Primary Pharmacokinetic Parameters Research Articles

Bioequivalence of Oseltamivir Phosphate 6 mg/mL Powder for Oral Suspension Formulations in Healthy Thai Volunteers under Fasting Conditions

Oseltamivir is an oral antiviral of choice indicated for treatment and prophylaxis of influenza A and B infections. Oseltamivir is an inactive prodrug of oseltamivir carboxylate, an active form exerting antiviral activity. Oseltamivir oral suspension is an alternative formulation for pediatric patients or adults with dysphagia. GPO-A-FLU ® , oseltamivir 6 mg/mL powder for oral suspension had been developed as a generic substitute for reference product, Tamiflu ® oral suspension. In this study, we investigated the pharmacokinetics and bioequivalence of the test oral suspension oseltamivir formulation with respect to the corresponding reference oral suspension formulation. A comparative open-label, randomized, single dose, two-way crossover study was conducted under fasting conditions. Blood samples were collected for 24 hours post-dose and the plasma was separated for oseltamivir assay using a validated liquid chromatography-mass spectrometry method. The pharmacokinetic parameters were determined from plasma concentration-time profiles after administration of the test and reference formulations. The pharmacokinetic parameters were in agreement with the previously published data. The primary pharmacokinetic parameters: AUC 0−tlast , AUC 0−  and C max obtained from 47 subjects who completed the study were statistically compared. The 90% confidence intervals of geometric least squares mean ratio (test/reference) for log-transformed parameters were within 80.00-125.00% of bioequivalence criteria: 92.33-98.52% for AUC 0−tlast , 92.28- 98.43% for AUC 0−  , and 81.82-94.26% for C max . Both products were generally well tolerated by healthy Thai subjects. This study successfully demonstrated bioequivalence between GPO-A-FLU ® and Tamiflu ® , and supported product registration.

Comparative Bioequivalence Studies of Two Metformin Extended- Release Formulations in Healthy Thai Volunteers

Metformin is a first-line treatment for type 2 diabetic mellitus commonly used as a monotherapy or in a combination with other antidiabetic drugs. To control blood glucose levels, patients should be able to access to the treatment continuously. Thus, the Government Pharmaceutical Organization (GPO) had developed a generic metformin extended-release formulation as a low-cost alternative for patients and physicians. Two bioequivalence studies were conducted under fasting and fed conditions to compare the rate and extent of absorption between the test (Metformin XR 1000 mg) and reference (Glucophage XR 1000 mg) formulations. The study design for both studies was comparative randomized, open-label, single-dose, two-way crossover. Twenty-four subjects and fourteen eligible subjects were enrolled in the single-dose fasting and fed studies, respectively. Plasma concentrations of metformin were determined using a validated liquid chromatography tandem mass spectrometry method. The primary pharmacokinetics parameters including AUC 0-tlast , AUC 0−∞ and C max were statistically compared. The 90% confidence intervals of the geometric least squares mean ratio of log-transformed AUC 0-tlast , AUC 0−∞ and C max between the formulations were within 80.00-125.00% of bioequivalence criteria for both fasting and fed studies. The pharmacokinetic parameters following oral administration under fasting and fed conditions were comparable suggesting insignificant food effect on the absorption. The safety of metformin extended-release formulations was evaluated in healthy Thai subject. The test and reference products were well tolerated by the study subjects and no serious adverse events were reported in both studies. Based on the statistical indices, it was concluded that two metformin extended-release formulations were bioequivalent.

Pharmacokinetics and Pharmacodynamics of a Proposed Pegfilgrastim Biosimilar MSB11455 Versus the Reference Pegfilgrastim Neulasta in Healthy Subjects: A Randomized, Double-blind Trial

PurposeMSB11455 is a proposed biosimilar to the reference pegfilgrastim (Neulasta®). This pivotal equivalence study (NCT03251248) assessed the pharmacokinetic and pharmacodynamic equivalence of MSB11455 to the reference product. MethodsThis 2-way, 2-sequence, group-sequential, crossover study was conducted in healthy subjects. Subjects received a single subcutaneous dose of MSB11455 or the reference product (both 6 mg/0.6 mL) on Day 1 of each study period. Pharmacokinetic and pharmacodynamic (absolute neutrophil count; ANC) samples were taken predose and up to day 16 post-dose. Non-compartmental parameters were calculated. Immunogenicity samples were taken pre-dose and up to day 84 after the first dose. Safety was assessed throughout the study. FindingsA total of 292 subjects were randomized to therapy and treated; 244 received both treatments. For all primary pharmacokinetic and pharmacodynamic parameters, 90% repeated confidence intervals of geometric means ratio of MSB11455 to the reference product were within the pre-defined equivalence range (80.00%–125.00%) for AUC0-∞ (96.59–112.82); AUC0–last (97.29–113.96), Cmax (97.13–114.99), maximum observed effect on ANC (98.74–102.39), and area under the effect–time curve from time zero to time to last quantifiable concentration (97.30–100.23). Safety, tolerability, and immunogenicity were comparable between treatments. No filgrastim-specific neutralizing antibodies were detected with either treatment sequence. ImplicationsPharmacokinetic and pharmacodynamic equivalence of MSB11455 and the reference product was shown, with comparable immunogenicity, safety, and tolerability between treatments. The study supports the biosimilarity of MSB11455 to the reference product. ClinicalTrials.gov identifier: NCT03251248.

Pharmacokinetic similarity demonstrated after crushing of the elbasvir/grazoprevir fixed-dose combination tablet for HCV infection.

