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See why FIRDAPSE is accessible and affordable for virtually every patient.

The recommended first-line therapy for patients living with Lambert-Eaton myasthenic syndrome (LEMS)1

Clinically proven to maintain muscle strength and mobility2-4

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The FIRDAPSE Pregnancy Registry: In conjunction with the FDA, Catalyst Pharmaceuticals has created a registry to collect information about the safety of FIRDAPSE use during pregnancy. Enroll patients with LEMS—even those not taking FIRDAPSE—as soon as you learn of their pregnancy by calling 1-855-212-5856 or visiting www.firdapsepregnancystudy.com.
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What Is LEMS?

LEMS is a rare, immune-mediated neuromuscular disorder that results in progressive, debilitating muscle weakness and fatigue.5,6
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About FIRDAPSE

The only FDA-approved treatment for LEMS that’s clinically proven to maintain muscle strength and improve patient reported sense of physical well-being vs placebo in clinical trials.2-4,7
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Watch LEMS experts discuss LEMS pathophysiology, clinical presentation, diagnostic challenges, and treatment options in our LEMS Video Library.
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Indication and Important Safety Information

indications and usage:

FIRDAPSE is a potassium channel blocker indicated for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) in adults and pediatric patients 6 years of age and older.

CONTRAINDICATIONS

FIRDAPSE is contraindicated in patients with:

  • A history of seizures
  • Hypersensitivity to amifampridine phosphate or another aminopyridine

WARNINGS AND PRECAUTIONS

Seizures: FIRDAPSE can cause seizures. Consider discontinuation or dose-reduction of FIRDAPSE in patients who have a seizure while on treatment.

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.

Please see full Prescribing Information for additional Important Safety Information.

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.

