Generic Drug User Fee Amendments Research Articles

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

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

Increasing impact of quantitative methods and modeling in establishment of bioequivalence and characterization of drug delivery.

Increasing impact of quantitative methods and modeling in establishment of bioequivalence and characterization of drug delivery.

Peltzman Revisited: Quantifying 21st-Century Opportunity Costs of Food and Drug Administration Regulation

Peltzman’s work is revisited in light of two recent opportunities to quantitatively assess trade-offs in drug regulation. First, reduced regulatory barriers to drug manufacturing associated with the 2017 reauthorization of generic-drug user fee amendments were followed by more entry and lower prices for prescription drugs. A simple, versatile industry model and historical data on entry indicate that easing restrictions on generics discourages innovation, but this cost is more than offset by benefits from enhanced competition, especially after 2016. Second, accelerated vaccine approval in 2020 had unprecedented net benefits as it improved health and changed the trajectory of the wider economy. Evidence suggests that cost-benefit analysis of Food and Drug Administration (FDA) regulation is incomplete without accounting for substitution toward potentially unsafe and ineffective treatments that are outside FDA jurisdiction and heavily utilized before FDA approval. Moreover, the policy processes initiating the regulatory changes show an influence of Peltzman’s findings. Consumer losses from purchases of ineffective drugs or hastily marketed unsafe drugs appear to have been trivial compared to gains from innovation. (Peltzman 1974, p. 82)

Considerations for the Forced Expiratory Volume in 1 Second-Based Comparative Clinical Endpoint Bioequivalence Studies for Orally Inhaled Drug Products.

Herein, we present the US Food and Drug Administration (FDA) Office of Research and Standards' current thinking, challenges, and opportunities for comparative clinical endpoint bioequivalence (BE) studies of orally inhaled drug products (OIDPs). Given the product-associated complexities of OIDPs, the FDA currently uses an aggregate weight-of-evidence approach to demonstrate that a generic OIDP is bioequivalent to its reference listed drug. The approach utilizes comparative clinical endpoint BE or pharmacodynamic BE studies, pharmacokinetic BE studies, and in vitro BE studies to demonstrate equivalence, in addition to formulation sameness and device similarity. For the comparative clinical endpoint BE studies, metrics based on forced expiratory volume in the first second (FEV1 ) are often the recommended clinical endpoints. However, the use of FEV1 can pose a challenge due to its large variability and a relatively flat dose-response relationship for most OIDPs. The utility of applying dose-scale analysis was also investigated by the FDA but often not recommended, due to either flat dose-response relationships or insufficient clinical study data. As a potential way to reduce sample size, we found adapting covariate analysis only explained a limited portion of the variation based on further investigation. The FDA continues to develop alternative methods to make BE assessment of OIDPs more cost- and time-efficient. Prospective generic drug applicants and academia are encouraged to participate in this effort by proposing new approaches in pre-abbreviated new drug application meeting requests and collaborating in the form of grants and contracts under the Generic Drug User Fee Amendments (GDUFA) Regulatory Science and Research Program.

Research and Education Needs for Complex Generics

Complex generics are generic versions of drug products that generally have complex active ingredients, complex formulations, complex routes of delivery, complex dosage forms, are complex drug-device combination products, or have other characteristics that can make it complex to demonstrate bioequivalence or to develop as generics. These complex products (i.e. complex generics) are an important element of the United States (U.S.) Food and Drug Administration’s (FDA’s) Generic Drug User Fee Amendments (GDUFA) II Commitment Letter. The Center for Research on Complex Generics (CRCG) was formed by a grant from the FDA to address challenges associated with the development of complex generics. To understand these challenges, the CRCG conducted a “Survey of Scientific Challenges in the Development of Complex Generics”. The three main areas of questioning were directed toward which (types of) complex products, which methods of analysis to support a demonstration of bioequivalence, and which educational topics the CRCG should prioritize. The survey was open to the public on a website maintained by the CRCG. Regarding complex products, the top three selections were complex injectables, formulations, and nanomaterials; drug-device combination products; and inhalation and nasal products. Regarding methods of analysis, the top three selections were locally-acting physiologically-based pharmacokinetic modeling; oral absorption models and bioequivalence; and data analytics and machine learning. Regarding educational topics, the top three selections were complex injectables, formulations, and nanomaterials; drug-device combination products; and data analytics, including quantitative methods and modeling & simulation. These survey results will help prioritize the CRCG’s initial research and educational initiatives.

Public Workshop Summary Report on Fiscal Year 2021 Generic Drug Regulatory Science Initiatives: Data Analysis and Model-Based Bioequivalence.