BackgroundFinding a suitable treatment for HCV patients with swallowing disorders is still a major challenge. In practice, direct-acting antivirals are crushed without knowledge of adequate absorption. Crushing can alter drug exposure, possibly leading to treatment failure, development of resistance or toxicity. Currently, there is no information about crushing of the fixed-dose combination tablet of elbasvir/grazoprevir; therefore, crushing of this tablet is not recommended.ObjectivesTo investigate the influence of crushing on the pharmacokinetics of the elbasvir/grazoprevir fixed-dose combination tablet.MethodsWe conducted an open-label, two-period, randomized, cross-over, Phase I, single-dose trial in 11 healthy adult volunteers. Subjects randomly received whole-tablet elbasvir/grazoprevir or crushed and suspended elbasvir/grazoprevir in a fasted state. Pharmacokinetic similarity criteria (90% CIs lie within 70%–143% acceptance range) were used for AUC0–∞ and AUC0–72.ResultsMean plasma concentration–time curves of elbasvir and grazoprevir showed similar pharmacokinetic profiles. The primary pharmacokinetic parameters AUC0–∞ and AUC0–72 of elbasvir and grazoprevir after intake of a crushed tablet were on average 12%–16% higher compared with the whole tablet, but 90% CIs were all within the predefined boundaries of pharmacokinetic similarity. Crushing leads to a higher Cmax of grazoprevir (42%); no significant difference was found between treatments with regard to the Cmax of elbasvir. No serious adverse events were reported during the trial.ConclusionsPharmacokinetic similarity could be demonstrated for a crushed and suspended tablet compared with a whole tablet, without impacting drug safety or efficacy. Crushed and suspended administration of elbasvir/grazoprevir can be used in patients with swallowing disorders.

Population Pharmacokinetic Analysis and Exploratory Exposure-Bleeding Rate Relationship of Emicizumab in Adult and Pediatric Persons with Hemophilia A.

BackgroundEmicizumab is a bispecific monoclonal antibody developed for routine prophylaxis of bleeding in people with hemophilia A (PwHA). This work characterizes the pharmacokinetics of emicizumab in adult and pediatric PwHA, identifies factors contributing to its between-person variabilities, compares the pharmacokinetics following different dosing regimens, and makes a descriptive assessment of the exposure–bleeding events relationship.MethodsA population pharmacokinetic model was developed, using a database of 389 PwHA from five clinical studies. Potential baseline covariate effects were assessed, including body size, age, race, presence of factor VIII inhibitors, and albumin levels. Using the population pharmacokinetic model, the estimated individual average exposures over the administration period were compared across categories of annualized bleeding rate.ResultsA linear one-compartment model with first-order absorption and elimination processes and no lag time best described the emicizumab pharmacokinetics. Body weight, albumin levels, age, and black race were statistically correlated with primary pharmacokinetic parameters, but only body weight had an important influence on exposure. Dosing regimens of 1.5 mg/kg weekly, 3 mg/kg every 2 weeks, or 6 mg/kg every 4 weeks provided similar average concentrations at steady state. A trend for lower exposure was observed in the small proportion of PwHA having an annualized bleeding rate > 4 (11.9%), suggesting that reducing exposure to lower levels may potentially increase the bleeding risk.ConclusionsEmicizumab pharmacokinetics in PwHA was described with dose-independent parameters. Body weight was an important predictor of emicizumab pharmacokinetics. All three dosing regimens are predicted to achieve similar exposure associated with clinically meaningful prevention of bleeding.Electronic supplementary materialThe online version of this article (10.1007/s40262-020-00904-z) contains supplementary material, which is available to authorized users.

Physiologically Based Dissolution Testing in a Drug Development Process\u2014a Case Study of a Successful Application in a Bioequivalence Study of Trazodone ER Formulations Under Fed Conditions

Development of generic extended-release (ER) formulations is challenging. Especially under fed conditions, the risk of failure in bioequivalence trials is high because of long gastric residence times and susceptibility to food effects. We describe the development of a generic trazodone ER formulation that was aided with a biorelevant dissolution evaluation. Trazodone hydrochloride 300-mg monolithic matrix tablets were dissolved both in USP and EMA compliant conditions and in the StressTest device that simulated both physicochemical and mechanical conditions of the gastrointestinal passage. The final formulation was tested against the originator, Trittico XR 300 mg, in a randomized cross-over bioequivalence trial with 44 healthy volunteers, in agreement with EMA guidelines. Initially developed formulations dissolved trazodone similarly to the originator under standard conditions (f2 factor above 50), but their dissolution kinetics differed significantly in the biorelevant tests. The formulation was optimized by the addition of low-viscosity hypromellose and mannitol. The final formulation was approved for the bioequivalence trial. Calculated Cmax were 1.92 ± 0.77 and 1.92 ± 0.63 [μg/mL], AUC0-t were 27.46 ± 8.39 and 29.96 ± 9.09 [μg∙h/mL], and AUC0-∞ were 28.22 ± 8.91 and 30.82 ± 9.41 [μg∙h/mL] for the originator and test formulations, respectively. The 90% confidence intervals of all primary pharmacokinetic parameters fell within the 80–125% range. In summary, biorelevant dissolution tests supported successful development of a generic trazodone ER formulation pharmaceutically equivalent with the originator under fed conditions. Employment of biorelevant dissolution tests may decrease the risk of failure in bioequivalence trials of ER formulations.

Intravenous immunoglobulin significantly reduces exposure of concomitantly administered anti-C5 monoclonal antibody tesidolumab.

