Do Cost-Effectiveness Analyses Account for Drug Genericization? A Literature Review and Assessment of Implications

Drug Prices After Patent Expirations in High-Income Countries and Implications for Cost-Effectiveness Analyses

Importance

Understanding how patent expirations affect drug prices is crucial because price changes directly inform accurate cost-effectiveness assessments. This study investigates the association between patent expirations and drug prices in 8 high-income countries and evaluates how the changes affect cost-effectiveness assessments.

Objective

To analyze how the expiration of drug patents is associated with drug price changes and to assess the implications of these price changes for cost-effectiveness evaluations.

Design, Setting, and Participants

This cohort study performed an event study design using data from 8 high-income countries to assess the association between patent expiration and drug prices, and created a simulation model to understand the implications for cost-effectiveness analyses. The simulation cost-effectiveness model analyzed the implications of including or ignoring postpatent price dynamics.

Exposure

Drug patent expiration.

Main Outcomes and Measures

Change in drug prices and differences in incremental cost-effectiveness ratios when considering vs ignoring postpatent price dynamics.

Results

The sample comprised 505 drugs undergoing patent expiration in Australia, Canada, France, Germany, Japan, Switzerland, UK, and US. Price decreases were statistically significant over the 8 years after patent expiration, with the fastest price declines observed in the US: 32% (95% CI, 24%-39%) in year 1 after patent expiration and 82% (95% CI, 71%-89%) in the 8 years after patent expiration. Estimates for other nations ranged from a decrease of 64% in Australia to 18% in Switzerland in the 8 years after expiration. The cost-effectiveness simulation model indicated that not accounting for generic entry into the market may produce biased incremental cost-effectiveness ratios of 40% to -40%, depending on the scenario.

Conclusions and Relevance

The findings of this cohort study demonstrate that drug prices were reduced substantially after patent expirations in high-income countries. Therefore, incorporating information on patent status and pricing dynamics in cost-effectiveness assessment analyses is necessary for producing accurate economic evaluations of new drugs.

Can Generalized Cost-Effectiveness Analysis Leverage Meaningful Use of Novel Value Elements in Pharmacoeconomics to Inform Medicare Drug Price Negotiation?

OBJECTIVES

Decision makers considering using cost-effectiveness analysis (CEA) to inform health-technology assessment must contend with documented and controversial shortfalls of CEA, including its assumption of disease severity independence and static pricing. ISPOR has recently introduced novel value elements besides direct healthcare cost and effectiveness for the patient, and these should be captured in CEA. Although novel value elements advance our understanding of "what" should be measured (value of hope, severity of disease, health equity, etc), there is limited direction on "how" to measure them in conventional CEA. Furthermore, with Medicare empowered to set drug prices under the Inflation Reduction Act, it is not clear what role CEA might have on where prices are set, given objections to the quality-adjusted life year in conventional approaches.

METHODS

We critically reviewed the evidence for expanding conventional CEA methods to a more generalized approach of generalized CEA (GCEA).

RESULTS

GCEA accounts for methods that address objections to the quality-adjusted life year and incorporate novel value elements. Although GCEA offers advantages, it also requires further research to develop "off-the-shelf" resources to help inform, for example, maximum fair price in the context of Medicare drug price negotiation.

CONCLUSIONS

Should a shift toward GCEA reveal that the societal value of novel medicines exceeds their market-based costs, which will raise the key question of what market failure Medicare negotiation is meant to solve, if any, and therefore what the appropriate role of such negotiation might be to maximize the value society might garner from the development of novel medicines.

Challenges of Incorporating Life Cycle Drug Pricing in Cost-Effectiveness Models: A Review of Methods and Modeling Suggestions

OBJECTIVES

This study aimed to conduct a review of existing methods used to incorporate life cycle drug pricing (LCDP) in cost-effectiveness analyses (CEAs), identify common methodological challenges, and suggest modeling approaches for prospectively implementing LCDP in CEA.

METHODS

Two complementary searches were conducted in PubMed, combined with hand searching and reference mining, to identify English language full-text articles that explored (1) how drug prices change over time and (2) methods used to apply dynamic pricing in cost-effectiveness models (CEMs). Relevant articles were reviewed, and authors discussed the common methodological practices used in the literature and their associated challenges on prospectively implementing LCDP in CEMs. For each key challenge identified, we provide modeling suggestions to address the issue.

