kinase (MAPK)-activated protein kinase-2 (MK2) is activated downstream of p38 MAPK and regulates stability of mRNAs encoding inflammatory cytokines. CC-99677 is a novel, irreversible, covalent MK2 inhibitor under development for the treatment of ankylosing spondylitis (AS) and other inflammatory diseases. As part of a phase I clinical trial to assess safety and tolerability, we evaluated target engagement, pharmacokinetics, and pharmacodynamics of CC-99677.

Methods

The MK2 inhibitor CC-99677 was evaluated for its effect on cytokine expression in vitro in peripheral blood mononuclear cells (PBMCs) from healthy donors and patients with a definitive AS diagnosis. A novel in vitro model was developed to compare the potential for tachyphylaxis of CC-99677 and p38 inhibitors in THP-1 cells. The effect of CC-99677 on tristetraprolin (TTP) and cytokine mRNA was assessed in stimulated human monocyte-derived macrophages. In a first-in-human study, thirty-seven healthy volunteers were randomly assigned to daily oral doses of CC-99677 or placebo, and blood was collected at pre-specified time points before and after dosing. CC-99677 concentrations were assessed in the plasma, and CC-99677 binding to MK2 was evaluated in PBMCs. Ex vivo stimulation of the whole blood was conducted from participants in the first-in-human study to assess the pharmacodynamic effects.

Results

In vitro, CC-99677 inhibited tumor necrosis factor (TNF), interleukin (IL)-6, and IL-17 protein production in samples of monocytes and macrophages from AS patients and healthy volunteers via an mRNA-destabilization mechanism. In the in vitro model of tachyphylaxis, CC-99677 showed a differentiated pattern of sustained TNF protein inhibition compared with p38 inhibitors. CC-99677 reduced TTP phosphorylation and accelerated the decay of inflammatory cytokine mRNA in lipopolysaccharide-stimulated macrophages. Administration of CC-99677 to healthy volunteers was safe and well-tolerated, with linear pharmacokinetics and sustained reduction of ex vivo whole blood TNF, IL-6, and chemokine synthesis.

Conclusions

CC-99677 inhibition of MK2 is a promising approach for the treatment of inflammatory diseases and may overcome the limitations of p38 MAPK inhibition.

Trial registration

ClinicalTrials.gov NCT03554993.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02850-6.

Structure‒tissue exposure/selectivity relationship (STR) correlates with clinical efficacy/safety

Drug optimization, which improves drug potency/specificity by structure‒activity relationship (SAR) and drug-like properties, is rigorously performed to select drug candidates for clinical trials. However, the current drug optimization may overlook the structure‒tissue exposure/selectivity-relationship (STR) in disease-targeted tissues vs. normal tissues, which may mislead the drug candidate selection and impact the balance of clinical efficacy/toxicity. In this study, we investigated the STR in correlation with observed clinical efficacy/toxicity using seven selective estrogen receptor modulators (SERMs) that have similar structures, same molecular target, and similar/different pharmacokinetics. The results showed that drug's plasma exposure was not correlated with drug's exposures in the target tissues (tumor, fat pad, bone, uterus), while tissue exposure/selectivity of SERMs was correlated with clinical efficacy/safety. Slight structure modifications of four SERMs did not change drug's plasma exposure but altered drug's tissue exposure/selectivity. Seven SERMs with high protein binding showed higher accumulation in tumors compared to surrounding normal tissues, which is likely due to tumor EPR effect of protein-bound drugs. These suggest that STR alters drug's tissue exposure/selectivity in disease-targeted tissues vs. normal tissues impacting clinical efficacy/toxicity. Drug optimization needs to balance the SAR and STR in selecting drug candidate for clinical trial to improve success of clinical drug development.

Impact of fedratinib on the pharmacokinetics of transporter probe substrates using a cocktail approach

INTRODUCTION

Fedratinib, an oral, selective Janus kinase 2 inhibitor, has been shown to inhibit P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), organic anion transporting polypeptide (OATP) 1B1, OATP1B3, organic cation transporter (OCT) 2, and multidrug and toxin extrusion (MATE) 1 and MATE2-K in vitro. The objective of this study was to evaluate the influence of fedratinib on the pharmacokinetics (PK) of digoxin (P-gp substrate), rosuvastatin (OATP1B1/1B3 and BCRP substrate), and metformin (OCT2 and MATE1/2-K substrate).

METHODS

In this nonrandomized, fixed-sequence, open-label study, 24 healthy adult participants received single oral doses of digoxin 0.25 mg, rosuvastatin 10 mg, and metformin 1000 mg administered as a drug cocktail (day 1, period 1). After a 6-day washout, participants received oral fedratinib 600 mg 1 h before the cocktail on day 7 (period 2). An oral glucose tolerance test (OGTT) was performed to determine possible influences of fedratinib on the antihyperglycemic effect of metformin.

RESULTS

Plasma exposure to the three probe drugs was generally comparable in the presence or absence of fedratinib. Reduced metformin renal clearance by 36% and slightly higher plasma glucose levels after OGTT were observed in the presence of fedratinib. Single oral doses of the cocktail ± fedratinib were generally well tolerated.

CONCLUSIONS

These results suggest that fedratinib has minimal impact on the exposure of P-gp, BCRP, OATP1B1/1B3, OCT2, and MATE1/2-K substrates. Since renal clearance of metformin was decreased in the presence of fedratinib, caution should be exercised in using coadministered drugs that are renally excreted via OCT2 and MATEs.

TRIAL REGISTRATION

Clinicaltrials.gov NCT04231435 on January 18, 2020.

Reappraisal of anticancer nanomedicine design criteria in three types of preclinical cancer models for better clinical translation

Anticancer nanomedicines are designed to improve anticancer efficacy by increasing drug accumulation in tumors through enhanced permeability retention (EPR) effect, and to reduce toxicity by decreasing drug accumulation in normal organs through long systemic circulation. However, the inconsistent efficacy/safety of nanomedicines in cancer patients versus preclinical cancer models have provoked debate for nanomedicine design criteria. In this study, we investigate nanomedicine design criteria in three types of preclinical cancer models using five clinically used nanomedicines, which identifies the factors for better clinical translations of their observed clinical efficacy/safety compared to free drug or clinical micelle formulation. When those nanomedicines were compared with drug solution or clinical micelle formulation in breast tumors, long and short-circulating nanomedicines did not enhance tumor accumulation by EPR effect in transgenic spontaneous breast cancer model regardless of their size or composition, although they improved tumor accumulations in subcutaneous and orthotopic breast cancer models. However, when tumors were compared to normal breast tissue, nanomedicines, drug solution and clinical micelle formulation showed enhanced tumor accumulation regardless of the breast cancer models. In addition, long-circulating nanomedicines did not further increase tumor accumulation in transgenic mouse spontaneous breast cancer nor universally decrease drug accumulations in normal organs; they decreased or increased accumulation in different organs, potentially changing the clinical efficacy/safety. In contrast, short-circulating nanomedicines decreased blood concentration and altered drug distribution in normal organs, which are correlated with their clinical efficacy/safety. A reappraisal of current nanomedicine design criteria is needed to ensure consistent clinical translation for improvement of their clinical efficacy/safety in cancer patients.

Effects of strong and moderate CYP3A4 inducers on the pharmacokinetics of fedratinib in healthy adult participants

PURPOSE

Fedratinib is an oral and selective Janus kinase 2 inhibitor that is indicated for treatment of adults with intermediate-2 or high-risk primary or secondary myelofibrosis. Fedratinib is metabolized by cytochrome P450s (CYPs), primarily CYP3A4. The objective of this study was to determine the effects of the strong CYP3A4 inducer rifampin and moderate CYP3A4 inducer efavirenz on the pharmacokinetics of single doses of fedratinib.

METHODS

This Phase 1, open-label, two-part study (Part 1 for rifampin and Part 2 for efavirenz) was conducted in healthy adult men and women. A single dose of fedratinib (500 mg) was administered on Day 1. Participants received rifampin 600 mg daily or efavirenz 600 mg daily on Days 9-18. On Day 17, a single dose of fedratinib (500 mg) was coadministered with rifampin or efavirenz. Plasma fedratinib concentrations were measured using validated liquid chromatography-tandem mass spectrometry.

RESULTS

Maximum observed plasma fedratinib concentrations were lowered by approximately 70% and 30% during coadministration with rifampin or efavirenz, respectively, compared with fedratinib alone. Geometric means of fedratinib area under the plasma concentration-time curve from 0 to infinity were decreased by 81% (90% confidence interval [CI], 77-83%) and 47% (90% CI, 40-53%) during coadministration with rifampin or efavirenz, respectively. Fedratinib was generally well tolerated when administered alone or in combination with rifampin or efavirenz.

CONCLUSION

Significant reductions in fedratinib exposure were observed in the presence of strong or moderate CYP3A4 inducers. These results suggest that agents that are strong or moderate inducers of CYP3A4 should be avoided when coadministered with fedratinib.

TRIAL REGISTRATION NUMBER

NCT03983239 (Registration date: June 12, 2019).