Awareness of drug-drug interactions is critical in organ transplant recipient management. However, biologic agents interfering with monoclonal antibodies is not widely considered. We report the effect of high-dose intravenous immunoglobulin (IVIg) on safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of the human anti-C5 monoclonal antibody tesidolumab (LFG316) in end-stage renal disease patients awaiting kidney transplant. In this single-center, phase 1, open-label, parallel-group study, 8 patients were assigned to receive either single-dose tesidolumab+IVIg or tesidolumab alone, with 56-day follow-up. Within-group PK parameters were consistent. Mean tesidolumab exposure decreased 34%, clearance increased 63%, and half-life decreased 41% comparing tesidolumab+IVIg to tesidolumab alone. IVIg influence on tesidolumab elimination was most evident in the first 3weeks. Complete suppression of both total and alternative complement activities was maintained for 4weeks in the tesidolumab alone group and for 2weeks in the tesidolumab+IVIg group. Tesidolumab was well tolerated. IVIg infused before tesidolumab affected tesidolumab PK and PD, resulting in a shortened period of full complement activity inhibition. These findings suggest a clinically relevant impact of IVIg on monoclonal antibody clearance and indirectly hint at an IVIg mechanism of action in treating autoimmune diseases and allosensitization by accelerating pathogenic IgG antibody degradation. Trial registration number: NCT02878616.

Abstract P5-14-16: Pharmacokinetics/pharmacodynamics of Sandoz biosimilar pegfilgrastim compared to both US- and EU-reference pegfilgrastim: A meta-analysis of three clinical studies in healthy subjects

Abstract Background. To further evaluate the pharmacokinetics (PK) and pharmacodynamics (PD) of Sandoz biosimilar, US-reference and EU-reference pegfilgrastim, a meta-analysis was conducted using data from three Phase I studies. Methods. All studies were single-dose, double-blind, randomized trials. The first was a three arm parallel-group study, the second a two-way crossover study, and the third a three-way crossover study. Healthy subjects were randomized to receive Sandoz biosimilar pegfilgrastim (all studies), US-reference (studies 1 and 3) or EU-reference (all studies). For each primary PK and primary PD (non-baseline corrected) parameter, geometric mean ratios and 90% confidence intervals (CIs) for the treatment comparisons were calculated using a meta-analysis approach with a fixed-effect model. PK/PD similarity was considered confirmed if the calculated 90% CIs of the ratios were within the pre-defined similarity margins of 0.8–1.25. Results. This meta-analysis showed that the 90% CIs of the geometric mean ratios (Sandoz biosimilar vs. US-reference, Sandoz biosimilar vs. EU-reference, and US- vs. EU-reference pegfilgrastims) of the primary PK parameters and primary PD parameters (see Table 1) were contained within the pre-defined similarity margins of 0.80–1.25, confirming PK/PD similarity for all pairwise comparisons. Safety and tolerability were similar between Sandoz biosimilar, US- and EU-reference biologic in healthy subjects. Conclusions. This is the first meta-analysis combining data from three Phase I studies to confirm PK/PD similarity of Sandoz biosimilar to US- and EU-reference pegfilgrastim, and PK/PD similarity between US- vs. EU-reference pegfilgrastim. No clinically meaningful differences in safety or tolerability were observed. Table 1. Results of the meta-analysis combining PK and PD data obtained with Sandoz biosimilar pegfilgrastim, US-reference pegfilgrastim, and EU-reference pegfilgrastim in healthy subjects included in three clinical studies.ParameterSandoz biosimilar vs. US-reference pegfilgrastimSandoz biosimilar vs. EU-reference pegfilgrastimEU-reference vs. US-reference pegfilgrastimGeometric mean ratio90% CIGeometric mean ratio90% CIGeometric mean ratio90% CILowerUpperLowerUpperLowerUpperPrimary PK parameters using pegfilgrastim serum concentrationsAUC0-last (h*ng/mL)1.06851.01501.12481.07891.03401.12560.98260.93331.0344AUC0-inf (h*ng/mL)1.07041.01841.12511.07511.03171.12040.97940.93181.0294Cmax (ng/mL)1.05161.00141.10431.05151.00981.09500.97590.92911.0250Primary PD parameters using Absolute Neutrophil CountAUEC0-last (h*109/L)0.99930.99091.00781.00430.99711.01151.00210.99371.0105Emax (109/L)0.99760.98681.00851.00350.99431.01271.00900.99811.0201Study one: n=277 (three-arm parallel group study: 93 for biosimilar, 93 for EU-reference pegfilgrastim, and 91 for US-reference)Study two: n=169 (two-way crossover study)Study three: n=496 (three-way crossover study)AUC0-inf, area under the serum concentration–time curve measured from time of dosing and extrapolated to infinity; AUC0-last, area under the serum concentration–time curve measured from time of dosing extrapolated to the last measurable concentration; CI, confidence interval; Cmax, maximum serum concentration; AUEC0-last, area under the effect curve using absolute neutrophil counts over time; Emax, maximum effect attributable to the therapy under investigation; n, number of subjects in study; PD, pharmacodynamic; PK, pharmacokinetic. Citation Format: Roumen Nakov, Jessie Wang, Anne Bellon, Sreekanth Gattu, Ramin Arani. Pharmacokinetics/pharmacodynamics of Sandoz biosimilar pegfilgrastim compared to both US- and EU-reference pegfilgrastim: A meta-analysis of three clinical studies in healthy subjects [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-14-16.

A phase 1, randomized, open-label, single-dose study to assess the relative bioavailability of a subcutaneous dose of FKB327 when administered using a prefilled syringe, a prefilled auto-injector, or a vial with disposable syringe in healthy subjects

