Clinical Trials List
Protocol NumberALXN1720-MG-301
Active
2023-01-01 - 2027-12-31
Phase III
Recruiting4
Terminated1
ICD-10G70.00
Myasthenia gravis without (acute) exacerbation
ICD-10G70.01
Myasthenia gravis with (acute) exacerbation
ICD-9358.0
Myasthenia gravis
A Phase 3, Randomized, Double-blind, Placebo-controlled, Parallel, Multicenter Study to Evaluate the Safety and Efficacy of ALXN1720 in Adults with Generalized Myasthenia Gravis
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Trial Applicant
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Sponsor
Alexion Pharmaceuticals, Inc.
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Trial scale
Multi-Regional Multi-Center
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Update
2026/02/01
Investigators and Locations
The Actual Total Number of Participants Enrolled
0 Recruiting
Co-Principal Investigator
- 林冠佑 Division of Neurology
The Actual Total Number of Participants Enrolled
0 Recruiting
Co-Principal Investigator
The Actual Total Number of Participants Enrolled
0 Recruiting
The Actual Total Number of Participants Enrolled
0 Terminated
Principal Investigator
Hou-Chang Chiu
Co-Principal Investigator
- Chien-Tai Hong
- Chen-Chih Chung
- Shu-Ping Chao Division of Neurology
The Actual Total Number of Participants Enrolled
0 Recruiting
Condition/Disease
Generalized Myasthenia Gravis
Objectives
To assess the efficacy of ALXN1720 compared
with placebo in the treatment of gMG based on
change in MG-ADL total score
Test Drug
injection
Active Ingredient
ALXN1720
Dosage Form
220
Dosage
150 mg/ml
Endpoints
Serum ALXN1720 concentrations
• Absolute values, change from Baseline, and
percent change from Baseline in serum free
and total C5 concentrations
• Absolute values, change from Baseline, and
percent change from Baseline in serum free
and total C5 concentrations
Inclution Criteria
Inclusion Criteria
Subjects are eligible for inclusion in this trial only if they meet all of the following criteria:
Age
1. Must be ≥18 years old at the time of signing the subject consent form.
Subject and Disease Characteristics
2. Must have been diagnosed with generalized myasthenia gravis (gMG) at least 3 months (90 days) prior to screening, based on clinical disease characteristics and at least one of the following confirmatory tests. Unless otherwise stated, test results may be collected from existing subject records or obtained during screening if:
a. A positive result on an acetylcholinesterase (AChE) inhibitor test (e.g., ehonium chloride test);
b. Abnormal neuromuscular conduction shown by repetitive nerve stimulation or single-fiber electromyography;
c. Previous improvement in myasthenia gravis (MG) related symptoms or signs with oral AChE inhibitor treatment, confirmed by the attending physician.
3. A positive serological test for acetylcholine receptor (AChR) autoantibodies at screening (if applicable, previous test results must be confirmed by a central laboratory during screening).
4. Classification II to IV by the American Myasthenia Gravis Foundation (MGFA) at screening.
5. A total score ≥5 on the Myasthenia Gravis Activities of Daily Living Scale (MG-ADL) at screening and before randomization on Day 1.
6. Subjects receiving any of the medications listed in Table A must maintain a stable dose for the specified period prior to screening and must not adjust the treatment duration anticipated during screening or a randomized controlled trial (RCT).
Table A: Permitted Medications and Therapies
Medication Name/Medication Category Name
Required Dosage and Duration Before Screening Follow-up
AChE Inhibitors
a Stable dose for ≥2 weeks (14 days)
Corticosteroids (oral)
b Stable and well-tolerated dose for ≥4 weeks (28 days)
Azathioprine
≥6 months (180 days) with a stable dose for ≥2 months (60 days)
Other immunosuppressive therapies, such as mycophenolate mofetil, methotrexate, cyclosporine, tacrolimus, or cyclophosphamide. Use of medication for ≥3 months (90 days), with a stable dose for ≥1 month (30 days). Regular (long-term) use of a stable and well-tolerated dose of IVIg or SCIg c for ≥6 months (180 days).
a. Intermittent use of AChE inhibitors is not permitted during the trial.
b. If the trial administrator intends to maintain a prednisolone dose higher than 20 mg/day or another corticosteroid dose higher than the equivalent dose during the RCT, the medical monitoring personnel should be notified.
c. The stable dose requirement does not apply to IVIg, SCIg, or high-dose corticosteroids administered as rescue therapy, such as for myasthenic crisis.
