Comparing Generic and Innovator Drugs: A Review of 12 Years of Bioequivalence Data from the United States Food and Drug Administration

Assessing the longevity of attribute framing in attenuating the nocebo effect to brand and generic medication

The perception of taking a generic, relative to brand, medication has been demonstrated to exacerbate the nocebo effect. Conversely, positive attribute framing has been shown to attenuate the nocebo effect. However, little is known about the longevity of positive attribute framing nor how it interacts with generic versus brand treatment cues. Healthy participants (N = 205) were randomised to receive either sham-modafinil capsules with a brand or generic appearance, in conjunction with standard negative side effect framing (brand-negative: N = 42; generic-negative: N = 41) or positive side effect framing (brand-positive: N = 40; generic-positive: N = 40). The remainder were randomised to a no-treatment control (N = 42). Participants were informed that modafinil could enhance alertness and cognitive performance and reduce fatigue. Critically, modafinil was described as having several potential side effects. Treatment-related side effects, alertness, fatigue and cognitive performance were measured at baseline, 30-min post-treatment and 24 h later. Nocebo and placebo effects were observed across modafinil-treated participants relative to control. Positive framing significantly reduced warned side effects for 24 h. Perceived side effect likelihood, severity, and worry mediated the nocebo, but not framing, effect. Results have important implications for the presentation of side effect information, providing a potential route to reduce unwanted negative effects of generic medication.

Assessing solubility of meloxicam in age-specific gastric and intestinal media relevant to adults and pediatric populations: implications for optimizing dosing in patients for postoperative pain

BACKGROUND

Oral dose formulations must be soluble in gastrointestinal fluids for systemic absorption. The solubility of meloxicam was determined in 16 different age-specific simulated gastric and intestinal media that mirrored the microenvironments in pediatrics and adults.

METHODS

The solubility of meloxicam in the 16 different age-specific simulated gastric and intestinal biorelevant media was assessed using the standard US pharmacopeial method. The molecular descriptors of meloxicam were used to assess its intestinal permeability.

RESULTS

Meloxicam exhibited low solubility in the age-specific simulated gastric media for fasted and fed states and in pediatrics and adults. Similarly, meloxicam exhibited low solubility in the age-specific simulated media that mirrored neonates fed cow milk-based formula. On the other hand, meloxicam exhibited high solubility in the rest of the age-specific pediatric and adult intestinal media that simulated the fasted and fed states. The pediatric-to-adult solubility ratios were outside the 80-125% range in 7 (58.3%) and was borderline in 1 (8.3%) out of the 12 calculated ratios. These findings indicated that the solubility of meloxicam showed clinically significant differences in 8 (66.7%) of the compared media.

CONCLUSION

Meloxicam exhibited low solubility in the age-specific simulated gastric media and high solubility in the simulated intestinal media for adults and pediatrics. Moreover, the pediatric-to-adult solubility ratios may have clinically significant implications. These differences can be translated into a higher likelihood of failing to demonstrate bioequivalence of different formulations containing meloxicam and variabilities in the performance of these formulations.

Establishing a standardised approach for the measurement of neonatal noxious-evoked brain activity in response to an acute somatic nociceptive heel lance stimulus

BACKGROUND

Electroencephalography (EEG) can be used in neonates to measure brain activity changes that are evoked by noxious events, such as clinically required immunisations, cannulation and heel lancing for blood tests. EEG provides an alternative approach to infer pain experience in infants compared with more commonly used behavioural and physiological pain assessments. Establishing the generalisability and construct validity of these measures will help corroborate the use of brain-derived outcomes to evaluate the efficacy of new or existing pharmacological and non-pharmacological methods to treat neonatal pain. This study aimed to test whether a measure of noxious-evoked EEG activity called the noxious neurodynamic response function (n-NRF), that was originally derived in a sample of term-aged infants at the Oxford John Radcliffe Hospital, UK, in 2017, can reliably distinguish noxious from non-noxious events in two independent datasets collected at University College London Hospital and at Royal Devon & Exeter Hospital. We aimed to reproduce three published results that use this measure to quantify noxious-evoked changes in brain activity. We used the n-NRF to quantify noxious-evoked brain activity to test (i) whether significantly larger noxious-evoked activity is recorded in response to a clinical heel lance compared to a non-noxious control heel lance procedure; (ii) whether the magnitude of the activity evoked by a noxious heel lance is equivalent in independent cohorts of infants; and (iii) whether the magnitude of the noxious-evoked brain activity increases with postmenstrual age (PMA) in premature infants up to 37 weeks PMA. Positive replication of these studies will build confidence in the use of the n-NRF as a valid and reliable pain-related outcome which could be used to evaluate analgesic efficacy in neonates. The protocol for this study was published following peer review (https://doi.org/10.17605/OSF.IO/ZY9MS).

RESULTS

The n-NRF magnitude to a noxious heel lance stimulus was significantly greater than to a non-noxious control heel lance stimulus in both the UCL dataset (n = 60; mean difference .88; 95% confidence interval (CI) .64-1.13; p < .0001) and the Exeter dataset (n = 31; mean difference .31; 95% CI .02-.61; p = .02). The mean magnitude and 90% bootstrap confidence interval of the n-NRF evoked by the heel lance did not meet our pre-defined equivalence bounds of 1.0 ± .2 in either the UCL dataset (n = 72; mean magnitude 1.33; 90% bootstrapped CI 1.18-1.52) or the Exeter dataset (n = 35; mean magnitude .92, 90% bootstrapped CI .74-1.22). The magnitude of the n-NRF to the noxious stimulus was significantly positively correlated with PMA in infants up to 37 weeks PMA (n = 65; one-sided Pearson's R, adjusted for site: .24; 95% CI .06-1.00; p = .03).

CONCLUSIONS

We have reproduced in independent datasets the findings that the n-NRF response to a noxious stimulus is significantly greater than to a non-noxious stimulus, and that the noxious-evoked EEG response increases with PMA. The pre-defined equivalence bounds for the mean magnitude of the EEG response were not met, though this might be due to either inter-site differences such as the lack of calibration of devices between sites (a true negative) or underpowering (a false negative). This reproducibility study provides robust evidence that supports the use of the n-NRF as an objective outcome for clinical trials assessing acute nociception in neonates. Use of the n-NRF in this way has the potential to transform the way analgesic efficacy studies are performed.

Interchangeability of generic drugs for subpopulations: Bioequivalence simulation from a nonparametric PK model of gabapentin generic drugs

Patients are often switched between generic formulations of the same drug, but in some cases generic interchangeability is questioned. For generic drugs to be approved, bioequivalence with the innovator drug should be demonstrated, but evidence of bioequivalence is not required in the intended patient population or relative to other approved generics.

AIM

We aim to identify pathophysiological pharmacokinetic subpopulations for whom there is a difference in comparative bioavailability compared to a healthy population.

METHODS

We used simulated exposures from a nonparametric model of multiple generics and the originator gabapentin. Exposure was simulated for virtual populations with pharmacokinetic characteristics beyond those of healthy subjects with regard to rate of absorption, volume of distribution and reduced renal function. Virtual parallel design bioequivalence studies were performed using a random sample of 24 simulated subjects, with standard acceptance criteria.

RESULTS

Results indicated increased pharmacokinetic variability for patient populations with a lower rate of absorption or a reduced renal function, but no change in the average comparable bioavailability ratio. This increased variability results in a reduced likelihood of demonstrating bioequivalence. Observations were similar for comparisons between all different formulations, as well as between subjects who received the identical formulation in a repeated fashion. No relevant effect was observed for simulations with increased volume of distribution.

CONCLUSION

Our simulations indicate that the reduced likelihood of demonstrating bioequivalence for subjects with altered pharmacokinetics is not influenced by a formulation switch, nor does the average comparable bioavailability ratio change, therefore these results support generic interchangeability and current approval requirements for generics.

