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Multicenter, double-blind, placebo-controlled, Randomized phase III study with an open phase extension of amifampridine phosphate (3,4-Diaminopyridine Phosphate) in patients with Lambert-Eaton myasthenic syndrome (LEMS)

Phase 1
Conditions
ambert-Eaton Myasthenic Syndrome (LEMS)
MedDRA version: 14.1Level: LLTClassification code 10067685Term: Lambert-Eaton myasthenic syndromeSystem Organ Class: 100000004852
Therapeutic area: Diseases [C] - Nervous System Diseases [C10]
Registration Number
EUCTR2010-021850-20-DE
Lead Sponsor
Catalyst Pharmaceutical Partners, Inc.
Brief Summary

Not available

Detailed Description

Not available

Recruitment & Eligibility

Status
ot Recruiting
Sex
All
Target Recruitment
79
Inclusion Criteria

• =18 years of age.
• Confirmed diagnosis of LEMS as documented by acquired (typical) proximal muscle weakness and at least 1 of the following:
o Nerve conduction findings (CMAP that increases at least 2-fold after maximum voluntary contraction of the tested muscle)
o Positive anti-P/Q type voltage-gated calcium-channel antibody test
• If currently receiving treatment with amifampridine for LEMS, a normal respiratory function as defined by an FVC = 80% of predicted.
• If not currently receiving treatment with amifampridine for LEMS and patient has no history of other current respiratory disease, an FVC of = 60% of predicted.
• Normal swallowing function as defined by the ability to swallow 4 ounces of water without coughing or throat clearing (score of 0 on this dimension of QMG).
• Completion of anti-cancer treatment at least 3 months (90 days) prior to Screening.
• A QMG score of = 5 is required for patients without any prior symptomatic treatment for LEMS.
• If currently receiving treatment for LEMS, patients must present with some signs and/or symptoms consistent with LEMS.
• If receiving peripherally acting cholinesterase inhibitors (eg, pyridostigmine), a stable dose of cholinesterase inhibitors is required for at least 7 days prior to Screening.
• If receiving permitted oral immunosuppressants (eg, prednisone or other corticosteroid, azathioprine, mycophenolate), a stable dose is required for at least 90 days prior to Screening.
• Negative pregnancy test for females of childbearing potential at Screening.
• If sexually active, willing to use 2 acceptable methods of contraception from Screening until 3 months after the last dose.
• Willing to perform all study procedures as physically possible.
• Willing and able to provide written informed consent after the nature of the study has been explained and prior to the start of any researchrelated procedures.
Are the trial subjects under 18? no
Number of subjects for this age range:
F.1.2 Adults (18-64 years) yes
F.1.2.1 Number of subjects for this age range 46
F.1.3 Elderly (>=65 years) yes
F.1.3.1 Number of subjects for this age range 33

Exclusion Criteria

• History of epilepsy or seizure (including 1 time seizure, but excluding generalized febrile seizures occurring before the age of 5 years).
•Known active brain metastasis. Patients with treated brain metastasis (radiotherapy and /or surgery) who have completed treatment for their brain metastasis > 90 days prior to Screening, are neurologically stable (neurological symptoms grade = 1), are on a stable dose of corticosteroids, and have no evidence of new disease on magnetic resonance imaging (MRI), are eligible provided they meet the other inclusion/exclusion of the study.
•Concurrent use of fampridine (4-aminopyridine), and any form of 3,4 diaminopyridine other than the IP provided, such as amifampridine base or FirdapseTM, during the study.
•Use of medications known to lower the epileptic threshold (eg, antidepressants such as tricyclics and bupropion; neuroleptics such as phenothiazines, butyrophenones, clozapine, olanzapine, quetiapine; immunosuppressants such as cyclosporine, tacrolimus; centrally active cholinesterase inhibitors such as donepezil, rivastigmine, galantamine; mefloquine) within 7 days or 5 half-lives, whichever is longer, prior to Screening.
- Selected antidepressants of the selective serotonin uptake inhibitor (SSRI) class and tramadol are acceptable provided the dose regimen has been stable (not as needed) for > 90 days prior to Screening without evidence of seizure.
•Use of medications which inhibit neuromuscular junction function within 7 days or 5 half-lives, whichever is longer, prior to Screening.
•Use of intravenous immunoglobulin (IVIG), plasmapheresis (plasma exchange), or immunoadsorption within 90 days prior to Screening.
•Use of guanidine hydrochloride within 7 days of Screening.
•Use of rituximab within 12 months prior to Screening.
•History of drug allergy to any pyridine-containing substances or any amifampridine phosphate excipient(s).
•Use of any investigational product (other than amifampridine base or phosphate) or an investigational medical device within 30 days prior to Screening or requirement for any investigational agent prior to completion of all scheduled study assessments.
•Treatment with a concomitant medication that prolongs the QT wave (QT)/ QT wave corrected for heart rate (QTc) interval within 7 days or 5 half-lives, whichever is longer, prior to Screening.
•Treatment with sultopride (4-amino-N-[(1-ethylpyrrolidin-2-yl)methyl]-5-ethylsulfonyl-2-methoxybenzamide) within 7 days prior to Screening.
•An ECG at Screening that, in the opinion of the external reviewing cardiologist, shows any of the following:
- Sinus arrhythmia with unacceptable rate variation (eg, > 20% RR variability)
- Excessive heart rate variation at rest
- QT wave corrected for heart rate using Bazett’s formula (QTcB) interval > 450 msec confirmed by a repeat ECG
- PR interval > 210 msec
- QRS interval > 120 msec if 35 years of age or younger, or > 110 msec if over 35 years
- Early repolarization pattern that increases the risk of participating in the study.
•Documented history of arrhythmias (eg, ventricular arrhythmias and atrial fibrillation).
•History of additional risk factors for TdP (eg, history of surviving a near drowning due to loss of consciousness, family history of congenital QT syndrome, Long QT Syndrome, family history of unexplained early sudden death, heart failure).
•Breastfeeding or pregnant at Screening or planning to become pregnant (self or partner) at any time during th

Study & Design

Study Type
Interventional clinical trial of medicinal product
Study Design
Not specified
Primary Outcome Measures
NameTimeMethod
Secondary Outcome Measures
NameTimeMethod
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