Zylbrisq prefilled syringe’s usability for generalized MG confirmed
Study shows it can be safely used by patients, caregivers, healthcare providers
The prefilled syringe used to administer Zylbrysq (zilucoplan) under the skin, or subcutaneously, can be safely and effectively used by generalized myasthenia gravis (gMG) patients, caregivers, and healthcare providers, a usability study in the U.S. shows.
Most participants were able to use the syringe, which contained a placebo solution, without critical mistakes. The errors observed administering it into a mock-up skin pad were almost completely eliminated after the participants were told to read the instructions for use (IFU). PLus, identifying those errors and their causes aided in making important adjustments to the IFU, which improved the user experience.
“Providing patients with a medical device that can improve their treatment experience has the potential to increase treatment adherence and improve health-related quality of life,” while also increasing patients’ independence, the researchers wrote.
The study, “Usability of the zilucoplan prefilled syringe for the treatment of generalized myasthenia gravis: insights from a human factors validation study,” was published in Expert Review of Medical Devices.
Generalized myasthenia gravis is an autoimmune disorder wherein symptoms like muscle weakness, fatigue, and sometimes breathing difficulties occur due to abnormal immune responses that impair nerve-muscle communication.
Zilbrysq is approved in several countries, including the U.S., for certain adults with gMG. It works by suppressing the activation of the complement cascade, a part of the immune system that becomes overly activated and contributes to the disease’s immune-related damage.nIts safety and efficacy were established in the Phase 3 RAISE clinical trial (NCT04115293), where three months of once-daily Zilbrysq injections resulted in significantly greater symptom reductions and quality of life improvements relative to a placebo. The therapy is available as a prefilled syringe, which allows patients to self-administer it, along with caregivers and healthcare providers.
Using the syringe appropriately is vital and human factors validation tests “are used to observe patients’ interactions with medical devices and obtain feedback from the patients in order to improve the device design,” the researchers wrote.
Studying prefilled syringe’s safety, effectiveness
An international team of researchers conducted a usability study to evaluate the safety and effectiveness of using prefilled syringes by gMG patients, their caregivers, and healthcare providers. The investigators recruited 75 participants across multiple locations in the U.S. who were divided into five groups of 15 each — patients and caregivers, with and without injection experience, and injection-experienced healthcare providers with experience in treating gMG. Injection experience was defined as having injected using a prefilled syringe and/or a vial with a syringe in the past year.
Simulated scenarios equipped with cameras let the researchers observe, live and in a recording, the participants using the syringe, which was filled with a placebo solution that was injected into a mock skin pad. The participants did it first without instructions and then with the provided IFU.
All but two participants (97.3%) could administer the placebo correctly during the first simulated use. With guidance from the IFU, all 75 participants successfully administered the medication, showing the instructions’ improved efficacy and safety.
Identifying user error, improving the instructions
The study also sought to identify use errors that could pose injury or impairment, especially for those less familiar with injections.
Observed errors were low across the different tasks, with pass rates from 85.3% to 100% before the participants were instructed to use the IFU. Importantly, “no new use errors were discovered during the validation usability study,” the researchers wrote.
Most mistakes involved removing the syringe from its packaging (11 participants) and removing the needle cap (three participants). Error rates were reduced once the participants consulted the IFU.
The researchers also analyzed the reasons behind the mistakes to enhance the clarity of the IFU.
“The root cause of these use errors was most often attributed to the instructions in the IFU not being clear, the system design not being intuitive, or a study limitation (e.g. participant’s behavior was influenced by the nature of the simulated task versus actual use),” the researchers wrote.
In response, they updated the IFU with a detailed pictogram for each injection step and critical instructions, like holding the syringe by the barrel when taking it out of the package and the needle cap location in the device and its discarding instructions.
The findings further supported that “clear and understandable instructions can aid self-injection both in clinical and home settings, highlighting the importance of the IFU in ensuring that patients safely use the device,” the researchers wrote. “The results from this human factors study, combined with the efficacy and safety results observed in the phase 3 RAISE study, support the use of [Zilbrysq] and highlight the benefits of subcutaneous self-administration at home for patients with gMG, in turn addressing the unmet need of this patient population.”
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