Safety and Efficacy of ALXN1720 in Adults With Generalized Myasthenia Gravis

June 15, 2026 updated by: Alexion Pharmaceuticals, Inc.

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

The purpose of this study is to evaluate the safety and efficacy of ALXN1720 for the treatment of generalized MG (gMG) in adults with autoantibodies against acetylcholine receptor (AChR).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
260

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Argentina
      • CABA, Argentina, C1192AAW
        • Research Site
      • Ciudad de Buenos Aires, Argentina, 1181
        • Research Site
      • Ciudad de Buenos Aires, Argentina, AR-CP 1221
        • Research Site
      • Ciudad de Buenos Aires, Argentina, 1015
        • Research Site
      • Rosario, Argentina, S2000BZL
        • Research Site
  • Austria
      • Innsbruck, Austria, 6020
        • Research Site
      • Wels, Austria, 4600
        • Research Site
  • Brazil
      • Barretos, Brazil, 14784-400
        • Research Site
      • Joinville, Brazil, 89202-190
        • Research Site
      • Porto Alegre, Brazil, 90620-130
        • Research Site
      • Ribeirão Preto, Brazil, 14051-140
        • Research Site
      • Salvador, Brazil, 41253-190
        • Research Site
      • São José do Rio Preto, Brazil, 15090-000
        • Research Site
      • São Paulo, Brazil, 05403-010
        • Research Site
  • Canada
    • Alberta
      • Edmonton, Alberta, Canada, T6G 2G3
        • Research Site
    • Ontario
      • Toronto, Ontario, Canada, M5G 2C4
        • Research Site
    • Quebec
      • Québec, Quebec, Canada, G1J 1Z4
        • Research Site
  • China
      • Beijing, China, 100730
        • Research Site
      • Beijing, China, 100034
        • Research Site
      • Changchun, China, 130021
        • Research Site
      • Changsha, China, 410008
        • Research Site
      • Chengdu, China, 610041
        • Research Site
      • Fuzhou, China, 350001
        • Research Site
      • Hangzhou, China, 310003
        • Research Site
      • Hangzhou, China, 310016
        • Research Site
      • Jinan, China, 250014
        • Research Site
      • Qingdao, China, 266035
        • Research Site
      • Shanghai, China, 200040
        • Research Site
      • Suzhou, China, 215006
        • Research Site
      • Wuhan, China, 430030
        • Research Site
      • Xi'an, China, 710000
        • Research Site
  • Denmark
      • Aalborg, Denmark, 9000
        • Research Site
      • Copenhagen, Denmark, 2100
        • Research Site
  • France
      • Garches, France, 92380
        • Research Site
      • Lille, France, 59037
        • Research Site
      • Marseille, France, 13385
        • Research Site
      • Nice, France, 06000
        • Research Site
      • Paris, France, 75651
        • Research Site
      • Strasbourg, France, 67098
        • Research Site
  • Germany
      • Berlin, Germany, 10117
        • Research Site
      • Düsseldorf, Germany, 40225
        • Research Site
      • München, Germany, 81675
        • Research Site
      • Würzburg, Germany, 97074
        • Research Site
  • Israel
      • Hadera, Israel, 38100
        • Research Site
      • Haifa, Israel, 3109601
        • Research Site
      • Petah Tikva, Israel, 4910000
        • Research Site
  • Italy
      • Bergamo, Italy, 24127
        • Research Site
      • Brescia, Italy, 25123
        • Research Site
      • Florence, Italy, 50139
        • Research Site
      • Milan, Italy, 20133
        • Research Site
      • Naples, Italy, 80131
        • Research Site
      • Palermo, Italy, 90127
        • Research Site
      • Pisa, Italy, 56126
        • Research Site
      • Roma, Italy, 00168
        • Research Site
      • Rome, Italy, 00189
        • Research Site
  • Japan
      • Chiba, Japan, 260-8677
        • Research Site
      • Fukushima, Japan, 960-1295
        • Research Site
      • Higashimatsuyama-shi, Japan, 355-0005
        • Research Site
      • Isehara-shi, Japan, 259-1193
        • Research Site
      • Itabashi-ku, Japan, 173-8610
        • Research Site
      • Kawasaki-shi, Japan, 216-8511
        • Research Site
      • Morioka, Japan, 020-8505
        • Research Site
      • Nagasaki, Japan, 852-8501
        • Research Site
      • Nagoya, Japan, 466-0065
        • Research Site
      • Nagoya, Japan, 467-0001
        • Research Site
      • Shinjuku-ku, Japan, 160-8582
        • Research Site
      • Shinjuku-ku, Japan, 160-0023
        • Research Site
      • Suita-shi, Japan, 565-0871
        • Research Site
  • Netherlands
      • Amsterdam, Netherlands, 1105 AZ
        • Research Site
  • Poland
