A Phase I Clinical Study Comparing the Pharmacokinetics, Safety, and Immunogenicity of GB221 Injection and Trastuzumab (Herceptin®) in Healthy Chinese Adults.

BACKGROUND AND OBJECTIVE: GB221 is a recombinant humanized anti-HER2 monoclonal antibody. The purpose of this study was to evaluate the pharmacokinetic, safety, and immunogenicity of GB221 in healthy Chinese adults in comparison to trastuzumab (Herceptin®). METHODS: In this randomized, double-blind, parallel-group phase I clinical trial, 88 subjects were randomized 1:1 to receive a single intravenous infusion (90-100 min) of GB221 or trastuzumab (6 mg/kg). The primary pharmacokinetic parameters-maximum observed serum concentration (Cmax), area under the serum concentration-time curve from zero to the last quantifiable concentration at time t (AUC0-t), and area under the serum concentration-time curve from time zero to infinity (AUC0-∞)-of GB221 and trastuzumab were compared to establish whether the 90% confidence interval (CI) attained the 80-125% bioequivalence standard. Safety and immunogenicity were also evaluated. RESULTS: The GB221 group (n = 43) and the trastuzumab group (n = 44) showed similar pharmacokinetic characteristics. The geometric mean ratios (90% CI) of Cmax, AUC0-t, and AUC0-∞ between the two groups were 107.53% (102.25-113.07%), 108.31% (103.57-113.26%), and 108.34% (103.57-113.33%), respectively. The incidence of treatment-emergent adverse events (TEAEs) was 83.7% (36/43) of the subjects in the GB221 group and 95.5% (42/44) of the subjects in the trastuzumab group. No subjects withdrew from the trial due to TEAEs, and there were no occurrences of serious adverse events. All subjects tested negative for antidrug antibodies (ADA). CONCLUSION: GB221 demonstrated similar pharmacokinetics to trastuzumab and comparable safety and immunogenicity in healthy Chinese adults.

Bioequivalence trials for the approval of generic drugs in Saudi Arabia: a descriptive analysis of design aspects.

BACKGROUND: This retrospective analysis aimed to comprehensively review the design and regulatory aspects of bioequivalence trials submitted to the Saudi Food and Drug Authority (SFDA) since 2017. METHODS: This was a retrospective, comprehensive analysis study. The Data extracted from the SFDA bioequivalence assessment reports were analyzed for reviewing the overall design and regulatory aspects of the successful bioequivalence trials, exploring the impact of the coefficient of variation of within-subject variability (CVw) on some design aspects, and providing an in-depth assessment of bioequivalence trial submissions that were deemed insufficient in demonstrating bioequivalence. RESULTS: A total of 590 bioequivalence trials were included of which 521 demonstrated bioequivalence (440 single active pharmaceutical ingredients [APIs] and 81 fixed combinations). Most of the successful trials were for cardiovascular drugs (84 out of 521 [16.1%]), and the 2 × 2 crossover design was used in 455 (87.3%) trials. The sample size tended to increase with the increase in the CVw in trials of single APIs. Biopharmaceutics Classification System Class II and IV drugs accounted for the majority of highly variable drugs (58 out of 82 [70.7%]) in the study. Most of the 51 rejected trials were rejected due to concerns related to the study center (n = 21 [41.2%]). CONCLUSION: This comprehensive analysis provides valuable insights into the regulatory and design aspects of bioequivalence trials and can inform future research and assist in identifying opportunities for improvement in conducting bioequivalence trials in Saudi Arabia.

Leveraging Modeling and Simulation to Enhance the Efficiency of Bioequivalence Approaches for Generic Drugs: Highlights from the 2023 Generic Drug Science and Research Initiatives Public Workshop.

The 2023 Generic Drug Science and Research Initiative Public Workshop organized by the U.S. Food and Drug Administration (FDA) discussed the research needs to improve and enhance bioequivalence (BE) approaches for generic drug development. FDA takes such research needs and panel discussions into account to develop its Generic Drug User Fee Amendments III (GDUFA III) Science and Research Initiatives specific to generics. During the five workshop sessions, presentations and panel discussions focused on identifying and addressing scientific gaps and research needs related to nitrosamine impurity issues, BE assessment for oral products, innovative BE approaches for long-acting injectable products, alternative BE approaches for orally inhaled products, and advanced BE methods for topical products. Specifically, this report highlights the discussions on how to improve BE assessment for developing generic drug products based on research priorities for leveraging quantitative methods and modeling, as well as artificial intelligence/machine learning (AI/ML).

The bioequivalence study design recommendations for immediate-release solid oral dosage forms in the international pharmaceutical regulators programme participating regulators and organisations: differences and commonalities.

