A Study to Assess the Efficacy and Safety of Empasiprubart Versus IVIg in Adults With Multifocal Motor Neuropathy (Empassion)

argenx

Status and phase: Enrolling; Phase 3

Conditions: Multifocal Motor Neuropathy (MMN)

Treatments: Other: Empasiprubart-placebo; Biological: IVIG (Intravenous Immunoglobulin); Biological: Empasiprubart; Other: IVIg-placebo

Study type: Interventional

Funder types: Industry

Identifiers

NCT06742190

ARGX-117-2302

2024-516473-72-00 (EU Trial (CTIS) Number)

Details and patient eligibility

About

The main purpose of this study is to compare empasiprubart and IVIg in adult patients with MMN. The study consists of a double-blinded part A (empasiprubart, IVIg) and an open-label part B (empasiprubart). The maximum study duration for participants is up to 49 months.

Enrollment: 100 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Is at least 18 years of age and the local legal age of consent for clinical studies
• Has a confirmed diagnosis of definite or probable MMN at screening according to the EFNS/PNS 2010 guidelines
• Has responded to IVIg in the past 5 years.
• Is receiving IVIg at a treatment interval of once every 2, 3, 4, or 5 weeks, and a dose of 0.4 to 2.0 g/kg body weight per cycle
• Is receiving a maintenance regimen (no change in frequency, and no change in dose >10%) of IVIg for at least 8 weeks before screening (or at least 10 weeks for participants receiving IVIg once every 5 weeks)
• Minimum converted weekly IVIg dose of ≥0.125 g/kg
• Has documented immunization against encapsulated bacterial pathogens (N meningitidis and S pneumoniae) within 5 years of screening or is willing to receive immunization at least 14 days before first study drug administration

Exclusion criteria

• Besides the indication under study, known autoimmune disease (eg, SLE) or any other medical condition that would confound the study results or put the participant at undue risk
• Clinical signs or symptoms suggestive of neuropathies other than MMN, such as motor neuron disease (eg, bulbar signs, brisk reflexes) or other inflammatory neuropathies (eg, sensory neuropathy)

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

---

100 participants in 3 patient groups

Part A - empasiprubart + IVIg-placebo

Experimental group

Description:

During the double blinded - double dummy part A, participants receive empasiprubart and a placebo resembling the IVIg treatment in this arm

Treatment:

Other: IVIg-placebo

Biological: Empasiprubart

Part A - IVIg + empasiprubart-placebo

Active Comparator group

Description:

During the double blinded - double dummy part A, participants receive IVIg and a placebo resembling the empasiprubart treatment in this arm

Treatment:

Biological: IVIG (Intravenous Immunoglobulin)

Other: Empasiprubart-placebo

Part B - empasiprubart

Experimental group

Description:

After completion of part A, participants can proceed to part B where they receive empasiprubart (no IVIg)

Treatment:

Biological: Empasiprubart