Postmarketing safety of orphan drugs: a longitudinal analysis of the US Food and Drug Administration database between 1999 and 2018

Special FDA designations for drug development: orphan, fast track, accelerated approval, priority review, and breakthrough therapy

BACKGROUND

Over the past decades, US Congress enabled the US Food and Drug Administration (FDA) to facilitate and expedite drug development for serious conditions filling unmet medical needs with five special designations and review pathways: orphan, fast track, accelerated approval, priority review, and breakthrough therapy.

OBJECTIVES

This study reviews the FDA's five special designations for drug development regarding their safety, efficacy/clinical benefit, clinical trials, innovation, economic incentives, development timelines, and price.

METHODS

We conducted a keyword search to identify studies analyzing the impact of the FDA's special designations (orphan, fast track, accelerated approval, priority review, and breakthrough therapy) on the safety, efficacy/clinical benefit, trials, innovativeness, economic incentives, development times, and pricing of new drugs. Results were summarized in a narrative overview.

RESULTS

Expedited approval reduces new drugs' time to market. However, faster drug development and regulatory review are associated with more unrecognized adverse events and post-marketing safety revisions. Clinical trials supporting special FDA approvals frequently use small, non-randomized, open-label designs. Required post-approval trials to monitor unknown adverse events are often delayed or not even initiated. Evidence suggests that drugs approved under special review pathways, marketed as "breakthroughs", are more innovative and deliver a higher clinical benefit than those receiving standard FDA approval. Special designations are an economically viable strategy for investors and pharmaceutical companies to develop drugs for rare diseases with unmet medical needs, due to financial incentives, expedited development timelines, higher clinical trial success rates, alongside greater prices. Nonetheless, patients, physicians, and insurers are concerned about spending money on drugs without a proven benefit or even on drugs that turn out to be ineffective. While European countries established performance- and financial-based managed entry agreements to account for this uncertainty in clinical trial evidence and cost-effectiveness, the pricing and reimbursement of these drugs remain largely unregulated in the US.

CONCLUSION

Special FDA designations shorten clinical development and FDA approval times for new drugs treating rare and severe diseases with unmet medical needs. Special-designated drugs offer a greater clinical benefit to patients. However, physicians, patients, and insurers must be aware that special-designated drugs are often approved based on non-robust trials, associated with more unrecognized side effects, and sold for higher prices.

Factors associated with hematological adverse reactions of drugs authorized via the centralized procedure

Serious hematological adverse drug reactions (HADRs) may lead to or prolong hospitalization and even cause death. The aim of this study was to determine the regulatory factors associated with HADRs caused by drugs that were authorized up to July 2023 by the European Medicines Agency (EMA) and to evaluate the frequency of HADRs. Using a cross-sectional approach, the type and frequency of HADRs were collected from the Summaries of Product Characteristics of Drugs Authorized by the EMA and analyzed within proprietary, nonproprietary, and biosimilar/biological frameworks. Multivariate statistical analysis was used to investigate the associations of generic status, biosimilar status, conditional approval, exceptional circumstances, accelerated assessment, orphan drug status, years on the market, administration route, and inclusion on the Essential Medicines List (EML) with HADRs. In total, 54.78% of proprietary drugs were associated with HADRs at any frequency, while anemia, leucopenia, and thrombocytopenia were observed in approximately 36% of the patients. The predictors of any HADR, anemia, and thrombocytopenia of any frequency are generic status, biosimilar status, and inclusion on the EML, while the only protective factor is the administration route. Biosimilars and their originator biologicals have similar frequencies of HADRs; the only exception is somatropin. Knowledge of the regulatory factors associated with HADRs could help clinicians address monitoring issues when new drugs are introduced for the treatment of patients.

