Neuromuscular junction (NMJ) disorders may be the result of exposure to certain toxins, immune-mediated diseases, or genetic disorders.7
SYMPTOMS
LEMS is a rare autoimmune neuromuscular disorder characterized by debilitating and progressive muscle weakness and fatigue.4,5 See more on the LEMS Symptoms Map.
BURDEN
LEMS results in diminished physical functioning, impairments in activities of daily living (ADL), and patients’ quality of life.7-10
PREVALENCE
LEMS affects up to 3,000 people in the US8—up to 50% of whom are currently undiagnosed or misdiagnosed.8,11
COMORBIDITY
LEMS is associated with an underlying cancer, usually small cell lung cancer, in up to 60% of cases.12,13 This paraneoplastic form of LEMS typically has a faster progression of symptoms than non-tumor LEMS.14 Because LEMS symptoms often precede tumor detection by months or years, LEMS patients’ lives may be saved by an earlier diagnosis and treatment of the cancer.
PATHOPHYSIOLOGY
LEMS is caused by autoantibodies to presynaptic P/Q-type voltage-gated calcium channels (VGCCs) that reduce the release of acetylcholine into the NMJ, inhibiting neuromuscular transmission.4,8,11
75% reported partial or total restriction in activities of daily living, such as rising from a chair or climbing stairs9
58% were hospitalized prior to diagnosis, while >90% were hospitalized after diagnosis9
More than 50% reported severe leg weakness, dry mouth, and difficulty focusing their sight9
Based on EQ-5D scores, the health-related quality of life for LEMS patients is comparable to the most severe forms of multiple sclerosis9
58% of patients were misdiagnosed at least once in a cohort of 241 adult patients with LEMS.11
The symptoms of LEMS are often mistaken for more common diseases and disorders, such as myasthenia gravis (MG), multiple sclerosis (MS), myopathies, fibromyalgia, amyotrophic lateral sclerosis (ALS), and depression.10,11
Prevalence of misdiagnoses among patients with LEMS11
indications and usage:
FIRDAPSE is a potassium channel blocker indicated for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) in adults.
CONTRAINDICATIONS
FIRDAPSE is contraindicated in patients with:
WARNINGS AND PRECAUTIONS
Seizures: FIRDAPSE can cause seizures. Consider discontinuation or dose-reduction of FIRDAPSE in patients who have a seizure while on treatment. FIRDAPSE is contraindicated in patients with a history of seizures.
Hypersensitivity: If a hypersensitivity reaction such as anaphylaxis occurs, FIRDAPSE should be discontinued and appropriate therapy initiated.
ADVERSE REACTIONS
The most common (> 10%) adverse reactions are: paresthesia, upper respiratory tract infection, abdominal pain, nausea, diarrhea, headache, elevated liver enzymes, back pain, hypertension, and muscle spasms.
To report SUSPECTED ADVERSE REACTIONS, contact Catalyst Pharmaceuticals at 1-844-347-3277 (1-844-FIRDAPSE) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
indications and usage:
FIRDAPSE is a potassium channel blocker indicated for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) in adults.
CONTRAINDICATIONS
FIRDAPSE is contraindicated in patients with:
WARNINGS AND PRECAUTIONS
Seizures: FIRDAPSE can cause seizures. Consider discontinuation or dose-reduction of FIRDAPSE in patients who have a seizure while on treatment. FIRDAPSE is contraindicated in patients with a history of seizures.
Hypersensitivity: If a hypersensitivity reaction such as anaphylaxis occurs, FIRDAPSE should be discontinued and appropriate therapy initiated.
ADVERSE REACTIONS
The most common (> 10%) adverse reactions are: paresthesia, upper respiratory tract infection, abdominal pain, nausea, diarrhea, headache, elevated liver enzymes, back pain, hypertension, and muscle spasms.
To report SUSPECTED ADVERSE REACTIONS, contact Catalyst Pharmaceuticals at 1-844-347-3277 (1-844-FIRDAPSE) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.