      • Bydgoszcz, Poland, 85-086
        • Research Site
      • Katowice, Poland, 40-689
        • Research Site
      • Krakow, Poland, 31-505
        • Research Site
      • Krakow, Poland, 31-202
        • Research Site
      • Lublin, Poland, 20064
        • Research Site
      • Poznan, Poland, 61-731
        • Research Site
  • Portugal
      • Almada, Portugal, 2805-267
        • Research Site
      • Porto, Portugal, 4099-001
        • Research Site
  • Serbia
      • Belgrade, Serbia, 11000
        • Research Site
      • Niš, Serbia, 18000
        • Research Site
  • South Korea
      • Busan, South Korea, 49241
        • Research Site
      • Daegu, South Korea, 41404
        • Research Site
      • Gwangju, South Korea, 61469
        • Research Site
      • Seoul, South Korea, 02841
        • Research Site
      • Seoul, South Korea, 03722
        • Research Site
      • Seoul, South Korea, 05505
        • Research Site
      • Seoul, South Korea, 06351
        • Research Site
      • Seoul, South Korea, 5030
        • Research Site
  • Spain
      • Badalona (Barcelona), Spain, 08916
        • Research Site
      • Córdoba, Spain, 14004
        • Research Site
      • L'Hospitalet de Llobregat, Spain, 08907
        • Research Site
      • Madrid, Spain, 28034
        • Research Site
      • Madrid, Spain, 28046
        • Research Site
      • Madrid, Spain, 28040
        • Research Site
      • Madrid, Spain, 28702
        • Research Site
      • Málaga, Spain, 29010
        • Research Site
      • Seville, Spain, 41009
        • Research Site
  • Switzerland
      • Sankt Gallen, Switzerland, CH-9007
        • Research Site
  • Taiwan
      • Kaohsiung City, Taiwan, 833401
        • Research Site
      • New Taipei City, Taiwan, 23561
        • Research Site
      • Tainan, Taiwan, 70403
        • Research Site
      • Taipei, Taiwan, 11101
        • Research Site
  • Turkey (Türkiye)
      • Bursa, Turkey (Türkiye), 16059
        • Research Site
      • Istanbul, Turkey (Türkiye), 34452
        • Research Site
      • Kocaeli, Turkey (Türkiye), 41380
        • Research Site
      • Samsun, Turkey (Türkiye), 55139
        • Research Site
  • United Kingdom
      • Liverpool, United Kingdom, L9 7AL
        • Research Site
      • London, United Kingdom, EC1A 7BE
        • Research Site
      • Oxford, United Kingdom, 0X3 7LE
        • Research Site
      • Sheffield, United Kingdom, S10 2JF
        • Research Site
  • United States
    • California
      • Orange, California, United States, 92868
        • Research Site
    • Colorado
      • Fort Collins, Colorado, United States, 80528
        • Research Site
    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20007
        • Research Site
    • Florida
      • Bradenton, Florida, United States, 34209
        • Research Site
      • Maitland, Florida, United States, 32751
        • Research Site
      • Tampa, Florida, United States, 33612
        • Research Site
    • Georgia
      • Augusta, Georgia, United States, 30912
        • Research Site
      • Gainesville, Georgia, United States, 30501
        • Research Site
      • Savannah, Georgia, United States, 31406
        • Research Site
    • Illinois
      • Springfield, Illinois, United States, 62769
        • Research Site
    • Kansas
      • Kansas City, Kansas, United States, 66160
        • Research Site
    • Kentucky
      • Lexington, Kentucky, United States, 40503
        • Research Site
    • Michigan
      • Detroit, Michigan, United States, 48202
        • Research Site
      • East Lansing, Michigan, United States, 48824
        • Research Site
    • Nevada
      • Las Vegas, Nevada, United States, 89117
        • Research Site
    • New York
      • Patchogue, New York, United States, 11772
        • Research Site
      • Rochester, New York, United States, 14620
        • Research Site
      • Syracuse, New York, United States, 13202
        • Research Site
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27599
        • Research Site
    • South Carolina
      • North Charleston, South Carolina, United States, 29406
        • Research Site
    • Texas
      • Houston, Texas, United States, 77030
        • Research Site
    • Virginia
      • Richmond, Virginia, United States, 23298
        • Research Site
    • West Virginia
      • Morgantown, West Virginia, United States, 26506
        • Research Site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Diagnosis of MG with generalized muscle weakness meeting the clinical criteria defined by Myasthenia Gravis Foundation of America (MGFA) Class II, III or IV
  • Positive serological test for autoantibodies against AChR