The Place of Generic Medicines in Hospital Prescriptions: A Survey Conducted in Medical Departments of the University Hospital of Marrakesh, Morocco

A generic medication is a copy of an original drug for which the patent has expired. It contains the same active substances and is equivalent in terms of safety, efficacy, and pharmaceutical quality. Generic drugs are produced after the expiration of the brand-name drug's patent, which enables greater competition and reduces costs for patients and healthcare systems. They are subjected to strict regulatory and quality control standards to ensure compliance with pharmaceutical norms. This study aims to determine the current status of generic drug prescribing within the medical departments of the Mohammed VI University Hospital (UH) of Marrakesh. This is a cross-sectional study with descriptive and analytical aims, involving 224 prescriptions issued in the medical departments of the Mohammed VI University Hospital (UH) of Marrakesh. To obtain the data required for the study, we included medical records, prescription sheets, and prescriptions delivered to hospitalized patients. In our study, 224 prescriptions were analyzed, with an overall total of 989 prescribed drugs, and a mean of 4.42 +- 2.39 drugs per prescription. Prescriptions from the Psychiatry Department accounted for 258 (26.09%) of total prescriptions, followed by those from the Cardiology Department at 130 (13.14%) and the Internal Medicine Department at 114 (11.53%). The generic prescribing rate for the UH's medical departments was 403 (40.75%). The Oncology Department had the highest generic prescribing rate (27 (64.29%)), followed by the Infectious Diseases and Rheumatology departments, at 29 (63.04%) and 34 (60.71%), respectively. In contrast, the Psychiatry Department had a generic prescribing rate of just 54 (20.93%). The most frequently prescribed classes as generic drugs were gastric antisecretory agents at 39 (100%), antiemetics at 32 (94.12%), and antivirals at nine (81.82%). The vast majority of drugs, 896 (90.59%), were reimbursable. In conclusion, we have noted that the generic drug prescription rate at the UH remains average compared with other institutions, and needs to be improved to optimize resources and control healthcare costs.

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.

Antimicrobial activity and pathogen mutation prevention of originator and generics of cefepime, linezolid and piperacillin/tazobactam against clinical isolates of Staphylococcus aureus

OBJECTIVES

Although generic medicinal products are required to have the same qualitative and quantitative composition of the active substance as their reference originator product, patients and health care professionals express concerns about their interchangeability and safety. Therefore, the present study investigated the antimicrobial activity and pathogen mutation prevention of original and generic cefepime, linezolid and piperacillin/tazobactam against Staphylococcus aureus.

METHODS

Two generic formulations of cefepime, linezolid and piperacillin/tazobactam were tested against their respective originator products. Susceptibility testing was performed with twenty-one clinical isolates of S. aureus and ATCC-29213 using broth microdilution. Time kill curves (TKC) were performed with ATCC-29213 at drug concentrations above and below the respective minimum inhibitory concentrations (MIC). Mutation prevention concentration was determined for each drug formulation against ATCC-29213. All experiments were performed in triplicate. Mutant colonies from mutation prevention concentration (MPC) experiments were genotypically tested by sequence analysis.

RESULTS

MIC ratios between contiguous originator and generic drugs were similar for each isolate. No visual differences were observed in TKCs between originator and generic substances. The MPC did not differ between different formulations of the same substance. Although sequence analysis of mutant colonies revealed genomic differences compared with the original ATCC-29213, no differences in mutation frequencies were observed between clinical isolates and ATCC-29213 treated with originator or generic substances.

CONCLUSIONS

Similar antimicrobial activity and pathogen mutation prevention was observed between contiguous substances. These results support the interchangeability of generic and originator drug formulations with the same active ingredient.

Generic lamotrigine extended-release tablets are bioequivalent to innovator drug in fully replicated crossover bioequivalence study

OBJECTIVE

Lamotrigine is a commonly prescribed antiepileptic drug. U.S. Food and Drug Administration (FDA)-funded clinical studies have demonstrated bioequivalence (BE) for generic lamotrigine immediate-release (IR) products in epilepsy patients with generic substitution. To address the potential concerns about the risk of generic-brand substitution of lamotrigine extended-release (ER) products, considering the complexity of controlled release systems and pharmacokinetic variations associated with possible within-subject variability (WSV), this prospective study assessed (1) BE of generic and brand lamotrigine ER products in a fully replicated BE study design in healthy subjects and (2) whether such fully replicated study design and WSV data can better support the approval of generic lamotrigine ER products.

METHODS

This open-label, single-dose, two-treatment, four-period, two-sequence, fully replicated crossover BE study compared generic lamotrigine ER tablet to brand Lamictal XR (200 mg) in 30 healthy subjects under fed conditions. Pharmacokinetics (PK) profiles were generated based on intensive blood sampling up to 144 h.

RESULTS

The two products showed comparable peak plasma concentration (C_max ), area under the concentration-time curve (AUC) from time zero to the last measurable time point (AUC_0-t ) and AUC extrapolated to infinity (AUC_0-inf ), whereas median time to C_max (T_max ) values differed, that is, 10 h for generic and 22 h for brand products, respectively. WSVs for PK metrics were small (~8% of C_max and ~6% of AUC) and similar between these two products. PK simulation predicted equivalent PK measurements of both products at steady state and after brand-to-generic switch, except the first day upon switching. No serious adverse events were reported.

SIGNIFICANCE

The generic lamotrigine ER tablet product demonstrates BE to the brand product in a fully replicated BE study design with healthy subjects, supporting the adequacy of the two-way crossover study design to demonstrate BE and generic-brand substitution of lamotrigine ER products.

Interchangeability between Generic and Reference Products: Limits of Average Bioequivalence Methodology

Marketing authorisation of generic drugs is based on a demonstration of the "average" bioequivalence (ABE), with acceptance limits of 0.8-1.25 for the 90% confidence interval (CI) of the ratio (generic versus reference) of geometric means of exposure (whole blood, serum or plasma drug concentration). However, when interchangeability of reference by one generic is considered during treatment of a given patient, such methodology cannot guarantee the lack of therapeutic impact especially for drugs with narrow therapeutic index. This review article describes the basis and limits of ABE methodology, and the adaptations that have been proposed by regulatory agencies. For highly variable drugs, given their large therapeutic margin, regulatory agencies even allow widening of the bioequivalence acceptance limits. For drugs with a narrow therapeutic index, the average bioequivalence methodology has been amended differently by regulatory agencies. The European Medicine Agency only requires the narrowing of the ABE acceptance limits to the 0.9-1.10 range. The US Food and Drug Administration (FDA) has proposed to narrow the ABE acceptance limits according to the reference within-subject variance. The FDA requires a fully replicate cross-over study (with four periods) which allows one to compare the within-subject variance between generic and reference drug, and to detect any subject-by-formulation interaction. Indeed, any within-subject variance difference or subject by formulation interaction is an obstacle to interchangeability at the individual level. These amendments for the ABE do not fundamentally change the fact that individual ratios of exposure (generic/reference) will vary to a larger extent than the ratio of their means. For these reasons, since true individual bioequivalence studies cannot be performed for practical reasons and statistical issues, one can suggest that, in addition to the usual average bioequivalence criteria, the limits of the 95% confidence interval of the individual generic/reference exposure ratios could be used to allow interchangeability during treatment (at least for narrow therapeutic index drugs). Limit values of such CI for interchangeability acceptance should be scaled to the therapeutic margin of the reference drug. Regulatory agencies could conduct calculations based on real datasets of bioequivalence studies to determine if such criteria could be acceptable to allow interchangeability.

Who initiates price competition when generic entrants are introduced into the South Korean pharmaceutical market?

Background

Price competition has the potential to reduce health expenditures without hindering pharmaceutical innovation. However, empirical evidence on price competition after generic drugs are introduced is scarce. This study investigates product- and substance-level determinants of price competition following the entry of generics into the South Korean market.

Methods

We selected substances that were approved by the Ministry of Food and Drug Safety from 2000 to 2019, linked their corresponding pharmaceutical products, measured the degree of price competition under various scenarios, and utilized multilevel analysis to investigate the determinants of price competition.

Results

A total of 986 substances and 12,109 corresponding pharmaceutical products were identified. Only 11% of products were affected by price competition in the 10% scenario. However, the number increased to 43% when we measured price competition at the substance level. Major domestic manufacturers mainly initiated price competition at the product level, while foreign manufacturers were reluctant to initiate price competition. At the substance level, the maximum reimbursement price was a significant determinant of price competition.

Conclusion

Price competition at the product level is rare in South Korea. In contrast, the market is quite price competitive at the substance level. Policy options could be introduced to encourage "discounted generic" substitution in an effort to maximize the effects of price competition at the substance level. Major domestic manufacturers are essential in the introduction of discounted generics into the South Korean health system.