The impact of level of documentation on the accessibility and affordability of new drugs in Norway

Introduction: Over the preceding decade, an increasing number of drugs have been approved by the European Medicines Agency (EMA) with limited knowledge of their relative efficacy. This is due to the utilization of non-randomized, single-arm studies, surrogate endpoints, and shorter follow-up time. The impact of this trend on the accessibility and affordability of newly approved drugs in Europe remains uncertain. The primary objective of this study is to provide insights into the issues of accessibility and affordability of new drugs in the Norwegian healthcare system. Method: The presented study entails an analysis of all reimbursement decisions for hospital drugs in Norway spanning 2021-2022. The included drugs were approved by the EMA between 2014 and 2022, with the majority (91%) receiving approval between 2018 and 2022. The drugs were categorized based on the level of documentation of relative efficacy. Approval rates and costs (confidential net-prices) were compared. Results: A total of 35% (70/199) of the reimbursement decisions were characterized by limited certainty regarding relative efficacy and as a consequence the Norwegian Health Technology Assessment (HTA) body did not present an incremental cost-effectiveness ratio (ICER) in the HTA report. Within this category, a lower percentage of drugs (47%) gained reimbursement approval compared to those with a higher certainty level, which were presented with an ICER (58%). On average, drugs with an established relative efficacy were accepted with a 4.4-fold higher cost (confidential net-prices). These trends persisted when specifically examining oncology drugs. Conclusion: Our study underscores that a substantial number of recently introduced drugs receive reimbursement regardless of the level of certainty concerning relative efficacy. However, the results suggest that payers prioritize documented over potential efficacy. Given that updated information on relative efficacy may emerge post-market access, a potential solution to address challenges related to accessibility and affordability in Europe could involve an increased adoption of market entry agreements. These agreements could allow for price adjustments after the presentation of new knowledge regarding relative efficacy, potentially resolving some of the current challenges.

Clinical benefit, development, innovation, trials, epidemiology, and price for cancer drugs and indications with multiple special FDA designations

BACKGROUND

This study analyzes the development, US Food and Drug Administration (FDA) approval, benefits, innovation, trials, epidemiology, and price of cancer drugs with multiple special designations: orphan, fast track, accelerated approval, priority review, and breakthrough therapy.

METHODS

In total, 355 FDA-approved cancer drug indications with 841 special designations were identified (2012-2022). Trial, epidemiology, and price data were collected from FDA labels, the Global Burden of Disease study, and Medicare and Medicaid. The association between efficacy outcomes and indications' number of special designations were compared in meta-analyses.

RESULTS

Median development times were 7.3, 7.8, and 5.4 months (P = .027) for drugs with 0 to 1, 2 to 3, and 4 to 5 special designations, respectively. Multiple special designations were associated with higher biotechnological and clinical innovation. Median patient enrollment in trials were 615, 471, 398, 168, 104, and 120 (P < .001) for indications with 0 to 5 special designations. Drugs for rare diseases supported by open-label phase 1/2 trials of single-arm design were granted more special designations. Hazard ratios for overall survival (0.80 vs 0.73 vs 0.73 vs 0.69 vs 0.56 vs 0.52; P = .003) and progression-free survival (0.70 vs 0.61 vs 0.59 vs 0.44 vs 0.37 vs 0.67; P < .001) substantially declined while tumor response increased with more special designations. Mean monthly prices increased for drugs with 0 to 4 but not 5 special designations ($21 596 vs $14 753 vs $32 410 vs $41 240 vs $38 703 vs $19 184).

CONCLUSIONS

Multiple special designations are associated with faster clinical development and greater benefits for patients with unmet needs but also with nonrobust trial evidence and a tendency toward higher drug prices.

Innovative thinking of clinical investigation for rare disease drug development

For the development of a test treatment or drug product, it is necessary to conduct composite hypothesis testing to test for effectiveness and safety simultaneously, since some approved drug products have been recalled due to safety concerns. One of the major issues in conducting a composite hypothesis testing for effectiveness and safety is the requirement of a huge sample size to achieve the desired power for detecting clinically meaningful differences in both safety and effectiveness. Situation can be much difficult in orphan drug development. In this article, a generalized two-stage innovative approach to test for effectiveness and safety simultaneously is proposed. Additionally, to alleviate the requirement of a large randomized clinical trial (RCT) and revealing effectiveness, real-world data is suggested to use in conjunction with RCT data for orphan drug development. The proposed approach can help investigators test for effectiveness and safety at the same time without worrying about the sample size. It also helps reduce the probability of approving a drug product with safety concerns.