Exclusion Criteria:

  • History of thymectomy, or any other thymic surgery within 12 months prior to Screening
  • Untreated thymic malignancy, carcinoma, or thymoma
  • History of Neisseria meningitidis infection
  • Pregnancy, breastfeeding, or intention to conceive during the course of the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Placebo Comparator: Placebo
Participants will receive placebo during the 26-week RCT period, after which they will enter the OLE period of the study and receive ALXN1720.
Combination product: Placebo
Combination product consisting of syringe prefilled with placebo.
Experimental: ALXN1720
Participants will receive a weight-based initial (loading) dose of ALXN1720 on Day 1, followed by weight-based maintenance treatment with ALXN1720 on Day 8 and once every week (Q1W) thereafter for a total of 26 weeks. Following this randomized controlled treatment (RCT) period, all participants will receive ALXN1720 in an open-label extension (OLE) period of 105 weeks.
Combination product: ALXN1720
Combination product consisting of syringe prefilled with ALXN1720.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Change From Baseline in Myasthenia Gravis-Activities of Daily Living (MG-ADL) Total Score at Week 26
Time Frame: Baseline, Week 26
Baseline, Week 26

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change From Baseline in Quantitative Myasthenia Gravis (QMG) Total Score at Week 26
Time Frame: Baseline, Week 26
Baseline, Week 26
Change From Baseline in Myasthenia Gravis Composite (MGC) Total Score at Week 26
Time Frame: Baseline, Week 26
Baseline, Week 26
Percentage of Responders Based on Reduction of the MG-ADL Total Score at Week 26
Time Frame: Baseline up to Week 26
Response is defined as reduction of the MG-ADL total score by >= 3 points from baseline at Week 26.
Baseline up to Week 26
Percentage of Responders based on Reduction of the QMG Total Score at Week 26
Time Frame: Baseline up to Week 26
Response is defined as reduction of the QMG total score by >= 5 points from baseline at Week 26
Baseline up to Week 26
Change from Baseline in the QMG total score at Week 4
Time Frame: Baseline, Week 4
Baseline, Week 4

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Alexion Pharmaceuticals, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 21, 2022

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 27, 2025

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 31, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 23, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 23, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 27, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 17, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 15, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ALXN1720-MG-301
  • 2022-000460-21 (EudraCT Number)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Alexion has a public commitment to allow requests for access to study data and will be supplying a protocol, CSR, and plain language summaries.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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