Background/objectiveFKB327 is a biosimilar of the adalimumab reference product (RP). The primary objective was to assess the relative bioavailability of FKB327 after a single subcutaneous (SC) dose via prefilled syringe (PFS), auto-injector (AI), or vial with a disposable syringe (vial), in healthy subjects.MethodsThis randomized, open-label, parallel-group, single SC-dose study was conducted in 195 healthy male and female subjects who were randomized 1:1:1 to receive FKB327 40 mg via PFS, AI, or vial. The primary pharmacokinetic (PK) parameters, areas under the serum concentration-time curve to the last detectable value (AUC0-t) and extrapolated to infinity (AUC0-∞), and maximum concentration (Cmax), were compared. Relative bioavailability was established if the ratio of geometric least squares (LS) means of the test product was within the predefined bioequivalence (BE) range of 0.80 to 1.25 of the RP for each comparison. Safety and immunogenicity were assessed.ResultsThe mean serum FKB327 concentration-time profiles appeared similar across all 3 presentations. AUC0-t, AUC0-∞, and Cmax were within the predefined BE range for PFS compared with vial, suggesting comparable bioavailability. AUC0-∞ and Cmax of AI compared with vial and PFS were fully contained within BE range, although the upper limit of 90% confidence intervals of the geometric LS means ratios for AUC0-t was slightly high. Treatment-emergent adverse events in all 3 groups were mild, with no new safety concern with FKB327 identified. Similar immunogenicity was observed among administrations.ConclusionAmong all 3 delivery methods, PK characteristics, safety profiles, and immunogenicity were similar.Trial registrationEU Clinical Trials Registry EudraCTN2014–004469-26, registered October 14, 2014.

Relationship between Pharmacokinetics and Antidrug Antibody Status of ABP 959, a Biosimilar Candidate to Eculizumab: Results from a Pharmacokinetic Similarity Study

Background: ABP 959 is being developed as a biosimilar to eculizumab, a recombinant humanized IgG2/4 chimeric monoclonal antibody that binds to the human C5 complement protein (C5), thereby inhibiting the complement cascade. Eculizumab is indicated for the treatment of patients with paroxysmal nocturnal hemoglobinuria (PNH), generalized myasthenia gravis (gMG), atypical hemolytic uremic syndrome (aHUS), and neuromyelitis optica spectrum disorder (NMOSD). ABP 959 has demonstrated pharmacokinetic (PK) and pharmacodynamic (PD) similarity to eculizumab reference product (RP) in healthy male subjects (Chow et al., EHA 2019). Treatment with eculizumab can result in the development of anti-drug antibodies (ADAs), which may lead to loss of clinical efficacy; therefore, evaluating the incidence of ADAs and assessing their relationship to PK parameters is important. Objectives: To assess the relationship between PK parameters and ADAs for ABP 959 and eculizumab RP. Methods: This was a randomized, double-blind, single-dose, 3-arm, parallel-group study in healthy adult male subjects, between 18 to 45 years of age, with a body mass index of 18 to 30.0 kg/m2, who were randomized to receive a 300 mg IV infusion of ABP 959, FDA-licensed eculizumab (eculizumab US), or EU-authorized eculizumab (eculizumab EU). Serum samples for PK evaluations were collected over 57 days. A primary objective of the study was to demonstrate PK equivalence of ABP 959 versus eculizumab RP, as assessed by area under the total serum concentration-time curve (AUC) from time 0 extrapolated to infinity (AUCinf). Secondary PK endpoints included AUC from time 0 to the time of the last observed quantifiable concentration (AUClast) and maximum observed concentration (Cmax). The pre-specified equivalence criterion for the primary PK parameters was a 90% confidence interval (CI) for the geometric means ratio (GMR) within 0.80 to 1.25, for ABP 959 versus eculizumab US and ABP 959 versus eculizumab EU comparisons. Immunogenicity assessment was a secondary endpoint of the study. Sensitivity analysis of the PK primary endpoint was performed for the binding ADA-negative and neutralizing ADA-negative subjects, with the point estimates and 90% CIs for test-to-reference GMR calculated for PK parameters (AUCinf, AUClast, and Cmax) for total eculizumab and total ABP 959. Samples for ADA assessments were collected predose on Day 1, Day 11, Day 29, and at the end of study (EOS) Visit (Day 57) or upon early study discontinuation. Results: A total of 219 subjects were enrolled (ABP 959, n=71; eculizumab US, n=74; eculizumab EU, n=74); overall, 19 (8.8%) subjects had positive binding ADAs over the course of the study. At any time during the study, the incidence of binding ADAs across treatments was: ABP 959, n=7 (9.9%); eculizumab US, n=5 (6.9%); and eculizumab EU, n=7 (9.5%). At EOS, 4 (1.9%) subjects had positive binding ADAs (ABP 959, n=1 [1.4%]; eculizumab US, n=2 [2.9%]; and eculizumab EU, n=1 [1.4%]). In these subjects, their PK or exposure was within the same range as ADA-negative subjects. In binding ADA-negative subjects, the 90% CIs for the adjusted least square GMRs for all comparisons were within the bioequivalence range of 0.80 to 1.25. No subjects developed neutralizing antibodies throughout the study. Conclusions: The incidence of ADAs was similar between ABP 959 and eculizumab RP and did not impact the overall PK similarity assessment. Disclosures Hanes: Amgen Inc.: Employment. Pan:Amgen Inc.: Employment. Mytych:Amgen Inc.: Employment. Chien:Amgen Inc.: Employment. Chow:Amgen Inc.: Employment.

The pharmacokinetics of 3-fluoroamphetamine following delivery using clinically relevant routes of administration.

3-Fluoroamphetamine (also called PAL-353) is a synthetic amphetamine analog that has been investigated for cocaine use disorder (CUD), yet no studies have characterized its pharmacokinetics (PK). In the present study, we determined the PK of PAL-353 in male Sprague Dawley rats following intravenous bolus injection (5 mg/kg). Plasma samples were analyzed using a novel bioanalytical method that coupled liquid-liquid extraction and LC-MS/MS. The primary PK parameters determined by WinNonlin were a C0 (ng/mL) of 1412.09 ± 196.12 and a plasma half-life of 2.27 ± 0.67 h. As transdermal delivery may be an optimal approach to delivering PAL-353 for CUD, we assessed its PK profile following application of 50 mg of transdermal gel (10% w/w drug over 5 cm2). The 10% w/w gel resulted in a short lag time, sustained delivery, and a rapid clearance in plasma immediately after removal. The rodent PK data were verified by examining in vitro permeation through human epidermis mounted on Franz diffusion cells. An in vitro-in vivo correlation (IVIVC) analysis was performed using the Phoenix IVIVC toolkit to assess the predictive relationship between rodent and human skin absorption/permeation. The in vitro permeation study revealed a dose-proportional cumulative and steady-state flux with ~ 70% of drug permeated. The fraction absorbed in vivo and fraction permeated in vitro showed a linear relationship. In conclusion, we have characterized the PK profile of PAL-353, demonstrated that it has favorable PK properties for transdermal administration for CUD, and provided preliminary evidence of the capacity of rodent data to predict human skin flux.

