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COPD and asthma are two of the most common chronic lung diseases, affecting over 545 million people globally and 34 million in the United States. Annual health care costs related to chronic lung disease are estimated at €380 billion in the European Union, and $24-$50 billion in the United States averaging to $4,000 in out-of-pocket costs per person in the U.S. A full-text literature search was conducted for English publications between January 1, 2005-March 18, 2024. It returned over 5,000 publications that were further narrowed using key search words, resulting in 172 peer-reviewed articles. Using their experience and subject expertise, the authors further narrowed the peer-reviewed articles to 55 that were in their opinion relevant. Also, 38 recently published industry reports and news articles specific to downstream effects of inhaler market changes and the future impact were included. The literature suggests that individuals with chronic lung disease face increased challenges with access to inhaled medication due to rising medication costs, discontinuation of branded medications, introduction of generic medications not covered by insurance, exclusionary preferred drug list tactics that force health care providers into non-medical switching of medication or devices, and ongoing medication shortages. Providers experience ongoing hurdles in prescribing appropriate inhaled medications for individuals with chronic lung disease, including increased time and costs spent on administrative tasks due to inhaler denials, a loss of patient trust, and limits on their ability to prescribe appropriate inhaled medication for individuals with chronic lung disease., Competing Interests: The authors have disclosed no conflicts of interest., (Copyright © 2024 by Daedalus Enterprises.)

Approval of drug products for market registration warrants, among other data, evidence to support their safety and effectiveness in the target populations. The extent of investigations to provide the supporting evidence varies between the new innovator products and their follow-on versions generally referred to as Generic Drugs Products in the United States and Hybrids in the Europe. The new drug applications entail large data sets encompassing both nonclinical and clinical product developments. Safety and effectiveness in man is studied in sequentially phased clinical trials, including post marketing evaluations (Where applicable). However, for the generic/hybrid products the safety and effectiveness are established through determination of bioequivalence in head-to-head comparison between the originator and the follow-ons. Methods for documentation of bioequivalence for drug products that reach target site(s) through systemic circulation are aligned worldwide. However, establishing bioequivalence of orally inhaled drug products is complex as drug delivery to the local site(s) of action is independent of the systemic circulation. Documentation of bioequivalence gets further complicated due to the Drug-Device combination nature of these products. The guidelines for establishment of BE of locally acting orally inhaled drugs products vary among certain geographies. This article examines the scientific underpinning of distinctions and similarities between the US and EU guidelines., (Copyright © 2024. Published by Elsevier B.V.)

Pharmacokinetic bioequivalence of orally inhaled drug products is a critical component of the US FDA's "weight of evidence" approach, and it can serve as the sole indicator of safety and effectiveness of follow-on inhalation products approved in Europe and some other geographic areas. The approved labels of the orally inhaled drug products recommend the maximum number of actuations that can be administered in a single dose on one occasion. This single maximum dose may consist of one or more inhalations depending upon the product. Bioequivalence studies for the inhalation drug product registrations in the US and EU have employed single and multiple actuation doses, in some cases over and above the approved single maximum labeled doses, thus, inconsistent with the approved labeling of the reference products. Pharmacokinetics of inhaled drug products after single and multiple doses may be different, with implications for bioequivalence determined at single and multiple doses. Scientific literature indicates that the relative bioavailability of the Test and Reference products may differ between administrations of doses in one and multiple inhalations. Multiple doses not only alter the pharmacokinetics but also may reduce the sensitivity of the bioassay to actual differences between the Test and Reference product performances. Ability of the pharmacokinetic bioassay to accurately determine the extent of difference between two products may also be substantially reduced at high doses. Therefore, in our opinion, pharmacokinetic bioequivalence to support regulatory approvals of inhalation products at doses above the recommended single maximum dose should be avoided. Furthermore, the bioequivalence of products (if any) established at doses exceeding the approved single maximum doses should be revisited to determine if the products maintain bioequivalence when evaluated at the clinically relevant single maximum doses.

Despite the continuous research on understanding how topical drugs and the skin interact, the development of a topical generic product remains a challenge. Due to their local action effect rather than systemic, establishing suitable frameworks for documenting bioequivalence between reference and test formulations is anything but straightforward. In previous years, clinical endpoint trials were considered the gold standard method to demonstrate bioequivalence between topical products. Nevertheless, significant financial and time resources were required to be allocated owing to the inherent complexity of these studies. To address this problem, regulatory authorities have begun to accept alternative approaches that could lead to a biowaiver, avoiding the need for clinical endpoint trials. These alternatives encompass various in vitro and/or in vivo techniques that have been analysed and the benefits and drawbacks of each method have been considered. Furthermore, other factors like the integration of a quality by design framework to ensure a comprehensive understanding of the product and process quality attributes have also been taken into account. This review delves into international regulatory recommendations for semisolid topical products, with a focus on those established by the European Medicines Agency, as well as the Food and Drug Administration. Both approaches were carefully examined, discussing aspects such as acceptance criteria, sample size, and microstructure evaluation. Additionally, novel and innovative therapeutic-driven approaches based on in vitro disease models for the rapid and effective development of topical generic products are presented., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: This article presents a strategy that a Drug Delivery Device Developer (DDDD) has adopted to support Abbreviated New Drug Application (ANDA) submissions of drug-device combination products. As per the related FDA guidance, a threshold analysis should be compiled. If 'other differences' between the Reference Listed Drug (RLD) and the generic drug devices are identified, a Comparative Use Human Factors (CUHF) study may be requested., Methods: The DDDD performed task analysis and physical comparison to assess the pen injector design differences. Then, a formative CUHF study with 25 participants simulating injections using both RLD and the generic pen injectors was conducted., Results: After each participant completed four simulated injections, similar type and rates of use error between the RLD (0.70) and generic (0.68) pen injectors were observed., Conclusion: DDDDs can support pharmaceutical companies in the ANDA submission strategy of their drug-device combination product by initiating comparative task analysis and physical comparison of the device as inputs for the threshold analysis. If 'other differences' are identified, a formative CUHF study can be performed. As shown in our case study, this approach can be leveraged to support the sample size calculation and non-inferiority margin determination for a CUHF study with the final combination product.

