REGULATORY FRAMEWORK FOR BIOENGINEERED ADHESION CONTROL THERAPIES IN JAPAN

1. INTRODUCTION

Bioengineered adhesion control therapies are advanced biomedical products and technologies designed to regulate, prevent, reduce or modify unwanted biological adhesion. They may be used to prevent postoperative tissue adhesions, control cellular attachment, improve tissue regeneration, support wound healing and regulate interactions between implanted biomaterials and biological tissues.

These technologies may include biodegradable anti-adhesion barriers, hydrogel-based materials, engineered extracellular matrices, bioactive polymer coatings, tissue adhesives and cell-based products.

In Japan, the regulatory classification of these therapies depends on their composition, intended medical purpose, mechanism of action and degree of biological manipulation. A conventional anti-adhesion barrier may be regulated as a medical device, whereas an engineered cellular product intended to reconstruct or repair human tissue may fall within the regenerative medicine product framework.

Japan does not have a single statute specifically dedicated to bioengineered adhesion control therapies. Instead, regulation operates through pharmaceutical and medical-device legislation, regenerative medicine legislation, clinical research requirements, manufacturing standards, product liability principles and patient safety obligations.

The central regulatory objective is to ensure that these therapies demonstrate appropriate quality, safety and clinical performance before and after their introduction into medical practice.

2. PRINCIPAL LEGAL AND REGULATORY FRAMEWORK

A. Pharmaceuticals and Medical Devices Act (PMD Act)

The Act on Securing Quality, Efficacy and Safety of Products Including Pharmaceuticals and Medical Devices is the principal legislation governing medical devices and regenerative medical products in Japan.

Its principal requirements include:

Appropriate product classification according to intended medical use.

Marketing authorisation or applicable certification.

Manufacturing and quality-management compliance.

Scientific evidence supporting safety and performance.

Appropriate labelling and instructions for use.

Post-marketing safety monitoring and reporting.

A bioengineered adhesion barrier intended to prevent postoperative adhesions may qualify as a medical device depending on its composition and principal mode of action.

A product whose therapeutic action principally depends on processed living cells may instead qualify as a regenerative medical product.

B. Act on the Safety of Regenerative Medicine (ASRM)

The Act on the Safety of Regenerative Medicine establishes safeguards for regenerative medical research and medical practice involving specified regenerative technologies.

It addresses:

Safety of regenerative medical procedures.

Ethical protection of patients and research participants.

Review by certified committees.

Preparation and submission of regenerative medicine provision plans.

Manufacturing controls for specified processed cell products.

Monitoring and reporting of adverse events.

The amended framework, effective from 31 May 2025, also clarifies and expands the regulatory treatment of certain technologies involving nucleic acids and other regenerative medicine-related interventions.

C. Clinical Research Act

The Clinical Research Act regulates specified clinical research involving medicines and medical devices, particularly research involving financial relationships and other statutory conditions.

Clinical investigations of bioengineered adhesion control products must be assessed to determine whether they fall under this Act, the PMD Act clinical trial framework or another applicable research regime.

D. Product Liability Act

Japan's Product Liability Act imposes liability on manufacturers and other statutory entities for damage caused by defects in products.

Potential defects in adhesion control products may include:

Inadequate biocompatibility.

Unexpected inflammatory reactions.

Unintended tissue damage.

Failure of the barrier to perform its intended function.

Defective manufacturing or sterilisation.

Inadequate warnings concerning foreseeable complications.

E. Personal Information Protection Act

Where development or clinical assessment involves patient tissue samples, genetic information or identifiable medical records, the Act on the Protection of Personal Information (APPI) may apply.

Research institutions must implement appropriate safeguards for sensitive personal information and comply with applicable consent, research ethics and data-handling requirements.3. PRODUCT CLASSIFICATION AND APPROVAL REQUIREMENTS

The regulatory pathway depends on the product's principal characteristics.

A. MEDICAL DEVICE CLASSIFICATION

Non-cellular adhesion barriers, biodegradable membranes, hydrogel implants and tissue-separation materials may be classified as medical devices under the PMD Act.

Manufacturers must establish:

Intended medical purpose and mechanism of action.

Biological compatibility and material safety.

Mechanical and physical performance.

Absorption and degradation characteristics.

Sterility and packaging integrity.

Evidence supporting clinical performance.

B. REGENERATIVE MEDICAL PRODUCT CLASSIFICATION

Where the therapeutic effect depends on processed living cells intended to reconstruct, repair or form human tissue, the product may qualify as a regenerative medical product.

The PMDA evaluates scientific evidence, quality and safety, while the MHLW is responsible for marketing authorisation.

C. CLINICAL TRIAL REQUIREMENTS

Clinical investigations should establish:

Safety and tolerability.

Effectiveness in preventing or controlling unwanted adhesions.

Appropriate dosage or implantation procedures.

Local and systemic inflammatory responses.

Long-term degradation and tissue compatibility.

Risks of fibrosis, infection and abnormal tissue formation.

4. MANUFACTURING AND QUALITY CONTROL

Bioengineered adhesion control products require appropriate manufacturing controls.

Relevant quality requirements include:

Good Manufacturing Practice (GMP), where applicable.

Quality Management System requirements for medical devices.

Validated sterilisation procedures.

Raw-material traceability.

Batch consistency and release testing.

Biocompatibility assessment.

Stability and shelf-life testing.

Manufacturing deviation investigation.

For cellular products, additional controls may apply to cell sourcing, processing, identity, purity, potency and contamination prevention.

