Safety, Pharmacokinetics, and Pharmacodynamics of Etrasimod: Single and Multiple Ascending Dose Studies in Healthy Adults.

Etrasimod is an investigational, once-daily, oral, selective sphingosine 1-phosphate receptor 1,4,5 modulator in development for immune-mediated inflammatory diseases (IMIDs). Here, we report the human safety, pharmacokinetics, and pharmacodynamics of etrasimod obtained from both a single ascending dose (SAD; 0.1-5 mg) study and a multiple ascending dose (MAD; 0.35-3 mg once daily) study. Overall, 99 healthy volunteers (SAD n = 40, MAD n = 59) completed the 2 studies. Evaluated single and multiple doses were well tolerated up to 3 mg without severe adverse events (AEs). Gastrointestinal disorders were the most common etrasimod-related AEs. Over the evaluated single- and multiple-dose ranges, dose-proportional and marginally greater-than-dose-proportional etrasimod plasma exposure were observed, respectively. At steady state, etrasimod oral clearance and half-life mean values ranged from 1.0 to 1.2 L/h and 29.7 to 36.4 hours, respectively. Dose-dependent total peripheral lymphocyte reductions occurred following etrasimod single and multiple dosing. Etrasimod multiple dosing resulted in reductions from baseline in total lymphocyte counts ranging from 41.1% to 68.8% after 21 days. Lymphocyte counts returned to normal range within 7 days following treatment discontinuation. Heart rate lowering from pretreatment baseline on etrasimod dosing was typically mild, with mean reductions seen after the first dose of up to 19.5 bpm (5 mg dose). The favorable safety, pharmacokinetic, and pharmacodynamic properties of etrasimod in humans supported its further development and warranted its investigation for treatment of IMIDs.

Investigation into MAO B-Mediated Formation of CC112273, a Major Circulating Metabolite of Ozanimod, in Humans and Preclinical Species: Stereospecific Oxidative Deamination of (S)-Enantiomer of Indaneamine (RP101075) by MAO B.

Ozanimod, recently approved for treating relapsing multiple sclerosis, produced a disproportionate, active, MAO B-catalyzed metabolite (CC112273) that showed remarkable interspecies differences and led to challenges in safety testing. This study explored the kinetics of CC112273 formation from its precursor RP101075. Incubations with human liver mitochondrial fractions revealed K Mapp, V max, and intrinsic clearance (Clint) for CC112273 formation to be 4.8 µM, 50.3 pmol/min/mg protein, and 12 µl/min/mg, respectively, whereas Michaelis-Menten constant (K M) with human recombinant MAO B was 1.1 µM. Studies with liver mitochondrial fractions from preclinical species led to K Mapp, V max, and Clint estimates of 3.0, 35, and 33 µM, 80.6, 114, 37.3 pmol/min/mg, and 27.2, 3.25, and 1.14 µl/min/mg in monkey, rat, and mouse, respectively, and revealed marked differences between rodents and primates, primarily attributable to differences in the K M Comparison of Clint estimates revealed monkey to be ∼2-fold more efficient and the mouse and rat to be 11- and 4-fold less efficient than humans in CC112273 formation. The influence of stereochemistry on MAO B-mediated oxidation was also investigated using the R-isomer of RP101075 (RP101074). This showed marked selectivity toward catalysis of the S-isomer (RP101075) only. Docking into MAO B crystal structure suggested that although both the isomers occupied its active site, only the orientation of RP101075 presented the C-H on the α-carbon that was ideal for the C-H bond cleavage, which is a requisite for oxidative deamination. These studies explain the basis for the observed interspecies differences in the metabolism of ozanimod as well as the substrate stereospecificity for formation of CC112273. SIGNIFICANCE STATEMENT: This study evaluates the enzymology and the species differences of the major circulating metabolite of ozanimod, CC112273. Additionally, the study also explores the influence of stereochemistry on MAO B-catalyzed reactions. The study is of significance to the DMD readers given that this oxidation is catalyzed by a non-cytochrome P450 enzyme, and that marked species difference and notable stereospecificity was observed in MAO B-catalyzed biotransformation when the indaneamine enantiomers were used as substrates.

Chitosan nanocarrier for FTY720 enhanced delivery retards Parkinson's disease via PP2A-EzH2 signaling in vitro and ex vivo.