Pharmacokinetics and tolerability of apremilast in healthy Korean adult men

We performed a two‐part study to evaluate the pharmacokinetics, safety, and tolerability of oral apremilast, a phosphodiesterase 4 inhibitor indicated for the treatment of psoriasis, in healthy Korean adult men. In part 1, there were 12 subjects who randomly received a single oral dose of apremilast at 20, 30, or 40 mg in each of 3 periods in a crossover fashion. In part 2, there were 16 subjects who randomly received 30 mg of apremilast or its matching placebo in a ratio of 3:1 twice daily for 14 days. Apremilast was rapidly absorbed (maximum concentration: ~2–3 h postdose), and eliminated according to a monoexponential pattern with a terminal‐phase elimination half‐life of 8–9 h. The exposure to apremilast increased in a dose‐proportional manner and accumulation was 1.6‐fold at steady‐state. Apremilast was well‐tolerated after a single oral administration and multiple oral administrations in Korean adult men; all of the treatment‐emergent adverse events were mild and recovered without sequelae. In conclusion, apremilast was safe and well‐tolerated in healthy Korean adult men when administered single oral doses of 20, 30, or 40 mg or when administered multiple oral doses of 30 mg b.i.d. for 14 days. Overall exposures increased in an approximate dose proportional manner in healthy Korean adult men.

Concentration-QTc Modeling of Ozanimod's Major Active Metabolites in Adult Healthy Subjects

Ozanimod, approved by regulatory agencies in multiple countries for the treatment of adults with relapsing multiple sclerosis, is a sphingosine 1-phosphate (S1P) receptor modulator, which binds with high affinity selectively to S1P receptor subtypes 1 and 5. The relationships between plasma concentrations of ozanimod and its major active metabolites, CC112273 and CC1084037, and the QTc interval (C-QTc) from a phase I multiple-dose study in healthy subjects were analyzed using nonlinear mixed effects modeling. QTc was modeled linearly as the sum of a sex-related fixed effect, baseline, and concentration-related random effects that incorporated interindividual and residual variability. Common linear, power, and maximum effect (E_max ) functions were assessed for characterizing the relationship of QTc with concentrations. Model goodness-of-fit and performance were evaluated by standard diagnostic tools, including a visual predictive check. The placebo-corrected change from baseline in QTc (ΔΔQTc) was estimated based on the developed C-QTc model using a nonparametric bootstrapping approach. QTc was better derived using a study-specific population formula (QTcP). Among the investigated functions, an E_max function most adequately described the relationship of QTcP with concentrations. Separate models for individual analytes characterized the C-QTcP relationship better than combined analytes models. Attributing QT prolongation independently to CC1084037 or CC112273, the upper bound of the 95% confidence interval of the predicted ΔΔQTcP was ~ 4 msec at the plateau of the E_max curves. Therefore, ΔΔQTcP is predicted to remain below 10 msec at the supratherapeutic concentrations of the major active metabolites.

Single-Dose Pharmacokinetics of Ozanimod and its Major Active Metabolites Alone and in Combination with Gemfibrozil, Itraconazole, or Rifampin in Healthy Subjects: A Randomized, Parallel-Group, Open-Label Study

INTRODUCTION

The aims of this study were to characterize the single-dose pharmacokinetics (PK) of the major active metabolites of ozanimod, CC112273 and CC1084037, and to evaluate the effect of gemfibrozil (a strong inhibitor of cytochrome P450 [CYP] 2C8), itraconazole (a strong inhibitor of CYP3A and P-glycoprotein [P-gp]), and rifampin (a strong inducer of CYP3A/P-gp and moderate inducer of CYP2C8) on the single-dose PK of ozanimod and its major active metabolites in healthy subjects.

METHODS

This was a phase 1, randomized, parallel-group, open-label study with two parts. In part 1, 40 subjects were randomized to receive a single oral dose of ozanimod 0.46 mg (group A, n = 20) or oral doses of gemfibrozil 600 mg twice daily for 17 days with a single oral dose of ozanimod 0.46 mg on day 4 (group B, n = 20). In part 2, 60 subjects were randomized to receive a single oral dose of ozanimod 0.92 mg (group C, n = 20), oral doses of itraconazole 200 mg once daily for 17 days with a single oral dose of ozanimod 0.92 mg on day 4 (group D, n = 20), or oral doses of rifampin 600 mg once daily for 21 days with a single oral dose of ozanimod 0.92 mg on day 8 (group E, n = 20). Plasma PK parameters for ozanimod, CC112273, and CC1084037 were estimated using noncompartmental methods.

RESULTS

Dose-proportional increases in maximum observed concentration (C_max) and area under the concentration-time curve (AUC) were observed for ozanimod, CC112273, and CC1084037. The mean terminal elimination half-life (t_1/2) for ozanimod was approximately 20-22 h while the mean t_1/2 for CC112273 and CC1084037 were approximately 10 days. CC112273 and CC1084037 exposures were highly correlated with or without interacting drugs. Itraconazole increased ozanimod AUC by approximately 13% while rifampin reduced ozanimod AUC by approximately 24%, suggesting a minor role of CYP3A and P-gp in the overall disposition of ozanimod. Gemfibrozil increased the AUC for CC112273 and CC1084037 by approximately 47% and 69%, respectively. Rifampin reduced the AUC for CC112273 and CC1084037, primarily via CYP2C8 induction, by approximately 60% and 55%, respectively.

CONCLUSIONS

Ozanimod's major active metabolites, CC112273 and CC1084037, exhibited similar single-dose PK properties and their exposures were highly correlated. CYP2C8 is one of the important enzymes in the overall disposition of CC112273 and subsequently its direct metabolite CC1084037.

TRIAL REGISTRATION

Clinical trial: NCT03624959.

First-in-Human, Single- and Multiple-Ascending-Dose Studies in Healthy Subjects to Assess Pharmacokinetics, Pharmacodynamics, and Safety/Tolerability of Iberdomide, a Novel Cereblon E3 Ligase Modulator

Pharmacokinetics, pharmacodynamics, and safety/tolerability of iberdomide (CC‐220), a highly potent oral cereblon E3 ligase modulator (CELMoD), were evaluated in escalating single‐dose (0.03, 0.1, 0.3, 1, 2, 4, 6 mg) and multiple‐dose (0.3 mg once daily for 14 days, 1 mg once daily for 28 days, 0.3 mg once daily for 28 days, or 1 mg once daily for 7 days with a 7‐day washout, then once daily for 7 more days) studies in healthy subjects (n = 99). Iberdomide exposure increased in a dose‐proportional manner. Terminal half‐life was 9‐13 hours after a single dose. Iberdomide decreased peripheral CD19+ B lymphocytes (E_max, 92.4%; EC₅₀, 0.718 ng/mL), with modest reductions in CD3+ T lymphocytes (E_max, 34.8%; EC₅₀, 0.932 ng/mL). Lipopolysaccharide‐stimulated proinflammatory cytokines (IL‐1α, IL‐1β) were reduced, but anti‐CD3‐stimulated IL‐2 and interferon‐γ were increased. Iberdomide 1 mg once daily partially decreased T‐cell‐independent antibody responses to PPV23 but did not change tetanus toxoid recall response. Pharmacodynamic data suggest dose‐dependent, differential immunomodulatory effects on B and T lymphocytes. Iberdomide was tolerated up to 6 mg as a single dose and at 0.3 mg once daily for 4 weeks. Grade 3 asymptomatic neutropenia was observed following 1 mg once daily for 21 days; a 7‐day drug holiday alleviated neutropenia. Further investigation of iberdomide in autoimmune and hematological diseases is warranted.

Excretion balance and pharmacokinetics following a single oral dose of [14C]-fedratinib in healthy subjects

PURPOSE

Fedratinib is an oral and selective kinase inhibitor with activity against wild type and mutationally activated Janus kinase 2 and FMS-like tyrosine kinase 3, for the treatment of adult patients with intermediate-2 or high-risk primary or secondary myelofibrosis. This open-label mass balance study in healthy subjects investigated the excretion balance and systemic exposure of radioactivity after oral administration of [¹⁴C]-fedratinib; and the pharmacokinetics of fedratinib and its contribution to overall exposure of radioactivity.

METHODS

Six healthy males received a single oral dose of 200 mg [¹⁴C]-fedratinib base (2.775 MBq, 75 μCi) as a solution. Blood, urine and feces samples were collected for up to 35 day postdose. Urine and feces samples were collected until the 24-h excretion of radioactivity fell below 0.5% of administered dose (at least 14 day postdose). Expired air was collected up to 8-h postdose. Total radioactivity (blood, plasma, urine, feces, and expired air) and fedratinib concentrations (plasma) were measured.

RESULTS

Approximately 77% (23% unchanged) of fedratinib derived radioactivity was excreted in feces and 5% (3% unchanged) was excreted in urine. Excretion via expired air was negligible. The time to maximum concentration for both total radioactivity and parent drug was similar, with unchanged drug representing the majority of the circulating radioactivity. The ratio of blood to plasma concentration of radioactivity ranged from 0.615 to 0.753 indicating limited distribution of fedratinib and/or its metabolites into red blood cells.

CONCLUSIONS

Fedratinib derived radioactivity was primarily excreted in feces following a single oral dose of radiolabeled fedratinib to healthy subjects.

A Phase 1, Open-Label Study in Healthy Subjects to Evaluate the Absolute Bioavailability of AG-221 by a Microtracer Approach

Introduction

The purpose of this study was to evaluate the absolute bioavailability (BA) of AG-221 following a single oral dose of 100 mg AG-221 and an intravenous (IV) dose of ~ 100 μg AG-221 containing approximately 300 nCi of [¹⁴C]-AG-221.