Use of follow-on disease-modifying treatments for multiple sclerosis: Consensus recommendations

BACKGROUND

As patents for multiple sclerosis (MS) therapies expire, follow-on disease-modifying treatments (FO-DMTs) become available at reduced cost. Concerns exist that cheaper FO-DMTs are used simply to reduce healthcare costs. However, the well-being of people with MS should take priority.

OBJECTIVES

To identify best practices for FO-DMT development and use by agreeing on principles and consensus statements through appraisal of published evidence.

METHODS

Following a systematic review, we formulated five overarching principles and 13 consensus statements. Principles and statements were voted on by a multidisciplinary panel from 17 European countries, Argentina, Canada and the United States.

RESULTS

All principles and statements were endorsed by >80% of panellists. In brief, FO-DMTs approved within highly regulated areas can be considered effective and safe as their reference products; FO-DMTs can be evaluated case by case and do not always require Phase III trials; long-term pharmacovigilance and transparency are needed; there is lack of evidence for multiple- and cross-switching among FO-DMTs; and education is needed to address remaining concerns.

CONCLUSION

Published data support the use of FO-DMTs in MS. The consensus may aid shared decision-making. While our consensus focused on Europe, the results may contribute to enhanced quality standards for FO-DMTs use elsewhere.

A randomized, cross-over trial of metoprolol succinate formulations to evaluate PK and PD end points for therapeutic equivalence

There are limited comparison data throughout the dosing interval for generic versus brand metoprolol extended-release (ER) tablets. We compared the pharmacokinetics (PKs) and pharmacodynamics of brand name versus two generic formulations (drugs 1 and 2) of metoprolol ER tablets with different time to maximum concentration (T_max ) in adults with hypertension. Participants were randomized to equal drug doses (50-150 mg/day) administered in one of two sequences (brand-drug1-brand-drug2 or brand-drug2-brand-drug1) and completed 24-h PK, digital heart rate (HR), ambulatory blood pressure (BP), and HR studies after taking each formulation for greater than or equal to 7 days. Metoprolol concentrations were determined by liquid chromatography tandem mass spectrometry, with noncompartmental analysis performed to obtain PK parameters in Phoenix WinNonlin. Heart rate variability (HRV) low-to-high frequency ratio was determined per quartile over the 24-h period. Thirty-six participants completed studies with the brand name and at least one generic product. Among 30 participants on the 50 mg dose, the primary PK end points of area under the concentration-time curve and C_max were similar between products; T_max was 6.1 ± 3.6 for the brand versus 3.5 ± 4.9 for drug 1 (p = 0.019) and 9.6 ± 3.2 for drug 2 (p < 0.001). Among all 36 participants, 24-h BPs and HRs were similar between products. Mean 24-h HRV low-to-high ratio was also similar for drug 1 (2.04 ± 1.35), drug 2 (1.86 ± 1.35), and brand (2.04 ± 1.77), but was more sustained over time for the brand versus drug 1 (drug × quartile interaction p = 0.017). Differences in T_max between metoprolol ER products following repeated doses may have implications for drug effects on autonomic balance over the dosing interval.

Therapeutic Basis of Generic Substitution of Antiseizure Medications

More than thirty antiseizure medications (ASMs) are available for treating epilepsy. ASMs differ in their potency and efficacy in controlling seizures by acting on diverse targets in the brain, often with variable pharmacokinetics. Moreover, nearly 30% of people with epilepsy have drug-resistant or intractable seizures. Generic substitution of ASMs is a complex issue. It is thought that frequent generic substitution in people with epilepsy may cause problems because the U.S. Food and Drug Administration (FDA) rules allow too much variability across products. The standard bioequivalence range (80% to 125%) appears too broad for many ASMs, especially those exhibiting little separation between therapeutic and toxic levels. Hence, sub-therapeutic concentration may lead to therapeutic failure with seizure recurrence, which could be life threatening. A supra-therapeutic level could result in adverse effects or compliance issues. There are reported issues with generic substitutions of phenytoin, topiramate, levetiracetam, carbamazepine, and lamotrigine. There is discussion in the epilepsy community about additional guidelines, including designation of generic ASMs as Narrow Therapeutic Index (NTI) drugs and how patient education plays a role in generic substitution. Overall, based on the published evidence on specific generic ASMs, FDA bioequivalence standards are not the cause of problems with generic ASM substitution. Rather, it is imperative that physicians and pharmacists provide adequate patient education on what to expect when switching to generic ASMs, including changes in medication shape and color. Another suggestion would be to consider that all ASMs be considered for inclusion in NTI class to prevent the clinical outcome issues associated with generic ASM switching. SIGNIFICANCE STATEMENT: There are critical aspects to consider when switching from a brand name antiseizure medication (ASM) when a generic becomes available or switching between generics. Generic ASMs are interchanged with little consideration of differences in therapeutic equivalence and other clinical factors. This article describes key issues on generic substitution of ASMs and highlights critical pharmacotherapeutic issues associated with generic ASMs.

Simultaneous Determination of Loratadine and Its Metabolite Desloratadine in Beagle Plasma by LC-MS/MS and Application for Pharmacokinetics Study of Loratadine Tablets and Omeprazole‑Induced Drug-Drug Interaction

Background

Loratadine (LTD) is a Biopharmaceutical Classification System II basic drug with pH-sensitive aqueous solubility and dissolution is a speed-limiting step of its absorption. The drug dissolution and the gastrointestinal tract pH conditions are likely to influence the in vivo pharmacokinetic behavior of LTD tablets.

Materials and Method

A rapid, sensitive, and reliable bioanalytical method for simultaneous quantitation of LTD and its active metabolite desloratadine (DL) in beagle plasma was developed and validated based on liquid chromatography tandem mass spectrometry (LC-MS/MS). Sample preparation in low plasma consumption was accomplished by liquid–liquid extraction. The chromatographic separation was achieved on a Phenomenex Kinetex C8 column using acetonitrile and 5 mM ammonium formate as the mobile phase. A comparative pharmacokinetics study of three LTD tablets with different dissolution rates was conducted in male beagles in fasting state and an omeprazole-induced drug–drug interaction (DDI) study was subsequently performed under pretreatment of omeprazole.

Results and Conclusion

The method showed a good linear correlation over the concentration ranges of 0.008–24 ng/mL for LTD and 0.8–800 ng/mL for DL, and was successfully applied to analyze the two compounds in beagle plasma. Pharmacokinetic results showed in the fasting state the three LTD tablets were equivalent in beagles in terms of effective components. DL of the three tablets were equivalent, indicating metabolite was less susceptible to pharmaceutic preparation factors for LTD tablets in beagles. Moreover, significant changes in LTD and DL pharmacokinetics parameters were observed under the effect of omeprazole-induced pH increase in gastrointestinal tract, suggesting that DDI effects are of concern for the curative effect of LTD when combined with omeprazole. The findings will contribute to the future pharmaceutical preparations research as well as the clinical application of LTD.

Meeting report: an exploration into the scientific and regulatory aspects of pharmaceutical drug quality in the United States

INTRODUCTION

The University of Florida College of Pharmacy, Department of Pharmaceutical Outcomes and Policy hosted a seminar 6-7 March 2021, on the quality of pharmaceutical products in the United States. This meeting report summarizes the topics presented at the seminar and highlights the expert opinions offered by the presenters.Areas Covered: The seminar, held virtually due to the COVID-19 pandemic, included slide presentations and faculty-moderated panel discussions from experts in the field. These experts from regulatory, academic, and private sectors discussed bioequivalence standards, existing and emerging efforts to promote quality in brand and generic manufacturing, as well as market-based solutions throughout the drug supply chain.Expert Opinion: The time spent understanding bioequivalence standards during the seminar felt especially important and relevant in our current pandemic environment, given the present need to have confidence in the science of drug development and to advocate for the safety of pharmaceuticals. Also an important point to emphasize from the seminar, was that every stakeholder along the drug supply chain has a responsibility to do their part to maintain its quality. And those in attendance, many of whom were students of healthcare sciences, were encouraged to be leaders in their fields and develop strategies to advance innovative improvements.