Parkinson's disease (PD) develops due to oxidative stress, mitochondrial aberrations, posttranslational modification, and α-Synuclein (α-Syn) aggregation. The α-synucleinopathy is attributed to phosphorylation and aggregation of α-Syn. A strategy to degrade or reduce phosphorylated protein paves the way to develop PD therapy. Hence, the neuroprotective efficiency of PP2A (Protein phosphatase 2) activator FTY720, loaded chitosan nanoformulation has been evaluated in vitro and ex vivo experimental PD models. Bio-compatible chitosan-based nanocarriers have been utilized to enhance the bio-availability and neuroprotective effect of FTY720. The neuroprotective effect of characterized nanoformulation was determined by the downregulation of PD hallmark phospho-serine 129 (pSer129) α-Syn, with anti-oxidative and anti-inflammatory potentials. The neuroprotective mechanism uncovered novel physical interaction of PP2A and polycomb group of protein Enhancer of zeste homolog 2 to mediate ubiquitination and degradation of agglomerated pSer129 α-Syn. Indeed, this study establishes the neuroprotective potential of chitosan based FTY720 nanoformulations by PP2A mediated epigenetic regulation for PD prevention.

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 (Emax ) 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 Emax 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 Emax curves. Therefore, ΔΔQTcP is predicted to remain below 10 msec at the supratherapeutic concentrations of the major active metabolites.

Ponesimod for the treatment of relapsing multiple sclerosis.

INTRODUCTION: Multiple Sclerosis (MS) is an immune-mediated, complex, chronic inflammatory, and neurodegenerative disease of the central nervous system. Among the several therapeutic options developed over the last decade for relapsing MS (RMS), fingolimod, a sphingosine 1-phosphate receptor (S1PR) modulator, was the first oral treatment. The adverse events associated with fingolimod have limited its use in certain populations, thus further stimulating the search for other S1PR modulators. AREAS COVERED: The authors reviewed the English-published literature on ponesimod using the PubMed database. The search terms used were 'ponesimod' or 'ACT-128,800' and 'multiple sclerosis.' Available data on the pharmacological profile of ponesimod and the information on clinical efficacy and safety drawn from clinical trials in comparison with other S1PR modulators are presented and discussed. EXPERT OPINION: Published peer-reviewed data on long-term safety and efficacy are still lacking but have been collected and regulatory authorities expressed a favorable opinion to market access. At present, we believe that ponesimod has little chance of becoming a leading treatment for RMS due to the availability of many alternative options and the timing of market access. Given its favorable risk-benefit and convenience profile, however, ponesimod might become a leading option among S1P receptor modulators used for RMS.

Effect of the sphingosine-1-phosphate receptor modulator ozanimod on leukocyte subtypes in relapsing MS.

OBJECTIVE: To better understand ozanimod's mechanism of action (MOA), we conducted exploratory analyses from a phase 1 study to characterize ozanimod's effect on circulating leukocyte subsets in patients with relapsing multiple sclerosis. METHODS: An open-label pharmacodynamic study randomized patients to oral ozanimod hydrochloride (HCl) 0.5 (n = 13) or 1 mg/d (n = 11) for ∼12 weeks (including 7-day dose escalation). Circulating leukocyte subsets were quantified using flow cytometry (days 28, 56, and 85) and epigenetic cell counting (days 2, 5, 28, 56, and 85) and compared with baseline (day 1) using descriptive statistics. RESULTS: Ozanimod caused dose-dependent reductions in absolute lymphocyte counts. Observed by both methodologies, circulating CD19+ B- and CD3+ T-cell counts were reduced by >50% with ozanimod HCl 0.5 mg and >75% with 1 mg at day 85. Based on flow cytometry, ozanimod HCl 1 mg showed greater decreases in CD4+ than CD8+ T cells, greater decreases in both CD4+ and CD8+ central memory vs effector memory T cells, and reductions in mean CD4+ and CD8+ naive T cells by ≥90% at day 85. In the flow cytometry analysis, changes in monocytes, natural killer, and natural killer T cells were minimal. Using epigenetic cell counting, greater reductions for Th17 than T regulatory cells were determined. CONCLUSION: Ozanimod induced dose-dependent reductions in circulating B- and T-cell counts and differential effects on naive and memory CD4+ and CD8+ T cells and CD19+ B cells. Data characterized with both a novel epigenetic cell-counting method and flow cytometry support ozanimod's MOA. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov NCT02797015.

Bioequivalence Study of 2 Capsule Formulations of Fingolimod 0.5 mg Assessing Both Parent Drug and Active Metabolite in New Zealand Healthy Subjects (Truncated Design).