Bioequivalence (BE) studies are considered the standard for demonstrating that the performance of a generic drug product in the human body is sufficiently similar to that of its comparator product. The objective of this article is to describe the recommendations from participating Bioequivalence Working Group for Generics (BEWGG) members of the International Pharmaceutical Regulators Programme (IPRP) regarding the conduct and acceptance criteria for BE studies of immediate release solid oral dosage forms. A survey was conducted among BEWGG members regarding their BE recommendations and requirements related to study subjects, study design, sample size, single or multiple dose administration, study conditions (fasting or fed), analyte to be measured, selection of product strength, drug content, handling of endogenous substances, BE acceptance criteria, and additional design aspects. All members prefer conducting single dose cross-over designed studies in healthy subjects with a minimum of 12 subjects and utilizing the parent drug data to assess BE. However, differences emerged among the members when the drug's pharmacokinetics and pharmacodynamics become more complex, such that the study design (e.g., fasting versus fed conditions) and BE acceptance criteria (e.g., highly variable drugs, narrow therapeutic index drugs) may be affected. The survey results and discussions were shared with the ICH M13 Expert Working Group (EWG) and played an important role in identifying and analyzing gaps during the harmonization process. The draft ICH M13A guideline developed by the M13 EWG was endorsed by ICH on 20 December 2022, under Step 2.

Demonstrating Bioequivalence for Two Dose Strengths of Niraparib and Abiraterone Acetate Dual-Action Tablets Versus Single Agents: Utility of Clinical Study Data Supplemented with Modeling and Simulation.

BACKGROUND AND OBJECTIVE: The combination of niraparib and abiraterone acetate (AA) plus prednisone is under investigation for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) and metastatic castration-sensitive prostate cancer (mCSPC). Regular-strength (RS) and lower-strength (LS) dual-action tablets (DATs), comprising niraparib 100 mg/AA 500 mg and niraparib 50 mg/AA 500 mg, respectively, were developed to reduce pill burden and improve patient experience. A bioequivalence (BE)/bioavailability (BA) study was conducted under modified fasting conditions in patients with mCRPC to support approval of the DATs. METHODS: This open-label randomized BA/BE study (NCT04577833) was conducted at 14 sites in the USA and Europe. The study had a sequential design, including a 21-day screening phase, a pharmacokinetic (PK) assessment phase comprising three periods [namely (1) single-dose with up to 1-week run-in, (2) daily dose on days 1-11, and (3) daily dose on days 12-22], an extension where both niraparib and AA as single-agent combination (SAC; reference) or AA alone was continued from day 23 until discontinuation, and a 30-day follow-up phase. Patients were randomly assigned in a parallel-group design (four-sequence randomization) to receive a single oral dose of niraparib 100 mg/AA 1000 mg as a LS-DAT or SAC in period 1, and patients continued as randomized into a two-way crossover design during periods 2 and 3 where they received niraparib 200 mg/AA 1000 mg once daily as a RS-DAT or SAC. The design was powered on the basis of crossover assessment of RS-DAT versus SAC. During repeated dosing (periods 2 and 3, and extension phase), all patients also received prednisone/prednisolone 5 mg twice daily. Plasma samples were collected for measurement of niraparib and abiraterone plasma concentrations. Statistical assessment of the RS-DAT and LS-DAT versus SAC was performed on log-transformed pharmacokinetic parameters data from periods 2 and 3 (crossover) and from period 1 (parallel), respectively. Additional paired analyses and model-based bioequivalence assessments were conducted to evaluate the similarity between the LS-DAT and SAC. RESULTS: For the RS-DAT versus SAC, the 90% confidence intervals (CI) of geometric mean ratios (GMR) for maximum concentration at a steady state (Cmax,ss) and area under the plasma concentration-time curve from 0-24 h at a steady state (AUC 0-24h,ss) were respectively 99.18-106.12% and 97.91-104.31% for niraparib and 87.59-106.69 and 86.91-100.23% for abiraterone. For the LS-DAT vs SAC, the 90% CI of GMR for AUC0-72h of niraparib was 80.31-101.12% in primary analysis, the 90% CI of GMR for Cmax,ss and AUC 0-24h,ss of abiraterone was 85.41-118.34% and 86.51-121.64% respectively, and 96.4% of simulated LS-DAT versus SAC BE trials met the BE criteria for both niraparib and abiraterone. CONCLUSIONS: The RS-DAT met BE criteria (range 80%-125%) versus SAC based on 90% CI of GMR for Cmax,ss and AUC 0-24h,ss. The LS-DAT was considered BE to SAC on the basis of the niraparib component meeting the BE criteria in the primary analysis for AUC 0-72h; abiraterone meeting the BE criteria in additional paired analyses based on Cmax,ss and AUC 0-24h,ss; and the percentage of simulated LS-DAT versus SAC BE trials meeting the BE criteria for both. GOV IDENTIFIER: NCT04577833.

