Published on 04/12/2025
Human factors considerations for on-body injectors and wearable combination devices
In the evolving landscape of healthcare, the significance of human factors engineering (HFE) in the design of combination products, specifically on-body injectors and wearable devices, cannot be overstated. As regulatory frameworks from the FDA, EMA, and MHRA emphasize patient safety and efficacy, a structured approach to HFE becomes imperative for regulatory affairs professionals.
Context
Human factors engineering focuses on optimizing the interaction between users and products to enhance usability and reduce the risk of user error. This is particularly pertinent for combination products that intertwine drug delivery systems with technological devices. The FDA defines combination products as therapeutic and diagnostic products that combine drugs, devices, and/or biological products. Given their complexity, these products require comprehensive evaluation under both drug and device regulations.
Legal/Regulatory Basis
The regulatory guidelines governing human factors engineering for combination products, particularly from the FDA, establish a critical framework for developers and regulatory affairs professionals. Key documents include:
- 21 CFR Part 820: Quality System Regulation (QSR), detailing requirements for a quality management system and appropriate readiness for human factors consideration.
- FDA Guidance for Industry and FDA Staff: Human Factors Studies and
Documentation
Documentation plays a pivotal role in demonstrating compliance with regulatory expectations. The following documents are crucial when preparing a human factors file:
- Usability Engineering File: An exhaustive record detailing the user requirements, design process, and usability testing results.
- Risk Management File: Including hazard analysis, risk assessment, and risk mitigation strategies, this file should reflect how human factors considerations are incorporated into the product design.
- Design History File (DHF): Maintains the complete history of the design from conception through to production, including human factors data.
Review/Approval Flow
The review and approval process for combination products with a focus on human factors engineering typically involves the following steps:
- Pre-Submission Consultation: Engaging with the FDA and other regulatory bodies early in the process can clarify expectations and streamline the approval process.
- Submission of Human Factors Data: Presenting the usability testing data along with risk analysis in the application is critical for demonstrating compliance.
- Agency Review: Regulators assess human factors data with respect to overall product safety and efficacy, posing queries where deficiencies are noted.
- Post-Market Surveillance: Continuous monitoring after approval to ensure ongoing compliance and safety should human factors issues arise.
Common Deficiencies
Understanding common deficiencies that may arise during the review of human factors submissions can aid in preempting regulatory challenges. Typical agency questions include:
- Lack of Robust Usability Testing: Agencies often ask for clarity regarding usability tests, including participant demographics and task simulation.
- Inadequate Risk Management Documentation: Missing or incomplete risk assessment documents can lead to significant delays, as regulators require comprehensive evidence of risk mitigation.
- Unsubstantiated Justifications: Failure to justify the design decisions based on user feedback and testing data may result in queries or rejections.
RA-specific Decision Points
When to file as variation vs. new application
Deciding between filing a variation or a new application depends significantly on the extent of changes made to an existing product:
- Filing for a New Application: If the new design significantly alters the intended use or involves a novel manufacturing process, a new application is warranted.
- Filing for a Variation: For modifications that do not substantially change the product’s intended use or risks, such as ergonomic improvements or stability updates, a variation filing is permissible.
How to Justify Bridging Data
When presenting bridging data, it is essential to define the rationale clearly:
- Scientific Basis: Provide references to prior studies that demonstrate the homogeneity of the risk profile and usability between the new and existing product.
- User Experience: Conduct comparative user testing if necessary and demonstrate how similar design features resulted in acceptable user outcomes in previously approved products.
Collaboration with Other Departments
Regulatory Affairs must work closely with various departments such as Clinical, Quality Assurance (QA), Chemistry, Manufacturing, and Controls (CMC), and Pharmacovigilance (PV) to ensure that human factors considerations are fully integrated throughout the product lifecycle.
- Clinical: Collaborate to identify user needs that may impact clinical study design.
- QA: Work on establishing protocols that ensure compliance with usability testing requirements.
- CMC: Ensure that the product design aligns with practical manufacturing capabilities and quality control measures.
- PV: Develop systems to capture user feedback post-market to continuously assess safety and usability.
Conclusion
As the landscape of combination products continues to evolve, the emphasis on human factors engineering becomes widely recognized as both a regulatory requirement and a facet of quality product design. For regulatory affairs professionals, a deep understanding of guidelines, clear documentation, and meticulous preparation for agency scrutiny is essential to navigate the complexities of this area. By adhering to FDA and EMA guidance, healthcare professionals can drive innovations that not only meet regulatory standards but also significantly improve patient outcomes.
For further details on many of the guidelines referenced in this article, please refer to the FDA’s Human Factors Guidance, the EMA’s Guidelines on HFE, and the MHRA’s Guidance for Combination Products.