On May 4, 2020, the US Food and Drug Administration (FDA) hosted an online public workshop titled "FY 2020 Generic Drug Regulatory Science Initiatives Public Workshop" to provide an overview of the status of the science and research priorities and to solicit input on the development of Generic Drug User Fee Amendments fiscal year 2021 priorities. This report summarizes the podium presentations and the outcome of discussions along with innovative ways to overcome challenges and significant opportunities related to model-based approaches in bioequivalence assessment for breakout session 4 titled, "Data analysis and model-based bioequivalence (BE)." This session focused on the application of model-based approaches in the generic drug development, with a vision of accelerating regulatory decision making for abbreviated new drug application assessments. The session included both podium presentations and panel discussions with three topics of interest: (i) in vitro study evaluation methods and their clinical relevance, (ii) challenges in model-based BE, (iii) emerging expertise and tools in implementing new BE approaches.

Regulating Generic Ophthalmologic Drug Bioequivalence-Envisioning Accessibility for Patients.

New, brand-name, ophthalmology drug products are developed, investigated, and submitted for marketing approval through premarket interactions with the Food and Drug Administration (FDA). These drug applications for novel drugs are reviewed by FDA for safety and effectiveness before being allowed on the market. Many brand-name drugs are allowed a period of marketing exclusivity and/or have patent protections that can delay generic competition. When these exclusivity periods or patents expire or are challenged (in the case of patents), generic competitors may then market equivalent products, as allowed by U.S. law (eg, Drug Price Competition and Patent Term Restoration Act, often referred to as "the Hatch-Waxman Act"). To be approved as a therapeutic equivalent, a generic product must demonstrate that it is both pharmaceutically equivalent and bioequivalent to the brand-name drug product, which can involve innovative analytical methods and study designs. To facilitate generic drug assessment and approval, the FDA has negotiated the Generic Drug User Fee Amendments (GDUFA) program that funds a rigorous generic drug development program that includes pre-Abbreviated New Drug Application (pre-ANDA) correspondence and meetings, targeted bioequivalence research, and publication of product-specific guidances (PSGs) to support generic drug research and development for manufacturers interested in developing generic drugs for the U.S. market. FDA's regulatory practices include the monitoring of quality and postapproval adverse events of all marketed products, including those for use in and around the eyes.

Addressing the Regulatory and Scientific Challenges with Generic Orally Inhaled Drug Products

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.

FDA’s Generic Drug Program: Decreasing Time to Approval and Number of Review Cycles

Implementation of the Generic Drug User Fee Amendments (GDUFA I) as part of the Food and Drug Administration Safety and Innovation Act of 2012 (Generic Drug User Fee Amendments. https://www.fda.gov/industry/fda-user-fee-programs/generic-drug-user-fee-amendments) successfully allowed the U.S. Food and Drug Administration (FDA) to modernize review of Abbreviated New Drug Applications (ANDAs) with goal dates. The goal of this study was to assess the success of GDUFA I in decreasing ANDA time to approval and the number of review cycles across the five fiscal years of GDUFA I. Results of this study underscore FDA's continuous progress within its generic drug program and highlight the ongoing collaborative communication process between FDA and ANDA applicants that must continue for the timely approval of high-quality, safe, and effective generic drugs for the American public.

Abbreviated New Drug Applications: Generic Drug User Fee Amendments Act Analysis of Application Quality Metrics.

Implementation of the first Generic Drug User Fee Amendments of 2012 (GDUFA I) provided funding to the US Food and Drug Administration (FDA) for modernizing review of the FDA/CDER Generic Drug Program. Under GDUFA I, FDA agreed to reduce the backlog of pending generic Abbreviated New Drug Applications (ANDAs), improve the efficiency of generic drug review, and reduce the number of review cycles with the goal of reducing overall time to approval. This study presents a preliminary analysis of initial filing and regulatory first actions on ANDAs during GDUFA I cohort year 3 (CY3) and cohort year 4 (CY4). It highlights initial successes and areas of improvement in the ANDA review process for both FDA and ANDA applicants to improve the efficiency of providing the public with high-quality, affordable generic drugs.

Decision Science for Generic Drug Development and Review.

Decision Science for Generic Drug Development and Review.

Innovation for Generic Drugs: Science and Research Under the Generic Drug User Fee Amendments of 2012.

Regulatory science is science and research intended to improve decision making in a regulatory framework. Improvements in decision making can be in both accuracy (making better decisions) and in efficiency (making faster decisions). Science and research supported by the Generic Drug User Fee Amendments of 2012 (GDUFA) have focused on two innovative methodologies that work together to enable new approaches to development and review of generic drugs: quantitative models and advanced in vitro product characterization. Quantitative models faithfully represent current scientific understanding. They are tools pharmaceutical scientists and clinical pharmacologists use for making better and faster product development decisions. Advances in the in vitro product comparisons provide the measurements of product differences that are the critical input into the models. This paper outlines four areas where science and research funded by GDUFA support synergistic use of models and characterization at critical decision points during generic drug product development and review.

The generic drug user fee amendments: an economic perspective.

