Patient Satisfaction with Use of Complement Inhibitor Injector in Paroxysmal Nocturnal Hemoglobinuria in the United States
Authors: Mulherin Brian , Laurence Lawton , Friddle Carl , Perler Jed , Locklear Logan , Bailey Lisa , Cassidy Amanda , Desai Dharmik , de Castro Carlos M 
Published: December 2024

Introduction: Pegcetacoplan is a C3/C3b inhibitor approved for paroxysmal nocturnal hemoglobinuria (PNH), a rare disease characterized by complement-mediated hemolysis that can lead to anemia and thrombosis. The previously approved C5 inhibitors (C5is) eculizumab and ravulizumab for PNH are administered in health care settings as intravenous infusions. In contrast, pegcetacoplan can be self-administered as a subcutaneous (SC) injection with an at-home infusion pump. On October 2, 2023, a wearable, single-use, SC pegcetacoplan injector with a hidden needle was approved by the US Food and Drug Administration after being validated for ease of use, safety, and effectiveness in a human factors study. This analysis of 2 US studies describes patients' experience with the new injector in the real world.

Methods: A US cross-sectional, mixed methods study is ongoing. Adults with PNH diagnosed for ≥6 months, who self-administered pegcetacoplan for &gt;3 months and switched to the new injector for ≥6 weeks could fill out a preliminary web-based survey (including 17 items with 1-7 Likert scale ratings [1-worst response, 7-best response]) before completing a qualitative, 45-minute telephone interview to discuss and rate their administration experience with the new injector compared with prior device and C5i therapies. Interview results were summarized in 7 items with Likert scale ratings from 1 (worst) to 7 (best), and 1 item (“overall administration experience”) rated from 1 (worst) to 100 (best). Interim findings on patients' experience with the new injector are presented ahead of full enrollment and final analysis.

In a separate US study, email and text messaging surveys (7 questions; 6 with yes/no answers) were sent out by care-coordinators from the ApellisAssist support program to patients who recently (~2 weeks) converted from an infusion pump to the new injector for their pegcetacoplan treatment.

Results: As of July 15, 2024, 7 patients have been recruited in the real-world injector users' experience study. Of the 6 patients who filled out the preliminary web-based survey, 5 reported they were “very confident” (7-rating) and 1 was “confident” (6-rating; 1-7-scale) overall about administering pegcetacoplan with the new injector at home; all (n=6) reported that it was “very easy” (7-rating; 1-7-scale) to administer pegcetacoplan with the new device without assistance. Among 6 of the 7 patients who participated in the telephone interviews, the mean of 6 individual “overall administration experience” ratings was 81 (1-100-scale from worst to best experience); the mean experience satisfaction ratings (1-7-scale) were 6.3 for convenience, 6.2 for ability to complete tasks around the house, 5.8 for ability to move freely and confidence in the administration, 5.3 for ease of use, and 5.2 for ability to run errands. Notably, 5 of the 6 patients generally gave high ratings for their experience with the new injector, and all 7 interviewed patients were very (n=1) or extremely (n=6) likely to recommend the new device to other patients with PNH (mean rating = 6.9; 1-7-scale [1-not at all likely; 7-extremely likely]).

In the email/text messaging study, 58 patients completed and returned the survey. Of these, 42/58 (72%) had used the injector ≥5 times. Almost all patients (56/58; 97%) were satisfied with the new injector and preferred it over their previous device (52/58; 90%); compared with their previous device, 79% (46/58) felt more confident about self-administration with the new device, 86% (50/58) stated it was faster to set up, 90% (52/58) felt the hidden needle helped them be more at ease with the infusion, and 90% (52/58) felt more mobile during the infusion.

Conclusions: Preliminary real-world findings suggest that most patients with PNH were satisfied with various aspects of their experience with the new single-use, wearable injector and were likely to recommend it to other patients with PNH. All patients found it easy to self-administer pegcetacoplan with the new injector without assistance and most were confident in the administration. Surveyed patients seemed to prefer the new device and feel more confident using it than their previous device. Although responses might have been impacted by recall and social desirability biases, these findings align with those from the device human factors evaluation study, suggesting that real-world evidence supports laboratory results on usability of the new injector.