What Is Known and Objectives: Despite the large body of evidence demonstrating equivalent efficacy and safety for branded drugs and their generic counterparts, some patients and providers have the perception that generics may be less safe and effective than branded agents. Authorized generics (AGs) are a category of generic drugs defined by the United States Food and Drug Administration (FDA) as being the same as the brand-name drug without the brand's name on the label and which may have minor differences, such as tablet or capsule markings for identification. Studies in which AGs are considered along with other generics may increase our understanding of factors that may influence perceptions about generics and shed light on areas where education may be impactful. The objectives of this paper are to provide information about AGs, review studies in which they have been evaluated and explore the role that AGs may fill in the individualized treatment of patients., Methods: A literature review was conducted on 30 September 2019 with follow-up search on 4 March 2020. The search was focussed on published papers and meeting abstracts that provided information on AGs with respect to medical and health outcomes of therapy as well as switching in individuals receiving branded, AG, or other generic agents. Information about patients' perceptions of generic medications and adherence to therapy was also included. Additional information, including relevant government sources, such as the FDA website and the Federal Trade Commission Report, was included as appropriate., Results: The literature specific to AGs is limited, but available data clearly highlight the importance of patient perception of generics as well as medication appearance as factors that may affect adherence and potentially more frequent switchbacks to branded agents from generics or AGs., What Is New and Conclusion: To our knowledge, this is the first narrative review to provide a summary of the published evidence about AGs with respect to clinical and health outcomes and switching. There is a need for more research and education regarding the use of AGs in clinical practice if they are to become more recognized as a potential treatment choice for patients. Generic medications play an important role in the healthcare system, and AGs may be able to provide an option to meet the specific needs of individual patients., (© 2021 John Wiley & Sons Ltd.)

Although the 3Rs are broadly applied in nonclinical testing, a better appreciation of the 3Rs is needed in the field of differentiated or value-added pharmaceutical generics because the minor changes in formulation, dosage form, indication, and application route often do not require additional safety testing. The US FDA and the EU EMA have comprehensive regulations for such drugs based on quality, therapeutic equivalence, and safety guidelines. However, no scientific publications on how the concept of replacement and reduction from 3Rs principles can be applied in the safety assessment of differentiated generics were found in the public domain. In this review, we discuss the application of 3Rs in nonclinical testing requirements for differentiated generics. Practical examples are provided in the form of case studies from regulated markets. We highlight the need for utilization of existing data to establish equivalence (differentiated generic vs innovator) in efficacy and safety. The case studies indicate that data requirements from animal experiments have been reduced to a large extent in some major markets without compromising quality and safety. In this context, we also highlight the problem that on a global scale, a true reduction of animal experiments will only be achieved when all countries adopt similar practices., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The cost of prescription drugs has increased at rates far exceeding general inflation in recent history, with topical drugs increasing at a disproportionate rate compared to other routes of administration. We assessed the relationship between net changes in the number of therapeutic options, defined as any approved drug or therapeutic equivalent on the market, and prescription topical drug spending. Drugs were divided based on the category of use through pairing of Medicare Part D Prescriber Public Use and Food and Drug Administration (FDA) approved drug products databases. Across drug classes, we modeled the log of the ratio of total spending per unit in 2015 to total spending per unit in 2011 as a linear function of net number of topical therapeutic options over this time period. Primary outcomes include total Medicaid Part D spending on topical drugs and net change in the number of available therapeutic options within each category of use. Total spending on topical drugs increased by 61%, while the number of units dispensed increased by only 18% from 2011-2015. The greatest total spending increases were in categories with few new therapeutic options, such as topical corticosteroid and antifungal medications. Each net additional therapeutic option during 2011-2015 was associated with an reduction in how much relative spending per unit increased (95% CI 2.5%-14.4%, p = 0.013). Stimulating greater competition through increasing the net number of therapeutic options within each major topical category of use may place downward pressure on topical prescription drug spending under medicare Part D.

A challenge in anticipating generic entry is elucidating which patents and regulatory protections constrain generic entry.

The anticoagulant response to warfarin, a narrow therapeutic index drug, increases with age, which may make older patients susceptible to adverse outcomes resulting from small differences in bioavailability between generic and brand products. Using US Medicare claims linked to electronic medical records from two large hospitals in Boston, we designed a cohort study of ≥ 65-year-old patients. Patients were followed for a composite effectiveness outcome of ischemic stroke or venous thromboembolism, a composite safety outcome, including major hemorrhage, and a 1-year all-cause mortality outcome. After propensity score fine-stratification and weighting to account for > 90 confounders, hazard ratios comparing brand vs. generic warfarin initiators (95% confidence intervals) for the effectiveness, safety, and all-cause mortality outcomes, were 0.97 (0.65-1.46), 0.94 (0.65-1.35), and 0.84 (0.62-1.13), respectively. Results from subgroup analyses of patients with atrial fibrillation, CHADS-VASc score ≥ 3, and HAS-BLED score ≥ 3 were consistent with the primary analysis., (© 2019 The Authors Clinical Pharmacology & Therapeutics © 2019 American Society for Clinical Pharmacology and Therapeutics.)

