Characteristics of non-randomised studies using comparisons with external controls submitted for regulatory approval in the USA and Europe: a systematic review
Bibliographic record
Abstract
OBJECTIVES: Non-randomised clinical trial designs involving comparisons against external controls or specific standards can be used to support regulatory submissions for indications in diseases that are rare, with high unmet need, without approved therapies and/or where placebo is considered unethical. The objective of this review was to summarise the characteristics of non-randomised trials submitted to the European Medicines Agency (EMA) or Food and Drug Administration (FDA) for indications in haematological cancers, haematological non-malignant conditions, stem cell transplants or rare metabolic diseases. METHODS: We conducted systematic searches of EMA databases of conditional approvals, exceptional circumstances, or orphan drug designations and FDA inventories of orphan drug designations, accelerated approvals, breakthrough therapy, fast-track and priority approvals. Products were included if reviewed by at least one agency between 2005 and 2017, the primary evidence base was non-randomised trial(s) and the indication was for haematological cancers, stem cell transplantation, haematological conditions or rare metabolic conditions. RESULTS: We identified 43 eligible indication-specific products using non-randomised study designs involving comparisons with external controls, submitted to the EMA (n=34) and/or FDA (n=41). Of the 43 indication-specific products, 4 involved matching external controls to the population of a non-randomised interventional study using individual patient-level data (IPD), 12 referred to external controls without IPD and 27 did not explicitly reference external controls. The FDA approved 98% of submissions, with 56% accelerated approvals; most required postapproval confirmatory randomised controlled trials (RCT). The EMA approved 79% of submissions, with a quarter of approvals conditional on completion of a postapproval RCT or additional non-randomised trials. CONCLUSIONS: There has been a large increase in submissions to the EMA and FDA using non-randomised study designs involving comparisons with external controls in recent years. This study demonstrated that regulators may be willing to approve such submissions, although approvals are often conditional on further confirmatory evidence from postapproval studies.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.046 | 0.006 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.011 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".