Catalyst Pharmaceuticals Applauds NCCN Guideline Update Adding LEMS Diagnosis And Amifampridine Support For SCLC Patients

• VGCC antibody testing in conjunction with neurologic consultation can diagnose LEMS
• Amifampridine may be considered as a supportive care treatment
• Guideline inclusion may raise clinical awareness of cancer-associated LEMS to support broader VGCC diagnostic testing and treatment adoption
  
  
  
   

CORAL GABLES, Fla., Aug. 06, 2025 (GLOBE NEWSWIRE) -- Catalyst Pharmaceuticals, Inc. ("Catalyst" or "Company") (NASDAQ:CPRX), a commercial-stage biopharmaceutical company focused on in-licensing, developing, and commercializing novel medicines for patients living with rare and difficult-to-treat diseases, today announced the National Comprehensive Cancer Network® (NCCN) Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Small Cell Lung Cancer (SCLC) now include new additions involving Lambert Eaton myasthenic syndrome (LEMS), amifampridine (FIRDAPSE®), and the tests for PQ- and N-type voltage-gated calcium channel (VGCC) antibodies.

The updated NCCN Clinical Practice Guidelines in Oncology for SCLC relating to LEMS now include symptom specificity—characterized by proximal muscle weakness and autonomic dysfunction. Under "Signs and Symptoms of Small Cell Lung Cancer" (SCL-A 2 of 2), the guidelines recommend diagnosis through a neurological evaluation, ideally in consultation with a neurologist, which may include testing for PQ- and N-type VGCC antibodies. Additionally, under "Principles of Supportive Care" (SCL-D), the guidelines recommend that amifampridine should be considered as a treatment in consultation with neurology.1

Approximately 50 percent of LEMS cases are associated with an underlying malignancy, most commonly SCLC. Literature suggests that LEMS is observed in 3 percent of SCLC patients. Based on an internal healthcare database analysis of SCLC claims, potentially 90 percent of LEMS patients with SCLC went undiagnosed. These undiagnosed LEMS patients may suffer from LEMS symptoms while undergoing treatment for SCLC.