Bioequivalence Between a Gantenerumab Disposable Syringe and an Autoinjector: A Randomized Controlled Trial in Healthy Volunteers

Gantenerumab, a monoclonal antibody targeting amyloid beta plaques in the brain, reduces plaque accumulation and was developed to slow Alzheimer's disease progression. Results from the pivotal GRADUATE I and II studies evaluating gantenerumab in people with early Alzheimer's disease were announced in 2022. The studies did not meet their primary endpoint of slowing clinical decline. This study evaluated the pharmacokinetics, immunogenicity, and safety of a high concentration liquid formulation of gantenerumab administered subcutaneously as a single dose using an autoinjector (AI) or a disposable syringe (DS). The DS was employed in pivotal clinical trials, while the AI was developed in parallel to ease SC administration. The study aimed to demonstrate bioequivalence (BE) between AI and DS administration in healthy participants, defined by 90% confidence intervals (CIs) for geometric least square (LS) mean ratios being within the 0.80-1.25 range for maximum observed plasma concentration (C_max) and area under the plasma concentration-time curve (AUC). Among the 266 healthy participants, 135 received 255 mg gantenerumab via AI and 131 received 255 mg via DS in a parallel group design. BE between AI and DS SC administration was demonstrated with geometric LS mean ratios (90% CIs) for C_max, AUC_0-inf, and AUC_0-last of 1.078 (1.006, 1.155), 1.053 (0.986, 1.124), and 1.054 (0.992, 1.121), respectively, all within the 0.80-1.25 BE range. Safety findings were consistent with the known safety profile of gantenerumab.