Objective:

Compare gefurulimab PK exposure in healthy adults following a single subcutaneous (SC) dose administered by autoinjector versus manual prefilled syringe with safety device (PFS-SD). Safety, tolerability, immunogenicity, pharmacodynamics (PD), and device performance will also be assessed.

Background:

Monoclonal antibodies targeting terminal complement component 5 (C5) are approved for the treatment of acetylcholine receptor antibody-positive generalized myasthenia gravis (AChR+ gMG). A phase 3 trial is investigating the safety and efficacy of PFS-SD–administered gefurulimab, a novel bispecific variable domain on a heavy chain (VHH) antibody that binds to C5 and albumin, in adults with AChR+ gMG (NCT05556096). Autoinjectors are prefilled, triggered devices designed for easy administration and have been shown to reduce pain at the injection site and improve adherence in individuals with chronic diseases versus alternatives. Autoinjectors represent an attractive option for at-home administration by the patient or caregiver.

Design/Methods:

This phase 1, open‑label, randomized, parallel‑group study will compare the PK of a single SC gefurulimab dose administered to the abdomen, thigh, or upper arm with either an autoinjector or PFS-SD in healthy adults aged 18-65 years. Approximately 174 participants will be enrolled, stratified into 3 weight groups, and randomized equally to one of six combinations of device and injection site. Participants are screened for ≤70 days prior to treatment on day 1 and remain at the clinic until day 5, after which visits occur throughout the 92-day evaluation period. Primary endpoints are serum gefurulimab PK parameters (areas under the curve and maximum observed concentration) for each device. Secondary endpoints are immunogenicity, safety, PD, additional PK parameters, and device performance

Results:

N/A

Conclusions:

This study will examine the PK, PD, safety, tolerability, immunogenicity, and device performance of the gefurulimab autoinjector in healthy adults. Results may support use of the autoinjector with the goals of providing convenient administration and enhancing patient experience in individuals with gMG.