ALXN1720 for Myasthenia Gravis

Not currently recruiting at 176 trial locations

Overseen By Alexion Pharmaceuticals, Inc. (Sponsor)

Age: 18+

Sex: Any

Trial Phase: Phase 3

Sponsor: Alexion Pharmaceuticals, Inc.

Disqualifiers: Thymic surgery, Thymic malignancy, Pregnancy, others

Pivotal Trial (Near Approval) This treatment is in the last trial phase before FDA approval

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: Unknown

Duration: 26 weeks

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new treatment called ALXN1720 for individuals with generalized Myasthenia Gravis (gMG), a condition that causes muscle weakness. Researchers aim to determine if ALXN1720 is safe and effective for those with gMG who have specific antibodies—proteins in the blood that attack the body's own cells. Participants will receive either ALXN1720 or a placebo (a substance with no active treatment) in the first part of the study. Afterward, all participants will receive ALXN1720. Suitable candidates have gMG with muscle weakness and a positive blood test for certain antibodies. As a Phase 3 trial, this study represents the final step before FDA approval, offering participants a chance to contribute to a potentially groundbreaking treatment.

Do I have to stop taking my current medications for this trial?

The trial protocol does not specify whether you need to stop taking your current medications.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

Is there any evidence suggesting that ALXN1720 is likely to be safe for humans?

Research shows that ALXN1720 is being tested for safety and effectiveness in treating generalized myasthenia gravis (gMG) in adults. Although detailed safety information from earlier studies is not available, ALXN1720's progression to a Phase 3 trial indicates it has passed initial safety tests. This suggests it was reasonably safe in earlier phases, where researchers closely monitored side effects and participant tolerance.

To reach this stage, a treatment typically needs to be well-tolerated in earlier studies with few serious side effects. Phase 3 trials are larger and help confirm safety on a broader scale. While specific safety data for ALXN1720 is not provided here, its advancement to this stage is a positive indicator of its safety profile. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising for MG?

Unlike the standard treatments for myasthenia gravis, which often include medications like anticholinesterase inhibitors, corticosteroids, or immunosuppressants, ALXN1720 stands out because it targets the complement system, specifically inhibiting the C5 protein. This mechanism of action is innovative because it directly addresses the underlying immune process responsible for muscle weakness in myasthenia gravis. Additionally, ALXN1720 is administered via a weekly injection, which may provide a more convenient dosing schedule compared to some existing treatments. Researchers are excited because this approach has the potential to offer a more targeted and efficient way to manage the symptoms of this challenging condition.

What evidence suggests that ALXN1720 might be an effective treatment for myasthenia gravis?

Research has shown that ALXN1720, which participants in this trial may receive, may help treat generalized myasthenia gravis (gMG). This treatment blocks a part of the immune system, reducing symptoms. In studies, ALXN1720 significantly improved patients' ability to perform daily activities and lessened disease severity. Improvements appeared as early as one week and continued for up to 26 weeks. This suggests that people with gMG could experience better muscle control and reduced fatigue. While more information is needed, these findings are promising for those considering this treatment. ^{1 2 4 5 6}

Are You a Good Fit for This Trial?

This trial is for adults with generalized Myasthenia Gravis (MG), a condition causing muscle weakness. Participants must have specific autoantibodies against AChR and meet certain MG severity criteria. Those who've had thymus surgery within the last year, untreated thymic tumors, or are pregnant/breastfeeding cannot join.

Inclusion Criteria

You have a positive blood test for autoantibodies against AChR.

You have a positive blood test for certain antibodies related to muscle function.

I have been diagnosed with MG and experience widespread muscle weakness.

Exclusion Criteria

You have had an infection with Neisseria meningitidis in the past.

Pregnancy, breastfeeding, or intention to conceive during the course of the study

I had surgery on my thymus gland within the last year.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive a weight-based initial (loading) dose of ALXN1720 on Day 1, followed by weight-based maintenance treatment once every week for 26 weeks

26 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

Open-label extension

All participants receive ALXN1720 in an open-label extension period

105 weeks

What Are the Treatments Tested in This Trial?

Interventions

• ALXN1720

Trial Overview The study tests ALXN1720's safety and effectiveness in treating generalized MG compared to a placebo. It targets patients with antibodies against acetylcholine receptors which are linked to this muscle weakness disorder.

How Is the Trial Designed?

Group I: ALXN1720 Experimental Treatment 1 Intervention

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.

Group II: Placebo Placebo Group 1 Intervention

Participants will receive placebo during the 26-week RCT period, after which they will enter the OLE period of the study and receive ALXN1720.

Who Is Running the Clinical Trial?

Alexion Pharmaceuticals, Inc.

Lead Sponsor

Trials

267

Recruited

141,000+

Dr. Alberto R. Martinez

Alexion Pharmaceuticals, Inc.