Fingolimod is indicated for the treatment of patients with the relapsing-remitting form of multiple sclerosis. The primary study objective was to evaluate the bioequivalence of a test formulation, 0.5 mg fingolimod HCl capsule (Lebrina, Asofarma Sociedad Anónima Industrial y Comercial, Argentina) relative to a reference formulation, 0.5 mg fingolimod capsule (Gilenya, Novartis Pharmaceutical, Australia). In a single-center, randomized, single-dose, single-blinded, 2-way crossover study, 33 New Zealand healthy subjects of both sexes were enrolled to receive a 0.5-mg dose of 3 capsules of each fingolimod formulation under fasting conditions, with a 42-day washout period between administrations. Additional pharmacokinetic information regarding its main active metabolite, fingolimod phosphate, was also provided. The point estimate and 90% confidence intervals of the ratios of maximum concentration and area under the plasma concentration-time curve from time 0 to 72 hours were 99.07 (95.83-102.41) and 97.64 (95.33-100.00) for fingolimod, and 95.60 (90.95-100.49) and 98.54 (96.19-100.96), for fingolimod phosphate. Primary parameters, maximum concentration and area under the plasma concentration-time curve from time 0 to 72 hours for fingolimod and fingolimod phosphate were found to have no significant difference when test and reference formulations were compared. Fingolimod and fingolimod phosphate of both formulations were within the accepted 90% confidence interval limits of 80.00% and 125.00%. No significant differences between the test and reference drug products were detected in any of the pharmacokinetic parameters estimated. Notwithstanding the primary conclusion of bioequivalence is focused on the measurement of the parent compound, compliance with the same criteria by the active metabolite reinforces the comparability between the pharmacokinetic profiles of both formulations (ClinicalTrials.gov Identifier: NCT03757338).

Safety, Tolerability, Pharmacodynamics and Pharmacokinetics of Intravenous Siponimod: A Randomized, Open-label Study in Healthy Subjects.

PURPOSE: The goal of this study was to assess the safety, tolerability, pharmacodynamics (PD) and pharmacokinetics (PK) of intravenous (IV) siponimod in healthy subjects. METHODS: This randomized, open-label study was conducted in 2 parts. In Part 1, a total of 16 eligible subjects received either a single oral dose of siponimod (0.25 mg) followed by a single IV infusion (0.25 mg/3 h) in Sequence 1, or vice versa in Sequence 2. In Part 2, a total of 17 eligible subjects received single IV infusions of siponimod (1 mg/24 h). FINDINGS: No clinically relevant effect on mean 5-minute or hourly average heart rate was observed following the siponimod IV dosing regimens and both remained above 50 beats/min. Observed atrioventricular blocks and sinus pauses were asymptomatic. The mean change in absolute lymphocyte count from baseline was comparable for the siponimod 0.25 mg oral regimen and the two IV siponimod regimens. Oral siponimod displayed a good absolute bioavailability of 84%. The mean peak exposure of oral siponimod was approximately 48% lower than that of IV siponimod. The M17 metabolite was found to be the most prominent systemic metabolite of siponimod in humans. IMPLICATIONS: Siponimod IV infusions were well tolerated, with safety and PD (absolute lymphocyte count) profiles similar to those of oral siponimod. The PD/PK findings supported the development of an innovative rapid IV titration regimen for patients with intracerebral hemorrhage.

Siponimod pharmacokinetics, safety, and tolerability in combination with the potent CYP3A4 inhibitor itraconazole in healthy subjects with different CYP2C9 genotypes.

PURPOSE: To evaluate the PK and safety of siponimod, a substrate of CYP2C9/3A4, in the presence or absence of a CYP3A4 inhibitor, itraconazole. METHODS: This was an open-label study in healthy subjects (aged 18-50 years; genotype: CYP2C9 *1*2 [cohort 1; n = 17] or *1*3 [cohort 2; n = 13]). Subjects received siponimod 0.25-mg single dose in treatment period 1 (days 1-14), itraconazole 100 mg twice daily in treatment period 2 (days 15-18), and siponimod 0.25-mg single dose (day 19) with itraconazole until day 31 (cohort 1) or day 35 (cohort 2) in treatment period 3. PK of siponimod alone and with itraconazole and safety were assessed. RESULTS: Overall, 29/30 subjects completed the study. In treatment period 1, geometric mean AUCinf, T1/2, and median Tmax were higher while systemic clearance was lower in cohort 2 than cohort 1. In treatment period 3, siponimod AUC decreased by 10% (geo-mean ratio [90% confidence intervals]: 0.90 [0.84; 0.96]) and 24% (0.76 [0.69; 0.82]) in cohorts 1 and 2, respectively. Siponimod Cmax was similar between treatment periods 1 and 3. In both cohorts, the Cmax and AUC of the metabolites (M17, M3, and M5) decreased in the presence of itraconazole. All adverse events were mild. CONCLUSIONS: The minor albeit significant reduction in plasma exposure of siponimod and its metabolites by itraconazole was unexpected. While the reason is unclear, the results suggest that coadministration of the two drugs would not cause a considerable increase of siponimod exposure independent of CYP2C9 genotype.