Participants who have recently discontinued any of the above medications must have completed a period equivalent to the stable dose required for that medication listed in Table A (e.g., azathioprine ≥2 months, corticosteroids ≥4 weeks) before day one of the screening period.
For subjects who experience a worsening of gMG symptoms or signs during screening (e.g., in a myasthenic crisis), rescue therapies, including plasmapheresis (PP), plasma exchange (PE), IVIg, SCIg, or high-dose corticosteroids, do not constitute grounds for exclusion. However, subjects requiring rescue therapy during screening may only be randomized after ≥4 weeks following the completion of rescue therapy. Subjects re-screened outside the initial screening period must sign a new Intended Participant Consent Form (ICF).
Vaccination
7. To reduce the risk of epidemic cerebrospinal meningitis infection, all subjects must have received a vaccine against cerebrospinal meningococcal serogroups A, C, W135, Y (and serogroup B, if applicable) within 3 years prior to Day 1. Subjects who do not meet this requirement will receive a vaccine against these cerebrospinal meningococcal serogroups before receiving their first dose of the investigational drug. If Day 1 falls < 2 weeks after vaccination, the subject will receive prophylactic antibiotics until 2 weeks after vaccination. Vaccination must follow national/local guidelines.
Weight
8. Subjects must weigh ≥ 40 kg and have a body mass index (BMI) ≥ 18.5 kg/m² and < 40. kg/m2
Gender
9. Male and/or female.
Contraceptive Requirements
10. Participants of fertility must adhere to the contraceptive methods specified in this trial protocol.
Informed Consent
11. Capable of providing signed participant consent forms that include compliance with the participant consent form and the requirements and restrictions set forth in this trial protocol.
Subjects are eligible for inclusion in this trial only if they meet all of the following criteria:
Age
1. Must be ≥18 years old at the time of signing the subject consent form.
Subject and Disease Characteristics
2. Must have been diagnosed with generalized myasthenia gravis (gMG) at least 3 months (90 days) prior to screening, based on clinical disease characteristics and at least one of the following confirmatory tests. Unless otherwise stated, test results may be collected from existing subject records or obtained during screening if:
a. A positive result on an acetylcholinesterase (AChE) inhibitor test (e.g., ehonium chloride test);
b. Abnormal neuromuscular conduction shown by repetitive nerve stimulation or single-fiber electromyography;
c. Previous improvement in myasthenia gravis (MG) related symptoms or signs with oral AChE inhibitor treatment, confirmed by the attending physician.
3. A positive serological test for acetylcholine receptor (AChR) autoantibodies at screening (if applicable, previous test results must be confirmed by a central laboratory during screening).
4. Classification II to IV by the American Myasthenia Gravis Foundation (MGFA) at screening.
5. A total score ≥5 on the Myasthenia Gravis Activities of Daily Living Scale (MG-ADL) at screening and before randomization on Day 1.
6. Subjects receiving any of the medications listed in Table A must maintain a stable dose for the specified period prior to screening and must not adjust the treatment duration anticipated during screening or a randomized controlled trial (RCT).
Table A: Permitted Medications and Therapies
Medication Name/Medication Category Name
Required Dosage and Duration Before Screening Follow-up
AChE Inhibitors
a Stable dose for ≥2 weeks (14 days)
Corticosteroids (oral)
b Stable and well-tolerated dose for ≥4 weeks (28 days)
Azathioprine
≥6 months (180 days) with a stable dose for ≥2 months (60 days)
Other immunosuppressive therapies, such as mycophenolate mofetil, methotrexate, cyclosporine, tacrolimus, or cyclophosphamide. Use of medication for ≥3 months (90 days), with a stable dose for ≥1 month (30 days). Regular (long-term) use of a stable and well-tolerated dose of IVIg or SCIg c for ≥6 months (180 days).
a. Intermittent use of AChE inhibitors is not permitted during the trial.
b. If the trial administrator intends to maintain a prednisolone dose higher than 20 mg/day or another corticosteroid dose higher than the equivalent dose during the RCT, the medical monitoring personnel should be notified.
c. The stable dose requirement does not apply to IVIg, SCIg, or high-dose corticosteroids administered as rescue therapy, such as for myasthenic crisis.
Participants who have recently discontinued any of the above medications must have completed a period equivalent to the stable dose required for that medication listed in Table A (e.g., azathioprine ≥2 months, corticosteroids ≥4 weeks) before day one of the screening period.