Methods

This was a phase 1, open-label study. Six subjects who met all of the inclusion criteria and none of the exclusion criteria were enrolled in the study. After an overnight fast of at least 10 h, the subjects received an oral dose (coated tablet) of 100 mg of AG-221 at 0 h on dosing day. Four hours after the oral dose, the subjects received 100 μg AG-221 containing ~ 300 nCi of [¹⁴C]-AG-221 administered as an IV bolus. Blood samples were collected and analyzed for plasma concentrations of AG-221 and [¹⁴C]-AG-221 using a validated liquid chromatography with tandem mass spectrometry (LC–MS/MS) system and high-performance liquid chromatography (HPLC) fractionation followed by accelerator mass spectrometry analysis (AMS), respectively. Safety was evaluated throughout the study.

Results

The absolute BA after a 100-mg oral dose of AG-221 was measured as 57.2%. While the total clearance was 1.37 L/h, ~ 1/60 of the liver blood flow in a typical 70-kg human subject, the first-pass extraction was estimated to be less than 2%, assuming that the total clearance was entirely due to liver metabolism. Thus, the fraction of the AG-221 dose absorbed was at least 50%. AG-221 was safe and well tolerated when given under fasted conditions in a single 100-mg dose as a coated tablet with a microtracer [¹⁴C]-AG-221 solution, as few drug-related treatment-emergent adverse events (TEAEs) were reported. No clinically significant changes or findings were noted in the clinical laboratory evaluations, vital sign measurements, and electrocardiograms (ECGs) performed during this study.

Conclusions

In healthy subjects under fasting conditions, the absolute BA following oral administration of a 100-mg AG-221 tablet was 57.2%. AG-221 was safe and well tolerated in healthy male subjects when administered as a single 100-mg film-coated tablet plus 100 µg [¹⁴C]-AG-221 given intravenously.

Trial Registration

ClinicalTrials.gov identifier, NCT02443168.

Funding

Celgene Corporation.

Population Pharmacokinetics and Exposure-Response Relationship of Luspatercept, an Erythroid Maturation Agent, in Anemic Patients With β-Thalassemia

β‐Thalassemia is an inherited blood disorder resulting from defects in hemoglobin production, leading to premature death of red blood cells (RBCs) or their precursors. Patients with transfusion‐dependent β‐thalassemia often need lifelong regular RBC transfusions to maintain adequate hemoglobin levels. Frequent transfusions may lead to iron overload and organ damage. Thus, there is a large unmet need for alternative therapies. Luspatercept, a first‐in‐class erythroid maturation agent, is the first approved therapy in the United States for the treatment of anemia in adult patients with β‐thalassemia who require regular RBC transfusions. The population pharmacokinetics and exposure‐response relationship of luspatercept were evaluated in 285 patients with β‐thalassemia. Luspatercept displayed linear and time‐invariant pharmacokinetics when administered subcutaneously once every 3 weeks. Body weight was the only clinically relevant covariate of luspatercept clearance, favoring weight‐based dosing. Magnitude and frequency of hemoglobin increase, if not influenced by RBC transfusions, was positively correlated with luspatercept area under the serum concentration‐time curve (AUC), 0.2‐1.25 mg/kg, whereas a significant reduction in RBC units transfused was observed in frequently transfused patients. The probability of achieving ≥33% or ≥50% reduction in RBC transfusion burden was similar across the time‐averaged AUC (0.6‐1.25 mg/kg), with the 1 mg/kg starting dose sufficient for most early responders (71%‐80%). Increasing luspatercept AUC (0.2‐1.25 mg/kg) did not increase incidence or severity of treatment‐emergent adverse events. These results provide a positive benefit‐risk profile for the recommended luspatercept doses (1‐1.25 mg/kg) in treating adult patients with β‐thalassemia who require regular RBC transfusions.

Evaluation of the Potential for QTc Prolongation With Repeated Oral Doses of Fedratinib in Patients With Advanced Solid Tumors

The impact of repeated daily 500-mg fedratinib (an oral selective Janus kinase [JAK] 2 inhibitor) on QTc and other electrocardiogram (ECG) parameters was assessed in 60 patients with advanced solid tumors. Patients received placebo on day 1 and fedratinib 500 mg daily for 14 days. Concentration-QTc analysis was performed with change-from-baseline QTc corrected by Fridericia's formula (ΔQTcF) as the dependent variable. Fedratinib median time to maximum plasma concentration (C_max ) was observed 3 hours postdose on day 15. The largest difference between means for fedratinib and placebo was 0.5 bpm (90%CI, -2.75 to 3.72 bpm) for heart rate (3 hours postdose) and 4.3 milliseconds (90%CI, 1.04-7.60 milliseconds) for QTcF (4 hours postdose). The estimated slope of the fedratinib concentration-QTcF relationship was shallow and not statistically significant: -0.0005 milliseconds per ng/mL (90%CI, -0.00145 to 0.00050 milliseconds per ng/mL). Predicted fedratinib placebo-corrected ΔQTcF was 0.6 milliseconds (90%CI, -1.80 to 2.93 milliseconds) at the geometric mean of the observed C_max (3615 ng/mL). Fedratinib did not affect PR or QRS intervals. No patients had QTcF > 60 milliseconds, and no patients experienced QTcF ≥ 500 milliseconds. Fedratinib did not cause clinically relevant ECG effects or QTc prolongation. Safety findings were consistent with the known safety profile.

Pharmacokinetic Disposition Difference Between Cyclosporine and Voclosporin Drives Their Distinct Efficacy and Safety Profiles in Clinical Studies

Background

Voclosporin, a more potent derivative of cyclosporine, has been studied extensively in patients with immunologic disorders such as psoriasis, organ transplantation, uvetitis and lupus nephritis. Although better tolerated and safer than cyclosporine, voclosporin is inferior to cyclosporine in treating psoriasis, non-inferior to tacrolimus in organ transplantation and efficacious in treating lupus nephritis.

Methods

The pharmacokinetic dispositions of voclosporin and cyclosporine in central and peripheral compartments were analyzed and correlated with their distinct clinical efficacy and safety profiles.

Results

Both drugs demonstrated non-linear pharmacokinetics with increasing doses, more prominently at lower doses of voclosporin than at 10-fold higher doses of cyclosporine. Repeated lower dosing of voclosporin produced preferential calcineurin inhibition in and near blood circulation, leading to relatively lower cardiovascular and renal adverse effects but inferior efficacy for psoriasis compared to cyclosporine. With 10-fold higher plasma levels and deeper tissue penetration, cyclosporine has more prevalent renal and cardiac toxicities but superior efficacy to treat psoriasis.

Conclusion

Although the two drugs are similar in structure and mechanism of action, the high potency and low dose compounded by the non-linear disposition of voclosporin resulted in more systemic versus local calcineurin inhibition than with cyclosporine. The dispositional difference between voclosporin and cyclosporine accounted for the puzzling efficacy and safety observations in different patients and was the basis for their optimal and differential use in treating diverse immunologic disorders.

Population Pharmacokinetics and Exposure-Response of Luspatercept, an Erythroid Maturation Agent, in Anemic Patients With Myelodysplastic Syndromes

Luspatercept is a recombinant fusion protein that enhances late‐stage erythroid maturation. This report describes the population pharmacokinetics and exposure–response relationship of luspatercept in 260 patients with anemia due to myelodysplastic syndromes. Luspatercept displayed linear and time‐invariant pharmacokinetics over a dose range of 0.125–1.75 mg/kg administered subcutaneously once every 3 weeks. Body weight was the only clinically relevant covariate of luspatercept exposure, supporting the weight‐based dosing. The probability of achieving transfusion independence ≥ 8 weeks increased with time‐averaged luspatercept serum exposure, reaching the plateau at doses 1.0–1.75 mg/kg. The probability of achieving multiple efficacy end points increased with slower luspatercept clearance, independent of effects of luspatercept exposure or disease characteristics. The probability of experiencing severe treatment‐emergent adverse events decreased with increasing luspatercept exposure, especially during long‐term treatment. These results provide a positive benefit–risk profile for the titration‐to‐response dose regimen (1.0–1.75 mg/kg) recommended for this population.

Assessment of effects of repeated oral doses of fedratinib on inhibition of cytochrome P450 activities in patients with solid tumors using a cocktail approach

PURPOSE

Fedratinib, an oral selective kinase inhibitor with activity against both wild type and mutationally activated Janus kinase 2, has been approved for the treatment of adult patients with intermediate-2 or high-risk myelofibrosis by the US Food and Drug Administration. In vitro studies indicated that fedratinib was an inhibitor of several cytochrome P450 (CYP) enzymes. The primary objective of this study was to evaluate the effects of repeated doses of fedratinib on the activity of CYP2D6, CYP2C19, and CYP3A4 in patients with solid tumors using a CYP probe cocktail.

METHODS

An open-label, one-sequence, two-period, two-treatment crossover study was conducted. Patients were administered a single oral dose cocktail of metoprolol (100 mg), omeprazole (20 mg), and midazolam (2 mg) used as probe substrates for CYP2D6, CYP2C19, and CYP3A4 enzyme activities, respectively, without fedratinib on Day -1 or with fedratinib on Day 15.