Purpose: Clinical trials have clearly documented the survival benefit of aromatase inhibitors (AIs); however, many women fail to initiate (primary nonadherence) or remain adherent to AIs (secondary nonadherence). Prior studies have found that costs impact secondary nonadherence to medications but have failed to examine primary nonadherence. The purpose of this study is to examine primary and secondary adherence following the reduction in copays due to the introduction of generic AIs., Methods: Using Surveillance, Epidemiology, and End Results-Medicare data, we identified 50 054 women diagnosed with incident breast cancer between 2008 and 2013. We compare women whose copays would change and those whose would not, due to the receipt of cost-sharing subsidies before and after generics were introduced using a difference-in-difference (DinD) analysis. To examine primary and secondary nonadherence, we rely on a multistate model with four states (Not yet initiated, User, Not Using, and Death). We adjusted for baseline factors using inverse probability treatment weights and then simulated adherence for 36 months following diagnosis., Results: The generic introduction of AIs resulted in patients initiating AIs faster (DinD = -4.7%, 95%CI = -7.0, -2.3; patients not yet initiating treatment at 6-months), being more adherent (DinD ranging in absolute increase of 8.1%-10.4%) and being less likely to not be using the therapy (DinD range in absolute decrease of 1.2% at 6 months to 8.8% at 24 months) for women that do not receive a subsidy after generics were available., Conclusions: Introduction of generic alternatives to AIs significantly reduced primary and secondary nonadherence., (© 2020 John Wiley & Sons Ltd.)

Generic products offer a considerable cost savings for American consumers and the US healthcare industry. While generics for many products have become available, the approval and adoption of generics for orally inhaled drug products (OIDPs) has lagged behind, owing to the difficulties in bringing these complex generic products to the market. As a complex product, OIDP performance is impacted by numerous factors derived from the product's formulation, delivery to a local site of action within the lung, the performance of the device, and the patient population that uses the medication. Therefore, determining equivalence between generic and brand-name OIDPs requires an approach that considers each of these aspects in order to ensure bioequivalence. FDA's recommended aggregate weight-of-evidence approach for generic OIDPs provides a paradigm where studies and conditions, when taken together, establish equivalence in device performance, systemic exposure, and local drug delivery. This review article covers the various aspects of OIDP complexity, the challenges each presents to equivalence, and FDA's efforts to address these challenges and complex drug development as a whole under the Generic Drug User Fee Amendments (GDUFA). The aggregate weight-of-evidence approach, its rationale, and scientific support is also described.

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., (© 2019 The Authors. Clinical and Translational Science published by Wiley Periodicals, Inc. on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Background: Statutory rebates and preferred drug lists (PDLs) may result in differential use of biosimilars and generics between Medicaid fee-for-service (FFS) and managed care organizations (MCOs), particularly for branded drugs with large price increases subject to large inflation rebates, which are not retained by MCOs., Objective: To compare the use of 2 biosimilar/generics of branded drugs whose list price tripled in 2008-2018 across states with only FFS Medicaid, with MCOs not subject to statewide PDLs, with MCOs subject to statewide PDLs, and with MCOs where drug benefits have been carved out., Methods: Using 2018 Medicaid drug utilization data, we extracted reimbursement records in Q1-Q3 2018 for insulin glargine 100 IU/mL and glatiramer. We calculated the market share of the biosimilar insulin glargine and generic glatiramer among the corresponding drugs. We compared the market share of these products across 4 state groups: states with only FFS Medicaid, states with MCOs not subject to statewide PDLs for each drug, states with MCOs subject to PDLs, and states with MCOs where drug benefits have been carved out into FFS. We evaluated the correlation between state-level penetration of MCOs and share of biosimilar/generic products., Results: Nationally, the market share of these biosimilar/specialty generics was higher among MCOs than FFS (60.5% vs. 3.7% for biosimilar insulin glargine; 59.4% vs. 5.7% for generic glatiramer; all P < 0.001). The market share of these products was highest in states where MCOs were not subject to statewide PDLs for these drugs (59.1% for biosimilar insulin glargine, 52.8% for glatiramer) compared with states with MCOs subject to PDLs (2.4%, 18.0%); states with only FFS Medicaid (0.9%, 1.7%); or states where drug benefits have been carved out of MCOs (0.0%, 1.0%; all P < 0.001). There was a significant correlation between state-level MCO penetration and share of generic/biosimilar products (R = 0.50 for biosimilar insulin glargine and 0.57 for glatiramer; all P < 0.001)., Conclusions: For 2 drug classes with large price increases, use of biosimilars/generics was greater in MCOs than FFS Medicaid, specifically in states without PDL requirements for MCOs. These findings may reflect financial incentives for MCOs to use drugs with lower list prices because they do not benefit from statutory Medicaid rebates., Disclosures: No outside funding supported this study. Hernandez was funded by the National Heart, Lung and Blood Institute (grant number K01HL142847). The authors have nothing to disclose.

Introduction: Imatinib is standard therapy for patients with chronic myeloid leukemia (CML). In February 2016, a generic formulation entered the US market. Physicians and patients are frequently concerned about whether switching from original to generic drugs may affect the efficacy and/or safety., Materials and Methods: This is an observational retrospective study using medical charts of patients diagnosed with CML in the chronic phase who were treated with original imatinib from the year 2000 to 2017 and who were subsequently switched to generic imatinib., Results: In this study, 38 patients have switched to generic imatinib. Before the switch, responses were assessed on all patients, all of them were in CCyR and 36 (95%) were in MMR, including 28 (74%) with MR4.5. Patients have received generic imatinib for a median of 19.4 (range, 3.4-46.3) months. Molecular responses after switching were stable in 89%, improved in 8%, and worsened in 3% of patients. After switching, 15 (39%) patients reported new or worsening adverse events, including 5 (13%) patients with edema, 8 (21%) muscle cramps, 7 (18%) nausea, 6 (16%) diarrhea, and 5 (13%) fatigue., Discussion: Bioequivalence studies demonstrated the same rate and extent of absorption of generic imatinib compared to the original form, which led to the FDA approval. In our observational series, most of the patients maintained their responses and none lost MMR. Adverse events noted were mild and well tolerated., Conclusion: A change from original to generic imatinib appears to maintain efficacy and be generally safe. More patients and longer follow-up are required to confirm these observations., (© 2019 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