Crushing tablets or sprinkling capsules: Implications for clinical strategy and study performance based on BE studies of rivaroxaban and deferasirox.

Administration of oral medicinal products as crushed tablets or open capsules is an important delivery option for patients suffering from dysphagia. To obtain full interchangeability of generics with the original products, demonstration of bioequivalence (BE) between both products administered as crushed tablets/open capsules was required for poorly soluble product by European Medicines Agency (EMA) at the time of development of our rivaroxaban and deferasirox generic products. We present the results of two BE studies with modified administration of these products, which compared relative bioavailability between generic and reference products. In the rivaroxaban study, the test product was administered as a capsule sprinkled on and mixed with applesauce, whereas the reference tablet was crushed and administered with applesauce under fed conditions. In the deferasirox study, both treatments were administered as crushed tablets under fasting conditions. Both studies applied a two-way crossover design and were conducted after a single-dose in healthy volunteers. The 90% confidence interval of the geometric mean ratio area under the analyte concentration versus time curve, from time zero to the time of the last measurable analyte concentration and maximum measured analyte concentration over the sampling period of the test to reference ratio were 103.36-110.37% and 97.98-108.45% for rivaroxaban, respectively, and 96.69-107.29% and 94.19-109.45% for deferasirox, respectively. Thus, the BE criteria (80.00-125.00%) were met in both studies which demonstrated that bioavailability was not affected when the test and reference products were administered in the form of crushed tablet/open capsule. These results support the argument of redundancy of crushed product studies for poorly soluble drugs, which is in line with the currently revised position of the EMA on this topic.

Clinical evaluation of PF614, a novel TAAP prodrug of oxycodone, versus OxyContin in a multi-ascending dose study with a bioequivalence arm in healthy volunteers.

PF614, a trypsin-activated abuse protection oxycodone prodrug designed to reduce recreational drug abuse, was compared to OxyContin for safety and pharmacokinetics (PKs) of plasma oxycodone following oral administration. This study was a two-part design including a multi-ascending dose (part A) and a bioequivalence (BE) study (part B) in healthy volunteers. In part A, 24 subjects were randomized 3:1 to receive PF614 (50, 100, or 200 mg, n = 6/cohort) or OxyContin (20, 40, or 80 mg; n = 2/cohort) in ascending cohorts, delivered every 12 h for a total of nine doses. In part B, 60 subjects randomized in a four-way crossover to evaluate BE, received PF614 100 mg and OxyContin 40 mg in fasted and fed (high-fat diet) states. All subjects were naltrexone blocked prior to first study drug administration to protect against opioid-related adverse effects; repeat doses were provided on days 1-5. In part A, PF614 was well-tolerated following twice daily doses of up to 200 mg for 5 days. Plasma oxycodone maximal plasma concentration and area under the concentration time curve increased linearly with increasing doses. Part B showed that plasma oxycodone BE was achieved following 100 mg PF614 or 40 mg OxyContin under both fasted and fed conditions. Additionally, PF614 provided similar oxycodone exposures following both fasted and fed states. This study confirms findings from our single-ascending dose study, showing that PF614 100 mg releases oxycodone with a PK profile comparable to 40 mg OxyContin under both fasted and fed conditions and with a similar safety profile under naltrexone-blocked conditions.

The novel rapid formulation of intravenous dantrolene (NPJ5008) versus standard dantrolene (Dantrium®): A clinical part-randomised phase 1 study in healthy volunteers.

BACKGROUND: Delays in treating anaesthesia-induced malignant hyperthermia increase risks of complications and death. NPJ5008 is a novel formulation of the indicated treatment, dantrolene sodium, developed to shorten preparation and administration times compared with the reference formulation Dantrium®. The two formulations have been compared preclinically. OBJECTIVES: Assess bioequivalence of overall dantrolene (free acid) exposure of NPJ5008 versus Dantrium® and ascertain similarities in their pharmacokinetics and safety/tolerability profiles. Evaluate preparation/administration time savings for the new formulation. DESIGN: Part 1 of this open-label trial in humans was a 1 : 1 randomised crossover study; part 2 was a single-arm study. Trial pharmacy data and laboratory simulations assessed preparation/administration step timings. SETTING: Single clinical centre in the UK, April to July 2021. PARTICIPANTS: Twenty-one healthy male and female individuals. INTERVENTIONS: Part 1: single intravenous 60 mg dose of NPJ5008 or Dantrium®, sequentially. Part 2: single intravenous 120 mg dose of NPJ5008. Simulation: five vials per formulation using paediatric and adult cannulas. MAIN OUTCOME MEASURES: Overall drug exposure to last measurable concentration (AUC 0 to last ) and extrapolated to infinity (AUC 0 to ∞ ) were primary endpoints. Other pharmacokinetic, clinical and muscle-function parameters, and adverse events, were monitored. RESULTS: Adjusted geometric mean ratios of NPJ5008 versus Dantrium® were 90.24 and 90.44% for AUC 0 to last and AUC 0 to ∞ , respectively, with the 90% confidence intervals (CI) within the 80 to 125% acceptance interval, establishing bioequivalence. No new safety issues emerged: any adverse events were of a similar magnitude across treatments and related to pharmacological properties of dantrolene. Pharmacy and simulation data revealed that every step in preparation and administration was 26 to 69% faster for NPJ5008 than Dantrium®. CONCLUSION: NPJ5008 showed comparable pharmacokinetic and safety profiles to Dantrium®, while reducing dantrolene dose preparation/administration times, potentially reducing patient complications/healthcare resourcing in malignant hyperthermia. TRIAL REGISTRATION: EudraCT Number: 2020-005719-35, MHRA approval.