Effects of Volume-Price Contracts on Pharmaceutical Prices: A Retrospective Comparative Study of Public Hospitals in Hubei of China

Background: Pharmaceutical expenditure has been increasing worldwide. Many countries have attempted to contain the increase through collective bargaining, including in China. In 2015, the Chinese government introduced a new policy to empower regional governments to reduce pharmaceutical prices through its existing tendering system which enables a lower price for products with higher procurement volumes. Xiangyang municipality in Hubei province took a lead in piloting this initiative. Objectives: This study aimed to evaluate the effects of the volume-price contract initiative on pharmaceutical price procured by the public hospitals in Xiangyang. Methods: A retrospective comparative design was adopted. The price of cardiovascular medicines (349 products under 164 International Nonproprietary Names) procured by the public hospitals in Xiangyang was compared with those procured in Yichang municipality in Hubei. A total of 15,921 procurement records over the period from January 2017 to December 2018 were examined (Xiangyang started the volume-price contract initiative in January 2018). Generalized linear regression models with a difference-in-differences approach which could reflect the differences between the two cities between January 2018 and December 2018 were established to test the effects of the volume-price contract initiative on pharmaceutical prices. Results: On average, the procurement price for cardiovascular medicines adjusted by defined daily dosage in Xiangyang dropped by 41.51%, compared with a 0.22% decrease in Yichang. The difference-in-differences results showed that the volume-price contract initiative resulted in a 36.24% drop (p = 0.006) in the price (30.23% for the original brands, p = 0.008), in addition to the therapeutic competition effect (31.61% reduction in the price, p = 0.002). The top 100 domestic suppliers were highly responsive to the initiative (82.80% drop in the price, p = 0.001). Conclusion: The volume-price contract initiative has the potential to bring down the price of pharmaceutical supplies. Higher responses from the domestic suppliers are evident.

Real world evidence in effectiveness, safety, and cost savings of generic levothyroxine: a systematic review

PURPOSE

Generic levothyroxine, approved through Abbreviated New Drug Application (ANDA), is available for generic substitution. But ANDA does not require nonclinical or clinical data to establish safety and efficacy. Post-marketing evidence in generic equivalence for marketed levothyroxine products is limited. We conducted a systematic review to synthesize evidence in effectiveness, safety, and cost savings between patients using generic and branded levothyroxine.

METHODS

We systematically searched published literature from Medline, International Pharmaceutical Abstracts, APA PsycInfo, and CINAHL from inception through 04/18/2021. Included studies were limited to post-marketing empirical studies including patients who used levothyroxine products, with direct comparison between generic and brand levothyroxine, and published in English. Risk of bias was assessed using the National Institute of Health Study Quality Assessment Tools. Two reviewers independently extracted data and conducted quality assessment for included studies. Given that the nine studies are so diverse, a meta-analysis was not possible. Therefore we provided a narrative review of the included studies.

RESULTS

Of 349 studies identified, nine met the inclusion criteria. Six studies compared thyrotropin levels and adverse events between generic and brand users and provided mixed findings. In addition, generic users may generate prescription cost savings for payers but had suboptimal medication adherence than brand users.

CONCLUSION

Findings from this systematic review highlighted the limited and mixed evidence in real-world clinical and economic outcomes for generic levothyroxine. Continuous post-marketing monitoring and assessment of generic drugs are warranted to ensure treatment effectiveness, patient safety, and achieve financial savings in prescription costs.

Model-Based Approach for Designing an Efficient Bioequivalence Study for Highly Variable Drugs

The statistical procedures as outlined by the European Medicines Agency (EMA) and United States Food and Drug Administration (FDA) guidelines for bioequivalence testing of highly variable drugs (HVDs) are complex. Additionally, the sample size is affected by clinical study designs or practical real-world problems, such as dropout rate or study budget. To overcome these difficulties, we propose a model-based approach for the selection of a study design with a sample size that satisfies the bioequivalence criteria using simulation studies based on a pharmacokinetic (PK) model. The designed approach was implemented using a simulation procedure considering some conventionally measured factors, such as geometric mean ratio and within-subject coefficient of variation, with various PK information important in determining bioequivalence. All simulation results were assessed according to the EMA and FDA guidelines. Furthermore, power calculations from simulation results were interpreted with regard to PK characteristics and compared among 2 × 2, 3 × 3, and 2 × 4 crossover designs to determine the efficient design considering appropriate sample size and duration of the clinical study. The proposed approach can be applied to bioequivalence studies of all drugs. However, the current study was targeted at HVDs, which are highly likely to require detailed decision making for sample size and study design.

A Proposed Approach for the Determination of the Bioequivalence Acceptance Range for Narrow Therapeutic Index Drugs in the European Union

The current regulatory criterion for bioequivalence of narrow therapeutic index (NTI) drugs in the European Union requires that the 90% confidence interval for the ratio of the population geometric means of the test product compared with the reference for area under the plasma concentration-time curve (AUC), and in certain cases maximum plasma drug concentration (C_max ), to be included within the tighter acceptance range of 90.00-111.11%. As a consequence, sponsors need to recruit a higher number of subjects to demonstrate bioequivalence and this may be seen as increasing the burden for the development of generics. This "one-size-fits-all" criterion is particularly questionable when the within-subject variability of the reference product is moderate to high. As an alternative, we propose a further refined statistical approach where the acceptance range is narrowed based on the within-subject variability of the reference product of the NTI drug, similar to the one used for widening the standard 80.00-125.00% acceptance range for highly variable drugs. The 80.00-125.00% acceptance range is narrowed, only if the within-subject variability is lower than 30%, down to the current NTI acceptance range of 90.00-111.11% when the within-subject variability is 13.93% or lower. Examples within the current European Medicines Agency list of NTI drugs show a considerable reduction in required sample size for drugs like tacrolimus and colchicine, where the predicted within-subject variability is 20-30%. In these cases, this approach is less sample size demanding without any expected increase in the therapeutic risks, since patients treated with reference products with moderate to high within-subject variability are frequently exposed to bioavailability differences larger than 10%.

Medical Service Use and Charges for Cancer Care in 2018 for Privately Insured Patients Younger Than 65 Years in the US

IMPORTANCE

Currently, there are limited published data regarding resource use and spending on cancer care in the US.

OBJECTIVE

To characterize the most frequent medical services provided and the associated spending for privately insured patients with cancer in the US.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from the MarketScan database for the calendar year 2018 from a sample of 27.1 million privately insured individuals, including patients with a diagnosis of the 15 most prevalent cancers, predominantly from large insurers and self-insured employers. Overall societal health care spending was estimated for each cancer type by multiplying the mean total spending per patient (estimated from MarketScan) by the number of privately insured patients living with that cancer in 2018, as reported by the National Cancer Institute's Surveillance, Epidemiology, and End Results program. Analyses were performed from February 1, 2018, to July 8, 2021.

EXPOSURES

Evaluation and management as prescribed by treating care team.

MAIN OUTCOMES AND MEASURES

Current Procedural Terminology and Healthcare Common Procedure Coding System codes based on cancer diagnosis code.

RESULTS

The estimated cost of cancer care in 2018 for 402 115 patients with the 15 most prevalent cancer types was approximately $156.2 billion for privately insured adults younger than 65 years in the US. There were a total of 38.4 million documented procedure codes for 15 cancers in the MarketScan database, totaling $10.8 billion. Patients with breast cancer contributed the greatest total number of services (10.9 million [28.4%]), followed by those with colorectal cancer (3.9 million [10.2%]) and prostate cancer (3.6 million [9.4%]). Pathology and laboratory tests contributed the highest number of services performed (11.7 million [30.5%]), followed by medical services (6.3 million [16.4%]) and medical supplies and nonphysician services (6.1 million [15.9%]). The costliest cancers were those of the breast ($3.4 billion [31.5%]), followed by lung ($1.1 billion [10.2%]) and colorectum ($1.1 billion [10.2%]). Medical supplies and nonphysician services contributed the highest total spent ($4.0 billion [37.0%]), followed by radiology ($2.1 billion [19.4%]) and surgery ($1.8 billion [16.7%]).