RESULTS

Coadministration of 500 mg once-daily doses of fedratinib for 15 days increased the mean area under the plasma concentration-time curve from time zero to infinity following a single-dose cocktail containing metoprolol (CYP2D6 substrate), omeprazole (CYP2C19 substrate), and midazolam (CYP3A4 substrate) by 1.77-fold (90% confidence interval [CI] 1.27-2.47) for metoprolol, 2.82-fold (90% CI 2.26-3.53) for omeprazole, and 3.84-fold (90% CI 2.62-5.63) for midazolam, respectively. The mean plasma Day 14/Day 1 ratio of 4β-hydroxycholesterol, an endogenous biomarker of CYP3A4 activity, was 0.59 (90% CI 0.54-0.66), suggesting a net inhibition of CYP3A4 by fedratinib.

CONCLUSION

Fedratinib is a weak inhibitor of CYP2D6, and a moderate inhibitor of CYP2C19 and CYP3A4. These results serve as the basis for dose modifications of these CYP substrate drugs when co-administered with fedratinib.

Population Pharmacokinetics and Exposure-Response Analysis of nab-Paclitaxel in Pediatric Patients With Recurrent or Refractory Solid Tumors

Pediatric malignancies are most commonly of primary central nervous system or hematopoietic origin. The main reason for cancer death in pediatrics is refractory and relapsed disease, and improved therapeutic options are needed in the pediatric population. Nanoparticle albumin-bound (nab)-paclitaxel (Abraxane) is a human albumin-stabilized formulation of paclitaxel and was designed to improve the chemotherapeutic effects of paclitaxel and to reduce toxicities. Although nab-paclitaxel pharmacokinetics (PK) has been extensively studied in adults, no information is available on its PK in children. ABI-007-PST-001 was the first nab-paclitaxel clinical trial conducted in pediatrics, and the current analysis is the first study of nab-paclitaxel PK in pediatrics. Our analyses suggested that ontogeny and maturation play a role in nab-paclitaxel PK disposition, as demonstrated by the finding that both blood clearance and volume of distribution increased from younger to older pediatric age groups and from pediatrics to adults. A 3-compartment population PK (PPK) model with saturable elimination was developed to describe the paclitaxel whole blood concentrations in pediatrics. The PPK model was customized by estimating the allometric function on PK parameters to take into account the ontogeny/maturation of patients. PPK estimates are consistent with the fast and deep distribution of paclitaxel that was previously observed in adults. Finally, the exposure-safety analysis showed an increased probability of drug-related adverse events (>grade 2) in cycle 1 and the first cycle of neutropenia (>grade 2) associated with higher doses. However, there is no statistically significant association between exposures (measured by area under the concentration-time curve) and the probabilities of either safety event.

Pharmacokinetics and tolerability of fedratinib, an oral, selective Janus kinase 2 inhibitor, in subjects with renal or hepatic impairment

PURPOSE

Fedratinib is an oral, selective Janus kinase 2 inhibitor that is approved in the United States for the treatment of patients with intermediate-2 or high-risk myelofibrosis. Pharmacokinetics and tolerability of fedratinib in subjects with renal impairment (RI) and hepatic impairment (HI) were evaluated in two separate studies.

METHODS

In the renal study, male and female subjects with stable, chronic mild, moderate, and severe RI, as well as those with end-stage renal disease, were included. The hepatic study included subjects with stable, chronic mild HI. Both were phase 1, multicenter, open-label, single-dose studies, and included matched healthy subjects. Subjects received a single oral dose of fedratinib 300 mg on day 1, were discharged on day 4, returned for clinical visits on days 5-12, and had their end-of-study visit between days 14 and 16.

RESULTS

Thirty-six and 17 subjects were included in the renal and hepatic studies, respectively. In the renal study, fedratinib area under the plasma concentration-time curve from time 0 to infinity (AUC_inf) was 1.9- and 1.5-fold higher in subjects with severe and moderate RI, respectively, than in matched healthy subjects. In the hepatic study, fedratinib AUC_inf did not appreciably differ between subjects with mild HI and matched healthy subjects. Overall, most treatment-emergent adverse events were gastrointestinal and mild.

CONCLUSION

Mild RI and HI do not necessitate fedratinib dosage adjustments. Subjects with moderate RI should be monitored (with dosage adjustments made as necessary), whereas those with severe RI should receive a daily dose of 200 mg, reduced from the indicated dose of 400 mg.

Effects of repeated oral doses of ketoconazole on a sequential ascending single oral dose of fedratinib in healthy subjects

PURPOSE

Fedratinib is an orally administered Janus kinase 2-selective inhibitor that is indicated for the treatment of adult patients with intermediate-2 or high-risk myelofibrosis in the United States. Fedratinib is metabolized by multiple cytochrome P450s (CYPs) in vitro, with the predominant contribution from CYP3A4. The primary objective of this study was to evaluate the effects of 14-day repeated 200 mg twice daily (BID) oral doses of a strong CYP3A4 inhibitor, ketoconazole, on a sequential ascending single oral dose of fedratinib in healthy male subjects.

METHODS

An open-label, fixed-sequence, two-treatment cross-over study was conducted. Two cohorts of healthy adult males received two single doses of fedratinib (50 mg in Cohort 1 and 300 mg in Cohort 2) with one dose administered alone on Day 1 of Period 1 and the other dose coadministered with ketoconazole in the morning of Day 6 of Period 2. Subjects in both cohorts received 200-mg BID (Days 1-14) ketoconazole during Period 2.

RESULTS

Coadministration of repeated 200-mg BID oral doses of ketoconazole for 14 days increased fedratinib exposure by 3.85- and 3.06-fold for area under the plasma concentration-time curve from time zero to infinity following a single oral dose of fedratinib of 50 and 300 mg, respectively. Oral administration of a single dose of 50 or 300 mg of fedratinib, administered alone or coadministered with steady-state ketoconazole, was safe and tolerable in the healthy male subjects.

CONCLUSIONS

These results serve as the basis for fedratinib dose reduction when fedratinib is coadministered with strong CYP3A4 inhibitors.

Population Pharmacokinetics and Exposure Response Analysis of Pomalidomide in Subjects With Relapsed or Refractory Multiple Myeloma From the Novel Combination Treatment of Pomalidomide, Bortezomib, and Low-Dose Dexamethasone

Multiple myeloma is an incurable progressive neoplastic disease that accounts for 10% of all hematologic malignancies. Even though significant progress has been made in the treatment of newly diagnosed multiple myeloma, the disease follows a relapsing course in the majority of patients, and there is a need for more effective therapeutic options for the treatment of relapsed or refractory multiple myeloma. CC-4047-MM-005 and CC-4047-MM-007 were phase 1 and 3 studies to evaluate the novel combination of pomalidomide, bortezomib, and low-dose dexamethasone for the treatment of patients with relapsed or refractory multiple myeloma who have already received lenalidomide-based treatments early. This analysis was performed to characterize the population pharmacokinetics (PK) of pomalidomide from the combination treatment and to examine exposure-response relationships. Our analysis showed that pomalidomide concentration-time profiles from the combination treatment were adequately described with a 1-compartment PK model, with first-order absorption and elimination and pomalidomide exhibiting linear and time-invariant PK with moderate variability from the combination treatment. Except for the body surface area, none of the tested covariates had an effect on pomalidomide PK. Although body surface area was identified as a statistically significant covariate of pomalidomide PK, the impact was not deemed clinically relevant. A flat exposure-response curve was observed, consistent with a near-saturated drug effect at the tested exposure range suggesting an appropriately recommended clinical dose of 4 mg of pomalidomide for the combination treatment. Finally, pomalidomide exposure was not associated with higher probabilities of dose interruption during cycle 1 or dose reduction during the treatment period.

Single-Dose Pharmacokinetics, Safety, and Tolerability of Avadomide (CC-122) in Subjects With Mild, Moderate, or Severe Renal Impairment

CC-122 (Avadomide) is a nonphthalimide analogue of thalidomide that has multiple pharmacological activities including immune modulation of several immune cell subsets, antigrowth activity, antiproliferative activity, and antiangiogenic activity. CC-122 as monotherapy and in combination with other agents is being evaluated for multiple indications including hematologic malignancies and advanced solid tumors. Given that renal clearance is one of the major routes of elimination for CC-122 and its clearance/exposure could be affected by renal impairment, a total of 50 subjects with various degrees of renal function were enrolled in an open-label, single-dose study to evaluate the impact of renal impairment on CC-122 pharmacokinetic disposition. The study showed that following administration of a single oral dose of 3 mg CC-122, renal impairment reduced both the apparent total plasma clearance and renal clearance of CC-122, but it had less impact on CC-122 absorption, as demonstrated by similar T_max and C_max among groups with various degrees of renal function. Compared with exposure in subjects with normal renal function, total plasma exposure to CC-122 increased by ∼20%, ∼50%, and ∼120% in subjects with mild, moderate, and severe renal insufficiency, respectively. Results from this study combined with modeling/simulation suggest that dose adjustments are necessary in patients with moderate or severe but not with mild renal impairment. Finally, a single dose of 3 mg CC-122 was safe and well tolerated by healthy subjects and subjects with mild, moderate, and severe renal impairment.

Population pharmacokinetics of fedratinib in patients with myelofibrosis, polycythemia vera, and essential thrombocythemia

PURPOSE

Fedratinib (SAR302503, TG101348) is an orally administered Janus kinase (JAK) 2-selective inhibitor that is being developed for the treatment of patients with myelofibrosis (MF). The objectives of this analysis were to develop a population pharmacokinetic (PK) model to characterize fedratinib concentration-time profiles in patients with MF, polycythemia vera (PV) and essential thrombocythemia (ET) following oral fedratinib administration; and to investigate the effects of selected covariates on fedratinib PK parameters.