Development of a New Bioequivalent Omeprazole Product.

Background and Objectives: The enteric form of omeprazole is one of the most commonly prescribed medications. Similarly to Europe, Kazakhstan relies on the localization of pharmaceutical drug production as one of its primary strategies to ensure that its population has access to affordable and good-quality medicines. This study comprehensively describes the technologically available development of bioequivalent delayed-release omeprazole. Materials and Methods: Various regimes and technological parameters were tested on laboratory- and production-scale equipment to establish a technical process where a functional and gastro-protective layer is essential. According to the ICH guidance on stability testing and Kazakhstan local rules, stability studies were conducted under conditions appropriate for climate zone II. The comparison of the rate and extent of absorption with subsequent assessment of the bioequivalence of the generic and reference drugs after a single dose of each drug at a dose of 40 mg was performed. Results: The quantitative and qualitative composition and technology of producing a new generic enteric form of omeprazole in capsules were developed and implemented at the manufacturing site of solid forms. Dissolution profiles in media with pH 1.2 and 6.8 were proven. During the accelerated six-month and long-term twelve-month studies, the developed formulation in both packaging materials at each control point passed the average weight and mass uniformity test, dissolution test, acid-resistance stage test, buffer stage test, impurity assay, and microbiological purity test and met all the specification criteria. A bioequivalence study in 24 healthy volunteers compared against the innovative drug showed the bioequivalency of the new generic system. The obtained values from the test and reference products were 1321 ± 249.0 ng/mL and 1274 ± 233 ng/mL for Cmax, 4521 ± 841 ng·h /mL and 4371 ± 695 ng·h /mL for AUC0-t, and 4636 ± 814 ng·h /mL and 4502 ± 640 ng·h /mL for AUC0-∞. Conclusions: Using affordable technologies, a bioequivalent generic delayed-release formulation of 20 and 40 mg omeprazole has been developed.

Comparative Bioequivalence and Food Effect of Two Formulations of 30-mg Nifedipine Controlled-Release Tablets in Healthy Chinese Adults.

Nifedipine is a potent antihypertensive medication classified as a dihydropyridine calcium channel blocker. The objective of this trial was to assess the bioequivalence of a 30-mg nifedipine controlled-release tablet and a reference drug in a cohort of healthy Chinese individuals. Two independent open-label, randomized, single-dose, crossover studies were conducted, 1 under fasting conditions (N = 44, with 1 participant dropping out midway) and the other under fed conditions (N = 44, with 4 participants dropping out midway). Plasma concentrations of nifedipine were determined using liquid chromatography-mass spectrometry, and pharmacokinetic (PK) parameters were calculated using noncompartmental analysis with Phoenix WinNonlin 8.0 software. In both fasting and fed studies, reasonable bioequivalence was observed for the PK parameters of both the test product and the reference drug. A good safety profile was demonstrated for both the test product and reference drug, with no serious adverse events reported, and both were similarly well tolerated. An important observation with food coadministration was that systemic exposure to nifedipine (based on area under the curve, AUC0-∞) was reduced by approximately 12%. The bioequivalence of the test product and reference drug under fasting/fed conditions in healthy subjects in China was demonstrated by the study results.

Pharmacokinetic and pharmacodynamic evaluation study of etomidate: a randomized, open-label, 2-period crossover study in healthy Chinese subjects.