RESULTS

We screened 1200 studies based on title and abstract; 117 were reviewed for eligibility, and 47 individual studies were included across both searches. Variations in prices over a product's life cycle are complex and multifactorial, and models applying LCDP in CEA varied in their methodology. We identified 4 key challenges to modeling LCDP in CEA, including how to model price trends before and after loss of exclusivity, how to capture the effect of price changes on future patient cohorts, and how to report results.

CONCLUSION

Accurately quantifying the impact of LCDP requires careful consideration of multiple aspects pertaining to both the evolution of drug prices and how to reflect these in CEA. Although uncertainties remain, our findings can aid implementation and evaluation of LCDP in economic evaluations.

It Is Time to Reconsider the 3% Discount Rate

OBJECTIVES

Health technology assessment (HTA) guidance often recommends a 3% real annual discount rate, the appropriateness of which has received limited attention. This article seeks to identify an appropriate rate for high-income countries because it can influence projected cost-effectiveness and hence resource allocation recommendations.

METHODS

The author conducted 2 Pubmed.gov searches. The first sought articles on the theory for selecting a rate. The second sought HTA guidance documents.

RESULTS

The first search yielded 21 articles describing 2 approaches. The "Ramsey Equation" sums contributions by 4 factors: pure time preference, catastrophic risk, wealth effect, and macroeconomic risk. The first 3 factors increase the discount rate because they indicate future impacts are less important, whereas the last, suggesting greater future need, decreases the discount rate. A fifth factor-project-specific risk-increases the discount rate but does not appear in the Ramsey Equation. Market interest rates represent a second approach for identifying a discount rate because they represent competing investment returns and hence opportunity costs. The second search identified HTA guidelines for 32 high-income countries. Twenty-two provide no explicit rationale for their recommended rates, 8 appeal to market interest rates, 3 to consistency, and 3 to Ramsey Equation factors.

CONCLUSIONS

Declining consumption growth and real interest rates imply HTA guidance should reduce recommended discount rates to 1.5 to 2+%. This change will improve projected cost-effectiveness for therapies with long-term benefits and increase the impact of accounting for long-term drug price dynamics, including reduced prices attending loss of market exclusivity.

Achieving dynamic efficiency in pharmaceutical innovation: Identifying the optimal share of value and payments required

It has been argued that cost-effectiveness analysis of branded pharmaceuticals only considers static efficiency, neglects dynamic effects and undermines incentives for socially valuable innovation. We present a framework for designing pharmaceutical pricing policy to achieve dynamic efficiency. We develop a coherent framework that identifies the long-term static and dynamic benefits and costs of offering manufacturers different levels of reward. The share of value that would maximise long-term population health depends on how the quantity and quality of innovation responds to payment. Using evidence of the response of innovation to payment, the optimal share of value of new pharmaceuticals to offer to manufacturers is roughly 20% (range: 6%-51%). Reanalysis of a sample of NICE technology appraisals suggests that, in most cases, the share of value offered to manufacturers and the price premium paid by the English NHS were too high. In the UK, application of optimal shares would offer considerable benefits under both a public health objective and a broader view of social welfare. We illustrate how an optimal share of value can be delivered through a range of payment mechanisms including indirect price regulation via the use of different approval norms by an HTA body.

A Framework for the Fair Pricing of Medicines

As high-cost medicines put increasing pressure on public health care budgets, the need to identify 'fair' prices for medicines has never been greater. This paper proposes a framework, built upon fundamental economic principles, that allows for the consideration of 'fair' prices for medicines. The framework incorporates key considerations from conventional supply-side and demand-side approaches for specifying a cost-effectiveness 'threshold', including the health opportunity cost borne by other patients ([Formula: see text]) and society's willingness to pay for marginal improvements in population health ([Formula: see text]). The costs incurred by manufacturers in developing and supplying new medicines are also considered, as are the incentives for manufacturers to strategically price up to any common price per unit of benefit (cost-effectiveness 'threshold') specified by the payer. The framework finds that, at any 'fair' price, a medicine's dynamically calculated incremental cost-effectiveness ratio (ICER) lies below [Formula: see text]. When pricing medicines collectively, the framework finds that a common price below [Formula: see text] is required to maximize population health (consumer surplus) or to maximize total welfare (consumer and producer surplus). This framework has important policy implications for payers who wish to improve population health outcomes from constrained health care budgets. In particular, existing approaches to 'value-based pricing' should be reconsidered to ensure that patients receive a 'fair' share of the resulting economic surplus.

