A Phase II Study of SHR-2173 Injection in Patients With Myasthenia Gravis

A Phase II, Randomized, Double-Blind, Placebo-Controlled Clinical Trial to Evaluate the Efficacy and Safety of SHR-2173 in Patients With Generalized Myasthenia Gravis

This study is a multicenter, randomized, double-blind, placebo-controlled Phase II clinical trial designed to evaluate the efficacy, safety, pharmacokinetics, and pharmacodynamics of SHR-2173 compared to placebo as an add-on therapy to standard of care (SOC) for the treatment of generalized myasthenia gravis (gMG). The study consists of a 4-week screening period, a 24-week treatment period, and a 12-week safety follow-up period.

Study Overview

• Status: Not yet recruiting
• Conditions: Generalized Myasthenia Gravis
• Intervention / Treatment: Drug: Placebo; Drug: SHR-2173 injection; Drug: SHR-2173 injection

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Kunming Li; Phone Number: 0518-82342973; Email: kunming.li@hengrui.com

Study Locations

• China
  • Hunan
    • Changsha, Hunan, China, 410008
      • Xiangya Hospital of Central South University
      • Principal Investigator: Huan Yang
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China, 200040
      • Huashan Hospital, Fudan University
      • Principal Investigator: Chongbo Zhao

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Male and female participants aged 18-75 years, confirmed diagnosis of generalized myasthenia gravis (gMG) (Myasthenia Gravis Foundation of America [MGFA] class II-IV).
2. Positive for anti-AChR antibody or anti-MuSK antibody.
3. MG-ADL total score ≥5 at screening and baseline, with >50% of the score attributable to non-ocular items.
4. QMG score ≥11 at screening and baseline.
5. Maintenance on stable standard of care (SOC) therapy.
6. No contraindication to at least one rescue therapy: IVIg or PLEX.
7. Provided written informed consent (ICF) after full understanding of the study content, procedures, and potential adverse reactions.
8. Female subjects with fertility or male participants whose partners are women of childbearing age must avoid donating sperm/eggs from the date of signing the ICF until 12 weeks after the last study medication, and agree to take contraceptive measures as specified in the protocol

Exclusion Criteria:

1. Presence of any of the following medical histories or comorbidities:

   1. Any untreated thymic epithelial tumor, mediastinal germ cell tumor, or other malignant mediastinal mass; or any thymic cyst or other mass requiring immediate intervention per investigator judgment;
   2. Previous history of thymic tumor not meeting protocol requirements;
   3. Myasthenic crisis (MGFA Class V) within 3 months prior to randomization;
   4. Any known disease other than gMG that may interfere with study procedures and assessments;
   5. A history of progressive multifocal leukoencephalopathy (PML);
   6. A history of body irradiation or organ transplantation.

2. Use of any of the following drugs/treatments or participation in a clinical study:

   1. Prior treatment with CAR-T or other cellular therapy, or T-cell engager (TCE) therapy;
   2. Anti-CD20 monoclonal antibody within 6 months prior to randomization; other B-cell or plasma cell-depleting therapy within 6-12 months prior to randomization;
   3. Alkylating agent within 12 weeks prior to randomization;
   4. Any biologic for MG treatment within 12 weeks prior to randomization;
   5. Neonatal Fc receptor antagonist therapy within 8 weeks prior to randomization;
   6. Janus kinase (JAK), Bruton tyrosine kinase (BTK), or tyrosine kinase 2 (TYK2) inhibitor within 12 weeks prior to randomization;
   7. IVIg, subcutaneous immunoglobulin, or PLEX therapy within 4 weeks prior to randomization;
   8. Live/attenuated live vaccine within 4 weeks prior to randomization, or planned vaccination during the study.
3. A history of malignancy within 5 years prior to screening;