Manufacturers must ensure that the final product consistently satisfies its approved specifications.

5. IMPORTANT JUDICIAL DECISIONS AND CASE LAWS

There is no identified Japanese appellate judgment specifically deciding the legality of bioengineered adhesion control therapies. Nevertheless, the following six decisions provide relevant direct or analogous judicial principles concerning medical-device defects, surgical implants, medical negligence and pharmaceutical safety.

1. Tokyo High Court, 7 February 2002, Case No. Heisei 13 (Ne) 2193

Direct analogous authority – Medical device liability.

The case involved a defective artificial-heart-lung machine blood pump that allowed air to enter the patient's bloodstream during cardiac surgery, causing serious neurological injury.

The court recognised liability involving the medical institution and the medical-device manufacturer.

Relevance: Manufacturers of engineered adhesion barriers must ensure product reliability, while hospitals must use medical devices with appropriate professional care.

2. Tokyo District Court, 19 September 2003, Brain Catheter Case, Hanrei Jiho No. 1843, p. 118

Direct analogous authority – Product defect.

A super-fine catheter broke during neurosurgery, resulting in serious injury. The court found the importer liable under the Product Liability Act, although the negligence claim against the surgeon and hospital was not established.

Relevance: A manufacturer or importer may incur product liability even where medical negligence is not established. This principle is relevant to defective adhesion-control implants and biodegradable materials.

3. Tokyo District Court, 20 March 2003, Medical Device Connection Failure Case

Direct analogous authority – Manufacturing and design defects.

The case concerned medical equipment connected to a respiratory circuit. A connection failure caused ventilation impairment and the death of an infant. Product liability against the manufacturers and employer liability concerning the medical professional's inspection failure were recognised.

Relevance: Bioengineered adhesion products must have reliable connections, instructions, compatibility specifications and appropriate warnings where these features are relevant to their use.

4. Osaka District Court, 25 February 2011, Iressa Litigation, Case No. 2004 (Wa) 7990

Analogous authority – Pharmaceutical safety and warnings.

The litigation concerned gefitinib, a lung cancer medicine, and allegations of inadequate safety warnings concerning serious adverse effects.

Relevance: Manufacturers of adhesion-control therapies must provide adequate information about foreseeable complications, including inflammatory reactions, tissue damage and other material risks.

5. Nagoya High Court, 25 October 2007, Case No. 2006 (Ne) 399

Direct analogous authority – Surgical implant and professional negligence.

The case concerned treatment using an artificial vascular stent graft. The court recognised surgical technical negligence in circumstances involving vascular injury and fatal haemorrhagic shock.

Relevance: Hospitals must ensure that implantation procedures involving engineered biomaterials are performed by appropriately qualified professionals using reasonable surgical care.

6. Supreme Court of Japan, 2013, Iressa Product Liability Litigation

Analogous authority – Scientific knowledge and warning obligations.

The Supreme Court considered product-defect and warning-defect issues concerning a pharmaceutical product. It addressed the importance of evaluating foreseeable risks against scientific and technical knowledge available when the product was delivered.

Relevance: The safety of bioengineered adhesion products must be assessed using the scientific knowledge reasonably available at the relevant time. Manufacturers should update safety information when new material risks emerge.

6. LIABILITY AND REGULATORY ENFORCEMENT

A. MANUFACTURER LIABILITY

Under the Product Liability Act, manufacturers and certain other statutory entities may be liable for damage caused by product defects.

B. MEDICAL NEGLIGENCE

Article 709 of the Civil Code provides a basis for tort liability where negligence causes injury. Hospitals may also face contractual liability under Article 415, depending on the circumstances.

C. REGULATORY VIOLATIONS

Unauthorised marketing, defective manufacturing, failure to comply with safety requirements and inadequate adverse-event reporting may lead to regulatory enforcement under the PMD Act and other applicable legislation.

D. POST-MARKETING SURVEILLANCE

Manufacturers should maintain systems for:

Adverse-event collection and assessment.

Product complaint investigation.

Recall and corrective-action management.

Periodic safety evaluation.

Traceability of implanted products.

Communication of newly identified risks.

7. PRACTICAL COMPLIANCE REQUIREMENTS

Japanese manufacturers, importers, hospitals and research institutions should:

Determine the correct regulatory classification before development and marketing.

Obtain the required approval, certification or notification.

Maintain documented quality-management procedures.

Establish validated biocompatibility and performance testing.

Obtain appropriate clinical research and ethical approvals.

Maintain informed-consent and patient-information procedures.

Implement post-marketing safety monitoring.

Maintain product traceability and recall procedures.

Ensure adequate professional training for implantation.

Review new MHLW and PMDA regulatory requirements.

8. CONCLUSION

Japan regulates bioengineered adhesion control therapies through an integrated framework involving the PMD Act, the Act on the Safety of Regenerative Medicine, the Clinical Research Act, the Product Liability Act and the Civil Code.

The regulatory pathway depends primarily on whether the technology functions as a conventional medical device, a pharmaceutical product or a regenerative medical product involving processed living cells.

Although Japanese courts have not established a specific body of case law for bioengineered adhesion control therapies, existing medical-device and pharmaceutical judgments provide important principles concerning product safety, manufacturing defects, informed warnings, surgical responsibility and compensation for injury.

Accordingly, successful regulatory compliance requires scientific validation, appropriate product classification, reliable manufacturing, ethical clinical investigation, transparent patient information and continuous post-market safety monitoring.