Talquetamab in Patients With Refractory Generalized Myasthenia Gravis

NCT07499323 | Not Yet Recruiting

• 1 other identifier: KX2026-KYC102-01
• Study Type: interventional
• Target: 2
• Locations: 0 countries
• Sites: N/A

Brief Summary

Myasthenia Gravis (MG) is a chronic autoimmune disease mediated by pathogenic antibodies. Approximately 10%-15% of patients present with refractory status, defined as having an inadequate response to existing therapies or an inability to tolerate the side effects of the medication, highlighting an urgent need for the development of more targeted innovative therapies. Talquetamab is a bispecific antibody that targets G Protein-Coupled Receptor Class C Group 5 Member D (GPRC5D) and the Cluster of Differentiation 3 (CD3) molecule on the surface of T cells, thereby inducing T cells to precisely eliminate GPRC5D-positive cells. This study will conduct an exploratory case series to investigate the efficacy and safety of Talquetamab in refractory MG.

Conditions

Myasthenia Gravis (MG)

Outcome Measures

Primary Outcomes (1)

• MG-ADL score

  Full scale title: Myasthenia Gravis Activities of Daily Living Profile (MG-ADL) Score range: 0-24 A higher score means worse outcomes (greater symptom severity and more impairment in daily functioning).

  baseline, and 1-6 months

Secondary Outcomes (1)

• QMG score

  baseline and 1-6 months

Study Arms (1)

treatment group

EXPERIMENTAL

Talquetamab

Drug: Talquetamab

Interventions

Talquetamab DRUG

Eligible patients will receive the drug via subcutaneous injection on Days 1, 3, and 5, respectively. The dose will be determined based on body weight measured before administration, according to the following table. A total of 3 doses will be administered. Administration Day and Dose: 0.01 mg/kg in Day 1; 0.06 mg/kg in Day 3; 0.4 mg/kg in Day 5.

treatment group

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• The patient must sign the informed consent form for participation in the study and agree to comply with the study procedures.
• Age 18-70 years.
• Must meet the clinical diagnostic criteria for MG, defined as presenting with a typical pattern of weakness (predominantly affecting proximal muscles, fatiguability, fluctuating severity, worse with prolonged effort and better after rest) and meeting any one of the following three conditions: documented history of abnormal neuromuscular transmission confirmed by single-fiber electromyography or repetitive nerve stimulation; documented history of a positive neostigmine test; or improvement in MG signs following oral administration of an acetylcholinesterase inhibitor. Additionally, the Myasthenia Gravis Foundation of America (MGFA) clinical classification must be II-IV, and the patient must be positive for anti-AChR antibodies.
• Must meet the definition of "refractory myasthenia gravis" according to the Chinese Guidelines for the Diagnosis and Treatment of Myasthenia Gravis (2025 Edition): defined as having a suboptimal response to conventional immunotherapeutic drugs, intolerance to or having contraindications for adverse drug reactions, or experiencing frequent disease relapses requiring regular rescue therapy, making it difficult to achieve treatment goals.
• Myasthenia Gravis Activities of Daily Living (MG-ADL, Appendix 1) score ≥6, with \>50% of the score derived from non-ocular items.
• Quantitative Myasthenia Gravis (QMG) score (Appendix 2) ≥8, with \>50% of the score derived from non-ocular items.
• The dosage of pyridostigmine bromide must be stable for at least 1 week prior to the treatment period.

You may not qualify if:

• Patients who have had their glucocorticoid dose adjusted, or who have received immunoglobulins, plasma exchange, neonatal Fc receptor inhibitors, or complement inhibitors within ≤4 weeks.
• Patients who have undergone thymectomy, received B-cell depletion therapy, or had their dose of non-steroidal immunosuppressants (such as azathioprine, tacrolimus, mycophenolate mofetil, cyclophosphamide, etc.) adjusted within ≤3 months.
• Patients who have participated in any interventional clinical trial or received investigational treatment within ≤3 months, or within 5 half-lives of the received investigational drug (whichever is longer).
• Patients with concurrent severe liver, kidney, cardiac, pulmonary, or coagulation dysfunction.
• Patients with concurrent chronic infections such as Human Immunodeficiency Virus, Hepatitis B Virus, Hepatitis C Virus, or Mycobacterium tuberculosis.

Sponsors & Collaborators

• First Affiliated Hospital of Chongqing Medical University: lead

MeSH Terms

Conditions

Myasthenia Gravis

Interventions

talquetamab

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

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: March 24, 2026
• First Posted: March 30, 2026
• Study Start: March 20, 2026
• Primary Completion (Estimated): March 20, 2027
• Study Completion (Estimated): April 1, 2027
• Last Updated: April 8, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will share