Expanded Access Study of Amifampridine Phosphate for Lambert-Eaton Myasthenic Syndrome (LEMS) and Congenital Myasthenic Syndrome (CMS)
Sponsor: Catalyst Pharmaceuticals, Inc.
ClinicalTrials ID:NCT02189720
This study provides access to amifampridine phosphate for patients with LEMS and CMS, focusing on long-term safety and effectiveness until the drug becomes widely available.
Patient Parameters
| Parameter | Options |
|---|
Program Overview
The main goal of this study is to allow doctors to use amifampridine phosphate to treat patients with Lambert-Eaton Myasthenic Syndrome (LEMS) and Congenital Myasthenic Syndrome (CMS) until the medication is available on the market. The study also aims to gather information on the long-term safety of the drug in both children and adults with these conditions.
Description
This study involves multiple centers and is designed to give doctors access to amifampridine phosphate for treating patients with LEMS, CMS, or downbeat nystagmus until the drug is commercially available. Since these are ongoing conditions, the study collects long-term safety data by monitoring side effects, physical exams, vital signs, and standard lab tests like blood and urine tests. Pregnancy tests and heart monitoring (ECG) are also part of the routine care provided by the patient's doctor.
The study planned to involve 100 sites in the US and up to 200 patients, but actually activated 50 sites with 200 patients enrolled. Patients were seen at the start, on Day 1, and at least once a year. Due to COVID-19, some visits were done via phone or video calls. Follow-up visits included physical exams, vital signs, lab tests, pregnancy tests, and ECGs.
Patients received a personalized dose of amifampridine phosphate based on the doctor's assessment. For those already on amifampridine, the new drug was started at an equivalent or lower dose. Doses ranged from 10 to 80 mg per day, divided into 2 to 4 doses, with a maximum single dose of 20 mg. The dose could be increased every 4 to 5 days up to a maximum of 80 mg per day for those over 16 years old, and 60 mg for those aged 2 to 16 years. The drug was initially given at the clinic, with subsequent doses sent to the patient's home.
In addition to amifampridine phosphate, patients received the best supportive care, which could include medications like prednisone or other corticosteroids, azathioprine, and pyridostigmine. Changes to this care were allowed as long as they didn't involve prohibited medications.
Firdapse® was approved for adult LEMS patients in November 2018 and for pediatric patients aged 6 and older in September 2022. The drug was not pursued for CMS and downbeat nystagmus.
Eligibility Criteria
Inclusion Criteria
- Male or female with a confirmed genetic diagnosis of CMS.
- Negative pregnancy test for females who can have children.
- If sexually active and able to have children, must use two forms of birth control during the study and for three months after the last dose.
- Willing to provide written consent after understanding the study details.
Exclusion Criteria
- History of epilepsy and currently on treatment for it.
- Certain CMS subtypes like slow-channel syndrome, LRP4 deficiency, and acetylcholinesterase deficiency.
- Current use of certain medications like dalfampridine or other forms of 3,4 DAP, unless willing to stop for the study.
- Use of guanidine hydrochloride within 7 days before starting the study drug.
- Allergy to pyridine substances or ingredients in amifampridine phosphate.
- Use of other investigational drugs or devices within 30 days before starting the study.
- Recent ECG showing significant abnormalities.
- Pregnant, breastfeeding, or planning to become pregnant.
- Any condition that may lead to poor compliance or not completing the study.
Get This Program In Your Inbox
Receive detailed information about this treatment opportunity to review with your healthcare provider.