Etomidate is a sedative and hypnotic drug through intravenous administration that act on the central nervous system through GABA (Gamma-Amino Butyric Acid) receptors, which is widely used in anesthesia induction and maintenance and long-term sedation in severe patients. The study aimed to evaluate the pharmacokinetic and pharmacodynamic properties of two etomidate fat emulsions after administration through the intravenous infusion pump in healthy Chinese subjects. A randomized, open-label, 2-period crossover study was performed in 52 healthy subjects. The wash-out period was 7 days. Blood samples and pharmacodynamic index values were collected at the specified time points. Etomidate concentrations were measured using validated liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were analyzed using a non-compartment model method. Pharmacodynamic parameters were calculated using pharmacodynamic index values. The study also evaluated the safety of the etomidate. Both the pharmacokinetic parameters and pharmacodynamic parameters result of the test and reference formulation were very similar. The 90% confidence intervals (CI) of the geometric least-squares mean (GLSM) ratios of the test to reference formulation were 91.33-104.96% for the maximum plasma concentration (Cmax), 97.21-102.03% for the area under the plasma concentration time curve from time 0 to the time of the last measurable concentration (AUC0-t), and 97.22-102.33% for the area under the plasma concentration time curve from time 0 to infinity (AUC0-∞). Meanwhile, the 90% CI of the GLSM ratios of the test to reference formulation were 102.28-110.69% for the minimal BIS value (BISmin), 99.23-101.17% for the area under the BIS time curve from time 0-60 min after administration (BISAUC0-60 min), respectively. The 90% CI of these pharmacokinetic and pharmacodynamic parameters all fall in the accepted bioequivalence range of 80.00-125.00%. No serious adverse events occurred during the study. This study has shown that the etomidate fat emulsion test and reference formulation had similar pharmacokinetic and pharmacodynamic characteristics in vivo. The two formulations exhibited good safety and well-tolerance.Clinical trials registration number: http://www.chinadrugtrials.org.cn/index.html . # CTR20191836.

The role of partial area under the curve and maximum concentrations in assessing the bioequivalence of long-acting injectable formulation of exenatide_A sensitivity analysis.

To ensure therapeutic equivalence between the long-acting injectable (LAI) products, additional PK metrics other than Cmax and AUC were considered necessary. However, regarding the selection of additional PK metrics for bioequivalence (BE) assessment of exenatide LAI, a discrepancy existed between EMA's and USFDA's product-specific guidance. The EMA recommends that both the maximum plasma concentration in the initial-release phase (Cmax,1) and the extended-release phase (Cmax,2) should be determined. Nevertheless, the USFDA recommends the use of the partial area under the curve (i.e., the area under the curve from week 4 to the last sampling point; pAUC4w-t). The focus of this study was to compare the sensitivity of different PK metrics, including Cmax,1, Cmax,2, pAUC4w-t, early and late pAUC metrics truncated at different time points (three, four, five, six and seven weeks), to formulation-related parameters and pharmacodynamic (PD) markers of glycemic control. A sensitivity analysis was conducted using the published PK/PD model of exenatide LAI. The results indicated that Cmax,1 and Cmax,2 exhibited comparable sensitivities. AUC4w-t was sensitive to changes in detecting the differences in formulation-related parameters and PD markers of glycemic control, but did not provide superior sensitivity performance compared to Cmax,1 and Cmax,2. Among all tested PK metrics, AUC7w-t was found to be the most sensitive. The optimal cut-off time point for the pAUC should be set at the time of maximum plasma concentration in the extended-release phase (approximately 6-7 weeks). These results may provide useful insights into the selection of appropriate PK metrics for BE determination of exenatide LAI.

Phase I Studies: Innovations and Issues.

INTRODUCTION: Emeritus Editor-in-Chief, Richard Shader, published 2 editorials in 2014 to state that Clinical Therapeutics' would no longer consider simple innovator vs generic bioequivalence studies for publication and would require a rationale for the choice of agents when submitting drug-drug interaction studies for consideration. The intervening decade of developments in this field provides an opportunity to comment on these trends. Lewis Scheiner anchors the subsequent discussion in a "Learn and Confirm" super-structure of thinking about the goals of early development of pharmaceutical agents. Subsequent experience with newer agents that are focused on immunological targets has led to a shift from the simple No Observable Effect Level (NOEL) model to the Minimal Anticipated Biological Effect Level (MABEL) model for biologically focused effects to assess pre-clinical data in guiding the selection of a starting dose for First-in-Human studies. ELEMENTS OF PHASE I STUDIES: The primary tasks of Phase I activities are to describe the pharmacokinetics (determination of absorption, distribution, metabolism, and excretion) and essential pharmacodynamics (the dose correlation with the physiological responses, plus any untoward effects, including idiosyncratic responses) keeping in mind reporting requirements. Other Phase I activities usually conducted later in the development cycle include evaluation of drug interactions with food and other pharmaceutical agents and thorough QT studies. INNOVATIONS: Phase I studies have been evolving in response to the unrelenting pressures to improve access and efficiencies in time, cost, and effort. Changes have been occurring in the characteristics of the participating populations, the starting dose, and shifts in the enrollment schedule to a more flexible, data-driven, adaptive design. ISSUES: Additional issues have gained attention in the recent past, including Phase 0/microdosing, use of Phase I studies explicitly for treatment in the case of oncological products, involvement of Data Safety Monitoring Committees especially for first-in-class molecules, and improved means of optimizing selection of candidate agents for advancement to subsequent stages of development. Of final importance is the need for greater transparency of the presently inaccessible, early development study data maintained in commercial corporate legacy databases. Taken together, these developments and innovations by a broad range of stakeholders point to continuing opportunities for clinical investigators to explore the potential of Phase I studies to contribute to their own specialties.

