Human Factors Studies : Demonstrating ZENEO®’s Real-World Effectiveness
Cross-interview
- Frédéric Mabile, Human Factors Engineering Manager
- Gwladys Gallet, Packaging Development Manager
- Clémence Mougenot, Pharmaceutical Development Project Manager
- Tony Tipton, U.S. Operations Director
Why has CROSSJECT chosen to go beyond industry standards?
The creation of ZENEO® is a revolution, conceived in the spirit of Apple: a creative act based on the patient’s real needs—both conscious and unconscious.
To ensure universal efficacy and safety, we broke all the rules and pushed the boundaries of technology. Saving a life in an emergency required overcoming some major barriers:
- no needle to prevent injuries,
- intramuscular administration for immediate action,
- built-in pyrotechnics for an instant injection faster than the human reflex,
- intuitive simplicity so that anyone can use it—even in the middle of a panic—without instructions or training.
It was a bold choice, and the journey was demanding. Tested under real-world conditions during the “Hazmat*” study, the ZENEO® needle-free autoinjector achieved a 98% success rate (369 successful injections out of 375), despite extreme situations. Most importantly, the only 6 deviations from the “protocol” were, in fact, intramuscular injections: the primary mission was therefore 100% successful.
This real-world effectiveness far outperforms conventional injectors—provided we don’t fall into the trap of relying exclusively on laboratory studies. According to independent academic studies**, 100% effectiveness in the laboratory can drop to between 60% and 80% in real-world situations.
In addition to safe and effective administration, ZENEO® is designed to be easy, intuitive, and fast for everyone.
* A Human Factors validation study simulating a disaster (chemical poisoning) involving 75 participants.
** Brown JC, Tuuri RE, Akhter S, Guerra LD, Goodman IS, Myers SR, Nozicka C, Manzi S, Long K, Turner T, Conners GP, Thompson RW, Park E. Lacerations and Embedded Needles Caused by Epinephrine Autoinjector Use in Children. Ann Emerg Med. 2016;67(3):307-15 e8.
What methods have enabled CROSSJECT to demonstrate ZENEO®’s real-world effectiveness?
These methods fall under the scope of “human factors engineering.” Once the technology has been stabilized and its mechanisms can be reproduced indefinitely, the user becomes the primary variable affecting effectiveness that requires attention.
Behavior and interactions with ZENEO® must therefore be analyzed in minute detail. Under real-world conditions, we break down each of the participants’ actions to detect even the slightest error, difficulty, or hesitation. We evaluate approximately 40 criteria per participant (including 15 during the injection). A comprehensive debriefing then allows us to understand each individual’s underlying needs and the root causes of their reflexes. In a study with 100 participants, this amounts to 4,000 elements evaluated in detail.
This iterative process (analysis, correction, re-evaluation) aims to eliminate any potential issues. It goes beyond basic effectiveness and safety: it’s not just about verifying whether the user can open the cap, but whether they intuitively recognize it, understand how to twist it, know where to place their hands, then do so and know they’ve done it correctly.
To achieve this, we test a wide variety of use cases: patients, caregivers, untrained bystanders, medical or emergency personnel, trained or untrained individuals, with or without instructions, instinctive or methodical users, in emergency situations, in the hospital, at home, and so much more.
How many Human Factors studies have been conducted?
Through 30 successive Human Factors studies, each stage has raised the bar for our standards. Our approach is based on a key principle: testing under “worst-case conditions” to ensure the solutions’ effectiveness in the field.
To achieve this, we exposed a wide range of user profiles to complex environments (children as young as 8, parents, people with arthritis, first responders, novices, Hazmat conditions—such as terrorist attacks or mass casualty incidents—and more).
More than 1,300 participants were involved, and their use of ZENEO® was thoroughly analyzed. This comprehensive analysis of every possible scenario allowed us to optimize every detail. The result: the latest version of ZENEO® incorporates all the practical solutions needed to enable anyone, anytime, anywhere, to save a life.
How has ZENEO® evolved between the first and most recent studies?
Initial human factors studies optimized the ergonomics of ZENEO® (handling, force required to open and activate) and confirmed that it is intuitive to use.
We then added instructions (arrows, step numbers, and visual and audible indicators of operation). Finally, significant work was carried out on the communication of instructions, beginning in 2012 with the first “quick guide.”
Today, every visible element (case, label, instructions) conveys information in a step-by-step manner (name, dose, needle-free autoinjector, injection site).
The prototypes resulting from user testing have evolved into concrete industrial solutions that meet economic constraints while ensuring complete understanding.
The latest versions (for individual or group use) represent the culmination of this successful synergy between industrial development and Human Factors.
How are Human Factors study data incorporated into regulatory submissions?
All data collected and analyzed as part of the Human Factors studies are an integral part of our market authorization applications. They are compiled into a “usability engineering report” that is strictly governed by regulations and included in the technical dossier. This report must demonstrate that the user interface enables effective and safe use; to this end, it includes the initial specifications:
- management of risks associated with use,
- a complete history of the studies, including the evolution of the user interface up to the detailed final solution,
- the results of the validation study proving risk control,
- and the benefit-risk assessment specific to human factors.
This “usability report” is also reviewed independently by the FDA, just like the clinical report.
How does CROSSJECT’s focus on Human Factors studies create a competitive advantage?
This importance is dual, as it enables:
A regulatory head start: Health authorities, led by the FDA, are tightening their requirements and now mandate rigorous “human factors” studies, failing which applications will be rejected. By anticipating these strict requirements for ZENEO®, CROSSJECT transforms a regulatory barrier into a major strategic advantage.
Absolute reliability: In urgent situations, healthcare professionals and families demand absolute reliability. As parents often put it: “If my child has a seizure, I want to be sure that the full dose is administered without error.” Meeting this vital, user-centered need reinforces our market positioning and secures our future market share.
How can CROSSJECT’s rigorous approach translate into commercial advantages?
It’s not just health authorities who are concerned about “proper use.” Expectations are also high among patients, caregivers, and prescribers. They know that during a medical emergency, stress and fear can make it difficult to take the right actions.
However, as we’ve seen, the Human Factors studies as a whole address this identified medical need. The variety of situations and profiles featured in the different scenarios gives us a competitive advantage that justifies the efforts and investments we’ve made.
However, the commercial value of this advantage remains contingent on the FDA’s approval of ZEPIZURE®. Only once our market authorization is granted will we be able to highlight it, for example through training programs, publications, and informational resources.