Human Factors Validation of a Pegcetacoplan On-Body Injector Demonstrates Ease of Use by Adolescents with C3 Glomerulopathy/Primary Immune-Complex Membranoproliferative Glomerulonephritis

Background: VALIANT (NCT05067127) demonstrated efficacy and safety of pegcetacoplan (C3/C3b inhibitor) in adults/adolescents (≥12 years) with C3 glomerulopathy (C3G)/primary immune-complex membranoproliferative glomerulonephritis (IC-MPGN). Pegcetacoplan is FDA-approved for adults with paroxysmal nocturnal hemoglobinuria, who can self-administer pegcetacoplan subcutaneously with an approved injector. Adolescent dosage is based on body weight, requiring different filling steps. This study aimed to validate injector use by the new user population (12–17 years). Methods: Testing facilities simulating at-home use recruited 15 adolescents (12–17 years) with chronic diseases representing C3G/IC-MPGN. After one-on-one training (2 hours) and learning decay (24 hours), participants completed 2 scenarios for first/initiation and second/maintenance doses and a knowledge assessment interview. Residual risk analysis evaluated potential harm from use errors/incorrect knowledge. Results: In scenario 1 (first 12-mL dose), 14 of 15 drew out the correct dose (1 drew out 14 mL [incorrect mental model, slip]), 11 filled the injector correctly (4 struggled to push the plunger), and 14 completed the injection (1 device filling error) (Figure). In scenario 2 (filling injector for second/maintenance 15-mL dose), 15 of 15 drew out the correct dose and 10 filled the injector correctly (5 struggled to push the plunger). Finally, all completed the tasks correctly. Residual risks of use errors/incorrect knowledge were reduced with minor edits to the instructions for use. Conclusion: The on-body injector was safe and effective for independent self-administration of pegcetacoplan by adolescents with C3G/IC-MPGN. Funding: Commercial Support - Apellis Pharmaceuticals, Inc.