CONCLUSIONS AND RELEVANCE

This analysis suggests that patients with breast, colorectal, and prostate cancers had the greatest number of services performed, particularly for pathology and laboratory tests, whereas patients with breast, lung, lymphoma, and colorectal cancer incurred the greatest costs, particularly for medical supplies and nonphysician services. The cost of cancer care in 2018 for the 15 most prevalent cancer types was estimated to be approximately $156.2 billion for privately insured adults younger than 65 years in the US.

Pharmacokinetics and Generic Drug Switching: A Regulator's View

There appears to be a mismatch between the assumed therapeutic equivalence of generic drugs, their interchangeability, and reported clinical discomfort following generic drug use and drug switches. In this article, we describe why we are of the opinion that the current regulatory approach to the evaluation of generic drugs based on average bioequivalence is sufficient to expect therapeutic equivalence in the clinical setting. This has often been debated, specifically as adverse drug reactions related to generic drug switches are regularly reported. We agree that clinical discomfort during a bioequivalent drug switch may indeed be caused by different exposures to the active substance. However, this difference in exposure is not a result of the characteristics or quality of generic drugs; it is caused by the pharmacokinetic within-subject variability of the active substance, i.e., the variability on the bioavailability of the active substance, when comparing two occasions of administration of the same drug product, to the same patient. Therefore, reported clinical discomfort following generic drug use and drug switches does not warrant a change in the regulatory approach to the evaluation of the bioequivalence of generic drugs. Switching from a brand-name drug to currently approved generic drugs, or between different generic drugs, will in principle result in comparable exposure, within boundaries determined by the within-subject variability of the pharmacokinetics of the active substance involved.

Global access to affordable direct oral anticoagulants

Poor control of cardiovascular disease accounts for a substantial proportion of the disease burden in developing countries, but often essential anticoagulant medicines for preventing strokes and embolisms are not widely available. In 2019, direct oral anticoagulants were added to the World Health Organization’s WHO Model list of essential medicines. The aims of this paper are to summarize the benefits of direct oral anticoagulants for patients with cardiovascular disease and to discuss ways of increasing their usage internationally. Although the cost of direct oral anticoagulants has provoked debate, the affordability of introducing these drugs into clinical practice could be increased by: price negotiation; pooled procurement; competitive tendering; the use of patent pools; and expanded use of generics. In 2017, only 14 of 137 countries that had adopted national essential medicines lists included a direct oral anticoagulant on their lists. This number could increase rapidly if problems with availability and affordability can be tackled. Once the types of patient likely to benefit from direct oral anticoagulants have been clearly defined in clinical practice guidelines, coverage can be more accurately determined and associated costs can be better managed. Government action is required to ensure that direct oral anticoagulants are covered by national budgets because the absence of reimbursement remains an impediment to achieving universal coverage. Tackling cardiovascular disease with the aid of direct oral anticoagulants is an essential component of efforts to achieve the World Health Organization’s target of reducing premature deaths due to noncommunicable disease by 25% by 2025.

Performance of Multiple-Batch Approaches to Pharmacokinetic Bioequivalence Testing for Orally Inhaled Drug Products with Batch-to-Batch Variability

Batch-to-batch pharmacokinetic (PK) variability of orally inhaled drug products has been documented and can render single-batch PK bioequivalence (BE) studies unreliable; results from one batch may not be consistent with a repeated study using a different batch, yet the goal of PK BE is to deliver a product comparison that is interpretable beyond the specific batches used in the study. We characterized four multiple-batch PK BE approaches to improve outcome reliability without increasing the number of clinical study participants. Three approaches include multiple batches directly in the PK BE study with batch identity either excluded from the statistical model (“Superbatch”) or included as a fixed or random effect (“Fixed Batch Effect,” “Random Batch Effect”). A fourth approach uses a bio-predictive in vitro test to screen candidate batches, bringing the median batch of each product into the PK BE study (“Targeted Batch”). Three of these approaches (Fixed Batch Effect, Superbatch, Targeted Batch) continue the single-batch PK BE convention in which uncertainty in the Test/Reference ratio estimate due to batch sampling is omitted from the Test/Reference confidence interval. All three of these approaches provided higher power to correctly identify true bioequivalence than the standard single-batch approach with no increase in clinical burden. False equivalence (type I) error was inflated above the expected 5% level, but multiple batches controlled type I error better than a single batch. The Random Batch Effect approach restored 5% type I error, but had low power for small (e.g., <8) batch sample sizes using standard [0.8000, 1.2500] bioequivalence limits.

Batch Selection via In Vitro/In Vivo Correlation in Pharmacokinetic Bioequivalence Testing

Pharmacokinetic differences between manufacturing batches, well established for inhaled drug products, preclude control of patient risk in the customary two-way (single batch) pharmacokinetic bioequivalence crossover design if batches are randomly chosen. European regulators have recommended selecting a "typical" in vitro batch to represent each product in pharmacokinetic bioequivalence testing. We explored the feasibility of this approach to control patient risk (the "false equivalence", or Type I, error rate). The probability of achieving a Test/Reference 90% confidence interval within (0.80, 1.25) for a true (non-equivalent) value of 1.25 was simulated for a two-way crossover design using the median in vitro batch across a range of number of in vitro batches, in vitro/in vivo correlation (IVIVC) quality (correlation coefficient, r, of zero to one), and within-subject between-batch pharmacokinetic variability. Even under extremely optimistic conditions, e.g., r=0.95 and >100 batches per product screened in vitro, patient risk for typical between-batch variability levels remained at least threefold higher than the 5% regulatory expectation for the significance level (the false equivalence error rate) of the pharmacokinetic bioequivalence test. This elevated error rate in bioequivalence decision-making occurs because of incomplete confidence that the true product average has been identified, and, importantly, omission of this uncertainty from the bioequivalence confidence interval.

Treatment optimization of maintenance immunosuppressive agents in pediatric renal transplant recipients

Introduction: Graft survival in pediatric kidney transplant patients has increased significantly within the last three decades, correlating with the discovery and utilization of new immunosuppressants as well as improvements in patient care. Despite these developments in graft survival for patients, there is still improvement needed, particularly in long-term care in pediatric patients receiving grafts from deceased donor patients. Maintenance immunosuppressive therapies have narrow therapeutic indices and are associated with high inter-individual and intra-individual variability.Areas covered: In this review, we examine the impact of pharmacokinetic variability on renal transplantation and its association with age, genetic polymorphisms, drug-drug interactions, drug-disease interactions, renal insufficiency, route of administration, and branded versus generic drug formulation. Pharmacodynamics are outlined in terms of the mechanism of action for each immunosuppressant, potential adverse effects, and the utility of pharmacodynamic biomarkers.Expert opinion: Acquiring abetter quantitative understanding of immunosuppressant pharmacokinetics and pharmacodynamic components should help clinicians implement treatment regimens to maintain the balance between therapeutic efficacy and drug-related toxicity.

Bioequivalence for a Fixed-Dose Combination Formulation of Bazedoxifene and Cholecalciferol Compared With the Corresponding Single Entities Given Together

A fixed-dose combination (FDC) formulation of bazedoxifene 20 mg and cholecalciferol 8 mg was developed to increase medication compliance and convenience for osteoporosis patients. This study was conducted to demonstrate bioequivalence by comparing the pharmacokinetic (PK) profiles and tolerability of an FDC tablet and the individual component tablets. A randomized, open-label, single-dosing, 2-treatment, 2-period, 2-sequence crossover study was conducted in 52 healthy subjects. All subjects were randomly assigned to 2 sequences, and they received FDC tablets of bazedoxifene and cholecalciferol and individual component tablets. Serial blood samples for PK evaluation were collected up to 24 hours predose and 120 hours postdose, and the PK parameters were estimated by noncompartmental methods. Throughout the study, tolerability was assessed based on adverse events, vital signs, and clinical laboratory tests. Of the enrolled 52 subjects, 47 subjects completed the study. The results, the geometric mean ratios (GMRs) and 90% confidence intervals (90%CIs), of bazedoxifene C_max and AUC_0-t for FDC to single entities given together were 0.98 (0.91-1.05) and 1.02 (0.97-1.07), respectively. The GMRs (90%CIs) of cholecalciferol C_max and AUC_0-t for FDC to single entities given together were 0.96 (0.91-1.00) and 0.94 (0.90-0.99), respectively. Overall, the GMRs (90%CIs) of the PK parameter of bazedoxifene and cholecalciferol fell within the conventional bioequivalence range of 0.8-1.25. There were no clinically significant differences in the safety profile between the 2 treatments. In conclusion, this study confirmed the development of a new FDC drug by demonstrating that the FDC formulation of bazedoxifene and cholecalciferol is biologically equivalent to the coadministered individual formulations.