References:
  1. Yoon CH, Owusu-Guha J, Smith A, Buschur P. Amifampridine for the management of Lambert-Eaton myasthenic syndrome: a new take on an old drug. Ann Pharmacother. 2020;54(1):56-63.
  2. Full Prescribing Information for FIRDAPSE (amifampridine). Catalyst Pharma; 2022.
  3. Oh SJ, Scherbakova N, Kostera-Pruszczyk A, et al; LEMS Study Group. Amifampridine phosphate (FIRDAPSE®) is effective and safe in a phase 3 clinical trial in LEMS. Muscle Nerve. 2016;53(5):717-725.
  4. Shieh P, Sharma K, Kohrman B, Oh SJ. Amifampridine phosphate (FIRDAPSE®) is effective in a confirmatory phase 3 clinical trial in LEMS. J Clin Neuromuscul Dis. 2019;20(3):111-119.
  5. Harms L, Sieb J-P, Williams AE, et al. Long-term disease history, clinical symptoms, health status, and healthcare utilization in patients suffering from Lambert Eaton myasthenic syndrome: results of a patient interview survey in Germany. J Med Econ. 2012;15(3):521-530.
  6. Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) Guideline for Small Cell Lung Cancer (Version v3.2023). © National Comprehensive Cancer Network, Inc. 2022. All rights reserved. Accessed February 20, 2023. To view the most recent and complete version of the guideline, go to NCCN.org. NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way.
  7. Orange Book: Approved drug products with therapeutic equivalence evaluations. US Food and Drug Administration. 42nd ed. 2022:47,1260.
  8. Muppidi S, Wolfe GI, Barohn RJ. Diseases of the neuromuscular junction. In: Swaiman K, Ashwal S, Ferriero D, Schor N, eds. Pediatric Neurology: Principles and Practice. 5th ed. Philadelphia, PA: Elsevier; 2011:1549-1569.
  9. Senanayake N, Roman GC. Disorders of neuromuscular transmission due to natural environmental toxins. J Neurol Sci. 1992;107:1-13.
  10. National Organization for Rare Disorders (NORD) website. Rare disease database: Myasthenia gravis. Accessed December 9, 2022. https://rarediseases.org/rare-diseases/myasthenia-gravis/.
  11. Sanders DB. Lambert-Eaton myasthenic syndrome: diagnosis and treatment. Ann NY Acad Sci. 2003;998:500-508.
  12. Titulaer MJ, Lang B, Verschuuren JJ. Lambert-Eaton myasthenic syndrome: from clinical characteristics to therapeutic strategies. Lancet Neurol. 2011;10(12):1098-1107.
  13. Ghandhi L, Johnson BE. Paraneoplastic syndromes associated with small cell lung cancer. J Natl Compre Canc Netw. 2006;4(6):631-638.
  14. Titulaer MJ, Wirtz PW, Willems LNA, et al. Screening for small-cell lung cancer: a follow-up study of patients with Lambert-Eaton myasthenic syndrome. J Clin Oncol. 2008;26(26):4276-4281.
  15. Wirtz PW, Wintzen AR, Verschuuren JJ. Lambert-Eaton myasthenic syndrome has a more progressive course in patients with lung cancer. Muscle Nerve. 2005;32(2):226-229.
  16. Wirtz PW, Smallegange TM, Wintzen AR, Verschuuren JJ. Differences in clinical features between the Lambert-Eaton myasthenic syndrome with and without cancer: an analysis of 227 published cases. Clin Neurol Neurosurg. 2002;104(4):359-363.
  17. Tarr TB, Wipf P, Meriney SD. Synaptic pathophysiology and treatment of Lambert-Eaton myasthenic syndrome. Mol Neurolbiol. 2015;52(1):456-463.
  18. Meriney SD, Hulsizer SC, Lennon VA, Grinnell AD. Lambert-Eaton myasthenic syndrome immunoglobulins react with multiple types of calcium channels in small-cell lung carcinoma. Ann Neurol. 1996;40:739-749.
  19. Vincent A, Lang B, Newsom-Davis J. Autoimmunity to the voltage-gated calcium channel underlies the Lambert-Eaton myasthenic syndrome, a paraneoplastic disorder. TINS. 1989;12(12):496-502.
  20. Maddison P, Lang B, Mill K, Newsom-Davis J. Long term outcome in Lambert-Eaton myasthenic syndrome without lung cancer. J Neurol Neurosurg Psychiatry. 2001;70(2):212-217.
  21. Merino-Ramírez MÁ, Bolton CF. Review of the diagnostic challenges of Lambert-Eaton syndrome revealed through three case reports. Can J Neurol Sci. 2016;43(5):635-647.
  22. Gilhus NE. Lambert-Eaton myasthenic syndrome; pathogenesis, diagnosis, and therapy. Autoimmune Dis. 2011;2011:973808.
  23. Kesner VG, Shin JO, Dimachkie MM, Barohn RJ. Lambert-Eaton myasthenic syndrome. Neurol Clin. 2018;36(2):379-394.
  24. Lipka AF, Boldingh MI, van Zwet EW, et al. Long-term follow-up, quality of life, and survival of patients with Lambert-Eaton myasthenic syndrome. Neurology. 2020;94(5):e511-e520.
  25. Quartel A, Turbeville S, Lounsbury D. Current therapy for Lambert-Eaton myasthenic syndrome: development of 3,4-diaminopyridine phosphate salt as first-line symptomatic treatment. Curr Med Res Opin. 2010;26(6):1363-1375.
  26. Wirtz PW, Verschuuren JJ, van Dijk JG, et al. Efficacy of 3,4-diaminopyridine and pyridostigmine in the treatment of Lambert-Eaton myasthenic syndrome: a randomized, double-blind, placebo-controlled, crossover study. Clin Pharmacol Ther. 2009;86(1):44-48.
  27. Ivanovski T, Miralles F. Lambert-Eaton myasthenic syndrome: early diagnosis is key. Degener Neurol Neuromuscul Dis. 2019;9:27-37.
  28. Bain PG, Motomura M, Newsom-Davis J, et al. Effects of intravenous immunoglobulin on muscle weakness and calcium-channel autoantibodies in the Lambert-Eaton myasthenic syndrome. Neurology. 1996;47(3):678-683.
  29. Chalk CH, Murray NM, Newsom-Davis J, O'Neill JH, Spiro SG. Response of the Lambert-Eaton myasthenic syndrome to treatment of associated small-cell lung carcinoma. Neurology. 1990;40(10):1552-1556.
  30. Oh SJ, Sieb JP. Update on amifampridine as a drug of choice in Lambert-Eaton myasthenic syndrome. US J Neurol. 2014;10(2):83-89.
  31. Strupp M, Teufel J, Zwergal A, et al. Aminopyridines for the treatment of neurologic disorders. Neurol Clin Pract. 2017;7(1):65-76.
  32. Lindquist S, Stangel M. Update on treatment options for Lambert-Eaton myasthenic syndrome: focus on use of amifampridine. Neuropsychiatr Dis Treat. 2011;7:341-349.
  33. Data on file, Catalyst Pharmaceuticals.
  34. Kirsch GE, Narahashi T. 3,4-diaminopyridine. A potent new potassium channel blocker. Biophys J. 1978;22(3):507-512.
  35. Dodson PD, Forsythe ID. Presynaptic K+ channels: electrifying regulators of synaptic terminal excitability. TINS. 2004;27(4):210-217.
  36. Sudhof TC. Calcium control of neurotransmitter release. Cold Spring Harb Perspect Biol. 2012;4:a011353.
  37. Ojala KS, Ginebaugh SP, Wu M, et al. A high-infinity, partial antagonist effect of 3,4-diaminopyridine mediates action potential broadening and enhancement of transmitter release at NMJs. J Biol Chem. Published online January 17, 2021. doi: https://doi.org/10.1016/j.jbc.2021.100302.
  38. Kuo IY, Ehrlich BE. Signaling in muscle contraction. Cold Spring Harb Perspect Biol. 2015;47:a006023.
  39. Jacob S, Muppidi S, Guidon A, et al; International MG/COVID-19 Working Group. Guidance for the management of myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS) during the COVID-19 pandemic. J Neurol Sci. 2020;412:116803.