For subjects who experience a worsening of gMG symptoms or signs during screening (e.g., in a myasthenic crisis), rescue therapies, including plasmapheresis (PP), plasma exchange (PE), IVIg, SCIg, or high-dose corticosteroids, do not constitute grounds for exclusion. However, subjects requiring rescue therapy during screening may only be randomized after ≥4 weeks following the completion of rescue therapy. Subjects re-screened outside the initial screening period must sign a new Intended Participant Consent Form (ICF).
Vaccination
7. To reduce the risk of epidemic cerebrospinal meningitis infection, all subjects must have received a vaccine against cerebrospinal meningococcal serogroups A, C, W135, Y (and serogroup B, if applicable) within 3 years prior to Day 1. Subjects who do not meet this requirement will receive a vaccine against these cerebrospinal meningococcal serogroups before receiving their first dose of the investigational drug. If Day 1 falls < 2 weeks after vaccination, the subject will receive prophylactic antibiotics until 2 weeks after vaccination. Vaccination must follow national/local guidelines.
Weight
8. Subjects must weigh ≥ 40 kg and have a body mass index (BMI) ≥ 18.5 kg/m² and < 40. kg/m2
Gender
9. Male and/or female.
Contraceptive Requirements
10. Participants of fertility must adhere to the contraceptive methods specified in this trial protocol.
Informed Consent
11. Capable of providing signed participant consent forms that include compliance with the participant consent form and the requirements and restrictions set forth in this trial protocol.
Exclusion Criteria
Subjects are ineligible to participate in the trial if they meet any of the following criteria: Medical Conditions
1. Any medical condition (e.g., heart, lung, kidney, tumor, neurological, or psychiatric illness) or risk factor that, as determined by the trial principal investigator or trial monitor, may interfere with trial participation, pose any additional risk to the subject, or obscure the safety or efficacy assessment of the investigational drug.
2. History of thymectomy or any other thymic surgery within 12 months prior to screening.
3. Any untreated thymic malignancy, cancer, or thymoma.
Subjects with a history of treated thymic malignancy or cancer are eligible if they meet all of the following criteria:
a. Completed treatment > 5 years prior to the screening follow-up visit.
b. No recurrence within 5 years prior to the screening follow-up visit.
c. Computed tomography (CT) or magnetic resonance imaging (MRI) scan performed within 6 months of randomization on Day 1. No radiographic evidence of recurrence on scans (including intravenous contrast agent administration).
Subjects with a history of treated benign thymoma are eligible if they meet all of the following criteria:
d. Histopathological or equivalent documentation confirming a benign thymoma diagnosis.
e. Treatment completed > 12 months prior to the screening follow-up visit.
f. No known recurrence within 12 months prior to the screening follow-up visit.
g. No radiographic evidence of recurrence on CT or MRI scans (including intravenous contrast agent administration) performed within 6 months of randomization on day 1.
h. If there is insufficient documentation to confirm a benign thymoma diagnosis, the subject must meet the eligibility criteria for thymic malignancy or cancer as described above.
According to the Masaoka staging system, thymoma stage ≤ II is considered benign; thymoma stage ≥ III is considered malignant.
4. History of meningococcal infection
5. History of any persistent or recurrent infection within the past 12 months that may pose an additional risk to the subject
6. Active systemic bacterial, viral, or fungal infection ≤14 days prior to randomization on day 1
7. History of hypersensitivity to any component of the investigational drug (including its device components)
8. History of malignancy within the past 5 years.
Exceptions that do not require exclusion from the trial are skin cancer other than malignant melanoma, and cervical carcinoma in situ that has been treated and has no evidence of recurrence
9. History of known or suspected alcohol or drug use disorder within the past 12 months according to the current diagnostic criteria provided in the Diagnostic and Statistical Manual of Mental Disorders.
Previous/Concomitant Therapies
10. Concomitant treatment with any of the following medications is not permitted, or prior treatment within the following specified timeframes is not permitted:
Complement inhibitors: Received within <5 half-lives prior to randomization on day 1. Subjects who received complement inhibitor therapy within ≥ 5 half-lives prior to randomization on Day 1 may be enrolled, provided they tolerated such therapy well and did not experience any side effects deemed by the trial administrator or monitoring officer that could interfere with trial participation, pose any additional risk to the subject, or confound the assessment of the investigational drug's safety or efficacy.