The development of generic, single-entity, drug-device combination products for orally inhaled drug products is challenging in part because of the complex nature of device design characteristics and the difficulties associated with establishing bioequivalence for a locally acting drug product delivered to the site of action in the lung. This review examines in silico models that may be used to support the development of generic orally inhaled drug products and how model credibility may be assessed., (© 2019. This article is a U.S. Government work and is in the public domain in the USA. CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Background: After new prescription drugs reach the market, manufacturers sometimes create modified versions of them. These new formulations can expand patient treatment options, but they may also be protected by later-expiring patents or data exclusivities, which can lead to later generic entry for the new formulations compared with the original product., Objective: To quantify how frequently manufacturers introduce new formulations of existing drugs and how often these new formulations earn additional years of market exclusivity beyond that of the original product., Methods: Using a cohort design and FDA databases, we assessed how frequently manufacturers introduced new formulations of 17 new small-molecule drugs approved in 2002 and when generic entry for the new formulations and original product occurred., Results: Through 2017, nine (53%) drugs approved in 2002 had been connected to 21 new formulations, most (11/21, 53%) introduced before 2007. Generic entry was observed in 6 of 9 (67%) cases and occurred more than 2 years later for the new formulations in 3 of the cases., Conclusions: Our results suggest that the introduction of new formulations of brand-name drugs occurs in about half of cases and sometimes provides manufacturers with a lengthy period of additional market exclusivity beyond that of the original product., Disclosures: This work was funded by the Laura and John Arnold Foundation. Kesselheim and Sarpatwari also receive support from the Harvard-MIT Center for Regulatory Science and the Engelberg Foundation. Beall has nothing to disclose.

Until 2016, a ratio of means (ROM) non-inferiority (NI) test was recommended in FDA product-specific guidances (PSGs) to evaluate adhesion performance for prospective generic transdermal delivery systems (TDS). However, the ROM NI test had low power for well-adhering TDS, which were becoming increasingly prevalent. Mathematical proof and simulation revealed that the low power wasn't because the non-normality of adhesion data violated the normality assumption of parametric methods; it was because the ROM NI test was coupled with an adhesion scale where scores approached 0 as adhesion got better. In June 2016, FDA published a draft general guidance on TDS adhesion and recommended a new statistical approach, replacing the ROM NI test with a difference-of-means (DOM) NI test, using the same scale and primary endpoint (mean adhesion scores). An analysis of 40 TDS adhesion studies submitted in ANDAs after the publication of the 2016 draft guidance suggests that, consistent with simulation results, the new statistical approach markedly improves the low power, and thereby reduces the sample size required by the old approach for moderately to well-adhering TDS, while retaining comparable power for poorly adhering TDS. The new statistical approach thus enhances the potential approvability and patient access to well-adhering generic TDS.

Introduction: Nearly 90% of drugs dispensed in the US are generic products., Objective: The aim of this study was to develop and implement a tool for analyzing manufacturer-level drug utilization and switching patterns within the US Food and Drug Administration's Sentinel system., Methods: A descriptive tool was designed to analyze data in the Sentinel common data model and was tested with two case studies-metoprolol extended release (ER) and lamotrigine ER-using claims data from four Sentinel data partners. We plotted initiators of each brand and generic product over time. For metoprolol ER, we evaluated rates of switching from generics around the time of manufacturing issues. For lamotrigine ER, we examined rates of switching back to the brand among those who switched from brand to generic., Results: We identified 1,651,285 initiators of metoprolol ER products between July 2008 and September 2015. We observed a large decrease in monthly metoprolol ER initiators (from 25,465 in December 2008 to 13,128 in February 2009), corresponding to recalls by generic manufacturers. We observed simultaneous increases in utilization of the authorized generic and brand products. We identified 4266 initiators of lamotrigine ER with an epilepsy diagnosis between January 2012 and September 2015. Among those who switched from brand to generic, the cumulative incidence of switching back was close to 20% at 2 years. Switchback rates were higher for the first available generic products., Conclusions: This developed tool was able to elucidate novel utilization and switching patterns in two case studies. Such information can be used to support surveillance of generic drugs and biosimilars.

Purpose: To identify associations between systemic medications and primary open-angle glaucoma (POAG) requiring a procedure using United States insurance claims data in a hypothesis-generating study., Design: Database study., Participants: In total, 6130 POAG cases (defined as patients with POAG undergoing a glaucoma procedure) were matched to 30 650 controls (defined as patients undergoing cataract surgery but without a coded glaucoma diagnosis, procedure, or medication) by age, gender, and region of residence., Methods: Participant prescription drug use was calculated for the 5-year period before the glaucoma procedure or cataract surgery. Separately for individual generic drugs and drug classes, logistic regression was used to assess the association with POAG status. This was done across all generic drugs and drug classes that were prescribed in at least 1% of cases and controls. Analyses were adjusted for age, sex, region of residence, employment status, insurance plan type, and the total number of drugs prescribed., Main Outcome Measures: Odds ratio (OR) and 95% confidence intervals (CIs) for the association between each drug or drug class and POAG., Results: The median age of participants was 72 years, and 52% were women. We tested for associations of POAG with 423 drug classes and 1763 generic drugs, resulting in a total of 2186 statistical tests and a Bonferroni-adjusted significance threshold of P < 2.3 × 10 -5 . Selective serotonin reuptake inhibitors (SSRIs) were strongly associated with a reduced risk of POAG (OR, 0.70; 95% CI, 0.64-0.76; P = 1.0 × 10 -15 ); the most significant drug in this class was citalopram (OR, 0.66; 95% CI, 0.57-0.77; P = 1.2 × 10 -7 ). Calcium channel blockers were strongly associated with an increased risk of POAG (OR, 1.26; 95% CI, 1.18-1.35; P = 1.8 × 10 -11 ); the most significant drug in this class was amlodipine (OR, 1.27; 95% CI, 1.18-1.37; P = 5.9 × 10 -10 )., Conclusions: We present data documenting potential associations of SSRIs and calcium channel blockers with POAG requiring a procedure. Further research may be indicated to better evaluate any associates of serotonin metabolism or calcium channels in glaucoma, or establish whether the associations are due to variations in the patterns for prescribing these drugs., (Copyright © 2018 American Academy of Ophthalmology. All rights reserved.)