Knowledge, opinions and attitudes of primary care physicians about generic drugs: a cross-sectional study

BACKGROUND

Generic drug (GD) use is affected by many factors, including physicians' approach.

OBJECTIVE

This study aimed to investigate the knowledge, opinions and attitudes of primary care physicians (PCPs) about GDs and potentially associated factors.

METHODS

An adequately representative sample (n = 354) of PCPs was determined via stratified and simple random sample selection method in this descriptive, cross-sectional study. The research data were collected through a face-to-face 40-item survey, where the knowledge, opinions and attitudes about GDs were questioned. The prescribing percentage of GDs overall was also examined.

RESULTS

The survey was completed by 305 PCPs (mean age: 49.2 ± 7.9 years; 57.4% male). The rate of correct responses about GDs was 67.6% for basic knowledge and 46.6% for the development process. The percentages of PCPs who declared that GDs were 'less efficacious', 'of lower quality' and 'less safe' than original drugs were 65.2%, 53.4% and 35.4%, respectively. More than half (60.3%) of the PCPs declared not to pay attention to whether the drug is generic while prescribing. It was observed that, as the knowledge level of the physicians increased, negative opinions and prescribing attitudes regarding the effectiveness, quality and safety of the GDs decreased. The rate of GD prescribing (51.6%) in Izmir was lower than the rest of the country (54.6%; P < 0.001).

CONCLUSION

This study shows that the knowledge of PCPs about GDs is generally inadequate, which reflects negatively on their opinions and attitudes regarding the use of GDs. Educational activities can help establish awareness that GDs can be used without doubt of their effectiveness, quality and safety.

Why Were More Than 200 Subjects Required to Demonstrate the Bioequivalence of a New Formulation of Levothyroxine with an Old One?

At the request of French Regulatory Authorities, a new formulation of Levothyrox^® was licensed in France in 2017, with the objective of avoiding the stability deficiencies of an existing licensed formulation. Before launching the new formulation, an average bioequivalence (ABE) trial was conducted, having enrolled 204 subjects and selected for interpretation a narrow a priori bioequivalence range of 0.90-1.11. Bioequivalence was concluded. In a previous publication, we questioned the ability of an ABE trial to guarantee the switchability within patients of the new and old levothyroxine formulations. It was suggested that the two formulations should be compared using the conceptual framework of individual bioequivalence. The present paper is a response to those claiming that, despite the fact that ABE analysis does not formally address the switchability of the two formulations, future patients will nevertheless be fully protected. The basis for this claim is that the ABE study was established in a large trial and analyzed using a stringent a priori acceptance interval of equivalence. These claims are questionable, because the use of a very large number of subjects nullifies the implicit precautionary intention of the European guideline when, for a Narrow Therapeutic Index drug, it recommends shortening the a priori acceptance interval from 0.80-1.25 to 0.90-1.11.

Market Exclusivity of the Originator Drugs in South Korea: A Retrospective Cohort Study

Introduction: Generic entry is a well-known driver of competition and cost containment.

Objectives: We aim to measure the market exclusivity of originator drugs and to determine what influences the entry of generics in South Korea.

Methods: A list of originator drugs approved by the authority from 2000 to 2013 and their corresponding generics were paired. An event history model was applied for a statistical estimation for the duration until generic entry and to identify abbreviating or prolonging factors on the duration.

Results: A total of 2,061 pairs of originator and generics were identified. The market exclusivity for the originator drugs, including NDAs and non-NDAs, has not notably changed. However, competition among non-NDAs was less common than we expected. We found delayed time to entry of generics in the long run, particularly for non-NDAs in injection forms and biologics, and this finding is partially associated with market attractiveness.

Conclusion: The authority should address the delayed availability of certain types of generic drugs. The government could provide information on off-patent pharmaceuticals with no generic competition, designate their corresponding submissions as prioritized in the review process, and provide additional market exclusivity when entering the market via a long period of exclusivity.

Appropriate use of generic and branded antiseizure medications in epilepsy: Updated recommendations from the Italian League Against Epilepsy (LICE)

Generic drugs are increasingly used to treat many diseases including epilepsy. The growing importance of generic antiseizure medications (ASMs) has led the ASMs commission of the Italian League Against Epilepsy (LICE) to review current evidence in the literature about efficacy and safety of these products. Recommendations from other scientific organizations have also been considered to provide an update of the LICE position about their utilization (List of Recommendations). Compared with the previous literature review, randomized controlled trials assessing bioequivalence among branded drugs and generics are currently available. Although some contrasting results have been reported, brand-to-generic switching was effective and tolerable in real-life settings, with similar adverse event ratios. Based on these findings, LICE concluded that, conforming to the rigorous regulation of USA and EU markets, generic ASMs are not inferior to the respective branded, providing a cost advantage for patients starting or replacing monotherapy or add-on, and for those with incomplete seizure control. Branded-to-generic (and vice versa) switching is not recommended (although applicable) during seizure remission, as well as the generic-to-other generic switching. Other recommendations focus on the appropriateness of therapeutic drug monitoring (TDM) when switching is required, paying attention to avoiding the erroneous switch between modified and immediate-release formulations during dispensation. Finally, to support patients' compliance, they should be assured of generics' safety and efficacy and carefully informed with practical advice, particularly when the switching is associated with aspect modifications (e.g. color and shape changes) of the pill or the packaging.

Manufacturer switch of anti-seizure drugs may not increase the risk of seizure recurrence in Children: A nationwide study of prescription data in Germany

OBJECTIVE

Several publications on the exchangeability of antiepileptic drugs in clinical settings revealed an increased risk for seizure recurrence after changing the manufacturer of anti-seizure drugs (ASD) in adults, possibly due to a decline of adherence. It is unclear whether this holds true in children and adolescents.

METHODS

Patient data of children and adolescents (<18 years) were collected anonymously from 236 German pediatricians and pediatric neurologists between January 2011 and December 2018 using the IMS® Disease Analyzer database (IQVIA, Frankfurt, Germany). Patients with epilepsy were included if at least 2 prescriptions within 360 days and 1 within 180 days prior to the index date were available. The cohort was separated into a seizure group and seizure-free controls. Both groups were matched 1:1 according to age, gender, insurance status, and treating pediatrician. The risk for seizure recurrence after a manufacturer switch of the same ASD at the last prescription before the index date was analyzed using a multivariate regression model.

RESULTS

A total of 678 children and adolescents with epilepsy were included (each group: n = 339; age: 9.6 ± 4.4 years). Comparing both groups, the risk for seizures recurrence was not increased after a manufacturer switch had occurred. Albeit changes during the last prescription before the index date had occurred more often in the seizure-free group, neither change of branded and generic products nor substances reached significance. Only change of ASD strength showed a significantly reduced odds ratio for seizures (OR 0.40, 95% CI 0.24-0.65, p < 0.001).

SIGNIFICANCE

In contrast to the available evidence in adults, changing the manufacturer did not appear to increase the risk for seizure recurrence in previously seizure-free children and adolescents with epilepsy.

Knowledge, attitude, and practice of generic medicines among physicians at multispecialty hospital: An observational study

Background:

Methods:

Results:

Conclusion:

Physician and Nurse Practitioner Attitudes on Generic Prescribing of Oral Contraceptive Pills and Antidepressants

IMPORTANCE

As prescription drug costs rise, it is important to understand attitudes among primary care physicians and nurse practitioners (NPs) towards generic drugs.

OBJECTIVE

We aimed to examine the generic skepticism index (GSI) among primary care clinicians, and their willingness to discuss and prescribe generic antidepressants (ADs) and generic oral contraceptives (OCPs).

DESIGN

We used a factorial vignette design survey to test 4 factors: message source, message, brand preference, and drug class. Participants were randomized to different combinations of factors.

SETTING

This was a cross-sectional study.

PARTICIPANTS

Physicians registered with the American College of Physicians (ACP) and NPs registered with the American Association of Nurse Practitioners (AANP) participated in the study.