4. Infection-related medical history and examinations:

   1. A history of herpes zoster meeting any of the following: 1) A history of disseminated herpes zoster, herpes zoster encephalitis, or ocular herpes zoster involving the retina; 2) Recurrent herpes zoster with 2 or more episodes within 2 years; 3) Herpes zoster infection not fully resolved within 12 weeks prior to screening;
   2. A history of tuberculosis (TB) or latent TB infection;
   3. A known history of primary immunodeficiency, splenectomy, or any underlying condition predisposing to infection;
   4. A history of recurrent infections requiring hospitalization and intravenous antibiotics;
   5. Any infection requiring hospitalization and/or intravenous antimicrobial therapy within 8 weeks prior to randomization, or any infection requiring oral antimicrobial therapy within 2 weeks prior to randomization;
   6. Positive test result for hepatitis B surface antigen (HBsAg), hepatitis C virus antibody, treponemal pallidum antibody, or human immunodeficiency virus (HIV) antibody; for patients with HBsAg-negative but hepatitis B core antibody (HBcAb)-positive, regardless of the status of hepatitis B surface antibody (HBsAb), HBV-DNA testing is required to confirm their condition, with HBV-DNA-positive patients excluded and HBV-DNA-negative patients eligible to participate in the study.

5. General situation:

   1. Pregnant or lactating females;
   2. A history of alcohol abuse or illicit drug abuse within 1 year prior to screening;
   3. A history of allergic diathesis, or known hypersensitivity/intolerance to any component of the investigational product;
   4. Major surgery within 3 months prior to the screening, or planned major surgery during the study;
   5. Any condition that, in the investigator's judgment, may affect evaluation of study drug safety and efficacy, or any other condition that renders the subject ineligible.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo	Drug: Placebo; Placebo
Experimental: Treatment group A: SHR-2173 injection	Drug: SHR-2173 injection; SHR-2173 injection；High dose; Drug: SHR-2173 injection; SHR-2173 injection；Low dose
Experimental: Treatment group B: SHR-2173 injection	Drug: SHR-2173 injection; SHR-2173 injection；High dose; Drug: SHR-2173 injection; SHR-2173 injection；Low dose

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change from baseline in MG-ADL total score	at Week 24

Secondary Outcome Measures

Outcome Measure	Time Frame
Change from baseline in Quantitative Myasthenia Gravis (QMG) score	at Week 24
Change from baseline in Myasthenia Gravis Composite (MGC) total score	at Week 24
Change from baseline in MG-ADL domain scores (ocular, bulbar, respiratory, limb)	at Week 24
Change from baseline in QMG domain scores (ocular, bulbar, respiratory, limb)	at Week 24
Proportion of participants with ≥3-point reduction from baseline in MG-ADL total score	at Week 24
Proportion of participants with ≥50% reduction from baseline in MG-ADL total score	at Week 24
Proportion of participants with ≥5-point reduction from baseline in QMG score	at Week 24
Proportion of participants achieving Minimal Symptom Expression (MSE; MG-ADL total score 0 or 1) at Week 24	at Week 24
Change from baseline in Myasthenia Gravis Quality of Life 15-item revised (MG-QoL15r) total score	at Week 24
Change from baseline in Neuro-QoL Fatigue subscale score	at Week 24
Change from baseline in European Quality of Life 5-Dimensions 5-Levels (EQ-5D-5L) index score	at Week 24
Proportion of participants without rescue therapy	through Week 24
Incidence, severity grading, and drug-relatedness of adverse events (AEs)	through Week 24
Incidence, severity grading, and drug-relatedness of serious adverse events (SAEs)	through Week 24
Incidence, severity grading, and drug-relatedness of adverse events of special interest (AESIs)	through Week 24
Change from baseline in C-SSRS	through Week 24

Collaborators and Investigators

• Sponsor: Guangdong Hengrui Pharmaceutical Co., Ltd

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): September 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: May 20, 2026
• First Submitted That Met QC Criteria: May 27, 2026
• First Posted (Actual): June 3, 2026

Study Record Updates

• Last Update Posted (Actual): June 3, 2026
• Last Update Submitted That Met QC Criteria: May 27, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nervous System Diseases; Neoplasms by Site; Neoplasms; Neuromuscular Diseases; Autoimmune Diseases; Immune System Diseases; Autoimmune Diseases of the Nervous System; Neurodegenerative Diseases; Paraneoplastic Syndromes, Nervous System; Nervous System Neoplasms; Paraneoplastic Syndromes; Neuromuscular Junction Diseases; Myasthenia Gravis
• Other Study ID Numbers: SHR-2173-206

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No