Long Term Safety Study of Amifampridine Phosphate in MuSK-MG (Muscle Specific Tyrosine Kinase Myasthenia Gravis)

NCT03579966 | Terminated Phase 3 Results FDA Drug

• 1 other identifier: MSK-003
• Study Type: interventional
• Target: 63
• Locations: 2 countries
• Sites: 3

Brief Summary

Evaluate the long-term safety of amifampridine phosphate in patients with MuSK antibody positive and AChR antibody positive myasthenia gravis.

Conditions

Myasthenia Gravis, MuSK; AChR Myasthenia Gravis

Keywords

Amifampridine Phosphate Amifampridine; 3,4-Diaminopyridine Phosphate; 3,4-Diaminopyridine; 3,4-DAP; Firdapse®; Myasthenia Gravis; MuSK; AChR

Outcome Measures

Primary Outcomes (1)

• Number of Participants With Treatment-Emergent Adverse Events (Safety and Tolerability)

  Evaluate the long-term safety and tolerability of amifampridine phosphate through the number of patients with treatment-emergent adverse events mapped to the Medical Dictionary for Regulatory Activities (MedDRA) SOCs and PTs. \[ Time Frame: over 39 months \] Descriptive statistics will be used to summarize study data.

  over 39 months

Study Arms (1)

amifampridine phosphate

EXPERIMENTAL

tablets equivalent to 10mg amifampridine, 3 to 4 times per day. Initially, the daily amifampridine doses were to be the doses that were determined at the end of the Run-in Period from the MSK-002 study. The usual range was from 30 to 80 mg total daily dose, given in three (3) or four (4) doses, with no single dose \> 20 mg

Drug: Amifampridine Phosphate

Interventions

Amifampridine Phosphate DRUG

tablets equivalent to 10mg amifampridine, titrated to an efficacious and tolerable dose, 3 to 4 times a day

amifampridine phosphate

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Participated in the MSK-002 study
• Willing and able to provide written informed consent after the nature of the study has been explained and before the start of any research-related procedures.
• Female patients of childbearing potential must have a negative pregnancy test (urine human chorionic gonadotropin \[HCG\] at the end of MSK-002 study); and must practice an effective, reliable contraceptive regimen during the study and for up to 30 days following discontinuation of treatment.
• Ability to participate in the study based on overall health of the patient and disease prognosis, as applicable, in the opinion of the Investigator; and able to comply with all requirements of the protocol, including completion of study questionnaires.

You may not qualify if:

• Epilepsy and currently on medication.
• Clinically significant abnormalities in 12 lead ECG, in the opinion of the Investigator.
• Breastfeeding or pregnant at Screening or planning to become pregnant at any time during the study.
• Intolerable amifampridine-related side effects
• Treatment with an investigational drug (other than amifampridine) or device while participating in this study.
• Any medical condition that, in the opinion of the Investigator, might interfere with the patient's participation in the study, poses an added risk for the patient, or confound the assessment of the patient.

Sponsors & Collaborators

• Catalyst Pharmaceuticals, Inc.: lead

Study Sites (3)

Cleveland Clinic

Cleveland, Ohio, 44195, United States

Location

Univerity of Pennsylvania

Philadelphia, Pennsylvania, 19104, United States

Location

Department of Neuroimmunology and Neuromuscular Diseases Carlo Besta Neurological Institute Via Celoria

Milan, 11-201332, Italy

Location

MeSH Terms

Conditions

Myasthenia Gravis

Interventions

Amifampridine

Condition Hierarchy (Ancestors)

Paraneoplastic Syndromes, Nervous System; Nervous System Neoplasms; Neoplasms by Site; Neoplasms; Paraneoplastic Syndromes; Autoimmune Diseases of the Nervous System; Nervous System Diseases; Neurodegenerative Diseases; Neuromuscular Junction Diseases; Neuromuscular Diseases; Autoimmune Diseases; Immune System Diseases

Intervention Hierarchy (Ancestors)

4-Aminopyridine; Aminopyridines; Amines; Organic Chemicals; Pyridines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds

Limitations and Caveats

The study was terminated due to lack of measure appropriate data. The analysis of the MG-ADL score was removed in Statistical Analysis Plan (SAP), dated 21FEB2023.

Results Point of Contact

• Title: Gary Ingenito, MD, Chief Medical Officer
• Organization: Catalyst Pharmaceuticals, Inc.

gingenito@catalystpharma.com

3054203200

Study Officials

• Renato Mantegazza, MD

  Carlo Besta Neurological Institute

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 5, 2018
• First Posted: July 9, 2018
• Study Start: June 11, 2018
• Primary Completion: August 5, 2022
• Study Completion: August 5, 2022
• Last Updated: May 7, 2024
• Results First Posted: May 7, 2024

Record last verified: 2024-04

Data Sharing

• IPD Sharing: Will not share

Locations

US (2); IT (1)