Background: Although cancer drug shortages are a persistent problem in oncology, little is known about the awareness and perspectives of the US population with respect to shortages., Methods: In 2016, we administered a 13-item cross-sectional survey to 420 respondents who were randomly selected from an online, probability-based sample demographically representative of the adult US population with respect to sex, age, race/ethnicity, education, geography, and income. Analyses applied poststratification sampling weights to draw national inferences., Results: Overall, 16% of respondents reported being aware of drug shortages. Those with a personal history of cancer were more likely to be aware (31% vs 14% [P = .03]). In the overall cohort, most reported wanting to be informed about a substitution due to shortage: 87% and 82% for major or minor differences in efficacy, and 87% and 83% for major or minor differences in side effects. Most also reported they would transfer care to avoid a substitution: 72% for major differences in efficacy, and 61% for major differences in side effects. Black respondents, the uninsured, the unemployed, those with lower income, and the less well-educated were all less likely to report that they would transfer care to avoid major differences in efficacy (all P < .05)., Conclusion: These data suggest that the US population is largely unaware of cancer drug shortages. Moreover, if being treated for cancer, most people would want to know about drug substitutions, even if it were to result in only minor differences in efficacy or side effects. With more significant differences, many would transfer care. Cancer 2018;124:2205-11. © 2018 American Cancer Society., (© 2018 American Cancer Society.)

To be considered bioequivalent to their branded counterparts, generic drugs must meet the standards for bioequivalence (BE) described by the regulatory agencies. While BE of generic inhalational drugs can be evaluated using a similar approach as that for oral dosage from products or drugs that are delivered systemically, the approach is insufficient to address the complexities of inhalational products (e.g., localized site of action, device-patient interface). Therefore, more considerations are needed and caution should be applied when evaluating BE of inhaled compounds. The purpose of this review is to highlight the considerations and challenges in establishing BE of inhaled compounds by (1) outlining the current regulatory approaches (from Health Canada, the U.S. Food and Drug Administration, and the European Medicines Agency) to assess BE for subsequent entry inhaled products (SEIPs) and (2) reviewing the literature pertaining to testing considerations of SEIPs to establish BE.

There are several drug products that bind phosphate or bile acid in the gastrointestinal (GI) tract to exert their therapeutic efficacy. In vitro binding studies are used to assess bioequivalence (BE) of these products. The objective of this study is to identify the common deficiencies in Abbreviated New Drug Applications (ANDAs) for these products. Deficiencies were compiled from ANDAs containing in vitro binding BE studies. The deficiencies were classified into eight categories: Pre-Study Method Validation, During-Study Sample Analysis, Study Design, Study Procedure, Dissolution/Disintegration, Analytical Site Inspection, Data Submission, and Formulations. Within each category, additional subcategories were defined to characterize the deficiencies. A total of 712 deficiencies from 95 ANDAs for 11 drug products were identified and included in the analysis. The four categories with the most deficiencies were During-Study Sample Analysis (27.8%), Pre-Study Method Validation (17.3%), Data Submission (16.7%), and Study Design (15.7%). For the During-Study Sample Analysis category, failure to submit complete raw data or analytical runs ranked as the top deficiency (32.8%). For the Study Design category, using an unacceptable alternate study design (26.8%) was the most common deficiency. Within this category, other commonly occurring deficiencies included incorrect/insufficient number of absorbent concentrations, failure to pre-treat drug product with acid, insufficient number of replicates in study, incorrect calculation of k1 and k2 values, incorrect dosage form or pooled samples used in the study, and incorrect pH of study medium. The review and approval of these products may be accelerated if these common deficiencies are addressed in the original ANDA submissions.