1815P - Randomized, double-blind, cross-over phase I study comparing pharmacokinetics, pharmacodynamics, safety and immunogenicity of a biosimilar pegfilgrastim with EU and US references

BackgroundThe pharmacokinetic (PK)/pharmacodynamic (PD), safety and immunogenicity profiles of Sandoz biosimilar pegfilgrastim (Ziextenzo®) and EU reference pegfilgrastim were shown to be similar in a pivotal phase I study. Similarity of efficacy and safety to the reference was demonstrated in two phase III studies in breast cancer patients receiving myelosuppressive chemotherapy. This 3-way study aimed to confirm similarity of PK/PD, safety and immunogenicity to US reference pegfilgrastim, and to bridge between the EU and US reference medicines. MethodsThis randomized, double-blind, 3-treatment, 6-sequence crossover phase I study included healthy volunteers (HVs) administered pegfilgrastim (biosimilar, EU reference, or US reference) once per treatment period. Primary objectives were to demonstrate PK similarity in AUC0-inf, AUC0-last and Cmax, and PD similarity in ANC AUEC0-last and ANC Emax. The study was powered (90%) to achieve confidence intervals within biosimilarity margins 0.8–1.25 in pairwise comparisons (biosimilar vs US reference, biosimilar vs EU reference, and US reference vs EU reference). Secondary objectives were safety, immunogenicity and additional PK/PD parameters. ResultsThe study included 577 male and female HVs. PK and PD similarity were demonstrated for primary PK and PD parameters between Sandoz biosimilar, US reference, and EU reference (Table). The safety profile of Sandoz biosimilar pegfilgrastim was similar across groups. Incidence of antidrug antibodies was similar across groups (biosimilar: 31/512 [6.1%]; US reference: 36/511 [7.0%]; EU reference: 39/501 [7.8%]). Secondary PK/PD parameters were also similar.Table1815P Summary of PK and PD similarityTableRatioCI 90%Biosimilar / US-referenceAUC0-last1.06351.0087, 1.1213AUEC0-last0.99970.9912, 1.0082Biosimilar / EU-referenceAUC0-last1.04690.9929, 1.1038AUEC0-last1.00120.9927, 1.0098US-reference / EU-referenceAUC0-last0.98440.9336, 1.0380AUEC0-last1.00150.9930, 1.0101 ConclusionsSandoz biosimilar demonstrated similar PK/PD, safety, tolerability and immunogenicity to US reference and EU reference pegfilgrastim in this large 3-way crossover phase I study. Clinical trial identificationEudraCT: 2016-003549-27. Editorial acknowledgementCaroline McGown of Spirit Medical Communications Ltd, supported by Hexal AG. Legal entity responsible for the studyHexal AG. FundingHexal AG. DisclosureM. Velinova: Full / Part-time employment: PRA; Honoraria (self), compensation as lead Principal Investigator in the study: Sandoz Biopharmaceuticals. A. Bellon: Full / Part-time employment: Hexal AG. R. Nakov: Full / Part-time employment: Hexal AG. S. Schussler: Full / Part-time employment: Sandoz Inc. S. Schier-Mumzhiu: Full / Part-time employment: Hexal AG. C. Schelcher: Full / Part-time employment: Hexal AG. S.D. Koch: Full / Part-time employment: Hexal AG. A. Skerjanec: Full / Part-time employment: Novartis. J. Wang: Full / Part-time employment: Sandoz Inc. A. Krendyukov: Full / Part-time employment: Hexal AG. G.P. Otto: Full / Part-time employment: Hexal AG.

Pharmacokinetics of 8-O-acetylharpagide in mouse blood by UPLC–MS/MS

8-O-Acetylharpagide is the main active component of the herb Ajuga decumbens, which possesses anti-tumor, anti-virus, and anti-inflammation properties. In this study, ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) was used to measure the concentration of 8-O-acetylharpagide in mouse blood, with subsequent investigation of the pharmacokinetics of the drug after intravenous or oral administration. Shanzhiside methyl ester was used as an internal standard, and the acetonitrile precipitation method was used to process the blood samples. Chromatographic separation was achieved using an ultra-performance liquid chromatography ethylene-bridged hybrid (UPLC BEH) column (2.1 mm × 50 mm, 1.7 μm) with a gradient methanol–water mobile phase (containing 0.1% formic acid). The flow rate was 0.4 mL/min, and the elution time was 5.0 min. 8-O-Acetylharpagide was quantitatively measured using electrospray ionization (ESI) tandem mass spectrometry in multiple reaction monitoring (MRM) mode with positive ionization. The result indicated that, within the range of 5–500 ng/mL, the linearity of 8-O-acetylharpagide in mouse blood was satisfactory (r > 0.995), and the lower limit of quantification (LLOQ) was 5 ng/mL. Intra-day precision relative standard deviation (RSD) of 8-O-acetylharpagide in blood was lower than 9%, and the inter-day precision RSD was lower than 13%. The accuracy range was between 94.3% and 107.1%, average recovery was higher than 91.3%, and the matrix effect was between 100.8% and 110.8%. This analytical method was sensitive and fast with good selectivity and was successfully applied to perform pharmacokinetic studies of 8-O-acetylharpagide in mice. The bioavailability of 8-O-acetylharpagide was 10.8%, and the analysis of the primary pharmacokinetic parameters after oral and intravenous administration indicated that 8-O-acetylharpagide had a significant first pass effect after oral administration.