Since the vast majority of prescription drugs consumed by Americans are off patent (‘generic’), their regulation and supply is of wide interest. We describe events leading up to the US Congress's 2012 passage of the Generic Drug User Fee Amendments (GDUFA I) as part of the Food and Drug Administration Safety and Innovation Act (FDASIA). Under GDUFA I, generic manufacturers agreed to pay approximately $300 million in fees each year of the five-year program. In exchange, the US Food and Drug Administration (FDA) committed to performance goals. We describe GDUFA I’s FDA commitments, provisions, goals, and annual fee structure and compare it to that entailed in the authorization and implementation of GDUFA II on October 1, 2017. We explain how user fees required under GDUFA I erected barriers to entry and created scale and scope economies for incumbent manufacturers. Congress changed user fees under GDUFA II in part to lessen these incentives. In order to initiate and sustain user fees under GDUFA legislation, FDA requires the submission of self-reported data on generic manufacturers including domestic and foreign facilities. These data are public and our examination of them provides an unprecedented window into the recent organization of generic drug manufacturers supplying the US market. Our results suggest that generic drug manufacturing is increasingly concentrated and foreign. We discuss the implications of this observed market structure for GDUFA II’s implementation among other outcomes.

Bioanalytical inspections: organizational changes and regulatory perspectives.

During January 2015, several offices within the Center for Drug Evaluation and Research (CDER) were re-organized to improve consistency of decision-making, and to streamline policy, procedures and communications. Some Divisions were elevated to Office status because of the increased number of personnel resulting from the passage of the Generic Drug User Fee Amendments of 2012 (GDUFA). The resources provided by the new user fees supported hiring more personnel to address the significantly increased workload and newly imposed timelines. The Division of Bioequivalence and GLP Compliance (DBGLPC), responsible for CDER’s Bioavailablity/Bioequivalence (BA/BE) Inspection Program and the Good Laboratory Practice (GLP) Inspection Program, became the Office of Study Integrity and Surveillance (OSIS). Additionally, OSIS became the newest suboffice under CDER’s Office of Translational Sciences. Previously, this group was in the Office of Scientific Investigations under CDER’s Office of Compliance. OSIS currently includes the Division of Generic Drug Bioequivalence Evaluation conducting and reviewing work under the BA/BE Inspection Program, and the Division of New Drug Bioequivalence Evaluation, which, in addition to the BA/BE program, also conducts and reviews inspections under the GLP Inspection Program. Concurrent with the reorganization, OSIS began to implement a surveillance approach to inspections in conjunction with the application-based inspections, conducted previously. This commentary provides an overview of changes in procedures within OSIS; it will also briefly discuss topics of interest that came up during the past year, including assays related to therapeutic biologics and immunogenicity testing.

Completeness assessment of type II active pharmaceutical ingredient drug master files under generic drug user fee amendment: review metrics and common incomplete items.

Under the Generic Drug User Fee Amendments (GDUFA) of 2012, Type II active pharmaceutical ingredient (API) drug master files (DMFs) must pay a user fee and pass a Completeness Assessment (CA) before they can be referenced in an Abbreviated New Drug Application (ANDA), ANDA amendment, or ANDA prior approval supplement (PAS). During the first year of GDUFA implementation, from October 1, 2012 to September 30, 2013, approximately 1,500 Type II API DMFs received at least one cycle of CA review and more than 1,100 Type II DMFs were deemed complete and published on FDA's "Available for Reference List". The data from CA reviews were analyzed for factors that influenced the CA review process and metrics, as well as the areas of DMF submissions which most frequently led to an incomplete CA status. The metrics analysis revealed that electronic DMFs appear to improve the completeness of submission and shorten both the review and response times. Utilizing the CA checklist to compile and proactively update the DMFs improves the chance for the DMFs to pass the CA in the first cycle. However, given that the majority of DMFs require at least two cycles of CA before being deemed complete, it is recommended that DMF fees are paid 6 months in advance of the ANDA submissions in order to avoid negatively impacting the filling status of the ANDAs.

USA FDA’s implementation of QbD and GDUFA: A wakeup call for other regulatory agencies across the globe

Pharmaceutical industries recently faced off some fresh challenges due to US FDA’s recommendation on implementation of refuse to receive file (RTF), quality by design (QbD), and generic drug user fee amendments (GDUFA). Those contributed a lot of changes in US generic regulatory environment. Now, major generic players are passing through a very tough time to understand these requirements. At this juncture, this paper is an attempt to understand what QbD and GDUFA are, their goodness and overall impact. By proper understanding and its ever increasing complexities, pharmaceutical companies, those intending to do business in USA, can map their regulatory strategy to move parallels with US FDA’s regulatory compliance expectations and also it can be a wakeup call for all other regulatory authorities to appreciate beauty of these initiatives. The other regulatory authorities can welcome these USFDA’s initiatives and, however, ultimately society will be benefited by having quality generic drugs at the earliest w...