Background: Patients and clinicians share concerns that generic drug substitution might lead to loss of efficacy or emergence of adverse events. In this trial, we assessed US Food and Drug Administration (FDA) bioequivalence standards by studying the effects of switching between two disparate generic immediate-release lamotrigine products in patients with epilepsy., Methods: The Equivalence among Generic Antiepileptic Drugs (EQUIGEN) chronic-dose study was a randomised, double-blind, crossover study that enrolled adults (aged ≥18 years) with epilepsy from six epilepsy centres at academic institutions across the USA who were receiving immediate-release lamotrigine dosed at 100 mg, 200 mg, 300 mg, or 400 mg twice daily. Eligible patients were randomly allocated (1:1) to one of two treatment sequences (sequence 1 or sequence 2), comprising four study periods of 14 days each. During each 14-day treatment period, patients received balanced doses of an oral generic lamotrigine product every 12 h (200-800 mg total, identical to lamotrigine dose prior to study enrolment); after each 14-day period, patients were crossed over to receive the other generic product. Computer-based randomisation was done using random permuted blocks of size two or four for each site to prevent sequence predictability. Both patients and study personnel were masked to the generic products selected, their predicted exposure (ie, "high" vs "low"), and their group allocation. The primary outcome of this trial was bioequivalence between the generic products, which was assessed at the end of the study through a comparison of maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC) for each product in the analysis population (all patients who completed all four treatment periods). Bioequivalence was established if the 90% CIs of the ratios of these two parameters for the two products were within equivalence limits (80-125%) in the analysis population. This study is registered with ClinicalTrials.gov\, number NCT01713777., Findings: Between April 25, 2013, and Aug 12, 2014, 35 eligible patients were enrolled and randomly assigned to treatment sequence 1 (n=15) or treatment sequence 2 (n=20). 33 patients completed all four treatment periods and were included in the primary outcome analysis. The 90% CIs of the ratios of both Cmax and AUC were within equivalence limits (AUC 90% CI 98-103, Cmax 90% CI 99-105), showing that lamotrigine exposures were equivalent between the generic products. No significant changes in seizure frequency or adverse events were recorded. No deaths, study-related serious adverse events, or changes in clinical laboratory values or vital signs occurred during this study., Interpretation: Disparate generic lamotrigine products in patients with epilepsy showed bioequivalence with no detectable difference in clinical effects, confirming that US Food and Drug Administration bioequivalence standards are appropriate., Funding: American Epilepsy Society, Epilepsy Foundation, and US Food and Drug Administration., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Biosimilars are biological products that are highly similar to their biological reference products, notwithstanding minor differences in clinically inactive components. However, unlike generics of small-molecule drugs, biosimilars are not identical to their reference products, since each manufacturer uses unique cell lines and processes, and these lead to slight structural differences between products. Because these structural variations can lead to differences in clinical response, clinical studies demonstrating biosimilarity are required before and robust pharmacovigilance after approval. Although the FDA has not yet issued formal guidance on interchangeable biosimilars, higher standards of similarity will be required in order to achieve an interchangeable designation. In this commentary, we review the differences between generics and biosimilars, describe their respective regulatory approval pathways, discuss interchangeability and substitution, and review substitution of interchangeable biosimilars, focusing on key professional considerations for pharmacists.

Objective: Medicare Part D claims are commonly used for research, but missing claims could compromise their validity. This study assessed 2 possible causes of missing claims: veteran status and Generic Drug Discount Programs (GDDP)., Materials and Methods: We merged medication self-reports from telephone interviews in the Atherosclerosis Risk in Communities (ARIC) Study with Part D claims for 6 medications (3 were commonly in GDDP in 2009). Merged records (4468) were available for 2905 ARIC participants enrolled in Part D. Multinomial logit regression provided estimates of the association of concordance (self-report and Part D, self-report only, or Part D only) with veteran and GDDP status, controlling for participant sociodemographics., Results: Sample participants were 74±5 years of age, 68% white and 63% female; 19% were male veterans. Compared with females, male veterans were 11% [95% confidence interval (CI), 7%-16%] less likely to have matched medications in self-report and Part D and 11% (95% CI, 7%-16%) more likely to have self-report only. Records for GDDP versus non-GDDP medications were 4% (95% CI, 1%-7%) more likely to be in self-report and Part D and 3% (95% CI, 1%-5%) less likely to be in Part D only, with no difference in self-report only., Conclusions: Part D claims were more likely to be missing for veterans, but claims for medications commonly available through GDDP were more likely to match with self-reports. Although researchers should be aware of the possibility of missing claims, GDDP status was associated with a higher rather than lower likelihood of claims being complete in 2009.

Bioequivalence (BE) is required for approving a generic drug. The two one-sided tests procedure (TOST, or the 90% confidence interval approach) has been used as the mainstream methodology to test average BE (ABE) on pharmacokinetic parameters such as the area under the blood concentration-time curve and the peak concentration. However, for highly variable drugs (%CV > 30%), it is difficult to demonstrate ABE in a standard cross-over study with the typical number of subjects using the TOST because of lack of power. Recently, the US Food and Drug Administration and the European Medicines Agency recommended similar but not identical reference-scaled average BE (RSABE) approaches to address this issue. Although the power is improved, the new approaches may not guarantee a high level of confidence for the true difference between two drugs at the ABE boundaries. It is also difficult for these approaches to address the issues of population BE (PBE) and individual BE (IBE). We advocate the use of a likelihood approach for representing and interpreting BE data as evidence. Using example data from a full replicate 2 × 4 cross-over study, we demonstrate how to present evidence using the profile likelihoods for the mean difference and standard deviation ratios of the two drugs for the pharmacokinetic parameters. With this approach, we present evidence for PBE and IBE as well as ABE within a unified framework. Our simulations show that the operating characteristics of the proposed likelihood approach are comparable with the RSABE approaches when the same criteria are applied., (Copyright © 2014 John Wiley & Sons, Ltd.)

Objective: This retrospective analysis assessed the capability of active and passive safety surveillance systems to track product-specific safety events in the USA for branded and generic enoxaparin, a complex injectable subject to immune-related and other adverse events (AEs)., Methods: Analysis of heparin-induced thrombocytopenia (HIT) incidence was performed on benefit claims for commercial and Medicare supplemental-insured individuals newly treated with enoxaparin under pharmacy benefit (1 January 2009 - 30 June 2012). Additionally, spontaneous reports from the FDA AE Reporting System were reviewed to identify incidence and attribution of enoxaparin-related reports to specific manufacturers., Results: Specific, dispensed products were identifiable from National Drug Codes only in pharmacy-benefit databases, permitting sensitive comparison of HIT incidence in nearly a third of patients treated with brand or generic enoxaparin. After originator medicine's loss of exclusivity, only 5% of spontaneous reports were processed by generic manufacturers; reports attributable to specific generics were approximately ninefold lower than expected based on market share., Conclusions: Claims data were useful for active surveillance of enoxaparin generics dispensed under pharmacy benefits but not for products administered under medical benefits. These findings suggest that the current spontaneous reporting system will not distinguish product-specific safety signals for products distributed by multiple manufacturers, including biosimilars.

