# Regulators recognise each other's companion diagnostic approvals

Source: https://onco.cc/ideas/idea-tr2-cdx-mutual-recognition/  
OnCo record `idea-tr2-cdx-mutual-recognition` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A test approved to select patients for a drug in the US must go through separate approval in Europe, Japan and elsewhere, delaying the drug. Accepting each other's test approvals would fix the delay.

## Summary

Companion diagnostics are regulated separately from drugs and differently by region (FDA premarket approval, EU IVDR, PMDA). Divergence delays drug access and multiplies bridging studies. A mutual-recognition agreement for companion diagnostics among ICH-aligned regulators, analogous to Project Orbis for drugs, with a shared analytical validation dossier and a single bridging-study standard, would remove months to years of delay.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: Mutual recognition reduces the median lag between drug approval and companion diagnostic availability in the second region from over a year to under three months.
- Rationale: Project Orbis and the Access Consortium show that regulators can share reviews; analytical validation of a test is less region-dependent than clinical practice.
- Proposed test: Pilot recognition of five companion diagnostics between two regulators and measure time to availability against contemporaneous non-pilot tests.
- Maturity: speculative
- Actor: regulator

## Sources

- Bottleneck evidence (Biomarkers are not validated or standardised): Fernandez et al., Examination of low ERBB2 protein expression in breast cancer tissue (JAMA Oncology 2022): https://doi.org/10.1001/jamaoncol.2021.7239

## Connected records

- companies: [Foundation Medicine (Roche)](https://onco.cc/companies/foundation-medicine/)
- drugs: [FoundationOne CDx / Liquid CDx](https://onco.cc/drugs/foundationone-cdx/)
- technologies: [Companion diagnostics](https://onco.cc/technologies/companion-diagnostic/)
- terms: [Companion diagnostic](https://onco.cc/terms/companion-diagnostic-term/)
- bottlenecks: [Biomarkers are not validated or standardised](https://onco.cc/bottlenecks/b-biomarker-validation/), [Regulatory divergence between regions](https://onco.cc/bottlenecks/b-regulatory-fragmentation/)
- key papers: [Examination of Low ERBB2 Protein Expression in Breast Cancer Tissue](https://onco.cc/key-papers/paper-fernandez-jama-oncol/)

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