MAIN MEASURES

The primary outcomes were generic skepticism as measured using the generic skepticism index (GSI), and clinician willingness to discuss and prescribe generics.

RESULTS

Surveys were completed by 56% of physicians (n = 369/661) and 60% of NPs (n = 493/819). Compared with physicians, NPs were younger (p < 0.001), predominantly female (p < 0.001), and differed in the race (p < 0.001). According to the GSI, 16% (n = 138/862) were identified as generic skeptics (18.5% of NPs and 12.7% of physicians, p = 0.023). Generic skeptics had lower odds of willingness to discuss switching (OR 0.22, 95% CI (0.14-0.35), p < 0.001) or prescribe (OR 0.18, 95% CI (0.11-0.28), p < 0.001) generic OCPs. Participants had lower odds of willingness to prescribe generic drugs to patients with brand preference compared with brand-neutral patients (OR 0.64, 95% CI 0.50-0.82, p < 0.001).

CONCLUSIONS AND RELEVANCE

Generic skepticism was associated with lower willingness to discuss or prescribe generic drugs. Clinicians reported lower willingness to discuss switching or prescribe generics for OCPs than for ADs. Patient brand preference hindered generic prescribing. Message source and message type were not significantly associated with outcomes.

Assessment of Purity Parameters of Generic and Brand Name Losartan Potassium

Background:

Generic products must be bioequivalent to the innovator brand product. Nevertheless, in addition to meeting bioequivalence standards, attention must be paid to the content of the active substance and contaminants in generic drugs.

Objective:

This study compared the pharmaceutical quality of four generic losartan potassium formulations with the brand-name product: Cozaar®.

Methods:

The United States Pharmacopeia (USP) losartan potassium standard was used as reference material. The products tested (all 50 mg formulations) included four generic tablet formulations and the innovator brand product Cozaar®. Active substance content, organic impurities, and elemental impurities were assessed following the USP monograph for losartan potassium tablets and USP Chapter <233> on Elemental Impurities.

Results:

The results showed that three of the four generic products had low content of the active ingredient. The values ranged from 86.4 to 93.8%, being acceptable not below 95% of the labeled amount. Organic impurities were not detected in any of the products, and of the 13 elemental impurities tested, only four elements were detected. The elemental impurities Cr, Ni, Cu, and As were, however, in amounts within the limits established by the USP monograph. The only concern on the generic drugs analyzed was the low content of the active ingredient in 75% of the products.

Conclusion:

Since losartan is a drug of continuous use, lower content of the active ingredient may go unnoticed by the users of the generic product and entailed clinical consequences during long-term therapy.

Comparison between Branded and Generic Furosemide 40 mg Tablets Using Thermal Gravimetric Analysis and Fourier Transform Infrared Spectroscopy

Background and Purpose

There has been a long-standing belief that generic drugs are of lower value in comparison to their branded name counterparts. They are in particular under scrutiny due to their low market price. Even though the reduction in costs is largely based on skipping expensive preclinical studies and clinical trials for generic drugs, the purity and quality of the raw materials in the production of generic drugs is debatable. Thus, the objective of the study was to analyze and assess the quality comparability of generic furosemide 40 mg (FSD) tablets to branded product available in the market.

Materials and Methods

Quality control tests, in vitro drug release assessments, and thermal analysis investigations for both analog products of FSD were performed. Various physical parameters related to the tablet quality, such as hardness, weight variation, and friability tests, were examined. In vitro drug release behavior evaluations were conducted according to United States Pharmacopeia (USP) specifications and guidelines, whereas thermal analysis was carried out using thermal gravimetric analysis (TGA), and tablets were further evaluated by Fourier transform infrared (FTIR) spectroscopy.

Results

The results indicated a significant variation between the two products in terms of hardness, weight variation, and friability. This could be correlated to variation appeared in thermal and spectroscopic spectra between the two products using TGA and FTIR. Drug release of FSD was slightly different between both products following incubation in different pH media (1.2, 3.0, and 6.5; 120 min), however, this was in accordance with USP dissolution requirements as < 80% of drug release was obtained within the first 30 min from each product.

Conclusion

This study is a useful example for the independent investigations using thermal and spectroscopic analysis to confirm potential hidden variations between generic and branded products that could not be obtained by the bioequivalence studies.

Quality Testing of Difficult-to-Make Prescription Pharmaceutical Products Marketed in the US

IMPORTANCE

Health care practitioners and patients must have information to support their confidence in the quality of prescription pharmaceuticals.

OBJECTIVE

To determine whether there were clear and substantive differences in major quality attributes between difficult-to-make solid oral dosage form pharmaceutical products marketed in the US.

DESIGN, SETTING, AND PARTICIPANTS

This quality improvement study analyzed US Food and Drug Administration-collected samples of 252 drug products marketed in the US and manufactured in the US, Canada, Europe, India, and the rest of Asia. These drug products were immediate-release solid oral dosage forms considered difficult to make on the basis of product quality history. This sampling included 35 innovator and 217 generic drug samples manufactured by 46 different firms containing 17 different active ingredients. Statistical analysis was performed from February to November 2019.

MAIN OUTCOMES AND MEASURES

All products were tested within their shelf life on the basis of the legally recognized tests of the US Pharmacopeia for the major quality attributes of dosage unit uniformity and dissolution. These tests measure dosage consistency and drug release, respectively. The consistency of either attribute was used to calculate a process performance index to describe the variability in manufacturing.

RESULTS

All 252 drug product samples met the US market standards for dosage unit uniformity and dissolution, although the process performance index (Ppk) for dissolution fell below the level of 4-sigma capability (ie, <1 error per 1600) for 11 different manufacturers and for generics in 4 of 5 regions, including the US. As part of a retrospective analysis, manufacturers performing above the median Ppk for either dissolution or dosage unit uniformity submitted fewer product quality defect reports (mean field alert reports of 0.22 and 0.63, respectively) than those falling at or below the median Ppk for these attributes (mean field alert reports of 2.1 and 1.7, respectively).

CONCLUSIONS AND RELEVANCE

All samples met the US market standards for dosage unit uniformity and dissolution, indicating acceptability for use by patients regardless of manufacturer or region. To our knowledge, this is the largest sampling study of pharmaceutical manufacturers for the US market and these data provide objective insight into the quality of prescription drugs with high manufacturing risks.

Treprostinil in the treatment of pulmonary arterial hypertension

Despite progress over the past 30 years, pulmonary arterial hypertension remains a condition with high morbidity and mortality. Pharmacological and technological advances have shifted the approach to treating pulmonary arterial hypertension. Recent developments revolve heavily around novel routes of drug administration and delivery. In 2009, inhaled treprostinil was approved followed by oral treprostinil in 2013 providing patients with more convenient routes of administration compared with the parenteral alternatives. We are on the cusp of having the first fully implantable infusion pump for continuous intravenous treprostinil delivery. In 2019, generic treprostinil was approved, making the medication much more affordable for patients. In this review, we discuss in detail the recent developments surrounding both traditional and novel treprostinil products.

Effects of generic exchange of solid oral dosage forms in neurological disorders: a systematic review

Background Generic drug exchange is common practice in most healthcare systems. While generics certainly contribute to economic savings, the altered drug formulation might be associated with potential therapeutic problems. Given the narrow therapeutic windows in neurologic indications, any detrimental effect on the therapy can lead to significant consequences. Aim of the review This review aims to investigate potential problems related to a switch from brand-name to generic or from generic to generic drug products in patients with neurologic diseases. Method The review was conducted following the PICO framework and the PRISMA guidelines. MEDLINE and Scopus databases were searched for articles published in English and German language between January 1, 1995 and October 17, 2018. Studies included in this review were randomized controlled studies, reviews, systematic reviews, overviews, cohort studies and case-control studies. Studies excluded were letters, comments, authors view, congress or seminar papers and studies with a focus on economic impact or costs. Results were synthesized qualitatively. The primary outcomes were pharmacokinetic parameters such as the area under the curve (AUC), the peak serum concentration (c_max) or the time at which c_max is observed (t_max). Results The search identified 67 studies with a great variety of endpoints and study designs. The leading indication was epilepsy. Two small RCTs were found on lamotrigine switch. Analysis of the other studies found no significant differences in pharmacokinetic parameters when switching to generic drugs. A more heterogeneous picture was revealed regarding hospitalizations, breakthrough seizures, failure of therapy, adherence and patient concerns. Conclusion While most reports were of poor quality, lamotrigine was the drug with the best available data. Summarizing the results of the available studies, pharmacokinetic parameters of antiepileptic drugs show low deviation. In contrast, data on clinical parameters are less consistent. Some studies found increased seizure frequencies and adverse-drug events, while others showed no complications. Adherence and patient satisfaction seemed to be impaired. In daily practice, generic exchange in epilepsy should be a carefully balanced decision, conducted with great caution. Further research is needed, especially regarding neurologic indications other than epilepsy.

