in ensuring safe and effective use.

For combination products, the FDA stipulates that human factors testing must be conducted to substantiate the usability of the drug-device combination, especially in the context of user interaction, labeling, and instructions. Relevant regulations include:

• 21 CFR Part 3 – Products that Combine Elements of Drug, Device, and Biological Products.
• 21 CFR Part 820 – Quality System Regulation for Medical Devices, particularly concerning design controls.
• 21 CFR Part 211 – Current Good Manufacturing Practice for Finished Pharmaceuticals.

In Europe, the regulatory landscape is defined by the Medical Device Regulation (MDR) and the In-Vitro Diagnostic Regulation (IVDR), which establish guidelines for assessing usability and human factors in medical devices and combination products.

Documentation

All documentation related to human factors must be meticulously compiled and structured to not only comply with regulatory expectations but also facilitate the approval process. Key documents typically include:

• Human Factors File: This file should contain the detailed HF plan, risk analysis, usability testing data, and any revisions made based on testing outcomes.
• Usability Engineering Report: A comprehensive report showcasing the human factors process applied, including user needs, design controls, and the results of usability tests.
• Risk Management File: Integration of human factors into the overall risk management process is necessary, detailing how usability considers potential misuse and associated risk mitigation strategies.
• Labeling and Instructions for Use (IFU): These documents should be tested using representative users to confirm that they are clear and comprehensible.

Preparing Human Factors Documentation

When compiling these documents, it is essential to follow the guidelines set forth in the FDA’s usability engineering guidance. A typical process for preparing human factors documentation involves:

1. Defining the user population and tasks: Identify who will use the combination product and the specific tasks they are expected to perform.
2. Conducting formative research: Gather input from target users via interviews and usability testing to understand their needs and environment.
3. Developing design specifications: Use data collected from formative research to inform design aspects that enhance usability.
4. Conducting summative testing: Implement usability testing with users to validate that the design meets their needs and is safe for use.
5. Documenting the process: Ensure that every step is carefully recorded to demonstrate adherence to regulatory expectations.

Review/Approval Flow

The review and approval flow for combination products incorporating human factors engineering involves several critical stages before reaching the market. The approval pathway can significantly depend on whether the product is classified as a drug, device, or both.

Pre-Submission Activities

Before submission, it is advisable to have pre-submission meetings with the FDA to discuss the planned human factors studies and seek advice on the adequacy of the proposed approach. This includes:

• Determining whether to submit a New Drug Application (NDA), Abbreviated New Drug Application (ANDA), or Premarket Approval (PMA) based on the product’s classification.
• Defining whether any variations are necessary based on significant design changes or variances in user requirements.
• Outlining the evidence of usability and user experience that validates user interaction with the product.

Submission and Review Process

Once the human factors documentation is prepared, the submission process can commence:

1. Submission of 510(k), PMA, NDA, or ANDA: The appropriate regulatory submission should be filed according to the classifications determined in the previous steps.
2. FDA Review: The FDA reviewers will assess the human factors data alongside the product’s safety and efficacy evidence during the review process.
3. Agency Feedback: If deficiencies are identifies related to human factors, agencies will issue queries that require prompt and well-documented responses.

Common Deficiencies

Understanding common deficiencies related to human factors engineering can help regulatory professionals preempt issues during the submission process:

• Inadequate user studies: Insufficient data from usability testing or failure to include diverse user populations can lead to questions regarding product safety in real-world situations.
• Failure to integrate human factors into the design process: Agencies may question how human factors considerations have been woven into the design from the outset.
• Lack of risk assessments: Not providing thorough risk assessments that account for potential misuse or user errors can raise red flags during review.
• Poor labeling and instructions: Test results indicating that users struggle with comprehension or execution of instructions may lead to requests for additional testing or redesign.

RA-Specific Decision Points

Regulatory affairs professionals must be vigilant about decision points that will influence how combination products are submitted and reviewed.

When to File as Variation vs. New Application

Deciding whether to submit a variation or a new application can hinge on the extent of changes made during the human factors evaluation:

• If the changes affect the risk profile or intended use but don’t alter the fundamental formulation, a variation may be appropriate.
• Conversely, if the updates fundamentally change user interaction or the product’s mechanism of action, a new application will typically be required.

Justifying Bridging Data

In situations where human factors studies may use bridging data (data from similar devices or previous studies), it is essential to justify this approach convincingly:

• Data must demonstrate the reliability of results obtained from the previous products to accurately reflect the safety and efficacy of the new combination product.
• Carefully outline the rationale for the applicability of bridging data, together with validation of assumptions and methodologies used in prior studies.

Conclusion

Human factors engineering is a critical component in the lifecycle of combination products. By building a thorough understanding of FDA human factors engineering requirements, regulatory professionals can play a vital role in facilitating the successful approval of combination products. Compliance with GxP standards, knowledge of agency expectations, and the preparation of robust human factors documentation will mitigate risks and streamline the regulatory approval process.

Staying informed about ongoing developments in guidance and regulations related to usability engineering is crucial, as is engaging with other functions such as Clinical, QA, and Commercial teams to ensure full alignment throughout the product development cycle.