A Phase 3, Multicenter, Randomized, Placebo-Controlled, Double-Blind Study to Assess the Efficacy and Safety of IMVT-1402 in Patients With Mild to Severe Generalized Myasthenia Gravis

This phase 3, multicenter, randomized, placebo-controlled, double-blind study evaluates the efficacy and safety of IMVT-1402, a solution for injection administered via subcutaneous route, in patients with mild to severe generalized myasthenia gravis. The primary objective is to assess the change from baseline in MG-ADL score (Myasthenia Gravis-Activities of Daily Living) for antibody-positive participants. This outcome measure is clinically relevant as it quantifies the impact of treatment on functional capacity and disease-related disability in daily activities, providing a patient-centered assessment of therapeutic benefit in myasthenia gravis management.

This clinical trial enrolled a total of **153 participants** diagnosed with **Generalized Myasthenia Gravis**. The study population included both **male and female** subjects comprising **adults** and **elderly** individuals. Participants were selected based on their ability to provide informed consent and comply with trial procedures. The trial specifically targeted individuals with **mild to severe** disease severity, classified as **Myasthenia Gravis Foundation of America (MGFA) Class II, III, or IV** at screening. Eligible participants were required to demonstrate a **Myasthenia Gravis Activities of Daily Living (MG-ADL) score** of 6 or greater at both screening and baseline visits. The study population consisted of **patients** with confirmed disease status, ensuring a clinically relevant cohort for evaluating changes in MG-ADL scores from baseline among antibody-positive participants. No vulnerable populations were included in this trial.

This is a **Phase 3**, **multicenter**, **randomized**, **placebo-controlled**, **double-blind** clinical trial designed to evaluate the efficacy and safety of **IMVT-1402** in patients with mild to severe **generalized myasthenia gravis**. The trial investigates IMVT-1402, a **solution for injection** administered via the **subcutaneous** route, compared to **placebo** in participants classified as Myasthenia Gravis Foundation of America (MGFA) Class II, III, or IV. The investigational medicinal product IMVT-1402 is a protein-based active substance manufactured by Immunovant Sciences GmbH. The maximum daily dose is **600 mg**, with a maximum total dose of **15600 mg** administered over a treatment period of **26 weeks**. The trial employs a therapeutic confirmatory design appropriate for Phase 3 studies, with participants randomized to receive either the test product or placebo.

The **primary endpoint** is the change from baseline in **MG-ADL score** (Myasthenia Gravis Activities of Daily Living) for antibody-positive participants. **Secondary endpoints** include the change from baseline in **Quantitative Myasthenia Gravis (QMG) score** for antibody-positive participants, the percentage of antibody-positive participants achieving an MG-ADL score of 0 or 1, and the percentage of antibody-positive participants with ≥50% improvement in MG-ADL score. The trial's main objective focuses on assessing clinical improvement in disease-specific functional measures in the antibody-positive population.

Eligible participants must have the ability to understand trial requirements, provide written informed consent, and comply with protocol procedures. Participants must have mild to severe generalized myasthenia gravis by MGFA classification of Class II, III, or IV at the **screening visit**. An MG-ADL score of ≥6 is required at both the screening visit and **baseline visit** (Day 1) for enrollment. The screening visit serves as the inclusion assessment phase to determine participant eligibility based on disease severity and functional status.

The estimated recruitment start date is October 13, 2025, with an estimated trial end date of December 31, 2027. Participant involvement includes the screening period, the 26-week treatment period during which study medication is administered, and subsequent **follow-up visits** to assess efficacy and safety outcomes. The **end-of-study visit** occurs after completion of the treatment period and follow-up assessments. Throughout the trial, participants attend scheduled visits for administration of study medication, efficacy assessments using validated MG-specific scales, and safety monitoring. Conditions that may lead to early termination from the study are not explicitly specified in the available protocol information.

**IMVT-1402** is administered as a **solution for injection** via the **subcutaneous route**. The active substance is IMVT-1402, which is classified as a protein of other origin. The maximum daily dose is **600 mg**, with a maximum total dose of **15600 mg** administered over a treatment period of **26 weeks**. The investigational medicinal product is manufactured by Immunovant Sciences GmbH. Participants receive the medication according to a defined dosing schedule throughout the study duration.

A **placebo** comparator is utilized in this study, which is identical in appearance to the investigational medicinal product but contains no active substance. The placebo is administered to maintain the **double-blind** design of the trial, ensuring that neither participants nor investigators are aware of treatment allocation. This approach allows for accurate assessment of the efficacy and safety profile of IMVT-1402 compared to a control intervention in patients with mild to severe **generalized myasthenia gravis**.

Efficacy will be assessed using multiple parameters in antibody-positive participants with **generalized myasthenia gravis**. The primary efficacy endpoint is the change from baseline in **MG-ADL** (Myasthenia Gravis Activities of Daily Living) score for antibody-positive participants. Secondary efficacy endpoints include the change from baseline in **QMG** (Quantitative Myasthenia Gravis) score for antibody-positive participants, the percentage of antibody-positive participants achieving an MG-ADL score of 0 or 1, and the percentage of antibody-positive participants with ≥50% improvement in MG-ADL score. Participants must have an MG-ADL score of ≥6 at both the screening visit and baseline visit (Day 1) to be eligible for enrollment. The treatment period extends for 26 weeks during which these efficacy parameters will be evaluated.