Chief Medical Officer since 2010

MD from University of Sao Paulo

Marc Dunoyer

Alexion Pharmaceuticals, Inc.

Chief Executive Officer since 2021

PhD in Molecular Biology

Alexion Pharmaceuticals

Lead Sponsor

Trials

231

Recruited

36,700+

Marc Dunoyer

Alexion Pharmaceuticals

Chief Executive Officer since 2021

B.A. in Psychology from the University of New Hampshire

Christophe Hotermans

Alexion Pharmaceuticals

Chief Medical Officer since 2023

MD

Alexion

Lead Sponsor

Trials

247

Recruited

38,600+

Marc Dunoyer

Alexion

Chief Executive Officer since 2021

PhD in Molecular Biology, University of Brussels

Christophe Hotermans

Alexion

Chief Medical Officer since 2021

MD, University of Leuven

Published Research Related to This Trial

In a prospective study of 22 patients with treatment-refractory myasthenia gravis, rituximab treatment led to significant clinical improvement, with manual muscle testing scores decreasing from an average of 10.6 to 3.3 over a mean follow-up of 28.8 months.

Rituximab also allowed for a substantial reduction in prednisone dosage, from 25.2 mg/d to 7.3 mg/d, indicating its potential to reduce reliance on steroids while managing the disease.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Rituximab in refractory myasthenia gravis: Extended prospective study results. Beecher, G., Anderson, D., Siddiqi, ZA.[2019]

A new sum score has been developed to define treatment-refractory generalized myasthenia gravis (TRgMG), which includes criteria such as disease severity and inefficacy of previous therapies, making it easier for clinicians to make treatment decisions.

This scoring system, created through a consensus of 12 experts and based on a thorough literature review, aims to clarify when eculizumab should be used and can also serve as a basis for inclusion criteria in future clinical studies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A Sum Score to Define Therapy-Refractory Myasthenia Gravis: A German Consensus. Schroeter, M., Berger, B., Blaes, F., et al.[2022]

Eculizumab, administered to 117 patients over a median of 22.7 months, demonstrated a long-term safety profile consistent with previous studies, with no reported cases of meningococcal infection.

The treatment significantly reduced myasthenia gravis exacerbation rates by 75% and maintained improvements in daily activities, muscle strength, and quality of life, with 56% of patients achieving minimal manifestations or pharmacological remission.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Long-term safety and efficacy of eculizumab in generalized myasthenia gravis. Muppidi, S., Utsugisawa, K., Benatar, M., et al.[2020]

Ravulizumab demonstrated sustained efficacy in treating generalized myasthenia gravis over 60 weeks, with significant improvements in Myasthenia Gravis-Activities of Daily Living (MG-ADL) scores for patients who continued treatment from the randomized controlled period.

The treatment was well tolerated with no reported cases of meningococcal infections, indicating a favorable safety profile for long-term use.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Long-term efficacy and safety of ravulizumab in adults with anti-acetylcholine receptor antibody-positive generalized myasthenia gravis: results from the phase 3 CHAMPION MG open-label extension. Meisel, A., Annane, D., Vu, T., et al.[2023]

In a study involving 10 patients with muscle-specific kinase antibody-positive myasthenia gravis, amifampridine phosphate demonstrated significant efficacy in improving muscle strength and daily living activities, with statistically significant results in multiple outcome measures.

The treatment was found to be safe, with transient paresthesias being the only reported adverse effect, indicating that amifampridine phosphate could be a promising option for this condition, warranting further investigation in larger trials.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Amifampridine phosphate in the treatment of muscle-specific kinase myasthenia gravis: a phase IIb, randomized, double-blind, placebo-controlled, double crossover study. Bonanno, S., Pasanisi, MB., Frangiamore, R., et al.[2022]

Eculizumab significantly improved outcomes in patients with anti-acetylcholine receptor-positive refractory generalized myasthenia gravis (gMG), with 25.0% achieving minimal manifestations (MM) after 26 weeks compared to 13.3% in the placebo group.

After 130 weeks of treatment, 88.0% of patients on eculizumab reported improved status, and 57.3% achieved MM, demonstrating both rapid and sustained efficacy without new safety concerns.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Post-intervention Status in Patients With Refractory Myasthenia Gravis Treated With Eculizumab During REGAIN and Its Open-Label Extension. Mantegazza, R., Wolfe, GI., Muppidi, S., et al.[2021]

Eculizumab has shown efficacy and safety in treating refractory generalized myasthenia gravis (gMG) in Phase II and III studies, potentially offering a new immunosuppressive approach that could reduce the need for corticosteroids.