A Phase I, Randomized, Single-Dose Study Evaluating the Biosimilarity of TAB008 to Bevacizumab in Healthy Volunteers.

Objective: This study compared the pharmacokinetics (PK), safety, and immunogenicity of the biosimilar TAB008 monoclonal antibody to bevacizumab (Avastin®) in normal healthy Chinese male volunteers. Methods: In this randomized, double-blind, parallel controlled study, a total of 100 healthy Chinese male subjects were randomized (1:1) to receive a single 1 mg/kg intravenous dose of TAB008 or Avastin® over a 90-min infusion. The subjects were followed for 99 days after drug administration. Primary endpoints were bioequivalence of major pharmacokinetic parameters (AUC0-t and AUC0-∞) and maximum observed serum concentration (Cmax). Secondary endpoints included safety and immunogenicity parameters. Results: The two groups of test subjects (49 subjects in the TAB008 group and 50 subjects in the Avastin® group) were well matched in regards to all demographic and baseline characteristics. The treatment group ratios of LS geometric means for the three primary PK parameters were fully contained within the bioequivalence limits of 80.00–125.00% (90% CI was 103.66–118.33% for Cmax, 94.32–111.72% for AUC0-t, and 94.69–112.23% for AUC0-∞). Treatment-emergent adverse events (TEAEs) were reported for 24 (49.0%) subjects in the TAB008 group and 22 (44.0%) subjects in the Avastin® group. TEAEs related to the study drug were reported for 19 (38.8%) subjects in the TAB008 group and 19 (38.0%) subjects in the Avastin® group. National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) Grade 3 TEAEs were reported for 1 (2.0%) subject in the TAB008 group and 3 (6.0%) subjects in the Avastin® group. There were no Grade 4 or 5 TEAEs or serious adverse events (SAEs) during the study. Anti-drug antibody generation was reported once only in each group, and neutralizing antibody (Nab) analysis was negative upon follow-up. Conclusion: TAB008 attained pharmacokinetic similarity to bevacizumab, and was safe and well tolerated.

Methods to Predict Volume of Distribution.

Prior to human studies, knowledge of drug disposition in the body is useful to inform decisions on drug safety and efficacy, first in human dosing, and dosing regimen design. It is therefore of interest to develop predictive models for primary pharmacokinetic parameters, clearance, and volume of distribution. The volume of distribution of a drug is determined by the physiological properties of the body and physiochemical properties of the drug, and is used to determine secondary parameters, including the half-life. The purpose of this review is to provide an overview of current methods for the prediction of volume of distribution of drugs, discuss a comparison between the methods, and identify deficiencies in current predictive methods for future improvement. Several volumes of distribution prediction methods are discussed, including preclinical extrapolation, physiological methods, tissue composition-based models to predict tissue:plasma partition coefficients, and quantitative structure-activity relationships. Key factors that impact the prediction of volume of distribution, such as permeability, transport, and accuracy of experimental inputs, are discussed. A comparison of current methods indicates that in general, all methods predict drug volume of distribution with an absolute average fold error of 2-fold. Currently, the use of composition-based PBPK models is preferred to models requiring in vivo input. Composition-based models perfusion-limited PBPK models are commonly used at present for prediction of tissue:plasma partition coefficients and volume of distribution, respectively. A better mechanistic understanding of important drug distribution processes will result in improvements in all modeling approaches.

PF347 PHARMACOKINETIC AND PHARMACODYNAMIC SIMILARITY OF ABP 959 WITH ECULIZUMAB: RESULTS FROM A RANDOMIZED, DOUBLE-BLIND, SINGLE-DOSE, PARALLEL-GROUP STUDY IN HEALTHY SUBJECTS