FDA approval, clinical trial evidence, efficacy, epidemiology, and price for non-orphan and ultra-rare, rare, and common orphan cancer drug indications: cross sectional analysis

OBJECTIVE

To analyze the US Food and Drug Administration (FDA) approval, trials, unmet needs, benefit, and pricing of ultra-rare (<6600 affected US citizens), rare (6600-200 000 citizens), and common (>200 000 citizens) orphan cancer drug indications and non-orphan cancer drug indications.

DESIGN

Cross sectional analysis.

SETTING

Data from Drugs@FDA, FDA labels, Global Burden of Disease study, and Medicare and Medicaid.

POPULATION

170 FDA approved drugs across 455 cancer indications between 2000 and 2022.

MAIN OUTCOME MEASURES

Comparison of non-orphan and ultra-rare, rare, and common orphan indications regarding regulatory approval, trials, epidemiology, and price. Hazard ratios for overall survival and progression-free survival were meta-analyzed.

RESULTS

161 non-orphan and 294 orphan cancer drug indications were identified, of which 25 were approved for ultra-rare diseases, 205 for rare diseases, and 64 for common diseases. Drugs for ultra-rare orphan indications were more frequently first in class (76% v 48% v 38% v 42%; P<0.001), monotherapies (88% v 69% v 72% v 55%; P=0.001), for hematologic cancers (76% v 66% v 0% v 0%; P<0.001), and supported by smaller trials (median 85 v 199 v 286 v 521 patients; P<0.001), of single arm (84% v 44% v 28% v 21%; P<0.001) phase 1/2 design (88% v 45% v 45% v 27%; P<0.001) compared with rare and common orphan indications and non-orphan indications. Drugs for common orphan indications were more often biomarker directed (69% v 26% v 12%; P<0.001), first line (77% v 39% v 20%; P<0.001), small molecules (80% v 62% v 48%; P<0.001) benefiting from quicker time to first FDA approval (median 5.7 v 7.1 v 8.9 years; P=0.02) than those for rare and ultra-rare orphan indications. Drugs for ultra-rare, rare, and common orphan indications offered a significantly greater progression-free survival benefit (hazard ratio 0.53 v 0.51 v 0.49 v 0.64; P<0.001), but not overall survival benefit (0.50 v 0.73 v 0.71 v 0.74; P=0.06), than non-orphans. In single arm trials, tumor response rates were greater for drugs for ultra-rare orphan indications than for rare or common orphan indications and non-orphan indications (objective response rate 57% v 48% v 55% v 33%; P<0.001). Disease incidence/prevalence, five year survival, and the number of available treatments were lower, whereas disability adjusted life years per patient were higher, for ultra-rare orphan indications compared with rare or common indications and non-orphan indications. For 147 on-patent drugs with available data in 2023, monthly prices were higher for ultra-rare orphan indications than for rare or common orphan indications and non-orphan indications ($70 128 (£55 971; €63 370) v $33 313 v $16 484 v $14 508; P<0.001). For 48 on-patent drugs with available longitudinal data from 2005 to 2023, prices increased by 94% for drugs for orphan indications and 50% for drugs for non-orphan indications on average.

CONCLUSIONS

The Orphan Drug Act of 1983 incentivizes development of drugs not only for rare diseases but also for ultra-rare diseases and subsets of common diseases. These orphan indications fill significant unmet needs, yet their approval is based on small, non-robust trials that could overestimate efficacy outcomes. A distinct ultra-orphan designation with greater financial incentives could encourage and expedite drug development for ultra-rare diseases.