Myasthenia Gravis Inebilizumab Trial (MINT)

Amgen

Status and phase: Active, not recruiting; Phase 3

Conditions: Myasthenia Gravis

Treatments: Drug: IV Placebo; Drug: inebilizumab

Study type: Interventional

Funder types: Industry

Identifiers

NCT04524273

VIB0551.P3.S1

Details and patient eligibility

About

Randomized, double-blind, placebo-controlled, Phase 3, parallel-group study with optional open-label extension.

Full description

This study is a phase 3, randomized, double-blind, placebo-controlled study, to be conducted at approximately 120 study sites. Approximately 230 participants (188 acetylcholine receptor antibody positive [AChR-Ab+] and 42 muscle-specific tyrosine kinase antibody positive [MuSK-Ab+]) will be enrolled. Participants with Myasthenia Gravis (MG) who are positive for anti-AChR or anti-MuSK antibodies will be enrolled and analyzed. Patients who do not have anti-AChR or anti-MuSK antibodies will not be enrolled. Patients with Myasthenia Gravis Foundation of America (MGFA) classification II, III, or IV disease, Myasthenia Gravis Activities of Daily Living (MG-ADL) score at screening and randomization between 6 and 10 with > 50% of this score attributed to non-ocular items, or an MG-ADL score >=11, Quantitative Myasthenia Gravis (QMG) score >= 11 at the time of screening and randomization, and use of a corticosteroid and/or non-steroidal immunosuppressant will be included in the study.

All subjects who complete the randomized controlled period (RCP) will have the option to enroll in a 3-year (156 weeks) open-label period.

Study acquired from Horizon in 2023.

Enrollment: 238 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Diagnosis of MG with anti-AChR or anti-MuSK antibody.

2. MGFA Clinical Classification Class II, III, or IV.

3. MG-ADL score of 6 or greater at screening and at randomization with > 50% of this score attributed to non-ocular items.

4. QMG score of 11 or greater.

5. Participants must be on:

   1. Corticosteroids only, with no dose increase within 4 weeks prior to randomization, or
   2. One allowed non-steroidal immunosuppressive therapy (IST), with continuous use for at least 6 months prior to randomization and no dose increase within 4 months prior to randomization, or
   3. Combination of (1) corticosteroids with no dose increase within 4 weeks prior to randomization and (2) one allowed non-steroidal IST with continuous use for at least 6 months prior to randomization and no dose increase within 4 months prior to randomization.

Allowed ISTs, alone or in combination with corticosteroids, are azathioprine, mycophenolate mofetil, and mycophenolic acid.

Exclusion criteria

1. Receipt of the following medications within the 4 weeks prior to Day 1:

   1. Cyclosporine (except eye drops)
   2. Tacrolimus (except topical)
   3. Methotrexate

2. Current use of:

   1. Corticosteroids (Prednisone > 40 milligram (mg)/day or > 80 mg over a 2-day period (or equivalent dose of other corticosteroids).
   2. Acetylcholinesterase inhibitors (pyridostigmine) > 480 mg/day) or unstable dose in the 2 weeks prior to Day 1.
   3. Azathioprine > 3 mg/kilogram (kg)/day
   4. Mycophenolate mofetil > 3 grams/day or mycophenolic acid > 1440 mg/day
   5. Any IST, alone or in combination with corticosteroids, except for azathioprine, mycophenolate mofetil, and mycophenolic acid.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

---

238 participants in 4 patient groups, including a placebo group

Inebilizumab, (AChR-Ab+) MG

Experimental group

Description:

Participants will receive inebilizumab administered intravenously (IV) on Days 1, 15, and 183 of the RCP. Participants who elect to enter the open label phase (OLP) will receive inebilizumab administered IV on OLP Days 1, IV placebo on OLP Day 15 (to avoid potential unblinding), and inebilizumab IV on OLP Days 183, 365, 547, 729, and 911.

Treatment:

Drug: inebilizumab

Placebo, (AChR-Ab+) MG

Placebo Comparator group

Description:

Participants will receive placebo administered IV on Days 1, 15, and 183 of the RCP. Participants who elect to enter the OLP will receive inebilizumab administered IV on OLP Days 1,15, 183, 365, 547, 729, and 911.

Treatment:

Drug: IV Placebo

Inebilizumab, (MuSK-Ab+) MG

Experimental group

Description:

Participants will receive inebilizumab administered IV on Days 1 and 15 of the RCP. Participants who elect to enter the OLP will receive inebilizumab administered IV on OLP Day 1, IV placebo on OLP Day 15 (to avoid potential unblinding), and inebilizumab IV on OLP Days 183, 365, 547, 729, and 911.

Treatment:

Drug: inebilizumab

Placebo, (MuSK-Ab+) MG

Placebo Comparator group

Description:

Participants will receive placebo administered IV on Days 1 and 15 of the RCP. Participants who elect to enter the OLP will receive inebilizumab administered IV on OLP Days 1,15, 183, 365, 547, 729, and 911.

Treatment:

Drug: IV Placebo