METHODS

Nonlinear mixed effects modeling was employed in developing a population PK model for fedratinib. Intensive or sparse fedratinib concentration data collected in adult subjects with MF, PV or ET from six studies were pooled, and a total of 452 subjects and 3442 plasma concentration observations were included in the final model.

RESULTS

Fedratinib PK in patients with MF/PV/ET was adequately described by a two-compartment structural PK model with first-order absorption incorporating a lag time and first-order elimination. Following oral administration, fedratinib undergoes biphasic disposition and exhibits linear, time-invariant PK at doses of 200 mg and above. Compared to MF/ET patients, PV patients had higher apparent clearance (CL/F) and apparent central volume of distribution. Creatinine clearance was a statistically significant covariate on CL/F, and patients with mild and moderate renal impairment had 10% and 37% increases in fedratinib exposure as compared to patients with normal renal function. No clinically meaningful effect on fedratinib exposure was observed regarding age, body weight, sex, race and liver function.

CONCLUSIONS

These results should serve as the basis for dose adjustment of fedratinib for special populations.

Population Pharmacokinetic Model to Assess the Impact of Disease State on Thalidomide Pharmacokinetics

A population pharmacokinetic (PPK) model to describe the pharmacokinetics of thalidomide in different patient populations was developed using data pooled from healthy subjects and patients with Hansen's disease, human immunodeficiency virus (HIV), and multiple myeloma (MM). The analysis data set had a total of 164 evaluable subjects who received various doses (50 to 400 mg) of oral thalidomide in single- and/or multiple-dose regimens. The plasma thalidomide concentrations were adequately described by a linear 1-compartment PPK model with first-order absorption and first-order elimination. Inclusion of MM as a covariate on apparent clearance (CL/F) accounted for 4.4% of the interindividual variability (IIV) of CL/F. Body weight as a covariate on CL/F and apparent volume of distribution (V/F) also improved model fitting slightly, accounting for 7.2% and 20% of IIV, respectively. Although inclusion of body weight and MM as covariates of CL/F and body weight on V/F improved the goodness of fit of the model in a statistically significant manner, the impact of this difference in CL/F is not considered clinically relevant. Other factors such as age, sex, race, creatinine clearance, and alanine transaminase had no effect on thalidomide pharmacokinetics. MM, HIV, and Hansen's disease have no clinically relevant effect on thalidomide disposition relative to healthy volunteers.

Drug-Drug Interaction Study to Assess the Effect of Cytochrome P450 Inhibition and Induction on the Pharmacokinetics of the Novel Cereblon Modulator Avadomide (CC-122) in Healthy Adult Subjects

Avadomide (CC‐122) is a novel immunomodulatory drug that binds to cereblon, a member of the Cullin 4‐RING E3 ubiquitin ligase complex. Avadomide has multiple pharmacologic activities including potent immune modulation, antiangiogenic, antitumor, and antiproliferative activity and is being evaluated as an oncology treatment for hematologic malignancies and advanced solid tumors. In vitro study has indicated that cytochrome P450 (CYP) 3A and CYP1A2 appear to be the major enzymes involved in the oxidative metabolism of avadomide. The effects of CYP3A inhibition/induction and CYP1A2 inhibition on the pharmacokinetics of avadomide in healthy adult subjects were assessed in 3 parts of an open‐label, nonrandomized, 2‐period, single‐sequence crossover study. Following a single oral dose of 3 mg, avadomide exposure when coadministered with the CYP1A2 inhibitor fluvoxamine was 154.81% and 107.59% of that when administered alone, for area under the plasma concentration‐time curve from time 0 to infinity (AUC_0‐inf) and maximum observed plasma concentration (C_max), respectively. Avadomide exposures, when coadministered with the CYP3A inhibitor itraconazole, were 100.0% and 93.64% of that when administered alone, for AUC_0‐inf and C_max, respectively. Avadomide exposures when coadministered with the CYP3A inducer rifampin were 62.83% and 88.17% of that when administered alone, for AUC_0‐inf and C_max, respectively. Avadomide was well tolerated when administered as a single oral dose of 3 mg alone or coadministered with fluvoxamine, itraconazole, or rifampin. These results should serve as the basis for avadomide dose recommendations when it is coadministered with strong CYP3A and CYP1A2 inhibitors and with rifampin.

Neonatal Fc Receptor (FcRn) Enhances Tissue Distribution and Prevents Excretion of nab-Paclitaxel

nab-Paclitaxel ( nab-P), an albumin-bound formulation of paclitaxel, was developed to improve the tolerability and antitumor activity of taxanes. The neonatal Fc receptor (FcRn) is a transport protein that can bind to albumin and regulate the homeostasis of circulating albumin. Therefore, the pharmacokinetics and pharmacodynamics of nab-P may be impacted by FcRn expression. This study aimed to investigate the effects of FcRn on nab-P elimination and distribution to targeted tissues. Wild-type and FcRn-knockout (FcRn-KO) mice were treated with nab-P, mouse-specific nab-P (distribution experiments only), and solvent-based paclitaxel (pac-T). Blood and tissue samples were collected for distribution analyses. Organ, urine, and fecal samples were collected for elimination analyses. The nab-P tissue penetration in the pancreas, fat pad, and kidney of wild-type mice, as reflected by the ratio of tissue/plasma concentration, was significantly higher (ranging from 5 to 80 fold) than that of FcRn-KO mice. In contrast, the tissue penetration of pac-T in these organs of FcRn-KO mice was similar to that of wild-type mice. More importantly, the excretion of nab-P in feces of FcRn-KO mice (45-68%) was significantly higher than that of wild-type mice (26-46%) from 8 to 48 h post treatment. In comparison, the difference of excretion of pac-T in feces between FcRn-KO mice and wild-type mice was smaller than that of nab-P. Furthermore, greater tissue penetration and fecal excretion were observed with nab-P than pac-T in both FcRn-KO and wild-type mice. These findings suggest that FcRn enhances the tissue distribution and penetration of nab-P in the targeted organs, while FcRn prevents excretion of nab-P to feces in the intestinal lumen. The findings support the notion that albumin nanoparticle delivery alters drug distribution and elimination through an FcRn-mediated process to impact drug efficacy and toxicity.

Modeling and simulation of the endogenous CYP3A induction marker 4β-hydroxycholesterol during enasidenib treatment

Background

Enasidenib (IDHIFA^®, AG-221) is a first-in-class, targeted inhibitor of mutant IDH2 proteins for treatment of relapsed or refractory acute myeloid leukemia. This was a Phase I/II study evaluating safety, efficacy, and pharmacokinetics/pharmacodynamics (PK/PD) of orally administered enasidenib in subjects with advanced hematologic malignancies with an IDH2 mutation.

Methods

Blood samples for PK and PD assessment were collected. A semi-mechanistic nonlinear mixed effect PK/PD model was successfully developed to characterize enasidenib plasma PK and to assess enasidenib-induced CYP3A activity.

Results

The PK model showed that enasidenib plasma concentrations were adequately described by a one-compartment model with first-order absorption and elimination; the PD model showed a high capacity to induce CYP3A (E_max=7.36) and a high enasidenib plasma concentration to produce half of maximum CYP3A induction (EC₅₀ =31,400 ng/mL). Monte Carlo simulations based on the final PK/PD model showed that at 100 mg once daily dose there was significant drug accumulation and a maximum of three-fold CYP3A induction after multiple doses. Although the EC₅₀ value for CYP3A induction by enasidenib is high, CYP3A induction was observed due to significant drug accumulation.

Conclusion

CYP3A induction following enasidenib dosing should be considered when prescribing concomitant medication metabolized via this pathway.

Pharmacokinetics and safety of Enasidenib following single oral doses in Japanese and Caucasian subjects

The aim of this study was to assess and compare the pharmacokinetics (PK) and safety of Enasidenib in healthy adult male Japanese subjects to healthy adult male Caucasian subjects. This was a phase 1, single dose study to evaluate the PK and safety of Enasidenib in healthy adult male Japanese subjects relative to healthy adult male Caucasian subjects. A total of 62 subjects (31 Japanese and 31 Caucasian) were enrolled into three dose cohorts (single doses of 50 mg, 100 mg, or 300 mg Enasidenib). Blood samples for PK assessment were collected up to 672 hours postdose. Safety was evaluated throughout the study. In the present study, we found that PK exposures of Enasidenib and its metabolite AGI-16903 for Caucasian and Japanese subjects were comparable at the 50, 100, and 300 mg dose levels, demonstrated by that the 90% confidence intervals (CIs) of geometric mean ratios for AUCs and Cmax between these two populations generally contained 100% from all three treatment cohorts. In conclusion, PK exposures of Enasidenib and its metabolite AGI-16903 for Caucasians and Japanese subjects were comparable and Enasidenib was safe and well tolerated with no apparent differences between Japanese and Caucasian subjects when administered as single oral doses of 50 mg, 100 mg, and 300 mg.

Cereblon modulator iberdomide induces degradation of the transcription factors Ikaros and Aiolos: immunomodulation in healthy volunteers and relevance to systemic lupus erythematosus

OBJECTIVES

IKZF1 and IKZF3 (encoding transcription factors Ikaros and Aiolos) are susceptibility loci for systemic lupus erythematosus (SLE). The pharmacology of iberdomide (CC-220), a cereblon (CRBN) modulator targeting Ikaros and Aiolos, was studied in SLE patient cells and in a phase 1 healthy volunteer study.

