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

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. 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. 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. 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. 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.

Michaeli DT ，Michaeli T ，Albers S ，Boch T ，Michaeli JC ... -  《-》

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

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. 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. 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). 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.

Michaeli DT ，Michaeli T ，Albers S ，Michaeli JC ... -  《-》

Ethical imperatives of timely access to orphan drugs: is possible to reconcile economic incentives and patients' health needs?

Rodriguez-Monguio R ，Spargo T ，Seoane-Vazquez E 《Orphanet Journal of Rare Diseases》

Initial and supplementary indication approval of new targeted cancer drugs by the FDA, EMA, Health Canada, and TGA.

Previous research focused on the clinical evidence supporting new cancer drugs' initial US Food and Drug Administration (FDA) approval. However, targeted drugs are increasingly approved for supplementary indications of unknown evidence and benefit. To examine the clinical trial evidence supporting new targeted cancer drugs' initial and supplementary indication approval in the US, EU, Canada, and Australia. 25 cancer drugs across 100 indications were identified with FDA approval between 2009-2019. Data on regulatory approval and clinical trials were extracted from the FDA, European Medicines Agency (EMA), Health Canada (HC), Australian Therapeutic Goods Administration (TGA), and clinicaltrials.gov. Regional variations were compared with χ2-tests. Multivariate logistic regressions compared characteristics of initial and supplementary indication approvals, reporting adjusted odds ratios (AOR) with 95% confidence intervals (CI). Out of 100 considered cancer indications, the FDA approved 96, the EMA 92, HC 86, and the TGA 83 (83%, p < 0.05). The FDA more frequently granted priority review, conditional approval, and orphan designations than other agencies. Initial approvals were more likely to receive conditional / accelerated approval (AOR: 2.69, 95%CI [1.07-6.77], p < 0.05), an orphan designation (AOR: 3.32, 95%CI [1.38-8.00], p < 0.01), be under priority review (AOR: 2.60, 95%CI [1.17-5.78], p < 0.05), and be monotherapies (AOR: 5.91, 95%CI [1.14-30.65], p < 0.05) than supplementary indications. Initial indications' pivotal trials tended to be shorter (AOR per month: 0.96, 95%CI [0.93-0.99], p < 0.05), of lower phase design (AOR per clinical phase: 0.28, 95%CI [0.09-0.85], p < 0.05), and enroll more patients (AOR per 100 patients: 1.19, 95%CI [1.01-1.39], p < 0.05). Targeted cancer drugs are increasingly approved for multiple indications of varying clinical benefit. Drugs are first approved as monotherapies in rare diseases with a high unmet need. Whilst expedited regulatory review incentivizes this prioritization, indication-specific safety, efficacy, and pricing policies are necessary to reflect each indication's differential clinical and economic value.

Michaeli DT ，Mills M ，Michaeli T ，Miracolo A ，Kanavos P ... -  《-》

Approval of Cancer Drugs With Uncertain Therapeutic Value: A Comparison of Regulatory Decisions in Europe and the United States.

Policy Points Regulatory agencies may have limited evidence on the clinical benefits and harms of new drugs when deciding whether new therapeutic agents are allowed to enter the market and under which conditions, including whether approval is granted under special regulatory pathways and obligations to address knowledge gaps through postmarketing studies are imposed. In a matched comparison of marketing applications for cancer drugs of uncertain therapeutic value reviewed by both the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA), we found frequent discordance between the two agencies on regulatory outcomes and the use of special regulatory pathways. Both agencies often granted regular approval, even when the other agency judged there to be substantial uncertainty about drug benefits and risks that needed to be resolved through additional studies in the postmarketing period. Postmarketing studies imposed by regulators under special approval pathways to address remaining questions of efficacy and safety may not be suited to deliver timely, confirmatory evidence due to shortcomings in study design and delays, raising questions over the suitability of the FDA's Accelerated Approval and the EMA's Conditional Marketing Authorization as tools for allowing early market access for cancer drugs while maintaining rigorous regulatory standards. Regulatory agencies are increasingly required to make market approval decisions for new drugs on the basis of limited clinical evidence, a situation commonly encountered in cancer. We aimed to investigate how regulators manage uncertainty in the benefit-risk profiles of new cancer drugs by comparing decisions for the world's two largest regulatory bodies-the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA)-over a 5-year period. We systematically identified a set of cancer drug-indication pairs for which data on efficacy and safety was less complete than that required for regular approval at time of market entry from 2009 to 2013, as determined by the FDA's use of Accelerated Approval (AA) or the EMA's use of Conditional Marketing Authorization (CMA) pathways, and matched these across the two agencies. Using publicly available information, we compared regulatory pathways and outcomes, final approved indications, and postmarketing obligations imposed by the agencies. We identified 21 cancer drug-indication pairs that received FDA AA, EMA CMA, or both. Although most applications relied on identical pivotal trials across the FDA and the EMA, regulatory pathways often differed; 57% of indications received either FDA AA or EMA CMA, and regular approval by the other agency. After approval, the EMA more often accepted single-arm studies to confirm clinical benefit compared to the FDA (75% vs. 29% of indications), and the FDA more commonly requested randomized controlled trials (85% vs. 50%). Forty-one percent of confirmatory trials after FDA AA were conducted in different populations than the approved indication, compared to 13% after EMA CMA. Both agencies relied primarily on surrogate measures of patient benefit for postmarketing obligations. After a median follow-up of 7.25 years, 40% of FDA and 61% of EMA postmarketing obligations after AA and CMA, respectively, were delayed. US and European regulators often deemed early and less complete evidence on benefit-risk profiles of cancer drugs sufficient to grant regular approval, raising questions over regulatory standards for the approval of new medicines. Even when imposing confirmatory studies in the postmarketing period through special approval pathways, meaningful evidence may not materialize due to shortcomings in study design and delays in conducting required studies with due diligence.

Salcher-Konrad M ，Naci H ，Davis C 《-》