Indication and Important Safety Information

indications and usage:

FIRDAPSE is a potassium channel blocker indicated for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) in adults and pediatric patients 6 years of age and older.

CONTRAINDICATIONS

FIRDAPSE is contraindicated in patients with:

  • A history of seizures
  • Hypersensitivity to amifampridine phosphate or another aminopyridine

WARNINGS AND PRECAUTIONS

Seizures: FIRDAPSE can cause seizures. Consider discontinuation or dose-reduction of FIRDAPSE in patients who have a seizure while on treatment.

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.

Please see full Prescribing Information for additional Important Safety Information.

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.

References:
  1. Yoon CH, Owusu-Guha J, Smith A, Buschur P. Amifampridine for the management of Lambert-Eaton myasthenic syndrome: a new take on an old drug. Ann Pharmacother. 2020;54(1):56-63.
  2. Full Prescribing Information for FIRDAPSE (amifampridine). Catalyst Pharma; 2022.
  3. Oh SJ, Scherbakova N, Kostera-Pruszczyk A, et al; LEMS Study Group. Amifampridine phosphate (FIRDAPSE®) is effective and safe in a phase 3 clinical trial in LEMS. Muscle Nerve. 2016;53(5):717-725.
  4. Shieh P, Sharma K, Kohrman B, Oh SJ. Amifampridine phosphate (FIRDAPSE®) is effective in a confirmatory phase 3 clinical trial in LEMS. J Clin Neuromuscul Dis. 2019;20(3):111-119.
  5. Harms L, Sieb J-P, Williams AE, et al. Long-term disease history, clinical symptoms, health status, and healthcare utilization in patients suffering from Lambert Eaton myasthenic syndrome: results of a patient interview survey in Germany. J Med Econ. 2012;15(3):521-530.
  6. Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) Guideline for Small Cell Lung Cancer (Version v3.2023). © National Comprehensive Cancer Network, Inc. 2022. All rights reserved. Accessed February 20, 2023. To view the most recent and complete version of the guideline, go to NCCN.org. NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way.
  7. Orange Book: Approved drug products with therapeutic equivalence evaluations. US Food and Drug Administration. 42nd ed. 2022:47,1260.
  8. Muppidi S, Wolfe GI, Barohn RJ. Diseases of the neuromuscular junction. In: Swaiman K, Ashwal S, Ferriero D, Schor N, eds. Pediatric Neurology: Principles and Practice. 5th ed. Philadelphia, PA: Elsevier; 2011:1549-1569.
  9. Senanayake N, Roman GC. Disorders of neuromuscular transmission due to natural environmental toxins. J Neurol Sci. 1992;107:1-13.
  10. National Organization for Rare Disorders (NORD) website. Rare disease database: Myasthenia gravis. Accessed December 9, 2022. https://rarediseases.org/rare-diseases/myasthenia-gravis/.
  11. Sanders DB. Lambert-Eaton myasthenic syndrome: diagnosis and treatment. Ann NY Acad Sci. 2003;998:500-508.
  12. Titulaer MJ, Lang B, Verschuuren JJ. Lambert-Eaton myasthenic syndrome: from clinical characteristics to therapeutic strategies. Lancet Neurol. 2011;10(12):1098-1107.
  13. Ghandhi L, Johnson BE. Paraneoplastic syndromes associated with small cell lung cancer. J Natl Compre Canc Netw. 2006;4(6):631-638.
  14. Titulaer MJ, Wirtz PW, Willems LNA, et al. Screening for small-cell lung cancer: a follow-up study of patients with Lambert-Eaton myasthenic syndrome. J Clin Oncol. 2008;26(26):4276-4281.
  15. Wirtz PW, Wintzen AR, Verschuuren JJ. Lambert-Eaton myasthenic syndrome has a more progressive course in patients with lung cancer. Muscle Nerve. 2005;32(2):226-229.
  16. Wirtz PW, Smallegange TM, Wintzen AR, Verschuuren JJ. Differences in clinical features between the Lambert-Eaton myasthenic syndrome with and without cancer: an analysis of 227 published cases. Clin Neurol Neurosurg. 2002;104(4):359-363.
