Evaluation of Nipocalimab Efficacy and Safety in Adults with Seropositive Generalized Myasthenia Gravis: A Phase 3 Randomized, Double-Blind, Placebo-Controlled Study

The primary objective of this Phase 3, multicenter, randomized, double-blind, placebo-controlled study is to evaluate the **efficacy** of **nipocalimab** compared to placebo in adults with **generalized myasthenia gravis** (gMG). This will be assessed using the Myasthenia Gravis-Activities of Daily Living (MG-ADL) scale in seropositive gMG participants when treatment is administered as directed. The clinical relevance of this objective lies in determining the potential of nipocalimab to improve daily living activities in patients with gMG, a chronic autoimmune neuromuscular disorder characterized by weakness and rapid fatigue of voluntary muscles.

The clinical trial involves a total of **104 participants** diagnosed with **Generalized Myasthenia Gravis**. The study population includes both male and female subjects, aged 18 years and older, who are not considered part of a vulnerable population. Participants were selected based on their diagnosis of generalized muscle weakness, meeting the clinical criteria for generalized myasthenia gravis as defined by the MGFA Clinical Classification Class II a/b, III a/b, or IV a/b. All participants must have a positive serologic test for a gMG-related pathogenic autoantibody. The trial does not impose specific lifestyle restrictions, but participants are required to maintain stable doses of any herbal, naturopathic, or nutritional supplements they may be using. The study ensures that participants have sufficient venous access for drug administration and blood sampling. Additionally, it is recommended that participants are up to date on all age-appropriate vaccinations, including COVID-19, prior to screening. The selection criteria emphasize the importance of a stable therapy regimen for gMG and the ability to comply with study procedures.

The clinical trial is a **Phase 3**, multicenter, randomized, double-blind, placebo-controlled study designed to evaluate the efficacy, safety, pharmacokinetics, and pharmacodynamics of **nipocalimab** in adults with **generalized myasthenia gravis**. The trial involves the administration of nipocalimab, a monoclonal antibody, via intravenous infusion, with a placebo group receiving saline. The study is expected to run from October 2021 to June 2026, with a maximum treatment period of 264 days for each participant.

Participants will undergo a series of study visits, beginning with an inclusion (screening) visit to assess eligibility based on criteria such as age, serologic test results, and current therapy response. Following randomization, participants will receive either nipocalimab or placebo and will be monitored through regular follow-up visits to evaluate changes in the Myasthenia Gravis-Activities of Daily Living (MG-ADL) scale, with primary endpoints measured over weeks 22 to 24. The end-of-study visit will conclude the participant's involvement, assessing overall outcomes and any adverse effects.

The expected length of participant involvement is approximately 9 months, contingent upon adherence to study protocols and absence of any conditions necessitating early termination, such as adverse reactions or non-compliance. Participants must maintain stable use of any concurrent therapies and adhere to contraceptive guidelines to minimize risks. The study aims to provide comprehensive data on the therapeutic potential of nipocalimab in managing generalized myasthenia gravis, contributing to the understanding of its clinical benefits and safety profile.

The clinical trial involves the administration of **nipocalimab**, a monoclonal antibody, under the product code JNJ-80202135. Nipocalimab is provided in two pharmaceutical forms: a **solution for infusion** and a **solution for injection**. The solution for infusion is administered intravenously, with the dosage expressed in milligrams per kilogram (mg/kg). The maximum treatment period for nipocalimab is 264 days. The active substance, nipocalimab, is a protein of other origin, specifically a human immunoglobulin G1-lambda against the neonatal Fc receptor. The administration schedule and dosage are determined based on the participant's body weight, and compliance is monitored throughout the study.

The study also includes a **placebo** control, which is a saline solution used in accordance with its marketing authorization. The placebo is administered to maintain the double-blind nature of the trial, ensuring that neither the participants nor the investigators know who receives the active treatment or the placebo. The placebo is used to evaluate the efficacy of nipocalimab by comparing outcomes between the treatment and control groups. The administration of the placebo follows the same route and schedule as the active treatment to ensure consistency in the trial protocol.

The efficacy of the investigational drug **nipocalimab** in the treatment of generalized myasthenia gravis (gMG) will be assessed in a Phase 3, multicenter, randomized, double-blind, placebo-controlled clinical trial. The primary endpoint for evaluating efficacy is the average change from baseline in the Myasthenia Gravis-Activities of Daily Living (MG-ADL) total score over Weeks 22, 23, and 24. This endpoint will be measured using the MG-ADL scale, a validated tool for assessing the impact of gMG on daily activities.

Participants will be evaluated at multiple timepoints, including screening, Day 1, and Weeks 22, 23, and 24, to determine changes in their MG-ADL scores. The trial aims to compare the efficacy of **nipocalimab** against a placebo in seropositive gMG participants, ensuring that the treatment is administered as directed. The data collected will be analyzed to determine the average change in MG-ADL scores, providing insights into the drug's efficacy in improving symptoms associated with generalized myasthenia gravis.