A Relative Bioavailability, Bioequivalence, and Food Effect Study of Niraparib Tablets in Patients with Advanced Solid Tumors.

PURPOSE: The poly (ADP-ribose) polymerase inhibitor niraparib is indicated as maintenance treatment in patients with certain subtypes of advanced ovarian cancer, and is being investigated in patients with other solid tumors. Niraparib is available in 100-mg capsules with a starting dosage of 200 or 300 mg/d. This study assessed the relative bioavailability (BA) and bioequivalence (BE) between a 1 × 300-mg tablet relative to 3 × 100-mg niraparib capsules. In addition, the food effect (FE) of a high-fat meal on the pharmacokinetic (PK) properties of tablet-formulated niraparib was investigated. METHODS: This was a US-based, 3-stage, open-label, multicenter, single-crossover, randomized-sequence study. Enrolled patients were 18 years and older, with histologically or cytologically confirmed advanced solid tumors (metastatic or local) and disease progression despite standard therapy. Patients were randomly assigned 1:1 to receive niraparib 1 × 300-mg tablet or 3 × 100-mg capsules in the BA and BE stages or 1 × 300-mg tablet in a fasted or fed (high-fat meal) state in the FE stage. Across all study stages, PK parameters were assessed for 7 days after each dose (tablet or capsule) or prandial state (fasted or fed). In the BA stage, patients crossed over to the other treatment after a 7-day washout period, which was extended to 14 days in the BE and FE stages. Tolerability was assessed for patients who received any amount of niraparib. FINDINGS: The BA-, BE-, and FE-evaluable populations comprised 23, 108, and 19 patients, respectively, who completed both treatment periods in each study stage, had sufficient concentration data to accurately estimate PK parameters without niraparib carryover, and did not experience disqualifying events. PK parameters were similar after dosing with tablet or capsule formulations; the 90% CIs of the geometric least square means for Cmax, AUC0-t, and AUC0-∞ were within the 0.80 to 1.25 BE limits. In the FE stage, Cmax, AUC0-t, and AUC0-∞ were 11%, 32%, and 28% higher, respectively, in the fed versus fasted state. The safety population included 29, 168, and 28 patients in the BA, BE, and FE stages, respectively, who received niraparib. No new safety signals were identified. IMPLICATIONS: Niraparib tablets were found to be bioequivalent to capsules. A modest (≤32%) FE was observed with a high-fat meal, but was not considered to be clinically meaningful, given niraparib's PK variability. CLINICALTRIALS: gov identifier: NCT03329001. (Clin Ther. 2024;46:XXX-XXX) © 2024 Elsevier HS Journals, Inc.

Pharmacokinetics and bioequivalence evaluation of two oral formulations of cotrimoxazole tablets in healthy Chinese volunteers under fasting conditions.

This bioequivalence study was conducted to evaluate two oral formulations of cotrimoxazole tablets in healthy Chinese subjects. All 26 subjects recruited to this study were randomly and evenly classified into two groups and received a single dose (sulfamethoxazole: 400 mg and trimethoprim: 80 mg) of test cotrimoxazole tablets (generic drug) or reference cotrimoxazole tablets (branded drug). After a 7-day washout period, these subjects received one dose of reference drug or test drug. Blood samples were collected from participants before and up to 48 h after dosing to assess the concentration of sulfamethoxazole (SMX) and trimethoprim (TMP) in plasma and a plasma concentration-time curve was drawn. Then, the pharmacokinetics parameters were calculated accordingly. Our data revealed that there were no significant differences observed in the maximum plasma concentration (Cmax), area under the curve from time 0 to the last measurable concentration (AUC0-t), and area under the curve from time 0 to infinity (AUC0-∞) between the two formulations. For SMX, the 90% confidence intervals (CI) of the geometric mean ratio for Cmax, AUC0-t, and AUC0-∞ were 104.03-113.92%, 100.46-103.70%, and 100.41-103.81%, respectively. Similarly, for Trimethoprim (TMP), the 90% CI ranged from 98.54 to 106.95% for Cmax, from 99.31 to 107.68% for AUC0-t, and from 99.49 to 107.55% for AUC0-∞. Importantly, all these 90% CI values fell within the range of 80.00-125.00%, indicating that the test drug is bioequivalent to the reference drug. Furthermore, throughout the entire trial, no suspected serious adverse events were reported, indicating the safety profile of the newly developed generic cotrimoxazole. In summary, our study demonstrates that the newly developed generic formulation of cotrimoxazole is bioequivalent to the branded formulation under fasting conditions.