Evaluation of fluticasone propionate/salmeterol for the treatment of COPD: a systematic review

Introduction: Recently, the generic formulation of FP/SAL FDC has been approved in COPD. Although FP/SAL FDC has been the first long-acting FDC approved in COPD, no systematic review assessed the effect of this combination for the treatment of COPD by considering specifically Phase IV studies. The aim of this review was to systematically assess the effect of FP/SAL FDC in COPD patients enrolled in Phase IV studies.Areas covered: The question of this systematic review was to examine the evidence regarding the impact of FP/SAL FDC for the treatment of COPD by searching for Phase IV studies in the ClinicalTrials.gov database.Expert opinion: Generic drugs represent an effective cost-saving step for health-care budgets in the treatment of COPD and should be used in agreement with current recommendations and prescription accuracy. FP/SAL FDC is recommended for the initiation therapy just in a small percentage of symptomatic patients that are at high risk of exacerbation with blood eosinophil counts ≥300 cells per μl. At follow-up, FP/SAL FDC can be escalated to triple ICS/LABA/LAMA combination or switched to LABA/LAMA combination by considering symptoms, exacerbations, lack of response to ICS, inappropriate original indication, and ICS-related adverse events such as pneumonia.

Predicting Cost-Effectiveness of Generic vs. Brand Dabigatran Using Pharmacometric Estimates Among Patients with Atrial Fibrillation in the United States

Generic entry of newer anticoagulants is expected to decrease the costs of atrial fibrillation management. However, when making switches between brand and generic medications, bioequivalence concerns are possible. The objectives of this study were to predict and compare the lifetime cost‐effectiveness of brand dabigatran with hypothetical future generics. Markov microsimulations were modified to predict the lifetime costs and quality‐adjusted life years of patients on either brand or generic dabigatran from a US private payer perspective. Event rates for generics were predicted using previously developed pharmacokinetic‐pharmacodynamic models. The analyses showed that generic dabigatran with lower‐than‐brand systemic exposure were dominant. Meanwhile, generic dabigatran with extremely high systemic exposure was not cost‐effective compared with the brand reference. Cost‐effectiveness of generic medications cannot always be assumed as shown in this example. Combined use of pharmacometric and pharmacoeconomic models can assist in decision making between brand and generic pharmacotherapies.

A Relative Bioavailability Study of Two Misoprostol Formulations Following a Single Oral or Sublingual Administration

Introduction

Misoprostol (Cytotec) was primarily made for treating gastric ulcers. However today it is mostly used for abortion, treating postpartum hemorrhage, and for induction of labor. The tablet contains 200 µg of misoprostol, yet the dosages used for induction of labor are much smaller (25–50 µg), leading to uncertainty of dosage in daily use.

Aim

To evaluate and compare the relative bioavailability of two misoprostol products (Angusta 25 µg and Cytotec 200 µg tablets) administered orally or sublingually given in a daily clinical setting to women admitted for induction of labor at term.

Methods

Women carrying a live, singleton fetus in a cephalic position and with a gestational age between 259 and 296 days were included. Blood samples were collected at 0, 5, 10, 20, 30, 40, 50, 75, 100, 120, 180, and 240 minutes. A serum analytical assay was performed and pharmacokinetic parameters were calculated. Patients were assigned to one of three groups.

Results

A total of 72 patients were included. No significant differences demographic characteristics were found. The ratios for AUC, AUC (_0−t), and C_max were similar in all three groups, but CI-values were outside the required 80–125%. Sublingual administration yielded a 20–30% higher bioavailability and a 50% higher C_max than compared to the oral route.

Conclusion

The relative bioavailability between Angusta and Cytotec could not be confirmed as being equal at the 25 µg or 50 µg level because the 90% CI-values when comparing the ratios for AUC, AUC_(0−t), and C_max were wider than accepted. The reason for this could be the real-life, non-standardized circumstances in which the study was conducted. Sublingual administration seems to have higher bioavailability than oral administration. More studies are needed to ascertain an optimal dosage regime balancing both safety and efficacy for mother and child.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier NCT02516631.

Deleterious impact of a generic temozolomide formulation compared with brand-name product on the kinetic of platelet concentration and survival in newly diagnosed glioblastoma

Chemo-induced thrombocytopenia is a limiting toxicity among patients receiving temozolomide (TMZ) as first-line treatment for glioblastoma. We aimed to compare early platelet concentration kinetics, hematological safety profile, and impact on survival following the initiation of either the brand-name or a generic TMZ formulation. A retrospective trial was conducted in patients suffering from newly diagnosed glioblastoma. Patients were treated with TMZ at 75 mg/m² per day during six weeks, concomitantly with radiotherapy. Platelet concentration was collected each week. Primary endpoint was to perform a linear mixed-effect model of platelet concentration kinetic over weeks. A total of 147 patients were included as follows: 96 received the brand-name TMZ, and 51 received a generic TMZ formulation. Exposition to the generic was a significant variable that negatively influenced the platelet kinetics in the radiotherapy and concomitant TMZ phase, P = 0.02. Grade ≥3 chemo-induced thrombocytopenia was more frequent in the generic group: 19.6% [95% CI 8.7-30.5%] vs 3.1% [0-6.6%], P = 0.001. Exposition to the generic formulation of TMZ led to increase early treatment discontinuation due to TMZ-induced thrombocytopenia and was a worsening independent prognostic factor on overall survival: adjusted HR 1.83 [1.21-2.8], P = 0.031. These data suggest that exposition to a generic formulation of TMZ vs the brand-name product is associated with higher early platelet decrease leading to clinically relevant impacts on treatment schedule in glioblastoma. Further prospective trials are needed to confirm these results.

Switching among branded and generic medication products during ongoing treatment of psychiatric illness

Switches between branded (reference) medications and the corresponding generic medications or between two different corresponding generic medications occur commonly during the treatment of central nervous system disorders. Prescribing a generic product in place of a reference product can reduce patient and pharmacy costs. But there can be implications. Planned or unplanned switches from one product to another during ongoing treatment may introduce variability in drug exposure which could in turn compromise efficacy and/or tolerability. Studies comparing the initiation of reference versus generic products do not provide clear evidence of the superiority of reference or generic products generally, whereas several studies examining a switch between reference and generic products suggest that reductions in efficacy or medication adherence and persistence may be associated with generic substitution. Clinicians should work with patients to facilitate a consistent supply of reference or generic drug product that provides stable exposure to avoid clinical deterioration or poor tolerability.

In vitro-In vivo Relationship and Bioequivalence Prediction for Modified-Release Capsules Based on a PBPK Absorption Model

A physiologically based pharmacokinetic (PBPK) absorption model was developed in GastroPlus™ based on data on intravenous, immediate-release (IR), and modified-release (MR) drug products. The predictability of the model was evaluated by comparing predicted and observed plasma concentration profiles; average prediction errors (PE) were below 10%. IVIVR was developed using mechanistic deconvolution for a MR drug product to evaluate the in vivo effect of a proposed change in dissolution specification. The predictability of the IVIVR was evaluated and PE were below 10%; however, external validation was not possible due to the lack of data. The developed PBPK absorption model and IVIVR were used to predict plasma concentration profiles and pharmacokinetic (PK) parameters for a hypothetical formulation with 0% of drug dissolved in 2 h in in vitro dissolution test. Both methods predicted the insignificant effect of a change in in vitro dissolution profile on in vivo product performance. The bioequivalence of a hypothetical formulation to the test product was evaluated using virtual clinical trial. The performed analysis supported the proposed change in dissolution specification. A validated PBPK absorption model was proposed as an adequate alternative to IVIVC, when IVIVC could not have been developed according to the guidelines.