Evaluate the Safety of HBM9161 (HL161) Subcutaneous Injection in Patients With Generalized Myasthenia Gravis

A Long-term Open-label Extension Study to Evaluate the Safety of HBM9161 (HL161) Subcutaneous Injection in Patients With Generalized Myasthenia Gravis

The primary study objective is to evaluate medium- and long-term safety of HBM9161 in combination with background treatment for gMG patients through the observation on adverse events and laboratory abnormalities during study period.

Study Overview

• Status: Completed
• Conditions: Myasthenia Gravis
• Intervention / Treatment: Drug: HBM9161 Injection (680mg)

• Study Type: Interventional
• Enrollment (Actual): 111
• Phase: Phase 3

Contacts and Locations

Study Locations

• China
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China
      • Huashan Hospital, Fudan University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Completed the HBM9161.3 Phase 3 study
2. Signed written informed consent.
3. Suitable for continued treatment with HBM9161 as judged by the investigator.
4. Female patients of childbearing potential and male patients with female partners of childbearing potential can participate in this study, but reliable contraceptive measures must be taken (such as physical barrier contraception (patients and their partners), contraceptive pills or patches, spermicide and barrier or intrauterine device). Up to 60 days after the last dose.
5. A negative urine pregnancy at baseline must be observed for women of childbearing age.

Exclusion Criteria:

1. Had received any other clinical study drug since the administration of the study drug in the 9161.3 Phase 3 study.
2. Females who are pregnant or lactating or planning to become pregnant during the study period, or females of childbearing potential who are not using an effective method of contraception.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: HBM9161 Drug Product (680mg); HBM9161 680mg: subcutaneous injection, 6 times per treatment cycle, once a week; the second cycle of treatment may start 4 weeks after the last dose of the previous treatment cycle; if the disease state is still stable 4 weeks after the last dose, the observation can be continued until the disease activity is aggravated (improvement of MG-ADL < 3 points compared with the previous treatment cycle), and the next treatment cycle can start. The dose may be reduced to 340 per investigator's discretion. Return to the dose of 680 mg is not permitted after a dose reduction is made.

Drug: HBM9161 Injection (680mg); HBM9161 Injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of AEs during the study	Incidence of AEs	during the study，up to 24 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Improvement of patients' quality of life	Improvement of patients' quality of life	during the study，up to 24 weeks
Incidence and duration of serum anti-HBM9161 antibodies and neutralizing antibodies	Incidence and duration of serum anti-HBM9161 antibodies and neutralizing antibodies	during the study，up to 24 weeks
Proportion of patients with sustained improvement	Sustained reduction defined as MG-ADL score improved by ≥ 3 points from baseline for at least 4 consecutive weeks during the 9-week treatment cycle	during each treatment cycle (5-week treatment period + 4-week observation period, from the first dose of the cycle to Day 64 of the cycle)
During the 24-week study, proportion of time that MG-ADL improved from baseline by 3 or more points		during the study，up to 24 weeks
Proportion of time remained in Minimal Symptom Expression	from baseline to Week 24, percentage of time MG-ADL score being 0 or 1	during the study，up to 24 weeks

Collaborators and Investigators

• Sponsor: Harbour BioMed (Guangzhou) Co. Ltd.

Study record dates

Study Major Dates

• Study Start (Actual): June 30, 2022
• Primary Completion (Actual): April 26, 2024
• Study Completion (Actual): April 26, 2024

Study Registration Dates

• First Submitted: April 6, 2022
• First Submitted That Met QC Criteria: April 12, 2022
• First Posted (Actual): April 18, 2022

Study Record Updates

• Last Update Posted (Actual): April 28, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: April 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; HBM9161
• Other Study ID Numbers: 9161.7

Drug and device information, study documents

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