Background: Nonadherence to hormonal therapy is common and is associated with increased copayment amount. We investigated the change in adherence after the introduction of generic aromatase inhibitors (AIs) in 2010., Methods: Using deidentified pharmacy and claims data from OptumInsight, we identified women older than 50 years on brand-name AIs (BAIs) and/or generic AIs (GAIs) for early breast cancer between January 1, 2007 and December 31, 2012. Clinical, demographic, and financial variables were evaluated. Adherence was defined as a medication possession ratio (MPR) 80% or greater., Results: We identified 5511 women, 2815 (51.1%) on BAI, 1411 (25.6%) on GAI, and 1285 (23.3%) who switched from BAI to GAI. The median 30-day copayment was higher for BAI ($33.3) than for GAI ($9.04). In a multivariable Cox-proportional hazard analysis, women who took GAI were less likely to discontinue therapy (hazard ratio [HR] = 0.69, 95% confidence interval [CI] = 0.57 to 0.84) compared with BAI. Discontinuation was positively associated with a higher monthly copayment of $15 to $30 (HR = 1.21, 95% CI = 1.01 to 1.44) and more than $30 (HR = 1.49, 95% CI = 1.23 to 1.80) compared with less than $15. In a multivariable logistic regression analysis, adherence (medication possession ratio ≥ 80%) was positively associated with GAI use (odds ratio = 1.53, 95% CI = 1.22 to 1.91) compared with BAI and inversely associated with increased monthly copayment. In addition, adherence was associated with a high annual income of more than $100k/year (odds ratio = 1.58, 95% CI = 1.17 to 2.11)., Conclusions: Higher prescription copayment amount was associated with nonadherence and discontinuation of AIs. After controlling for copayment, discontinuation was higher and adherence was lower with Brand AIs. Because nonadherence is associated with worse survival, efforts should be directed towards reducing out-of-pocket costs for these life-saving medications., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Biopharmaceutical performance refers to the influence of pharmaceutical formulation variables on in vivo performance. New drug product success depends on formulation design for sufficient bioavailability for clinically desired dosing. Regulatory interest in biopharmaceutical performance includes batch-to-batch consistency, acceptability of postapproval changes, and evaluation of bioequivalence (BE) for generic drug products. This Commentary summarizes biopharmaceutical modeling and simulation in the US Food and Drug Administration (FDA) Office of Generic Drugs (OGD) for orally administered generic drugs.

Background: Health plans may achieve cost savings by limiting the daily average consumption (DACON) of certain medications and encouraging members and prescribers to select lower cost dosing options. Various strengths of a given medication may be similarly priced per unit; therefore, a single unit of a higher-strength medication may cost less than multiple lower-strength units that provide the same dose. For instance, a single 10 mg tablet may cost less than two 5 mg tablets. , Objective: To measure the economic impact of implementing DACON limits for selected medications. , Methods: RegenceRx prescription claims data for the top 200 brand and select generic medications from the first quarter of 2011 were searched for DACON limit opportunities. DACON limits were placed on medications that were available in multiple strengths that were similar in cost, and at least one strength was double another (e.g., 5 mg and 10 mg).Phase 1 of the program occurred in December 2011 and consisted of messaging to dispensing pharmacies (either electronic or direct contact). In Phase 2 (effective January 1, 2012), the claims system was coded to prevent payment for prescription claims in quantities exceeding DACON limits ( greater than 1.9 tablets/day). During this phase, dispensing pharmacists received electronic messaging at the point of service recommending a transition to the least costly dosing option. If the dispensing pharmacist determined transition was not clinically appropriate, the pharmacy was able to contact RegenceRx customer service for an override.Impact was determined by analyzing prescription claims for the selected medications for the 3 months following implementation of DACON limits (January-March 2012). Specific measurements analyzed included number of claims not paid because of exceeding DACON limits, health plan administrative burden, and cost avoidance. , Results: DACON limits were placed on 41 medications for commercial lines of business and 35 medications for Medicare Part D lines of business, based on the medication selection criteria (DACON limits were not placed on classes of clinical concern for Medicare Part D). A total of 5,100 claims across both commercial and Medicare Part D lines of business for January to March 2012 were impacted by implementation of DACON limits at the point of service. Duloxetine, niacin CR, and generic temazepam were responsible for more than 60% of the DACON limit claims volume. Implementing DACON limits resulted in a total cost avoidance of approximately $730,000 across both commercial and Medicare Part D lines of business for January to March 2012. Duloxetine, niacin CR, and aripiprazole were responsible for nearly 60% of the total aggregate cost avoidance. After adjustment for health plan administrative costs, the total cost avoidance was just under $720,000. , Conclusion: Implementing DACON limits on selected medications provided a cost avoidance of approximately $720,000 over a 3-month period with limited interruption to patient access and relatively low administrative burden. This reduction could result in annualized savings of nearly $3 million.

Purpose: Pharmacy commercial claims databases are widely used for pharmacoepidemiologic research. However, concerns have been raised that these databases may not fully capture claims for generic medications as a result of patients filling outside the context of their insurance. This has implications for many research activities and quality improvement programs. We sought to estimate the percentage of missing prescriptions in US commercial claims data using a novel design., Methods: Using a large US commercial insurance database, we examined the completeness of warfarin prescription claims among patients with atrial fibrillation receiving regular medical follow-up and testing to manage warfarin dosing. We examined 14 different 6-month cross sections. Each cross section was treated independently to identify patients with at least two outpatient diagnoses of atrial fibrillation, two international normalized ratio tests, and one pharmacy claim. Trends in the percentage of patients with prescription claims for generic and branded warfarin were compared by year and 6-month periods using chi-square tests and generalized linear models adjusting for patient characteristics., Results: Out of 111 170 patients, the percentage of patients with any warfarin drug decreased slightly from 91.7% (95% CI: 91.0, 92.4) in early 2003 to 87.1% (95% CI: 86.7-87.6) in late 2009 (χ(2)  = 93.8, p < 0.0001). Over the same interval, the proportion of patients with generic warfarin exposure appearing increased significantly, whereas the proportion of patients with branded warfarin exposure decreased significantly., Conclusions: Our study supports the possibility that some prescriptions may not be captured in US commercial insurance databases., (Copyright © 2013 John Wiley & Sons, Ltd.)

