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Partial Change Approval (Ichibu Henko)

JP-unique

Ichibu Henko (一部変更承認 — partial change approval) is Japan's process for obtaining MHLW approval before making significant changes to an approved Shonin device. It is analogous to EU MDR significant change assessments and FDA PMA supplements, but has its own set of trigger criteria and process requirements.

What Ichibu Henko is​

Ichibu Henko is a formal application to MHLW to amend an existing Shonin approval. It is required when a planned change to the device, its manufacturing, or its intended use is "significant" as defined by MHLW notification.

The change cannot be implemented until MHLW issues the amended approval — unlike minor change notifications (below), which the MAH can file after implementation.

What changes require Ichibu Henko​

MHLW has published guidance classifying device changes by type and magnitude. Changes typically requiring Ichibu Henko include:

Design changes:

  • Change in materials in contact with the patient that could affect biocompatibility
  • Change in the mechanism of action or operating principle
  • Change in device dimensions beyond specified tolerances

Manufacturing changes:

  • Transfer of manufacturing to a new site (different FMR)
  • Major changes to sterilisation method or parameters

Intended use changes:

  • Addition of new indications
  • Change in the indicated patient population (e.g. extension to paediatric use)
  • Addition of new anatomical locations

Software changes (for software-enabled devices):

  • Changes that significantly affect the safety or efficacy of the device's software functions

Application requirements and process​

An Ichibu Henko application is submitted to PMDA and follows a similar process to the original Shonin application, but typically with a narrower scope. The application includes:

  • Description of the change and the reason for the change
  • Technical data supporting the safety and efficacy of the modified device
  • Updated modules of the original dossier affected by the change (risk management, testing, labelling)
  • Updated Essential Principles checklist if affected

PMDA reviews the application and MHLW issues the amended approval. Timelines are typically shorter than a full Shonin review but depend on the nature and complexity of the change.