Comparación indirecta ajustada de zanubrutinib e ibrutinib en el tratamiento de primera línea de la leucemia linfocítica crónica / Adjusted indirect comparison of zanubrutinib and ibrutinib in first-line treatment of chronic lymphocytic leukemia

Objetivo el objetivo del presente trabajo fue realizar una comparación indirecta ajustada, según el perfil citogenético, en términos de eficacia, entre los distintos inhibidores de la tirosin cinasa de bruton empleados como monoterapia en primera línea para la leucemia linfocítica crónica. Asimismo, se evaluaron los resultados de seguridad considerados de interés para establecer si dichas opciones pueden ser consideras alternativas terapéuticas equivalentes. Método con fecha 10 de noviembre del 2022, se llevó a cabo una búsqueda bibliográfica en las bases de datos de Pubmed y Embase de ensayos clínicos fase III que estudiaran los inhibidores de la tirosin cinasa de Bruton en monoterapia en contexto de primera línea para la leucemia linfocítica crónica. Se incluyeron ensayos en los que se empleara la combinación de bendamustina y rituximab como comparador y que presentaran poblaciones y tiempos de seguimiento semejantes. Se combinaron mediante metaanálisis los resultados de los subgrupos según las características mutacionales clasificando a los pacientes en alto y bajo riesgo citogenético. Se desarrolló una comparación indirecta ajustada utilizando el método de Bucher. Se determinó la posible equivalencia terapéutica aplicando para ello la guía de alternativas terapéuticas equivalentes. Resultado de los 39 estudios obtenidos en la revisión, se seleccionaron 2 ensayos clínicos: uno para zanubrutinib y otro para ibrutinib. El resto de estudios no se incluyeron por incumplimiento de los criterios de inclusión. Los resultados obtenidos en la comparación indirecta ajustada para ambos subgrupos de riesgo citogenético no mostraron diferencias estadísticamente significativas. En cuanto a la seguridad, las diferencias más relevantes se encontraron en la incidencia de fibrilación auricular, hipertensión arterial y eventos cardiovasculares en los pacientes tratados con ibrutinib, y mayor incidencia de cánceres secundarios en los pacientes tratados con zanubrutinib (AU)

Objective The aim of this study was to perform an adjusted indirect treatment comparison, according to the cytogenetic profile, in terms of efficacy between different Bruton tyrosine kinase inhibitors used as first-line monotherapy for chronic lymphocytic leukemia. Safety outcomes considered of interest were also evaluated to establish whether these options can be considered equivalent therapeutic alternatives. Method A literature search was conducted in Pubmed and Embase on 10 November 2022 for phase III clinical trials studying Bruton's tyrosine kinase inhibitors in monotherapy in the first-line setting for CLL. Results were filtered according to whether the combination of bendamustine and rituximab was used as comparator and whether they had similar populations and follow-up times. Subgroup results were meta-analyzed according to mutational characteristics by classifying patients into high and low cytogenetic risk. An adjusted indirect comparison was developed using Bucher's method. Possible therapeutic equivalence was determined by applying the guide to equivalent therapeutic alternatives. Result Of the 39 studies obtained in the review, two clinical trials were selected: one for zanubrutinib and one for ibrutinib. The remaining studies were not included because they did not meet the inclusion criteria. The results obtained in the adjusted indirect treatment comparison for both cytogenetic risk subgroups showed no statistically significant differences. The most relevant safety differences were auricular fibrillation, hypertension and cardiovascular events in patients treated with ibrutinib and higher incidence of secondary cancers in patients treated with zanubrutinib. Applying the ATE guideline criteria, both treatments cannot be considered equivalent therapeutic alternatives (AU)

Determining topical product bioequivalence with stimulated Raman scattering microscopy.

Generic drugs are essential for affordable medicine and improving accessibility to treatments. Bioequivalence (BE) is typically demonstrated by assessing a generic product's pharmacokinetics (PK) relative to a reference-listed drug (RLD). Accurately estimating cutaneous PK (cPK) at or near the site of action can be challenging for locally acting topical products. Certain cPK approaches are available for assessing local bioavailability (BA) in the skin. Stimulated Raman scattering (SRS) microscopy has unique capabilities enabling continuous, high spatial and temporal resolution and quantitative imaging of drugs within the skin. In this paper, we developed an approach based on SRS and a polymer-based standard reference for the evaluation of topical product BA and BE in human skin ex vivo. BE assessment of tazarotene-containing formulations was achieved using cPK parameters obtained within different skin microstructures. The establishment of BE between the RLD and an approved generic product was successfully demonstrated. Interestingly, within the constraints of the current study design the results suggest similar BA between the tested gel formulation and the reference cream formulation, despite the differences in the formulation/dosage form. Another formulation containing polyethylene glycol as the vehicle was demonstrated to be not bioequivalent to the RLD. Compared to using the SRS approach without a standard reference, the developed approach enabled more consistent and reproducible results, which is crucial in BE assessment. The abundant information from the developed approach can help to systematically identify key areas of study design that will enable a better comparison of topical products and support an assessment of BE.