Background: Generic alendronate was approved in the United States on February 6, 2008. Medicare beneficiaries might pay for generic alendronate out-of-pocket without having claims submitted, resulting in misclassification of generic alendronate use in Medicare data., Objectives: To estimate the completeness of generic alendronate use in 2008 Medicare Part D data; to identify factors associated with staying on branded alendronate versus switching to a generic product., Methods: We identified Medicare beneficiaries highly adherent (medication possession ratio ≥80%) with branded alendronate during 1/1/06-2/6/07 ("2007 cohort") and during 1/1/07-2/6/08 ("2008 cohort"). The outcome was medication status at the end of follow-up (12/31/2007 or 12/31/2008), classified as continued branded alendronate, switched to generic alendronate, switched to another bisphosphonate or presumed discontinued bisphosphonate therapy. Cox regression estimated the hazard ratio (HR) for discontinuation in 2008 compared to 2007. Multinomial logistic regression identified factors associated with medication status for the 2008 cohort., Results: Among 15,310 subjects using branded alendronate in the 2008 cohort, 81% switched to generic alendronate. The proportion presumably discontinuing bisphosphonate therapy was 8.9% in 2008 compared to 7.7% in the 2007 cohort (adjusted HR, 1.15; 95% confidence interval, 1.05, 1.26). Factors associated with staying on branded alendronate in 2008 were higher income, eligibility for a low income subsidy and use of Fosamax® plus vitamin D., Conclusion: Evaluation of Medicare prescription drug data suggests that the amount of missing claims for generic alendronate in 2008 was not substantial, and misclassification of exposure in studies examining alendronate use post-generic product availability should be minimal., (Copyright © 2012 John Wiley & Sons, Ltd.)

This is a review of the current regulatory requirements associated with development and submission of abridged dossiers for locally acting inhalation drugs intended for the treatment of asthma and chronic obstructive pulmonary disease. The current EU law does not provide for submission of such products as generics due to the definition of bioequivalence and bioavailability; instead they must be submitted as hybrids. A guideline from 2009 is available that suggests a stepwise approach toward approval. An applicant should first consider the degree of in vitro match with the reference product; provided that the match is extensive, approval may be granted. If the in vitro match cannot be proven, the next step is comparison of lung deposition and systemic exposure. If this match is proven, approval may be granted; otherwise, the final step is pharmacodynamic evaluation. In the United States, submission as a generic is possible, but only a single specific guidance document from 1989 is in force. It describes in vitro requirements for comparison of albuterol and metaproterenol pressurized metered dose inhalers. Applicants are encouraged to seek dialogue with regulators prior to and during development. Although parallel scientific advice procedures have been established between the US Food and Drug Administration and the European Medicines Agency, the two authorities give independent and individual advice.

Background: Widely accepted treatment guidelines and performance measures encourage patients to stay on antidepressant medication beyond the acute phase of treatment in order to achieve full remission and reduce risk of relapse. However, many patients discontinue antidepressant medication treatment prematurely for various reasons, including side-effects or nonresponse to the initial medication prescribed. Customization of medications to differing patient profiles could potentially improve medication treatment duration, but for many diseases physicians tend to concentrate on a limited subset of available medications. Little is known about the effects of concentration in prescribing on medication treatment duration and expenditures., Aims of the Study: To determine the extent to which prescribing for treatment of depression is concentrated, using data from a privately insured population. To evaluate the relationship between prescribing concentration and subsequent duration of medication treatment, expenditure on medications, and the number of distinct medications used., Study Population: Individuals receiving antidepressant treatment paid for by a large private managed behavioral health organization, in the US., Methods: The study uses psychotropic pharmacy claims data for 2003-06 for plan members who received a depression diagnosis and had an antidepressant claim. The resulting sample includes 9,017 patients seen by 543 prescribers. For each prescriber, we compute prescribing concentration, using the Herfindahl index and the share for the three most-used medications. Treatment expenditure is computed as the sum of payments by plan and by patients. Regression analysis is used to identify the association of prescribing concentration with medication treatment duration, expenditures and other utilization measures., Results: For these physicians, the mean share of the physician's total antidepressant prescribing accounted for by their three most-used regimens was 72%. The mean value of the Herfindahl index was 0.27. Over the 180-day follow-up period, the average patient had 103 days covered by antidepressant prescriptions, resulting in mean expenditures of $286, or $2.25 per day of medication supplied. Regression analysis indicates that higher concentration in a physician's prescribing was associated with fewer days of antidepressant coverage, lower medication expenditures, and subsequent use of fewer distinct medications., Discussion: Higher concentration in prescribing is associated with shorter observed duration of medication treatment and lower expenditures on medications. The lower expenditures appear to be due to earlier discontinuation and fewer different medications, not to a lower cost per day supplied. Limitations of this study include lack of data on medical visits or on reasons for medication discontinuation, as the study is based on pharmacy claims data, not medical claims or surveys. In addition, it is not known whether the patient's antidepressant use represents a new episode. Finally, lack of randomization implies that the associations identified may not be causal., Implications for Health Care Provision and Use: Concentration of physicians on certain medications may run counter to the increasing calls for customization of medication selection., Implications for Health Policy: Insurer policies which limit physicians' choice of medications may be lowering expenditures in part by reducing patients' medication treatment duration., Implications for Further Research: Additional studies are needed to understand what mechanisms may link concentration in prescribing to medication treatment duration and expenditures.