Human neonatal Fc receptor (FcRn) inhibitors: Received within < 5 half-lives prior to randomization on Day 1. Subjects who received FcRn inhibitor therapy within ≥ 5 half-lives prior to randomization on Day 1 may be enrolled, provided their total immunoglobulin G (IgG) concentration is above the lower limit of normal (LLN) before randomization.
Rituximab, ocrelizumab, or other anti-B-cell therapies: Received within ≤ 6 months (180 days) prior to randomization on Day 1, or scheduled to receive such therapy within this timeframe. Subjects who have previously received anti-B cell therapy may be enrolled after that treatment period, provided that their B cell and platelet counts are above the lower limit of normal (LLN) prior to randomization.
Subjects who have received, or are scheduled to receive, regular (long-term) PP/PE (therapeutic plasmapheresis/plasma exchange) as maintenance therapy within ≤ 6 months (180 days) prior to randomization on Day 1, are eligible. PP/PE may be used as a rescue therapy.
Alexion Pharmaceuticals, Inc., the manufacturer of the investigational drug, does not recommend discontinuing any treatment solely for the purpose of qualifying for this trial.
Previous/Concurrent Clinical Trial Experience
11. Participation in another trial involving an investigational drug, biologic, device, or combination drug, procedure, or any other intervention within 5 treatment half-lives (if known) or 30 days (whichever is longer) prior to the first dose of the investigational drug.
12. Participation in another trial involving an investigational drug, biologic, device, combination drug, procedure, or any other intervention at any time during this trial. If participation in other non-invasive trials is considered, consultation with Alexion is necessary. Alexion may, at his discretion, allow participation in other non-invasive trials concurrently.
Diagnostic Assessment
13. History of human immunodeficiency virus (HIV) infection, or positive HIV-1 or HIV-2 serological test.
14. Evidence of hepatitis B infection (positive hepatitis surface antigen [HBsAg] or positive core antibody [anti-HBc] and negative surface antibody [anti-HBs]) or hepatitis C virus infection (positive HCV antibody, except for subjects with documented successful treatment). If locally feasible, a sustained virological response (SVR) should be documented or established at screening.
15. Subjects who test positive for pregnancy at screening or on Day 1.
16. Subjects with fever within 7 days prior to randomization on Day 1, with evidence of a temperature ≥ 38°C.
17. Subjects with abnormal laboratory test results at screening follow-up, including:
a. Alanine transaminase (ALT) > 2 times the upper limit of normal (ULN)
b. Direct bilirubin > 2 times the ULN
c. Estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m2 or subjects undergoing dialysis.
d. Any other clinically significant abnormal laboratory test result that, according to the trial administrator, would make the subject unsuitable for participation in the trial or place the subject at excessive risk.
Other Exclusion Criteria
18. Pregnant, breastfeeding, or intending to conceive during the trial.
19. Subjects or caregivers who cannot or are unwilling to administer the investigational drug.
20. Subjects who cannot or are unwilling to comply with the trial protocol requirements and restrictions, including attending scheduled trial follow-up visits.
1. Any medical condition (e.g., heart, lung, kidney, tumor, neurological, or psychiatric illness) or risk factor that, as determined by the trial principal investigator or trial monitor, may interfere with trial participation, pose any additional risk to the subject, or obscure the safety or efficacy assessment of the investigational drug.
2. History of thymectomy or any other thymic surgery within 12 months prior to screening.
3. Any untreated thymic malignancy, cancer, or thymoma.
Subjects with a history of treated thymic malignancy or cancer are eligible if they meet all of the following criteria:
a. Completed treatment > 5 years prior to the screening follow-up visit.
b. No recurrence within 5 years prior to the screening follow-up visit.
c. Computed tomography (CT) or magnetic resonance imaging (MRI) scan performed within 6 months of randomization on Day 1. No radiographic evidence of recurrence on scans (including intravenous contrast agent administration).
Subjects with a history of treated benign thymoma are eligible if they meet all of the following criteria:
d. Histopathological or equivalent documentation confirming a benign thymoma diagnosis.
e. Treatment completed > 12 months prior to the screening follow-up visit.
f. No known recurrence within 12 months prior to the screening follow-up visit.
g. No radiographic evidence of recurrence on CT or MRI scans (including intravenous contrast agent administration) performed within 6 months of randomization on day 1.
h. If there is insufficient documentation to confirm a benign thymoma diagnosis, the subject must meet the eligibility criteria for thymic malignancy or cancer as described above.