METHODS

CRBN, IKZF1 and IKZF3 gene expression was measured in peripheral blood mononuclear cells (PBMC) from patients with SLE and healthy volunteers. Ikaros and Aiolos protein levels were measured by Western blot and flow cytometry. Anti-dsDNA and anti-phospholipid autoantibodies were measured in SLE PBMC cultures treated for 7 days with iberdomide. Fifty-six healthy volunteers were randomised to a single dose of iberdomide (0.03-6 mg, n=6 across seven cohorts) or placebo (n=2/cohort). CD19+ B cells, CD3+ T cells and intracellular Aiolos were measured by flow cytometry. Interleukin (IL)-2 and IL-1β production was stimulated with anti-CD3 and lipopolysaccharide, respectively, in an ex vivo whole blood assay.

RESULTS

SLE patient PBMCs expressed significantly higher CRBN (1.5-fold), IKZF1 (2.1-fold) and IKZF3 (4.1-fold) mRNA levels compared with healthy volunteers. Iberdomide significantly reduced Ikaros and Aiolos protein levels in B cells, T cells and monocytes. In SLE PBMC cultures, iberdomide inhibited anti-dsDNA and anti-phospholipid autoantibody production (IC50 ≈10 nM). Single doses of iberdomide (0.3-6 mg) in healthy volunteers decreased intracellular Aiolos (minimum mean per cent of baseline: ≈12%-28% (B cells); ≈0%-33% (T cells)), decreased absolute CD19+ B cells, increased IL-2 and decreased IL-1β production ex vivo.

CONCLUSIONS

These findings demonstrate pharmacodynamic activity of iberdomide and support its further clinical development for the treatment of SLE.

TRIAL REGISTRATION NUMBER

NCT01733875; Results.

Different Nanoformulations Alter the Tissue Distribution of Paclitaxel, Which Aligns with Reported Distinct Efficacy and Safety Profiles

Previous studies have shown that different paclitaxel formulations produce distinct anticancer efficacy and safety profiles in animals and humans. This study aimed to investigate the distinct pharmacokinetics and tissue distribution of various nanoformulations of paclitaxel, which may translate into potential differences in safety and efficacy. Four nanoparticle formulations ( nab-paclitaxel, mouse albumin nab-paclitaxel [m -nab-paclitaxel], micellar paclitaxel, and polymeric nanoparticle paclitaxel) as well as solvent-based paclitaxel were intravenously administered to mice. Seventeen blood and tissue samples were collected at different time points. The total paclitaxel concentration in each tissue specimen was measured with liquid chromatography-tandem mass spectrometry. Compared with solvent-based paclitaxel, all four nanoformulations demonstrated decreased paclitaxel exposure in plasma. All nanoformulations were associated with paclitaxel blood-cell accumulation in mice; however, m- nab-paclitaxel was associated with the lowest accumulation. Five minutes after dosing, the total paclitaxel in the tissues and blood was approximately 44% to 57% of the administered dose of all paclitaxel formulations. Paclitaxel was primarily distributed to liver, muscle, intestine, kidney, skin, and bone. Compared with solvent-based paclitaxel, the different nanocarriers altered the distribution of paclitaxel in all tissues with distinct paclitaxel concentration-time profiles. nab-paclitaxel was associated with increased delivery efficiency of paclitaxel in the pancreas compared with the other formulations, consistent with the demonstrated efficacy of nab-paclitaxel in pancreatic cancer. All the nanoformulations led to high penetration in the lungs and fat pad, which potentially points to efficacy in lung and breast cancers. Micellar paclitaxel and polymeric nanoparticle paclitaxel were associated with high paclitaxel accumulation in the heart; thus, the risk of cardiovascular toxicity with these formulations may warrant further investigation. The solvent-based formulation was associated with the poorest paclitaxel penetration in all tissues and the lowest tissue-to-plasma ratio. The different nanocarriers of paclitaxel were associated with distinct pharmacokinetics and tissue distribution, which largely align with the observed efficacy and toxicity profiles in clinical trials.

A Phase I, open-label, randomized, crossover study in healthy subjects to evaluate the bioavailability of, and the food effect on, a pomalidomide oral liquid suspension

Objective

The aim of this study was to evaluate the bioavailability of a pomalidomide oral liquid suspension relative to the commercial capsule formulation and to assess the food effect on the pomalidomide oral liquid suspension when administered as a single 4 mg dose.

Methods

This was an open-label, randomized, three-period, two-sequence crossover study in healthy subjects consisting of a screening phase, a baseline assessment phase, a treatment phase with three periods, and a follow-up phone call phase. Blood samples for pharmacokinetics (PK) assessment were collected up to 48 h postdose during each treatment period. Safety was evaluated throughout the study.

Results

Pomalidomide exposures were comparable in healthy subjects administered with a single oral 4 mg dose as the reference capsule or as the test liquid suspension formulations, demonstrated as the 90% confidence intervals of the geometric mean ratios for area under the plasma concentration–time curve calculated from time 0 to the last measurable concentration at time t (AUC_0–t), area under the plasma concentration–time curve from time 0 to infinity (AUC_0–∞), and peak (maximum) plasma drug concentration (C_max) were completely contained within the bioequivalence range of 80–125%. Administration of the pomalidomide liquid suspension with a high fat meal resulted in a 3.0 h delay in pomalidomide time to C_max (t_max) and an ~ 34.5% reduction in C_max. However, the AUCs were comparable after dose administration with and without food.

Conclusion

A single oral dose of 4 mg of liquid suspension was bioequivalent to a single oral dose of 4 mg of capsule formulation. There was no clinically relevant impact of food on pomalidomide liquid suspension. Single oral doses of 4 mg pomalidomide were safe and well tolerated when administered as a liquid suspension under fed and fasted conditions or as a capsule under fasted conditions.

Distribution of pomalidomide into semen of healthy male subjects after multiple doses

Objective

To assess whether pomalidomide can distribute into human semen and its duration in human semen.

Method

A phase 1, randomized, double-blind, placebo-controlled study (CC-4047-CP-006) was conducted to evaluate the safety, tolerability, and pharmacokinetics of pomalidomide (CC-4047) following multiple daily doses in healthy male subjects. Semen samples were collected on Day −1 and 4 hours after dosing on Day 4 to quantify the pomalidomide concentrations in ejaculate after multiple oral doses of pomalidomide.

Result

Our study showed that pomalidomide was present in male subjects’ semen samples, and the average amount of pomalidomide in a single ejaculate 4 hours after dosing was less than 0.0022% of the daily 2 mg dose. There was a good correlation between the semen concentrations and the plasma concentrations, suggesting that the plasma concentration may be the main driving force for the distribution of pomalidomide into the seminal reservoirs. Simulation results suggest that pomalidomide was undetectable in semen 48 hours after stopping dosing.

Conclusion

Based on the results from this study, the pomalidomide prescribing information approved by the US Food and Drug Administration includes a statement that “pomalidomide is present in the semen of patients receiving the drug. Therefore, males must always use a latex or synthetic condom during any sexual contact with females of reproductive potential while taking POMALYST and for up to 4 weeks after discontinuing POMALYST, even if they have undergone a successful vasectomy. Male patients taking POMALYST must not donate sperm.”

In Vivo Assessment of the Effect of CYP1A2 Inhibition and Induction on Pomalidomide Pharmacokinetics in Healthy Subjects

Pomalidomide is an immunomodulatory drug, and the dosage of 4 mg per day taken orally on days 1‐21 of repeated 28‐day cycles has been approved in the European Union and the United States to treat patients with relapsed/refractory multiple myeloma. In vitro data showed that pomalidomide is a substrate of multiple cytochrome P450 (CYP) isozymes and that its oxidative metabolism is mediated primarily by CYP1A2 and CYP3A4, with minor contributions from CYP2C19 and CYP2D6. The effect of CYP1A2 inhibition by fluvoxamine (a strong CYP1A2 inhibitor) and CYP1A2 induction by smoking on pomalidomide pharmacokinetics in healthy subjects has been assessed in 2 separate phase 1 open‐label, single‐dose studies. Following administration of a single oral dose of 4 mg pomalidomide, the plasma exposure when coadministered with fluvoxamine was 225.1% and 123.7% of that when administered alone for the total plasma exposure (AUC_0‐inf) and the plasma peak exposure (C_max), respectively. In smokers with elevated CYP1A2 activity demonstrated by high caffeine clearance (a marker of CYP1A2 induction), the AUC_0‐inf was 32.3% lower, whereas the C_max was 14.4% higher than that in nonsmokers. In addition, pomalidomide was safe and well tolerated as a single oral dose of 4 mg in healthy male smokers and nonsmokers ≥ 40 to ≤ 80 years old, and a single oral dose of 4 mg pomalidomide coadministered with multiple oral 50‐mg doses of the CYP1A2 inhibitor fluvoxamine compared with pomalidomide alone was safe and well tolerated by the healthy male subjects.