Cardiodynamic Interactions between Two S1P1 Receptor Modulators in an Experimental Clinical Setting: Different Pharmacokinetic Properties as an Opportunity to Mitigate First-Dose Heart Rate Effects.

A decrease in heart rate (HR) is a well-established first-dose effect of sphingosine-1-phosphate subtype 1 receptor (S1P1R) modulators. For compounds with a short half-life (t1/2), this can be mitigated by gradual up-titration to therapeutic doses, whereas this is not required for compounds with a long t1/2 due to the less pronounced first-dose-related negative chronotropic effects. Based on this conceptual framework, this mechanistic study investigated whether first-dose HR effects of ponesimod (t1/2 ~32 h) can be mitigated by prior administration of cenerimod (t1/2 ~415 h). Healthy subjects (n = 12) were randomly assigned to active or placebo (2:1 ratio). Active treatment consisted of a single dose of 10 mg ponesimod on Day 1, 18, and 37 and multiple-dose administration of 2 mg once daily cenerimod (Day 9-36). Placebos of cenerimod and ponesimod were used as reference treatment. Cardiodynamic parameters were derived from 24 h Holter electrocardiogram (ECG) assessments on Day 1, 9, 10, 18, 36, and 37. Ponesimod (10 mg) alone triggered a transient mean decrease from baseline in hourly mean HR of 17 bpm. In contrast, decreases of 5.0 and 4.8 bpm were observed when ponesimod was given at near half steady-state (Day 18) or steady-state (Day 37) cenerimod, respectively. Hourly mean HR decreased after first administration of cenerimod and placebo was 7.4 and 4.0 bpm, respectively. Treatment with ponesimod and cenerimod alone or in combination was safe and tolerated. First-dose-related negative chronotropic effects of ponesimod were less pronounced when administered after initiation of cenerimod suggesting mitigation of this class-related liability.

Effect of Fluconazole Coadministration and CYP2C9 Genetic Polymorphism on Siponimod Pharmacokinetics in Healthy Subjects.

OBJECTIVES: The aim of this study was to assess the pharmacokinetics (PK) and safety/tolerability of siponimod in healthy subjects when coadministered with (1) the moderate cytochrome P450 (CYP) 2C9 and CYP3A inhibitor fluconazole (Study A), and (2) with three different CYP2C9 genotype variants (Study B). METHODS: Study A was an open-label, single-dose study comprising periods 1 (14 days; day 1: siponimod 4 mg) and 2 (20 days; day 1: fluconazole 200 mg twice daily; days 2-19: fluconazole 200 mg once daily; day 3: siponimod 4 mg) in healthy subjects (n = 14) with the wild-type CYP2C9 genotype (CYP2C9*1/*1). Study B was a multicentre, open-label study comprising parts 1 (day 1: siponimod 0.25 mg once daily in the CYP2C9*1/*1, CYP2C9*2/*3 and CYP2C9*3/*3 genotypes) and 2 (days 1-2: 0.25 mg once daily; day 3: 0.5 mg once daily in the CYP2C9*2/*3 and CYP2C9*3/*3 genotypes only) in healthy subjects with polymorphic variants of CYP2C9 (n = 24). Pharmacokinetic parameters were calculated using noncompartmental methods. RESULTS: In Study A, coadministration with fluconazole produced an approximately twofold increase in mean area under the curve (AUC) versus siponimod alone (from 1110 to 2160 h*ng/mL), and an increase in maximum plasma concentration (Cmax; from 31.2 to 34.0 ng/mL) and elimination half-life (T½; from 40.6 to 61.6 h). In Study B, the AUCs of siponimod were approximately two to fourfold greater in subjects with the CYP2C9*2/*3 and CYP2C9*3/*3 genotypes, with a minor increase in Cmax versus the CYP2C9*1/*1 genotype. The mean T½ was prolonged in the CYP2C9*2/*3 (51 h) and CYP2C9*3/*3 (126 h) genotypes versus the CYP2C9*1/*1 (28 h) genotype. Siponimod did not result in increased adverse events in healthy subjects in both studies. CONCLUSIONS: Changes in siponimod PK, when coadministered with fluconazole at steady-state and in subjects with different CYP2C9 genotypes, indicate that the reduced CYP2C9 enzymatic activity does not affect the absorption phase of siponimod but prolongs the elimination phase. These results confirm the relevance of CYP2C9 activity on siponimod metabolism in humans.