Endocrine Abstracts

Background: Lonapegsomatropin (SKYTROFA™; TransCon hGH), an FDA and EMA approved once-weekly prodrug of somatropin for pediatric growth hormone deficiency (pGHD), uses TransCon® technology to transiently link an inert carrier to a parent drug to achieve sustained release. Daily growth hormone injection, standard treatment for pGHD for decades, may be associated with challenges including needle anxiety and low adherence. The lonapegsomatropin Auto-Injector, winner of two innovation awards for drug delivery and patient-centric design, was developed through user testing and feedback to complement weekly lonapegsomatropin and minimize challenges in reconstitution and injection. Key design features of the Auto-Injector include a hidden needle, empty-all cartridge design, and icons to indicate and guide completion of all steps.

Aim: The lonapegsomatropin Auto-Injector was evaluated under simulated use conditions as outlined in FDA guidance: “human factors and usability engineering processes are performed to maximize the likelihood that new medical devices will be safe and effective for the intended users, uses and use environments… without serious use errors or problems.”

Methods: Usability of the lonapegsomatropin Auto-Injector was evaluated in trained and untrained patients (pGHD or other chronic conditions requiring injection,) caregivers, and health care providers (HCPs) responsible for giving injections or training patients/caregivers. Auto-Injector, cartridges, packaging, instructions for use (IFU), quick reference guide, helpline, and training video were available for self-exploration. Participants were evaluated on device use, charging, and comprehension of IFU.

Results: All participants, (120 children and caregivers, 60 injection-naïve, and 15 HCPs) were able to complete an injection successfully with the lonapegsomatropin Auto-Injector. Usability issues observed for injection tasks for all participants were low and comparable to typical observations in usability studies: patients (3.2%), caregivers (2.4%), and HCPs (2.8%). All participants reported they could follow the instructions as written and 98% of participants felt they could use the device as intended on their own or with supervision (patients only).

Conclusions: The patient-centric design of the award-winning lonapegsomatropin Auto-injector leads to successful, confident usage in which participants can follow the instructions to deliver an injection as intended. Together with once-weekly lonapegsomatropin, the lonapegsomatropin Auto-Injector may overcome challenges in treatment of pGHD such as needle anxiety and difficulties with injection, with the potential to improve adherence which has been shown to impact outcomes in real-world use.