An Open-Label, Phase 1 Study to Assess the Effects of Hepatic Impairment on Pomalidomide Pharmacokinetics

Pomalidomide is an immunomodulatory drug and the dosage of 4 mg per day taken orally on days 1-21 of repeated 28-day cycles has been approved in the European Union and United States to treat patients with relapsed/refractory multiple myeloma. Because pomalidomide is extensively metabolized prior to excretion, a total of 32 subjects (8 healthy subjects in group 1; 8 subjects with severe hepatic impairment in group 2; 8 subjects with moderate hepatic impairment in group 3; and 8 subjects with mild hepatic impairment in group 4) were enrolled in a multicenter, open-label, single-dose study to assess the impact of hepatic impairment on pomalidomide exposure. Following administration of a single oral dose of 4-mg pomalidomide, the geometric mean ratios of pomalidomide total plasma exposures (AUC) were 171.5%, 157.5%, and 151.2% and the geometric mean ratios of pomalidomide plasma peak exposures (C_max ) were 75.8%, 94.8%, and 94.2% for subjects with severe, moderate, or mild hepatic impairment, respectively, versus healthy subjects. Pomalidomide administered as a single oral 4-mg dose was safe and well tolerated by healthy subjects and subjects with severe, moderate, or mild hepatic impairment. Based on the pharmacokinetic results from this study, the pomalidomide prescribing information approved by the US Food and Drug Administration recommends for patients with mild or moderate hepatic impairment (Child-Pugh classes A or B), a 3-mg starting daily dose (25% dose reduction) and for patients with severe hepatic impairment (Child-Pugh class C), a 2-mg starting daily dose (50% dose reduction).

Dynorphinergic system alterations in the corticostriatal circuitry of neuropathic mice support its role in the negative affective component of pain

The dynorphinergic system is involved in pain transmission at spinal level, where dynorphin exerts antinociceptive or pronociceptive effects, based on its opioid or non‐opioid actions. Surprisingly, little evidence is currently available concerning the supraspinal role of the dynorphinergic system in pain conditions. The present study aimed to investigate whether neuropathic pain is accompanied by prodynorphin (Pdyn) and κ‐opioid receptor (Oprk1) gene expression alterations in selected mouse brain areas. To this end, mice were subjected to chronic constriction injury of the right sciatic nerve and neuropathic pain behavioral signs were ascertained after 14 days. At this interval, a marked increase in Pdyn mRNA in the anterior cingulate cortex (ACC) and prefrontal cortex (PFC) was observed. Oprk1 gene expression was increased in the PFC, and decreased in the ACC and nucleus accumbens (NAc). No changes were observed in the other investigated regions. Because of the relationship between dynorphin and the brain‐derived neurotrophic factor, and the role of this neurotrophin in chronic pain‐related neuroplasticity, we investigated brain‐derived neurotrophic factor gene (Bdnf) expression in the areas showing Pdyn or Oprk1 mRNAs changes. Bdnf mRNA levels were increased in both the ACC and PFC, whereas no changes were assessed in the NAc. Present data indicate that the dynorphinergic system undergoes quite selective alterations involving the corticostriatal circuitry during neuropathic pain, suggesting a contribution to the negative affective component of pain. Moreover, parallel increases in Pdyn and Bdnf mRNA at cortical level suggest the occurrence of likely interactions between these systems in neuropathic pain maladaptive neuroplasticity.

Population pharmacokinetics of pomalidomide in patients with relapsed or refractory multiple myeloma with various degrees of impaired renal function

Pomalidomide is an immunomodulatory drug for treatment of relapsed or refractory multiple myeloma (rrMM) in patients who often have comorbid renal conditions. To assess the impact of renal impairment on pomalidomide exposure, a population pharmacokinetics (PPK) model of pomalidomide in rrMM patients with various degrees of impaired renal function was developed. Intensive and sparse pomalidomide concentration data collected from two clinical studies in rrMM patients with normal renal function, moderately impaired renal function, severely impaired renal function not requiring dialysis, and with severely impaired renal function requiring dialysis were pooled over the dose range of 2 to 4 mg, to assess specifically the influence of the impaired renal function as a categorical variable and a continuous variable on pomalidomide clearance and plasma exposure. In addition, pomalidomide concentration data collected on dialysis days from both the withdrawal (arterial) side and from the returning (venous) side of the dialyzer, from rrMM patients with severely impaired renal function requiring dialysis, were used to assess the extent to which dialysis contributes to the removal of pomalidomide from blood circulation. PPK analyses demonstrated that moderate to severe renal impairment not requiring dialysis has no influence on pomalidomide clearance or plasma exposure, as compared to those patients with normal renal function, while pomalidomide exposure increased approximately 35% in patients with severe renal impairment requiring dialysis on nondialysis days. In addition, dialysis increased total body pomalidomide clearance from 5 L/h to 12 L/h, indicating that dialysis will significantly remove pomalidomide from the blood circulation. Thus, pomalidomide should be administered post-dialysis on the days of dialysis.

Population Pharmacokinetics of Lenalidomide in Healthy Volunteers and Patients With Hematologic Malignancies

A population pharmacokinetic (PopPK) model of lenalidomide was developed using data pooled from 13 clinical studies (dose range, 5-400 mg) in participants who were considered to have adequate capability for renal excretion of lenalidomide (creatinine clearance [CrCl] > 50 mL/min). The analysis population included 305 healthy volunteers and 83 patients with multiple myeloma or myelodysplastic syndromes. A 1-compartment model with linear absorption and elimination described well the observed data for both healthy volunteers and patients. Covariate analysis suggested lenalidomide apparent clearance was positively correlated with CrCl, and lenalidomide volume of distribution was positively correlated with body weight. Both pharmacokinetic parameters were reduced by 29% in patients, independent of the effect of CrCl or body weight. Despite their statistical significance, effects of study population and body weight are considered clinically unimportant in adult patients with CrCl > 50 mL. After accounting for the above effects, body weight had no significant effect on CL/F, whereas age, sex, race, and mild hepatic impairment had no significant effect on either lenalidomide parameter. The PopPK model should be useful for future modeling of lenalidomide pharmacokinetics in the pediatric population and for further comparison of pharmacokinetic properties among structurally similar immunomodulatory drugs.

N/OFQ system in brain areas of nerve-injured mice: its role in different aspects of neuropathic pain

Several studies showed that chronic pain causes reorganization and functional alterations of supraspinal brain regions. The nociceptin-NOP receptor system is one of the major systems involved in pain control and much evidence also suggested its implication in stress, anxiety and depression. Therefore, we investigated the nociceptin-NOP system alterations in selected brain regions in a neuropathic pain murine model. Fourteen days after the common sciatic nerve ligature, polymerase chain reaction (PCR) analysis indicated a significant decrease of pronociceptin and NOP receptor mRNA levels in the thalamus; these alterations could contribute to the decrease of the thalamic inhibitory function reported in neuropathic pain condition. Nociceptin peptide and NOP mRNA increased in the anterior cingulate cortex (ACC) and not in the somatosensory cortex, suggesting a peculiar involvement of this system in pain regulating circuitry. Similarly to the ACC, an increase of nociceptin peptide levels was observed in the amygdala. Finally, the pronociceptin and NOP mRNAs decrease observed in the hypothalamus reflects the lack of hypothalamus-pituitary-adrenal axis activation, already reported in neuropathic pain models. Our data indicate that neuropathic pain conditions affect the supraspinal nociceptin-NOP system which is also altered in regions known to play a role in emotional aspects of pain.

Population Pharmacokinetics and Exposure Response Assessment of CC-292, a Potent BTK Inhibitor, in Patients With Chronic Lymphocytic Leukemia

CC‐292, a potent Bruton tyrosine kinase inhibitor, is under development for the treatment of B‐cell malignancies. An analysis was performed to develop a population pharmacokinetic model of CC‐292 and assess the influence of demographics and disease‐related covariates on CC‐292 exposure and to assess the exposure‐response (overall response rate) relationship in patients with chronic lymphocytic leukemia. Population pharmacokinetic analysis was based on a 2‐compartment base model conducted in NONMEM. Categorical exposure‐response analysis was performed using logistic regression in SAS. The population pharmacokinetic analysis results indicated that CC‐292 pharmacokinetic disposition is similar between healthy subjects and patients. CC‐292 showed a larger central compartment volume of distribution than the peripheral compartment volume of distribution (158 L and 72 L, respectively) and a faster clearance than intercompartmental clearance (134 L/h and 18.7 L/h, respectively), indicating that for CC‐292, clearance from blood occurs faster than distribution into deep tissues and organs. CC‐292 clearance is not affected by demographics or baseline clinical lab factors, except for sex. Although sex significantly reduced variation of apparent clearance, the sex effect on apparent clearance is unlikely to be clinically relevant. The exposure‐response analysis suggested that higher drug exposure is linearly correlated with higher overall response rate. A twice‐daily dose regimen showed higher overall response rate as compared to once‐daily dosing, consistent with a threshold concentration of approximately 300 ng/mL, above which the probability of overall response rate significantly increases.