Is the price right? Paying for value today to get more value tomorrow

BACKGROUND

Contemporary debates about drug pricing feature several widely held misconceptions, including the relationship between incentives and innovation, the proportion of total healthcare spending on pharmaceuticals, and whether the economic evaluation of a medicine can be influenced by things other than clinical efficacy.

MAIN BODY

All citizens should have access to timely, equitable, and cost-effective care covered by public funds, private insurance, or a combination of both. Better managing the collective burden of diseases borne by today's and future generations depends in part on developing better technologies, including better medicines. As in any innovative industry, the expectation of adequate financial returns incentivizes innovators and their investors to develop new medicines. Estimating expected returns requires that they forecast revenues, based on the future price trajectory and volume of use over time. How market participants decide what price to set or accept can be complicated, and some observers and stakeholders want to confirm whether the net prices society pays for novel medicines, whether as a reward for past innovation or an incentive for future innovation, are commensurate with those medicines' incremental value. But we must also ask "value to whom?"; medicines not only bring immediate clinical benefits to patients treated today, but also can provide a broad spectrum of short- and long-term benefits to patients, their families, and society. Spending across all facets of healthcare has grown over the last 25 years, but both inpatient and outpatient spending has outpaced drug spending growth even as our drug armamentarium is constantly improving with safer and more effective medicines. In large part, this is because, unlike hospitals, drugs typically go generic, thus making room in our budgets for new and better ones, even as they often keep patients out of hospitals, driving further savings.

CONCLUSION

A thorough evaluation of drug spending and value can help to promote a better allocation of healthcare resources for both the healthy and the sick, both of whom must pay for healthcare. Taking a holistic approach to assessing drug value makes it clear that a branded drug's value to a patient is often only a small fraction of the drug's total value to society. Societal value merits consideration when determining whether and how to make a medicine affordable and accessible to patients: a drug that is worth its price to society should not be rendered inaccessible to ill patients by imposing high out-of-pocket costs or restricting coverage based on narrow health technology assessments (HTAs). Furthermore, recognizing the total societal cost of un- or undertreated conditions is crucial to gaining a thorough understanding of what guides the biomedical innovation ecosystem to create value for society. It would be unwise to discourage the development of new solutions without first appreciating the cost of leaving the problems unsolved.

The Influence of US Drug Price Dynamics on Cost-Effectiveness Analyses of Biologics

OBJECTIVES

This study aimed to evaluate the influence of drug price dynamics in cost-effectiveness analyses.

METHODS

We evaluated scenarios involving typical US drug price increases during the exclusivity period and price decreases after the loss of exclusivity (LOE). Worked examples are presented using the Institute for Clinical and Economic Review's assessments of tezepelumab for the treatment of severe asthma and targeted immune modulators for rheumatoid arthritis.

RESULTS

Tezepelumab case: yearly 2% price increases during the period of exclusivity and a post-LOE price decrease of 25% yielded an incremental cost per quality-adjusted life-year (QALY) gained that increased over the base case from $430 300 to $444 600 (+3.2%). Yearly 2% price increases followed by a steeper post-LOE price reduction of 40% resulted in a cost per QALY gained of $401 400 (6.8% reduction vs the base case). Rheumatoid arthritis case: incorporating post-LOE price reductions for etanercept (intervention) and adalimumab (comparator) ranging from 25% to 40% yielded an incremental cost per QALY of $121 000 and $122 300, respectively (< 3% increase from the base case of $119 200/QALY). Including a 2% yearly price increase during the projected exclusivity periods of both intervention and comparator increased the cost per QALY gained by > 60%.

CONCLUSION

Two biologic treatment cases incorporating price dynamics in cost-effectiveness analyses had varied impacts on the cost-effectiveness ratio depending on the magnitude of pre-LOE price increase and post-LOE price decrease and whether the LOE also affected the comparator. Yearly price increase magnitude during the period of exclusivity, among other factors, may counterbalance the effects of lower post-LOE intervention prices.

Value-Based Pricing for Patent-Protected Medicines Over the Product Life Cycle: Pricing Anomalies in the "Age of Cures" and Their Implications for Dynamic Efficiency

OBJECTIVES

Conventional cost-effectiveness analysis (CEA) for the value-based pricing of new medicines largely ignores the implications of limited market exclusivity (ie, patent-protection periods plus any exclusivity granted by regulators). This paper explores the implications of this methodological shortcoming, which produces several pricing anomalies with potentially unintended effects on research and development (R&D) incentives.

