Platform Combination Product Strategies for Human Factors
Platform Combination Product Strategies for Human Factors
There is an increasing rate of popularity in the concept of platform drug delivery systems to reduce the amount of Design Verification testing. The concept of platform systems and identifying which tests can be applied across a platform system seems easy enough to strategize, but how can we apply this to human factors (HF) activities?
To help guide you through this concept, we will use a single-use single-dose autoinjector as an example throughout.
First, some background.
There is no official definition of “platform” for combination products in any major market. This has been a term coined by the industry. Regulatory authorities, such as the US Food and Drug Administration (FDA), are hesitant to use the term. Because there is no definition, each company’s use of the term “platform” varies.
Using our autoinjector example, if all the constituent parts are the same – i.e., syringe barrel, stopper, needle, plunger rod, spring, autoinjector casing and other format parts – and only the drug contents change, is this a platform?
What happens if the volume of the drug changes, requiring a change to the plunger rod and potentially other format parts – is this still a platform then?
What if the drug formulation is altered? Can the definition of platform vary even internally when discussing what Design Verification specifications can be tested on a platform level versus what usability and labeling aspects can be tested on a platform level?
Hopefully, these questions help you understand the confusion and regulatory authorities’ hesitation to define “platform.”
Since Agilis is primarily a human factors consulting group, this article will focus on strategies to advance platform combination product human factors activities.
Can we apply a platform approach to an HF program, and can it be used in multiple markets? Yes and yes – the key to this is planning early in the product development. In addition to the standard HF resources – such as IEC 62366-1:2015+AMD-1:2020 (see January’s newsletter for a great IEC 62366 refresher)[1] – the FDA’s draft guidance Bridging for Drug-Device and Biologic-Device Combination Products (2019) is a good place to start. The assessments listed can be applied to platform systems.
The first step is to identify the strategy for implementing a platform system, and while this needs to be done for all aspects of the product, the following is focused on HF. The strategy will be different depending on the stage of development of the initial platform system: is it in feasibility, design freeze, or already on the market? These three examples require very different strategies. Going forward, we will focus on a platform system still in the feasibility stage.
For a brand-new platform system, the first step is to identify which deliverables will be product-specific and which will be platform-specific. For example, Context of Expected Use (i.e., Use Specification) are typically product-specific. They describe the specific users, along with patients, user characteristics, and disease state overview. Other documentation, such as the User Interface Specification, can be platform-specific. Task and Use Error Analysis are also typically platform-specific, while Use-Related Risk Analyses are product-specific (see Figure 1).
Figure 1
Exploratory usability testing, Instructions for Use (IFU) development, and initial formative testing can be performed at the platform level. This assumes that the only differences in how the autoinjector is used (i.e., tasks performed by the user) are going to the be same regardless of the user:
Performing these evaluations with the general population will help to develop the user interface, and identify risks that require mitigation, along with potential mitigation strategies.
Once the user interface is developed, a final formative or a pre-summative evaluation with the product-specific users is recommended. This ensures several things:
Provides confidence going into the summative validation study that all use errors for the product-specific user groups have been identified and mitigated as far as possible;
There are no previously unidentified differences between user groups that impact the user interface;
It allows you to pilot your summative validation study methodology to ensure it is sound, and to make adjustments prior to the summative validation study itself; and
It allows you to collect more representative and high-fidelity data in the formative phase to identify any remaining use errors that may occur in actual use.
Summative validation studies are almost always performed on product-specific users. I say almost as there is an instance or two where a user population is rare enough where surrogates may be justified – but that’s a conversation for a different day.
At this point, there is still a key piece missing, a discussion with the regulatory authorities. FDA strongly recommends discussing platform strategies with them well in advance of executing. Requesting meetings to review your plan, agreeing to the appropriate storage of documents (i.e., where do you keep your documents with the agency, so they do not have to review platform documents each time you submit a new drug), and ensuring the FDA agrees with your validation study protocol are great ways to help ensure successful submissions.
This is not feasible in every market. For example, in the European Union, Notified Bodies do not consult, so how do you know the strategy will be accepted? Start with your MDR/IVDR General and Safety Performance Requirements (GSPR) checklist early. Make sure your HF platform strategy will give you the evidence you need to meet the usability-related requirements.
As stated at several points throughout this article, there are lots of grey areas and Agilis can help you develop a platform strategy based on where you are and where you are going. We have resources to help with Design Verification platform planning, can help plan for user populations with rare disease or co-morbidities, or HFE platform strategies at different design stages. Reach out to see how we can best help you today.
[1] Other Great Reference Documents:
IEC/TIR 62366-2:2016
ANSI/AAMI HE75:2009
FDA HF Guidance
About the Author:
Stephanie Canfield, MS
Stephanie is a Senior Consultant in Human Factors Engineering at Agilis Consulting Group and is active on standards committees and industry groups for medical devices and combination products. In her current role, Stephanie manages projects of varying complexity for both medical devices and combination products, preparing various documentation and executing HF evaluations. Stephanie integrates risk management and human factors to support successful regulatory submissions and ensure regulatory compliance.
Stephanie has a Master of Science in Biology and over 10 years of experience in academia and industry. Stephanie has practical experience in a range of areas, from product feasibility, research and development, process validation, quality engineering, and human factors engineering throughout the IVD, medical device, and combination product space.