A Phase 3 Study to Evaluate Claseprubart in Adults With Generalized Myasthenia Gravis (EMERGE)

NCT07647510 | Not Yet Recruiting Phase 3 FDA Drug

• 2 other identifiers: DNTH103-MG-3012026-525298-38-00
• Study Type: interventional
• Target: 195
• Locations: 0 countries
• Sites: N/A

Brief Summary

The purpose of this Phase 3 study is to demonstrate the efficacy, safety, and tolerability of claseprubart in participants with generalized myasthenia gravis (gMG).

Conditions

Myasthenia Gravis, Generalized

Outcome Measures

Primary Outcomes (1)

• Change from Baseline to Week 17 in Myasthenia Gravis Activities of Daily Living (MG-ADL) Scale Score

  The MG-ADL score is an 8-item patient reported outcome (PRO) instrument. The MG-ADL targets symptoms of disability across ocular, bulbar, respiratory, and axial symptoms. The item responses are scored from 0 to 3, and the total score of the MG-ADL is the sum of the 8 items and ranges from 0 to 24, with a higher score indicating more disability.

  Baseline (Day 1) to Week 17

Secondary Outcomes (10)

• Change from Baseline to Week 17 in Quantitative Myasthenia Gravis (QMG) Scale Score

  Baseline (Day 1) to Week 17

• Change from Baseline to Week 17 in Myasthenia Gravis Composite (MGC) Scale Score

  Baseline (Day 1) to Week 17

• Proportion of Participants with Greater Than or Equal to (≥) a 5-point Reduction in MG-ADL Scale Score at Week 17 Compared to Baseline

  Baseline (Day 1) to Week 17

• Proportion of Participants Who Reach Minimal Symptom Expression (MSE), Defined as MG-ADL 0 or 1 at Week 17, Without Use of Rescue Therapy

  Baseline (Day 1) to Week 17

• Proportion of Participants with a ≥ 5-point Reduction in QMG Scale Score at Week 17 Compared to Baseline

  Baseline (Day 1) to Week 17

Study Arms (3)

Placebo

PLACEBO COMPARATOR

Intravenous (IV) infusion of Placebo on Day 1 followed by subcutaneous (SC) injections of Placebo every 2 weeks (Q2W) starting at Week 1 (Day 8).

Drug: Placebo; Combination Product: Placebo

Claseprubart Q2W

EXPERIMENTAL

IV loading dose of claseprubart on Day 1 followed by SC injections of claseprubart Q2W starting at Week 1 (Day 8).

Drug: Claseprubart; Combination Product: Claseprubart

Claseprubart Every 4 weeks (Q4W)

EXPERIMENTAL

IV loading dose of claseprubart on Day 1 followed by SC injections of claseprubart or Placebo Q2W starting at Week 1 (Day 8), with doses alternating between claseprubart and placebo.

Drug: Claseprubart; Combination Product: Claseprubart; Combination Product: Placebo

Interventions

Placebo DRUG

IV infusion on Day 1

Placebo

Claseprubart DRUG

IV loading dose on Day 1

Also known as: DNTH103

Claseprubart Every 4 weeks (Q4W); Claseprubart Q2W

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Must have given written informed consent before any study-related activities are carried out
• Weight range between 40-130 kg at Screening
• Diagnosis of gMG by the following tests:
• Acetylcholine receptor antibody (AChR Ab) positive, and
• One of the following:
• i. History of abnormal neuromuscular transmission test; ii. History of positive anticholinesterase test; iii. Clinical response to acetylcholinesterase inhibitors.
• Myasthenia Gravis Foundation of America (MGFA) Class II-IVa
• MG-ADL scale score of 6 or more
• QMG scale score of 10 or more
• Documented vaccinations against encapsulated bacteria in accordance with local requirements and based on vaccine availability
• Female participants must be of non-childbearing potential, or if of childbearing potential, must agree not to donate ova, not to attempt to become pregnant and, if engaging in sexual intercourse with a male partner, must agree to use a highly effective method of contraception
• Male participants agree not to donate sperm and, if engaging in sexual intercourse with a female partner who could become pregnant, must agree to use an acceptable method of contraception

You may not qualify if:

• History or presence of significant medical/surgical condition including any acute illness, mental illness, or major surgery considered to be clinically significant or that could have potential impact on safety/efficacy or study procedures
• Known complement deficiency
• Prior history (at any time) of N. meningitidis infection
• Participants with known seropositivity or who test positive for an active viral infection with human immunodeficiency virus (HIV-1 or HIV-2), hepatitis B (HBV; except participants who are seropositive because of HBV vaccination) or hepatitis C virus (HCV) during Screening
• Previous treatment with claseprubart (DNTH103) or participation in a clinical trial with claseprubart. \[
• Any thymic surgery/biopsy within 1 year of Screening
• Any known or untreated thymoma.
• Any history of thymic carcinoma or thymic malignancy
• History of active malignancy within 5 years prior to Screening, except basal cell carcinoma of the skin, curatively resected squamous cell carcinoma of the skin, cervical carcinoma in situ curatively treated or low-grade prostate adenocarcinoma for which appropriate management is observation alone
• Concurrent or previous use of the following medication within the time periods specified below.
• Rituximab or other B-cell targeting therapies (ie, inebilizumab) within 6 months (180 days) prior to randomization (Day 1);
• Intravenous immunoglobulin (IVIg) and plasma exchange (PLEX) within 4 weeks (28 days) prior to randomization (Day 1)
• Participation in another clinical study of an investigational drug within 90 days or 5 half-lives of the investigational agent
• Diagnosis of systemic lupus erythematosus (SLE) or family history (defined as a parent, sibling, or child) of SLE

Sponsors & Collaborators

• Dianthus Therapeutics: lead

MeSH Terms

Conditions

Myasthenia Gravis

Condition Hierarchy (Ancestors)

Paraneoplastic Syndromes, Nervous System; Nervous System Neoplasms; Neoplasms by Site; Neoplasms; Paraneoplastic Syndromes; Autoimmune Diseases of the Nervous System; Nervous System Diseases; Neurodegenerative Diseases; Neuromuscular Junction Diseases; Neuromuscular Diseases; Autoimmune Diseases; Immune System Diseases

Central Study Contacts

Dianthus Clinical Contact Center

CONTACT

929-999-4055; clinicaltrials@dianthustx.com

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 27, 2026
• First Posted: June 15, 2026
• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): December 1, 2028
• Study Completion (Estimated): September 1, 2031
• Last Updated: June 15, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share