Scaled average bioequivalence methods for highly variable drugs: Leveling-off soft limits and the EMA's 2010 guideline (some ways to improve its type I error control).

The regulatory EMA's reference scaled average bioequivalence (RSABE) approach for highly variable drugs suffers from some type I error control problems at the neighborhood of the 30% coefficient of variation (CV), where the bioequivalence (BE) limits change from constant to linearly scaled. This paper analyses BE inference methods based on the "Leveling-off" (LO) soft sigmoid expanding BE limits that were proposed as an appealing surrogate for the EMA's limits and compares both approaches, on the replicated and partially replicated crossover designs. The initially proposed version of the LO method also has type I error inflation problems, albeit attenuated. But given its more mathematically regular character, it is more suitable for analytical corrections. Here we introduce two improvements over LO, one based on the application of Howe's method and the other based on correcting the estimation error. They further reduce the type I error inflation, although it does not disappear completely. Finally, the effect of heteroscedasticity on the above results is studied. It leads to inflation or deflation of the type I error, depending on the design and the type of heteroscedasticity (variability of the test product greater than that of the reference product or the opposite). The replicated design is much more stable against these effects than the partially replicated design and maintains these improvements much better.

Bioequivalence of rimegepant, a small molecule CGRP receptor antagonist, administered as an oral tablet, a sublingual orally disintegrating tablet, and a supralingual orally disintegrating tablet: two phase 1 randomized studies in healthy adults.

BACKGROUND: Rimegepant is an orally administered small molecule calcitonin gene-related peptide receptor antagonist indicated for the acute and preventive treatment of migraine. METHODS: Two single-center, phase 1, open-label, randomized bioequivalence studies were conducted in healthy adult non-smokers, aged 18-55 years. One study compared the rate and extent of absorption of the marketed formulation of rimegepant 75 mg orally disintegrating tablet (ODT) administered sublingually with rimegepant 75 mg oral tablet, an earlier development formulation; the second compared the rate and extent of absorption of 75 mg rimegepant ODT administered supralingually with rimegepant oral tablet. RESULTS: The ln-transformed geometric mean ratios for the area under the curve (AUC) from time 0 to the last available concentration time point (time t) (AUC0-t), AUC from time 0 to infinity (AUC0-inf), and maximum observed concentration (Cmax) of sublingual rimegepant ODT vs. rimegepant tablet were 97, 97, and 105%, respectively, and the 90% confidence intervals (CIs) were all within the predefined range (80-125%) for bioequivalence. The ln-transformed geometric mean ratios for the AUC0-t and AUC0-inf of supralingual rimegepant ODT vs. rimegepant tablet were 98%, the 90% CIs were within the predefined range (80-125%), and the geometric mean ratio for Cmax was 103% with the 95% upper confidence bound for the scaled average bioequivalence criterion of -0.0575 (within-participant coefficient of variation for the reference for Cmax > 30%) for bioequivalence. CONCLUSIONS: Rimegepant 75 mg ODT, administered sublingually or supralingually, and rimegepant 75 mg oral tablet were bioequivalent.

Liquid chromatography-tandem mass spectrometry determination of bumetanide in human plasma and application to a clinical pharmacokinetic study.

Determining a drug's bioavailability and bioequivalence is important for developing and approving a drug product. The procedure supports applications for generic drug products and novel therapeutic substances, makes important decisions regarding safety and efficacy, and measures a drug's concentration in biological matrices. This study aimed to develop and validate a specific, simple, sensitive, and accurate method using liquid chromatography-tandem mass spectrometry (LC-MS) for measuring bumetanide (BUM) in human plasma. Chromatographic separation was achieved using a Hypurity C18 column (4.6 × 50 mm, 5 µm) under isocratic conditions, and LC-MS detected positive ionization acquisition modes. Protonated precursor to product ion transitions were observed at m/z 365.08 → 240.10 and 370.04 → 244.52 for BUM and internal standard, respectively. The linear range of BUM in plasma samples was 3.490-401.192 ng/mL. The inter-precision value ranged from 1.76% to 4.75%. The inter-accuracy value ranged from 96.46% to 99.95%. The method was adequately validated per the U.S. Food and Drug Administration guidelines, and the results were within permissible bounds. The Cmax and Tmax values were ~53.097 ± 13.537 ng/mL and 1.25 (0.67-5.00) h, respectively. The new approach showed satisfactory results for studying BUM in human plasma with potential use in pharmacokinetic and bioequivalence investigations.