Long Term Safety of Amifampridine Phosphate in Spinal Muscular Atrophy 3

Phase 2

Terminated

• Conditions: Spinal Muscular Atrophy Type 3
• Interventions: Drug: Amifampridine Phosphate 10 MG Oral Tablet

• Registration Number: NCT03819660
• Lead Sponsor: Catalyst Pharmaceuticals, Inc.

Brief Summary

A long term safety study of amifampridine phosphate in patients with spinal muscular atrophy (SMA) Type 3.

Detailed Description

This open-label outpatient extension study was designed to evaluate the long-term safety and tolerability of amifampridine in patients diagnosed with SMA Type 3. In addition, the evaluation of the effects of amifampridine on the QoL was performed. The study was planned to enroll those patients who had completed the SMA-001 study and after all final evaluations for that study had been completed, or those who demonstrated benefit after completing the dose titration period but failed to meet the randomization criteria on Day 0 of SMA-001.

The duration of participation for each patient was expected to be at least 12 months as patients could continue in the study until amifampridine was approved by Regulatory Agencies or the clinical development of amifampridine was terminated for this indication. In addition to amifampridine, patients continued to receive previous concomitant medications, as needed.

Study Timeline

• Study First Submitted: 2019-01-23
• Study First Submitted QC: 2019-01-24
• Study First Posted: 2019-01-28
• Study Start: 2019-03-07
• Primary Completion: 2021-09-13
• Study Completion: 2021-09-13
• Results First Submitted: 2023-09-01
• Status Verified: 2023-11
• Results First Submitted QC: 2023-11-29
• Last Update Submitted: 2023-11-29
• Results First Posted: 2023-11-30
• Last Update Posted: 2023-11-30

Recruitment & Eligibility

• Status: TERMINATED
• Sex: All
• Target Recruitment: 13

Inclusion Criteria

Individuals eligible to participate in this study must meet all the following inclusion criteria:

1. Participated in the SMA-001 study
2. 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.
3. Female patients of childbearing potential must have a negative pregnancy test (urine human chorionic gonadotropin [HCG] at the end of SMA-001 study); and must practice an effective, reliable contraceptive regimen during the study and for up to 30 days following discontinuation of treatment.
4. 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.

Exclusion Criteria

Individuals who met any of the exclusion criteria in the original protocol or those listed below are not eligible to participate in the study:

1. Epilepsy and currently on medication.
2. Uncontrolled asthma.
3. Concomitant use with sultopride.
4. Concomitant use with medicinal products with a narrow therapeutic window.
5. Concomitant use with medicinal products with a known to cause QTc prolongation.
6. Clinically significant abnormalities in 12 lead ECG, in the opinion of the Investigator.
7. Subjects with congenital QT syndromes.
8. Breastfeeding or pregnant at Screening or planning to become pregnant at any time during the study.
9. Intolerable amifampridine-related side effects
10. Treatment with an investigational drug (other than amifampridine) or device while participating in this study.
11. 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.
12. History of drug allergy to any pyridine-containing substances or any amifampridine excipient(s).

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
amifampridine phosphate	Amifampridine Phosphate 10 MG Oral Tablet	The dose of amifampridine was based on optimal neuromuscular benefit determined from the Run-in Period from SMA-001 or could be modified as the discretion of the Investigator. The maximum single dose was 20 mg. The dose range for patients 6 to 16 years of age was 15 to 60 mg, and for those 17 years and older the range was from 30 to 80 mg daily.

Primary Outcome Measures

Name	Time	Method
Long-term Safety and Tolerability of Amifampridine	18 months	Number of subjects with treatment emergent adverse events (TEAE).

Secondary Outcome Measures

Name	Time	Method
To Assess the Clinical Efficacy of Amifampridine Phosphate Over Time in Patients With SMA Type 3 Based on Changes in Quality of Life (QoL).	Screening to end of study.	Quality of life (QoL): the Individualized Quality of Life for neuromuscular disease (INQoL) or the Pediatric Quality of Life (PEDSQLTM) was used for adult or pediatric patients, respectively. Since there were no pediatric patients, none of the patients completed the PEDSQL.; The INQol evaluated weakness, pain, fatigue, double vision, muscle locking, droopy eyelids, swallowing difficulties, activities, social relationships, emotions and body image. Each of these areas were measured in four categories as follows: 1- Incidence (0= No, 1 =Yes), 2-Severity (0= None to 7 = extreme), 3- Impact - (0= None to 6 = extreme) and 4-Importance (0= None to 6 = extreme). The numbers were summative and are input to the QOL calculation, which is a percentage of severity on a scale of 0-100. The mean value was taken across this population. The higher scores were a worse outcome.

Trial Locations

Locations (1)

Neurological Institute Carlo Besta; 🇮🇹 Milano, Lombardy, Italy