The precedent
External control arms
already support approvals.
These are industry precedents showing regulators already accept external control arms. They are public FDA and EMA facts. They are not Sapien trials.
01Named approvals
Six approvals, each on the public record.
| Approval | Sponsor | Area | What happened |
|---|---|---|---|
| Blincyto (blinatumomab) | Amgen | Leukemia | Accelerated approval supported by an external comparator built from historical US and EU patient records, later a Ph-positive ALL label expansion. |
| Zolgensma | Novartis, 2019 | Rare disease | Spinal muscular atrophy. Single-arm results contextualized against a natural-history external control of around twenty-three patients. |
| Brineura | BioMarin, 2017 | Rare disease | CLN2 disease. A single-arm trial compared against an untreated natural-history cohort. |
| Bavencio (avelumab) | Merck, 2017 | Oncology | Metastatic Merkel cell carcinoma. A single-arm trial with a matched historical synthetic comparator. |
| Alecensa (alectinib) | Roche, EU | Oncology | A 67-patient synthetic control arm accelerated EU access by around eighteen months across twenty countries. |
| Ibrance (palbociclib) | Pfizer | Oncology | Real-world evidence supported a male breast cancer label expansion. |
An FDA-focused review found roughly forty-five approvals from 2000 to 2019 where FDA accepted external-control data. Source: Jahanshahi et al., Ther Innov Regul Sci (2021).
02Where the precedent is thinMost of this is oncology and rare disease.
Most of this is oncology and rare disease.
That is the point.
Be candid: the strongest precedent sits where endpoints are objective, in oncology and rare disease. Psychiatry's subjective scales are harder, and the approvals are fewer and earlier. That gap is exactly the problem Sapien built its engine to solve, by deriving validated, traceable scales from unstructured clinical narratives.