According to the Masaoka staging system, thymoma stage ≤ II is considered benign; thymoma stage ≥ III is considered malignant.
4. History of meningococcal infection
5. History of any persistent or recurrent infection within the past 12 months that may pose an additional risk to the subject
6. Active systemic bacterial, viral, or fungal infection ≤14 days prior to randomization on day 1
7. History of hypersensitivity to any component of the investigational drug (including its device components)
8. History of malignancy within the past 5 years.
Exceptions that do not require exclusion from the trial are skin cancer other than malignant melanoma, and cervical carcinoma in situ that has been treated and has no evidence of recurrence
9. History of known or suspected alcohol or drug use disorder within the past 12 months according to the current diagnostic criteria provided in the Diagnostic and Statistical Manual of Mental Disorders.
Previous/Concomitant Therapies
10. Concomitant treatment with any of the following medications is not permitted, or prior treatment within the following specified timeframes is not permitted:
Complement inhibitors: Received within <5 half-lives prior to randomization on day 1. Subjects who received complement inhibitor therapy within ≥ 5 half-lives prior to randomization on Day 1 may be enrolled, provided they tolerated such therapy well and did not experience any side effects deemed by the trial administrator or monitoring officer that could interfere with trial participation, pose any additional risk to the subject, or confound the assessment of the investigational drug's safety or efficacy.
Human neonatal Fc receptor (FcRn) inhibitors: Received within < 5 half-lives prior to randomization on Day 1. Subjects who received FcRn inhibitor therapy within ≥ 5 half-lives prior to randomization on Day 1 may be enrolled, provided their total immunoglobulin G (IgG) concentration is above the lower limit of normal (LLN) before randomization.
Rituximab, ocrelizumab, or other anti-B-cell therapies: Received within ≤ 6 months (180 days) prior to randomization on Day 1, or scheduled to receive such therapy within this timeframe. Subjects who have previously received anti-B cell therapy may be enrolled after that treatment period, provided that their B cell and platelet counts are above the lower limit of normal (LLN) prior to randomization.
Subjects who have received, or are scheduled to receive, regular (long-term) PP/PE (therapeutic plasmapheresis/plasma exchange) as maintenance therapy within ≤ 6 months (180 days) prior to randomization on Day 1, are eligible. PP/PE may be used as a rescue therapy.
Alexion Pharmaceuticals, Inc., the manufacturer of the investigational drug, does not recommend discontinuing any treatment solely for the purpose of qualifying for this trial.
Previous/Concurrent Clinical Trial Experience
11. Participation in another trial involving an investigational drug, biologic, device, or combination drug, procedure, or any other intervention within 5 treatment half-lives (if known) or 30 days (whichever is longer) prior to the first dose of the investigational drug.
12. Participation in another trial involving an investigational drug, biologic, device, combination drug, procedure, or any other intervention at any time during this trial. If participation in other non-invasive trials is considered, consultation with Alexion is necessary. Alexion may, at his discretion, allow participation in other non-invasive trials concurrently.
Diagnostic Assessment
13. History of human immunodeficiency virus (HIV) infection, or positive HIV-1 or HIV-2 serological test.
14. Evidence of hepatitis B infection (positive hepatitis surface antigen [HBsAg] or positive core antibody [anti-HBc] and negative surface antibody [anti-HBs]) or hepatitis C virus infection (positive HCV antibody, except for subjects with documented successful treatment). If locally feasible, a sustained virological response (SVR) should be documented or established at screening.
15. Subjects who test positive for pregnancy at screening or on Day 1.
16. Subjects with fever within 7 days prior to randomization on Day 1, with evidence of a temperature ≥ 38°C.
17. Subjects with abnormal laboratory test results at screening follow-up, including:
a. Alanine transaminase (ALT) > 2 times the upper limit of normal (ULN)
b. Direct bilirubin > 2 times the ULN
c. Estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m2 or subjects undergoing dialysis.
d. Any other clinically significant abnormal laboratory test result that, according to the trial administrator, would make the subject unsuitable for participation in the trial or place the subject at excessive risk.
Other Exclusion Criteria
18. Pregnant, breastfeeding, or intending to conceive during the trial.
19. Subjects or caregivers who cannot or are unwilling to administer the investigational drug.
20. Subjects who cannot or are unwilling to comply with the trial protocol requirements and restrictions, including attending scheduled trial follow-up visits.
The Estimated Number of Participants
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Taiwan
15 participants
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Global
254 participants