Background: ABP 959 is being developed as a biosimilar candidate to eculizumab. Eculizumab is a recombinant humanized IgG2/4 chimeric monoclonal antibody that binds to the human C5 complement protein (C5), thereby inhibiting the complement cascade. It is indicated for the treatment of patients with generalized myasthenia gravis (gMG), paroxysmal nocturnal hemoglobinuria (PNH) to reduce hemolysis, and atypical hemolytic uremic syndrome (aHUS) to inhibit complement-mediated thrombotic microangiopathy. ABP 959 has been evaluated to be analytically similar to eculizumab. Aims: To demonstrate pharmacokinetic (PK) and pharmacodynamic (PD) similarity of ABP 959 relative to the reference product (RP) eculizumab. Methods: This was a randomized, double-blind, single-dose, 3-arm, parallel-group study in healthy adult male subjects, between 18 to 45 years of age, with a body mass index of 18 to 30.0 kg/m2, who were randomized to receive a 300-mg IV infusion of ABP 959, or FDA-licensed eculizumab (eculizumab US), or EU-authorized eculizumab (eculizumab EU). Serum samples for PK and PD evaluations were collected over 56 days. Primary objectives were to demonstrate PK and PD equivalence of ABP 959 versus eculizumab US and ABP 959 versus eculizumab EU, as assessed by area under the total serum concentration—time curve (AUC) from time 0 extrapolated to infinity (AUCinf) and an area between the effect curve (ABEC) of 50% total hemolytic complement activity (CH50). Secondary PK endpoints included AUC from time 0 to the time of the last observed quantifiable concentration (AUClast) and maximum observed concentration (Cmax). Pre-specified equivalence criterion for the primary PK and PD parameters was 90% confidence interval (CI) for geometric mean (GM) ratios within 0.80 to 1.25. Other secondary endpoints included the safety, tolerability, and immunogenicity of the investigational products (IPs). Results: A total of 219 subjects were enrolled (ABP 959, n = 71; eculizumab US, n = 74; eculizumab EU, n = 74). The GM of PK and PD parameters following a single IV infusion of IP, were similar between ABP 959 vs. eculizumab US and ABP 959 vs. eculizumab EU. The GM of AUCinf (h.μg/mL) was: 18996.3 for ABP 959; 19777.5 for eculizumab US and 18921.1 for eculizumab EU. The GM of ABEC of CH50 (%∗h) was 17724.5 for ABP 959; 16549.4 for eculizumab US and 16361.1 for eculizumab EU. For both PK and PD comparisons of ABP 959 with eculizumab US and ABP 959 with eculizumab EU, the 90% CIs of the GM ratios were fully contained within the bioequivalence criteria of 0.80 to 1.25 for all PK (AUCinf, Cmax, AUClast) and PD (ABEC of CH50) evaluations, confirming the PK and PD bioequivalence between ABP 959 and eculizumab US and ABP 959 and eculizumab EU. Additionally, eculizumab US and eculizumab EU were similar in PK and PD assessments. There were no deaths or treatment-emergent adverse events (TEAEs) leading to study discontinuation. Five subjects experienced 8 SAEs; only the SAE of headache was considered probably related to study drug. The incidence of overall TEAEs or any single category of TEAE was similar across treatment groups. A total of 19 (8.8%) subjects had positive binding ADAs over the course of the study; the incidence of binding ADAs was similar across treatments. No subjects developed neutralizing antibodies. Summary/Conclusion: This phase 1 study demonstrated PK and PD bioequivalence of ABP 959 to eculizumab RP. Safety and immunogenicity profiles were similar between ABP 959 and eculizumab RP.

A New UPLC-MS/MS Method Validated for Quantification of Jervine in Rat Plasma and the Study of Its Pharmacokinetics in Rats.

The aim of this study was to develop an ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to assess the concentration of jervine in rat plasma and its pharmacokinetics. Diazepam was used as internal standard (IS). The chromatographic separation of jervine and IS was carried out on an UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with a flow rate of 0.4 mL/min. A mixture of acetonitrile and water (0.1% formic acid) was used as a mobile phase. The UPLC-MS/MS was equipped with an electrospray ionization (ESI), adopting multiple reactive monitoring mode to determine jervine in rat plasma. The retention times of jervine and the internal standard were 1.71 and 2.13 min, respectively. The calibration curve of jervine ranged between 1 and 1000 ng/mL. The lower limit of quantitation (LLOQ) was 1 ng/mL, and the lower limit of determination (LLOD) was 0.2 ng/mL. The accuracy was ±6%; the interday precision and intraday precision were no more than 9%. The recovery was higher than 90.3%, and the matrix effect was lower than 10%. The UPLC-MS/MS method was successfully developed and used for the application of the pharmacokinetic study. The primary pharmacokinetic parameters of jervine in this study were as follows: the AUC(0–∞) was 969.3 ± 277.7 ng/mL·h, the Cmax was 506.6 ± 192.8 ng/mL, the CL/F was 1.7 ± 0.5 L/h/kg, and the t1/2 was 3.4 ± 1.2 h.

Abstract P4-16-14: Meta-analysis of Phase I pharmacokinetic/pharmacodynamic results of proposed biosimilar pegfilgrastim

Abstract Background The long-acting granulocyte colony-stimulating factor (G-CSF) pegfilgrastim is widely used to prevent chemotherapy-induced neutropenia (CIN). Biosimilars could potentially improve sustainability of cancer care. Sandoz proposed biosimilar pegfilgrastim is under development and has been evaluated in Phase I and III studies.1,2 The current meta-analysis uses data from two Phase I studies in healthy volunteers (HVs) comparing pharmacokinetic (PK)/pharmacodynamic (PD) properties of Sandoz proposed biosimilar and EU-reference (Neulasta®) pegfilgrastim. Methods Data from two studies were included: a single-dose, double-blind, parallel-group study (study 1, data on file) and a single-dose, double-blind, crossover study (study 2),3 both in HVs randomized to receive proposed biosimilar or reference biologic (PK/PD analysis populations: study 1, n=93 per arm; study 2, n=169 per arm). Primary PK and PD parameters were AUC0–inf, AUC0–last, Cmax and ANC AUEC0–last, ANC Emax, respectively. For each parameter, geometric mean ratios and confidence intervals (CIs) for treatment comparisons (proposed biosimilar vs reference biologic) from the two studies were combined using meta-analytical techniques with a fixed-effects model. The 90% (PK) or 95% (PD) CIs were calculated and PK/PD biosimilarity was demonstrated if all CIs fell within equivalence margins of 80% to 125%. Non-baseline corrected PD parameters were used. Results The combined CIs of the geometric mean ratios for primary PK and PD parameters were all contained within the predefined equivalence margins. Safety, tolerability and immunogenicity were found to be similar between proposed biosimilar and EU-reference biologic in HVs (data not shown). Combined geometric mean with 90% (PK)/95% (PD) CICombined ratio with 90% (PK)/95% (PD) CI Proposed biosimilarEU-referenceProposed biosimilar vs EU-referencePK parametersAUC0–last (ng×h/mL)N93+16993+169 Geometric mean 90% CI6823 [6122, 7603]6034 [5404, 6738]1.1385 [1.0606, 1.2221]AUC0–inf (ng×h/mL)N92+168a93+168a Geometric mean 90% CI6973 [6268, 7757]6183 [5560, 6876]1.1335 [1.0570, 1.2156]Cmax (ng/mL)N93+16993+169 Geometric mean 90% CI196 [178, 216]180 [163, 198]1.0994 [1.0265, 1.1774]PD parametersAUEC0–last (109×h/L)N93+16993+169 Geometric mean 95% CI4986 [4855, 5121]4952 [4816, 5093]1.0119 [0.9959, 1.0281]Emax (109/L)N93+16993+169 Geometric mean 95% CI36.4 [35.3, 37.5]36.2 [35.1, 37.2]0.9981 [0.9790, 1.0175]AUC=area under serum-concentration curve; AUEC=area under effect curve; CI=confidence interval; Cmax=maximum observed serum concentration; Emax=maximum effect attributable to investigational medicinal product; PD=pharmacodynamic; PK=pharmacokinetic. aOne subject in study 2 had AUC0–inf extrapolated >20% and was excluded from AUC0–inf analysis Conclusions This meta-analysis of two Phase I studies supports PK/PD similarity of Sandoz proposed biosimilar to EU-reference pegfilgrastim. Also, no clinically meaningful differences in safety, tolerability and immunogenicity were found. Sandoz proposed biosimilar pegfilgrastim presents as a sustainable option to manage CIN in patients with cancer. References 1Blackwell et al. Oncologist 2016;21:789–94 2Harbeck et al. Future Oncol 2016;12:1359–67 3Nakov et al. Cancer Res 2018;78:P3-14-10 Citation Format: Nakov R, Wang J, Chen Y, Bellon A, Gattu S, Krendyukov A, Li Y. Meta-analysis of Phase I pharmacokinetic/pharmacodynamic results of proposed biosimilar pegfilgrastim [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-16-14.