METHODS

We illustrate these implications by comparing 4 stylized examples of increasing complexity, from short-term cures for acute conditions to long-term cures for rare, health-catastrophic conditions.

RESULTS

(1) Conventional-CEA will project a different result than an adjusted CEA that considers generic or biosimilar entry; (2) free and flexible pricing of long-term treatments (eg, statins for hypercholesterolemia) or repeated-dose cures (eg, insulin for type 1 diabetes) for chronic conditions will likely result in predictable price increases at the end of the exclusivity period that may be perceived as unjustified or unsupported; and (3) one-time administration "cures" (eg, gene therapy for spinal muscular atrophy) have the potential to allocate a large share of the social surplus to the manufacturer over the product lifetime, which may or may not be dynamically efficient per se, but may also inadvertently disadvantage the development of valuable long-term treatments or repeated-dose cures for chronic conditions.

CONCLUSIONS

We highlight the need for additional research on long-term solutions to these issues that would aim to promote dynamically efficient global R&D. More work is needed on the following: (1) relationships between social surplus allocation and the amount and composition of global R&D, as we may be as likely to be encouraging excessive R&D in some areas as to be undersupplying it in others; and (2) relating the size of the surplus reward to R&D cost and, thus, the return on investment.

The Impact on Cost-Effectiveness of Accounting for Generic Drug Pricing: Four Case Studies

OBJECTIVES

Guidance on the conduct of health technology assessments rarely recommends accounting for anticipated future price declines that can follow loss of marketing exclusivity. This article explores when it is appropriate to account for generic pricing and whether it can influence cost-effectiveness estimates.

METHODS

This article presents 4 case studies. Case study 1 considers a hypothetical drug used by a first patient cohort at branded prices and by subsequent, "downstream" cohorts at generic prices. Case study 2 explores whether statin assessments should account for generic prices for downstream cohorts that gain access after the initial cohort. Case study 3 uses a simplified spreadsheet model to assess the impact of accounting for generic pricing for inclisiran, used when statins insufficiently reduce cholesterol. Case study 4 amends this model for a hypothetical, advanced, follow-on treatment displacing inclisiran.

RESULTS

Assessments should include generic pricing even if the first cohort using a drug pays branded prices and only downstream cohorts pay generic prices (case study 1). Because eventual generic pricing for statins did not depend on decisions for downstream cohorts, assessing reimbursement for those cohorts could safely omit generic pricing (case study 2). For inclisiran (case study 3), including generic pricing notably improved estimated cost-effectiveness. Displacing inclisiran with an advanced therapy (case study 4) modestly affected estimated cost-effectiveness.

CONCLUSIONS

Although this analysis relies on simplified and hypothetical models, it demonstrates that accounting for generic pricing might substantially reduce estimated cost-effectiveness ratios. Doing so when warranted is crucial to improving health technology assessment validity.

Incorporating Dynamic Pricing in Cost-Effectiveness Analysis: Are Known Unknowns Valuable?

BACKGROUND

Current practice in health technology assessment (HTA) of pharmaceuticals conducts cost-effectiveness analyses (CEAs) based on a static price or the estimated price at market launch. Recent publications suggest incorporating dynamic pricing. To test the feasibility and importance of including dynamic pricing, we compared the standard static approach to four dynamic scenarios by replicating US-based HTA evaluations with dynamic pricing inputs.

METHODS

The four case examples included omalizumab (Xolair®) for the treatment of allergic asthma, elagolix (Orilissa®) for the treatment of endometriosis, ocrelizumab (Ocrevus®) for the treatment of primary progressive multiple sclerosis (PPMS), and dupilumab (Dupixent®) for the treatment of atopic dermatitis (AD). The primary outcome was the relative percentage change in incremental cost-effectiveness ratios (ICERs) per quality-adjusted life-year (QALY) for two dynamic pricing scenarios versus static pricing. Secondary outcomes included the absolute difference in ICERs versus base-case and an assessment of decision uncertainty.

RESULTS

Base-case ICERs were $327,000, $102,000, $700,000, and $102,000 for allergic asthma, endometriosis, PPMS, and AD, respectively. Across scenarios and case examples, the range of ICERs versus base-case varied from decreases of 56% to increases of 232%. The absolute difference in ICERs versus base-case ranged from decreases of $120,000 to increases of $758,000. Conclusions on cost effectiveness were altered in 2/16 scenarios across the four case examples.