Clinical Pharmacokinetics and Pharmacodynamics of Lenalidomide

Lenalidomide is a lead therapeutic in multiple myeloma and deletion 5q myelodysplastic syndromes and shows promising activities in other hematologic malignancies. This article presents a comprehensive review of the clinical pharmacokinetics and pharmacodynamics of lenalidomide. Oral lenalidomide is rapidly and highly absorbed (>90 % of dose) under fasting conditions. Food affects oral absorption, reducing area under the concentration-time curve (AUC) by 20 % and maximum concentration (C max) by 50 %. The increase in AUC and C max is dose proportional, and interindividual variability in plasma exposure is low to moderate. Lenalidomide distributes into semen but is undetectable 3 days after stopping treatment. Biotransformation of lenalidomide in humans includes chiral inversion, trivial hydroxylation, and slow non-enzymatic hydrolysis. Approximately 82 % of an oral dose is excreted as lenalidomide in urine within 24 h. Lenalidomide has a short half-life (3-4 h) and does not accumulate in plasma upon repeated dosing. Its pharmacokinetics are consistent across patient populations, regardless of the type of hematologic malignancy. Renal function is the only important factor affecting lenalidomide plasma exposure. Lenalidomide has no QT prolongation risk at approved doses, and higher plasma exposure to lenalidomide is associated with increased risk of neutropenia and thrombocytopenia. Despite being a weak substrate of P-glycoprotein (P-gp) in vitro, lenalidomide does not have clinically significant pharmacokinetic interactions with P-gp substrates/inhibitors in controlled studies. The AUC-matched dose adjustment is recommended for patients with renal impairment at the start of therapy. No dose adjustment for lenalidomide is needed on the basis of age, ethnicity, mild hepatic impairment, or drug-drug interactions.

Distinct biodistribution of doxorubicin and the altered dispositions mediated by different liposomal formulations

The liposomal formulations of doxorubicin produced distinct efficacy and toxicity profiles compared to doxorubicin solution in cancer patients. This study aims to investigate the drug tissue distribution and the driving force for tissue distribution from doxorubicin solution and two liposomal delivery systems, Doxil and Myocet. These three formulations were intravenously administered to mice at a single dose of 5mg/kg. Eleven organs, plasma and blood were collected at different time points. Total doxorubicin concentrations in each specimen were measured with LC-MS/MS. Compared to doxorubicin solution, both Doxil and Myocet produced distinct doxorubicin tissue exposure in all 11 tissues. Interestingly, the tissue exposure by Myocet was drastically different from that of Doxil and showed a formulation-dependent pattern. Cmax of doxorubicin in heart tissue by Doxil and Myocet was approximately 60% and 50% respectively of that by doxorubicin solution. The predominant driving force for doxorubicin tissue distribution is liposomal-doxorubicin deposition for Doxil and free drug concentration for doxorubicin solution. For Myocet, the driving force for tissue distribution is predominately liposomal-doxorubicin deposition into tissues within the first 4h; as the non-PEGylated doxorubicin liposomal decomposes, the driving force for tissue distribution is gradually switched to the released free doxorubicin. Unique tissue distributions are correlated with their toxicity profiles.

Exposure-response analysis to assess the concentration-QTc relationship of CC-122

CC-122 hydrochloride is a novel pleiotropic pathway modifier compound that binds cereblon, a substrate receptor of the Cullin 4 RING E3 ubiquitin ligase complex. CC-122 has multiple activities including modulation of immune cells, antiproliferative activity of multiple myeloma and lymphoma cells, and antiangiogenic activity. CC-122 is being developed as an oncology treatment for hematologic malignancies and advanced solid tumors. Cardiovascular and vital sign assessments of CC-122 have been conducted in hERG assays in vitro and in a 28-day good laboratory practice monkey study with negative signals. To assess the potential concentration–QTc relationship in humans and to ascertain or exclude a small QT effect by CC-122, a plasma concentration exposure- and ΔQTcF-response model of CC-122 was developed. Intensive CC-122 concentration and paired triplicate electrocardiogram data from a single ascending dose study were included in the analysis. The parameters included in the final linear exposure-response model are intercept, slope, and treatment effect. The slope estimate of 0.0201 with 90% CI of (0.009, 0.035) indicates a weak relationship between ΔQTcF and CC-122 concentration. The upper bounds of the 90% CI of the model-predicted ΔΔQTcF effect at C_max from the 4 mg clinical dose and the supratherapeutic dose of 15 mg (1.18 ms and 8.76 ms, respectively) are <10 ms threshold, suggesting that the risk of CC-122 QT prolongation effect at the relevant therapeutic dose range from 1 mg to 4 mg is low.

JNK inhibition reduces lung remodeling and pulmonary fibrotic systemic markers

BACKGROUND

Lung remodeling and pulmonary fibrosis are serious, life-threatening conditions resulting from diseases such as chronic severe asthma and idiopathic pulmonary fibrosis (IPF). Preclinical evidence suggests that JNK enzyme function is required for key steps in the pulmonary fibrotic process. However, a selective JNK inhibitor has not been investigated in translational models of lung fibrosis with clinically relevant biomarkers, or in IPF patients.

METHODS

The JNK inhibitor CC-930 was evaluated in the house dust mite-induced fibrotic airway mouse model, in a phase I healthy volunteer pharmacodynamic study, and subsequently in a phase II multicenter study of mild/moderate IPF (n = 28), with a 4-week, placebo-controlled, double-blind, sequential ascending-dose period (50 mg QD, 100 mg QD, 100 mg BID) and a 52-week open-label treatment-extension period.

RESULTS

In the preclinical model, CC-930 attenuated collagen 1A1 gene expression, peribronchiolar collagen deposition, airway mucin MUC5B expression in club cells, and MMP-7 expression in lung, bronchoalveolar lavage fluid, and serum. In the phase I study, CC-930 reduced c-Jun phosphorylation induced by UV radiation in skin. In the phase II IPF study, there was a CC-930 dose-dependent trend in reduction of MMP-7 and SP-D plasma protein levels. The most commonly reported adverse events were increased ALT, increased AST, and upper respiratory tract infection (six subjects each, 21.4 %). A total of 13 subjects (46.4 %) experienced adverse events that led to discontinuation of study drug. Nine out of 28 subjects experienced progressive disease in this study. The mean FVC (% predicted) declined after 26-32 weeks at doses of 100 mg QD and 100 mg BID. Changes in MMP-7, SP-D, and tenascin-C significantly correlated with change in FVC (% predicted).

CONCLUSIONS

These results illustrate JNK enzymatic activity involvement during pulmonary fibrosis, and support systemic biomarker use for tracking disease progression and the potential clinical benefit of this novel intervention in IPF. Trial registration ClinicalTrials.gov NCT01203943.

Impact of Renal Impairment on the Pharmacokinetics of Apremilast and Metabolite M12

The pharmacokinetics of apremilast and its major metabolite M12 were evaluated in subjects with varying degrees of renal impairment. Men and women with renal impairment (estimated glomerular filtration rate, 60‒89 mL/min [mild, n = 8], 30‒59 mL/min [moderate, n = 8], or <30 mL/min [severe, n = 8]) or demographically healthy matched (control) subjects (n = 24) received a single oral dose of apremilast 30 mg. Plasma apremilast and metabolite M12 concentrations were determined, and pharmacokinetic parameters were calculated from samples obtained predose and up to 72 hours postdose. In subjects with mild to moderate renal impairment, apremilast pharmacokinetic profiles were similar to healthy matched subjects. In subjects with severe renal impairment, apremilast elimination was significantly slower, and exposures based on area under the plasma concentration‐versus‐time curve from time zero extrapolated to infinity and maximum observed plasma concentration were increased versus healthy matched subjects. Metabolite M12 pharmacokinetic profiles for subjects with mild renal impairment were similar to those of the healthy matched subjects; however, they were increased in both the moderate and severe renally impaired subjects. Dose reduction of apremilast is recommended in individuals with severe renal impairment, but not in those with mild to moderate renal impairment.

Slow drug delivery decreased total body clearance and altered bioavailability of immediate- and controlled-release oxycodone formulations

Oxycodone is a commonly used analgesic with a large body of pharmacokinetic data from various immediate‐release or controlled‐release formulations, under different administration routes, and in diverse populations. Longer terminal half‐lives from extravascular administration as compared to IV administration have been attributed to flip‐flop pharmacokinetics with the rate constant of absorption slower than elimination. However, PK parameters from the extravascular studies showed faster absorption than elimination. Sustained release formulations guided by the flip‐flop concept produced mixed outcomes in formulation development and clinical studies. This research aims to develop a mechanistic knowledge of oxycodone ADME, and provide a consistent interpretation of diverging results and insight to guide further extended release development and optimize the clinical use of oxycodone. PK data of oxycodone in human studies were collected from literature and digitized. The PK data were analyzed using a new PK model with Weibull function to describe time‐varying drug releases/ oral absorption, and elimination dependent upon drug input to the portal vein. The new and traditional PK models were coded in NONMEM. Sensitivity analyses were conducted to address the relationship between rates of drug release/absorption and PK profiles plus terminal half‐lives. Traditional PK model could not be applied consistently to describe drug absorption and elimination of oxycodone. Errors were forced on absorption, elimination, or both parameters when IV and PO profiles were fitted separately. The new mechanistic PK model with Weibull function on absorption and slower total body clearance caused by slower absorption adequately describes the complex interplay between oxycodone absorption and elimination in vivo. Terminal phase of oxycodone PK profile was shown to reflect slower total body drug clearance due to slower drug release/absorption from oral formulations. Mechanistic PK models with Weibull absorption functions, and release rate‐dependent saturable total body clearance well described the diverging oxycodone absorption and elimination kinetics in the literature. It showed no actual drug absorption during the terminal phase, but slower drug clearance caused by slower release/absorption producing the appearance of flip‐flop and offered new insight for the development of modified release formulations and clinical use of oxycodone.