Impact of Endogenous Insulin Adjustment Methods on the Assessment of Insulin Pharmacokinetics and Pharmacodynamics

Assessing reliable insulin pharmacokinetics (PK) and pharmacodynamics (PD) following an exogenous insulin administration is a scientific challenge due to the circulating endogenous insulin. Effect of exogenous insulin on the endogenous insulin through the sensitive glucose homeostatic system in the body could further confound the PK/PD data. We compared results of PK/PD parameters of methods in literature for the estimation of insulin PK and PD, namely total method without adjustment (method 1), a simple baseline method (method 2), elimination rate constant method (method 3), empirical C-peptide correction method (method 4), and conventional PK/PD modeling method (method 5). We also developed new PK/PD modeling method reflecting the effect of glucose on endogenous insulin release based on C-peptide (method 6). Subject-level time-matching insulin and glucose concentrations without external glucose administration were collected from clinical trials with regular human insulin administration to healthy subjects under fasting conditions (n=23). Primary insulin PK parameters (i.e., the maximum concentration (Cmax) and area under the concentration-time profile (AUC)) were estimated using subjects’ insulin, glucose and C-peptide level data. Our results indicate that insulin AUC and Cmax differ by up to 32 and 17%, respectively, among different methods. Further, the contribution of endogenous insulin to total insulin AUC is estimated to be approximately 55% but varies depending upon estimation methods. Insulin PD parameters are apparently similar among different methods (e.g., area under the glucose concentration-time profile; 8121.4 and 8293.3 mg/dL*min for method 1-5 and method 6, respectively). The results call for a careful selection of the method for the assessment of insulin PK and PD parameters depending upon the objectives of study as the relationship between PK and PD could vary among methods and may lead to misinterpretation of data. Disclosure S.M. Chung: None. J.A. Penzenstadler: None. M. Khurana: None. C. Sahajwalla: None.

In vitro studies and in silico predictions of fluconazole and CYP2C9 genetic polymorphism impact on siponimod metabolism and pharmacokinetics

PurposeThe purpose of the study is to investigate the enzyme(s) responsible for siponimod metabolism and to predict the inhibitory effects of fluconazole as well as the impact of cytochrome P450 (CYP) 2C9 genetic polymorphism on siponimod pharmacokinetics (PK) and metabolism.MethodsIn vitro metabolism studies were conducted using human liver microsomes (HLM), and enzyme phenotyping was assessed using a correlation analysis method. SimCYP, a physiologically based PK model, was developed and used to predict the effects of fluconazole and CYP2C9 genetic polymorphism on siponimod metabolism. Primary PK parameters were generated using the SimCYP and WinNonlin software.ResultsCorrelation analysis suggested that CYP2C9 is the main enzyme responsible for siponimod metabolism in humans. Compared with the CYP2C9*1/*1 genotype, HLM incubations from CYP2C9*3/*3 and CYP2C9*2/*2 donors showed ~ 10- and 3-fold decrease in siponimod metabolism, respectively. Simulations of enzyme contribution predicted that in the CYP2C9*1/*1 genotype, CYP2C9 is predominantly responsible for siponimod metabolism (~ 81%), whereas in the CYP2C9*3/*3 genotype, its contribution is reduced to 11%. The predicted exposure increase of siponimod with fluconazole 200 mg was 2.0–2.4-fold for CYP2C9*1/*1 genotype. In context of single dosing, the predicted mean area under the curve (AUC) is 2.7-, 3.0- and 4.5-fold higher in the CYP2C9*2/*2, CYP2C9*2/*3 and CYP2C9*3/*3 genotypes, respectively, compared with the CYP2C9*1/*1 genotype.Conclusion.Enzyme phenotyping with correlation analysis confirmed the predominant role of CYP2C9 in the biotransformation of siponimod and demonstrated the functional consequence of CYP2C9 genetic polymorphism on siponimod metabolism. Simulation of fluconazole inhibition closely predicted a 2-fold AUC change (ratio within ~ 20% deviation) to the observed value. In silico simulation predicted a significant reduction in siponimod clearance in the CYP2C9*2/*2 and CYP2C9*3/*3 genotypes based on the in vitro metabolism data; the predicted exposure was close (within 30%) to the observed results for the CYP2C9*2/*3 and CYP2C9*3/*3 genotypes.