The drug works by blocking C5, which protects the neuromuscular junction from damage caused by autoantibodies, suggesting it could modify the disease course and improve patient outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Eculizumab for the treatment of myasthenia gravis. Mantegazza, R., Cavalcante, P.[2021]

In a study of 21 patients with MuSK-MG, most were female (81%) with an average onset age of 51.9 years, and symptoms often progressed rapidly, particularly from ocular to generalized myasthenia gravis within about 4.4 months.

While conventional treatments like pyridostigmine and corticosteroids were used, only 4.8% achieved complete stable remission, indicating a need for more effective therapies as nearly 15% of patients had poor responses to current treatments.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Spotlight on MuSK positive myasthenia gravis: clinical characteristics, treatment and outcomes. Huang, Q., Li, F., Zhao, S.[2022]

Among 10,277 cancer patients treated with nivolumab, 12 cases of myasthenia gravis (MG) were reported, indicating a rare but serious side effect of this immune checkpoint inhibitor, particularly with severe symptoms and rapid deterioration.

Nivolumab-related MG showed more severe symptoms compared to idiopathic MG, including higher rates of bulbar symptoms and myasthenic crisis, highlighting the need for prompt recognition and treatment, as immunosuppressive therapy was effective in managing the condition.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Nivolumab-related myasthenia gravis with myositis and myocarditis in Japan. Suzuki, S., Ishikawa, N., Konoeda, F., et al.[2022]

About 10% of myasthenia gravis (MG) patients do not respond well to current treatments and are considered treatment refractory, with certain factors like being anti-MuSK positive or having a history of thymoma increasing this risk.

New therapies, including monoclonal antibodies like rituximab, eculizumab, and belimumab, are being proposed for patients who do not respond to standard treatments, aiming to improve outcomes for those with treatment-refractory MG.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

When myasthenia gravis is deemed refractory: clinical signposts and treatment strategies. Mantegazza, R., Antozzi, C.[2022]

Eculizumab significantly improves symptoms in patients with refractory anti-acetylcholine receptor antibody-positive myasthenia gravis (AChR+ gMG), regardless of prior treatment with rituximab, as shown in a subgroup analysis of 14 patients from the phase 3 REGAIN study.

The safety profile of eculizumab remains consistent and well-tolerated among patients with a history of rituximab use, with similar efficacy observed in both groups over 130 weeks of treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Eculizumab in refractory generalized myasthenia gravis previously treated with rituximab: subgroup analysis of REGAIN and its extension study. Siddiqi, ZA., Nowak, RJ., Mozaffar, T., et al.[2022]

Citations

1. astrazeneca-us.com astrazeneca-us.com/media/press-releases/2025/Gefurulimab-demonstrates-statistically-significant-and-clinically-meaningful-improvement-in-Myasthenia-Gravis-Activities-of-Daily-Living-MG-ADL-at-week-26-with-clinically-meaningful-improvement-seen-as-early-as-week-one-in-adults-with-gMG-in-PREVAIL-Phase-III-trial.html

Gefurulimab demonstrates statistically significant and ... Trial met all secondary endpoints including change from baseline in quantitative myasthenia gravis total score at week four and week 26.

2. clinicaltrials.gov clinicaltrials.gov/study/NCT05556096

NCT05556096 | Safety and Efficacy of ALXN1720 in Adults ... 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 ...

3. astrazeneca.com astrazeneca.com/content/astraz/media-centre/press-releases/2025/gefurulimab-nanobody-met-phase-iii-endpoints.html

Gefurulimab dual-binding nanobody demonstrated ... Once-weekly self-administered subcutaneous C5 inhibitor showed statistically significant and clinically meaningful reduction in disease ...

4. neurology.org neurology.org/doi/10.1212/WNL.0000000000208763

The Phase 3 PREVAIL Study Assessing the Efficacy and ... Gefurulimab is a new investigational complement inhibitor that binds C5, blocks its enzymatic cleavage, and thus, inhibits the terminal complement pathway.

5. astrazeneca-us.com astrazeneca-us.com/media/press-releases/2025/Alexion-data-presented-at-2025-AANEM-Annual-Meeting-and-MGFA-Scientific-Session-underscores-pioneering-C5-inhibition-leadership-in-gMG.html

Alexion data presented at 2025 AANEM Annual Meeting ... Presentations will feature topline data from the global PREVAIL Phase III trial evaluating gefurulimab in adults with anti-acetylcholine ...

6. astrazeneca.com astrazeneca.com/media-centre/press-releases/2025/alexion-data-presented-at-2025-aanem-annual-meeting-and-mgfa-scientific-session-underscores-pioneering-c5-inhibition-leadership-in-gmg.html

Alexion data presented at 2025 AANEM Annual Meeting ... The trial met its primary and all secondary endpoints, with gefurulimab demonstrating a statistically significant and clinically meaningful ...