CONCLUSIONS

Given the decision context that US payers face, with prices varying over time, findings suggest further research to reduce uncertainty around price trajectories, as well as conducting or updating multiple assessments over the lifecycle of pharmaceutical products.

The Effect of the Drug Life Cycle Price on Cost-Effectiveness: Case Studies Using Real-World Pricing Data

OBJECTIVES

Cost-effectiveness analyses (CEAs) generally assume constant drug prices throughout the model time horizon, yet it is known that prices are not constant, often with price decreases near loss of exclusivity (LOE). This study explores the impact of using dynamic drug-specific prices on the incremental cost-effectiveness ratio (ICER) using selected reproduced case studies.

METHODS

Case studies were selected following explicit criteria to reflect a variety of drug characteristics. For each drug, a published CEA model was identified, replicated, and modified with dynamic real-world pricing data, to compare ICERs based on constant drug prices with estimates obtained when including drug life cycle pricing. The impact of dynamic real-world pricing-inclusive LOE-was analyzed using a single patient cohort and multiple cohorts over time.

RESULTS

Fluvastatin, alendronic acid + colecalciferol combination therapy, letrozole and clopidogrel were selected as case studies. Inclusion of real-world pricing data compared with applying constant prices reduced the ICER in a single-cohort setting up to 43%. In the multicohort analyses, further reductions of the ICERs were observed of up to 113%. The ICERs were sensitive to the period of drug usage relative to the models' time horizons, the relative proportions of drug costs in the overall treatment costs, and timing of LOE compared with the cost year of the original analysis.

CONCLUSIONS

Assuming dynamic drug prices may lead to more representative ICER estimates. Future CEAs for drugs could account for predicted and disaggregated life cycle price developments based on retrospective data.

The History and Future of the "ISPOR Value Flower": Addressing Limitations of Conventional Cost-Effectiveness Analysis

OBJECTIVES

Since its publication as part of the 2018 ISPOR Special Task Force (STF) on US Value Assessments, the "ISPOR value flower," with its petals highlighting elements that may be overlooked or underappreciated in conventional drug value assessments, has been discussed and debated. We review the history of the value flower, describe recent developments, and consider implications for future value assessments.

METHODS

We discuss various antecedents to the value flower, as well as conceptual and empirical articles published in the past 4 years.

RESULTS

Since the publication of the ISPOR STF report, researchers have provided more rigorous theoretical and mathematical foundations for certain novel value elements (eg, severity of illness, value of insurance, value of hope) through "generalized risk-adjusted cost-effectiveness analysis," which incorporates risk aversion in people's preferences and uncertainty in treatment outcomes. Empirical estimates are also emerging to support key elements, such as insurance value, real option value, value of hope, and value of knowing. Although health technology assessment bodies have applied or are considering certain elements (eg, severity modifiers to cost-effectiveness thresholds), other elements have yet to gain traction.

CONCLUSIONS

Five years after the STF began its work, the development of novel value measures continues to evolve. Although it is encouraging to see supporting empirical studies emerging, more are needed. Additional efforts are also needed to illustrate how the estimates can be used in the deliberative processes that are integral to health technology assessments.

The ethics of aggregation in cost-effectiveness analysis or, "on books, bookshelves, and budget impact"

In deciding how to allocate resources, healthcare priority-setters are increasingly paying attention to an intervention's budget impact alongside its cost-effectiveness. Some argue that approaches that use budget impact as a substantive consideration unfairly disadvantage individuals who belong to large patient groups. Others reject such claims of "numerical discrimination" on the grounds that consideration of the full budget impact of an intervention's adoption is necessary to properly estimate opportunity cost. This paper summarizes this debate and advances a new argument against modifying the cost-effectiveness threshold used for decision-making based on a technology's anticipated budget impact. In making this argument, the paper sets out how the apparent link between budget impact and opportunity cost is largely broken if the effects of a technology's adoption are disaggregated, while highlighting that the theoretical aggregation of effects during cost-effectiveness analysis likely only poorly reflects the operation of the health system in practice. As such, it identifies a need for healthcare priority-setters to be cognizant of the ethical implications associated with aggregating the effects of a technology's adoption for the purpose of decision-making. Throughout the paper, these arguments are illustrated with reference to a "bookshelf" analogy borrowed from previous work.