  17. Tarr TB, Wipf P, Meriney SD. Synaptic pathophysiology and treatment of Lambert-Eaton myasthenic syndrome. Mol Neurolbiol. 2015;52(1):456-463.
  18. Meriney SD, Hulsizer SC, Lennon VA, Grinnell AD. Lambert-Eaton myasthenic syndrome immunoglobulins react with multiple types of calcium channels in small-cell lung carcinoma. Ann Neurol. 1996;40:739-749.
  19. Vincent A, Lang B, Newsom-Davis J. Autoimmunity to the voltage-gated calcium channel underlies the Lambert-Eaton myasthenic syndrome, a paraneoplastic disorder. TINS. 1989;12(12):496-502.
  20. Maddison P, Lang B, Mill K, Newsom-Davis J. Long term outcome in Lambert-Eaton myasthenic syndrome without lung cancer. J Neurol Neurosurg Psychiatry. 2001;70(2):212-217.
  21. Merino-Ramírez MÁ, Bolton CF. Review of the diagnostic challenges of Lambert-Eaton syndrome revealed through three case reports. Can J Neurol Sci. 2016;43(5):635-647.
  22. Gilhus NE. Lambert-Eaton myasthenic syndrome; pathogenesis, diagnosis, and therapy. Autoimmune Dis. 2011;2011:973808.
  23. Kesner VG, Shin JO, Dimachkie MM, Barohn RJ. Lambert-Eaton myasthenic syndrome. Neurol Clin. 2018;36(2):379-394.
  24. Lipka AF, Boldingh MI, van Zwet EW, et al. Long-term follow-up, quality of life, and survival of patients with Lambert-Eaton myasthenic syndrome. Neurology. 2020;94(5):e511-e520.
  25. Quartel A, Turbeville S, Lounsbury D. Current therapy for Lambert-Eaton myasthenic syndrome: development of 3,4-diaminopyridine phosphate salt as first-line symptomatic treatment. Curr Med Res Opin. 2010;26(6):1363-1375.
  26. Wirtz PW, Verschuuren JJ, van Dijk JG, et al. Efficacy of 3,4-diaminopyridine and pyridostigmine in the treatment of Lambert-Eaton myasthenic syndrome: a randomized, double-blind, placebo-controlled, crossover study. Clin Pharmacol Ther. 2009;86(1):44-48.
  27. Ivanovski T, Miralles F. Lambert-Eaton myasthenic syndrome: early diagnosis is key. Degener Neurol Neuromuscul Dis. 2019;9:27-37.
  28. Bain PG, Motomura M, Newsom-Davis J, et al. Effects of intravenous immunoglobulin on muscle weakness and calcium-channel autoantibodies in the Lambert-Eaton myasthenic syndrome. Neurology. 1996;47(3):678-683.
  29. Chalk CH, Murray NM, Newsom-Davis J, O'Neill JH, Spiro SG. Response of the Lambert-Eaton myasthenic syndrome to treatment of associated small-cell lung carcinoma. Neurology. 1990;40(10):1552-1556.
  30. Oh SJ, Sieb JP. Update on amifampridine as a drug of choice in Lambert-Eaton myasthenic syndrome. US J Neurol. 2014;10(2):83-89.
  31. Strupp M, Teufel J, Zwergal A, et al. Aminopyridines for the treatment of neurologic disorders. Neurol Clin Pract. 2017;7(1):65-76.
  32. Lindquist S, Stangel M. Update on treatment options for Lambert-Eaton myasthenic syndrome: focus on use of amifampridine. Neuropsychiatr Dis Treat. 2011;7:341-349.
  33. Data on file, Catalyst Pharmaceuticals.
  34. Kirsch GE, Narahashi T. 3,4-diaminopyridine. A potent new potassium channel blocker. Biophys J. 1978;22(3):507-512.
  35. Dodson PD, Forsythe ID. Presynaptic K+ channels: electrifying regulators of synaptic terminal excitability. TINS. 2004;27(4):210-217.
  36. Sudhof TC. Calcium control of neurotransmitter release. Cold Spring Harb Perspect Biol. 2012;4:a011353.
  37. Ojala KS, Ginebaugh SP, Wu M, et al. A high-infinity, partial antagonist effect of 3,4-diaminopyridine mediates action potential broadening and enhancement of transmitter release at NMJs. J Biol Chem. Published online January 17, 2021. doi: https://doi.org/10.1016/j.jbc.2021.100302.
  38. Kuo IY, Ehrlich BE. Signaling in muscle contraction. Cold Spring Harb Perspect Biol. 2015;47:a006023.
  39. Jacob S, Muppidi S, Guidon A, et al; International MG/COVID-19 Working Group. Guidance for the management of myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS) during the COVID-19 pandemic. J Neurol Sci. 2020;412:116803.
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