Last updated: February 20, 2026
What is NDC 51991-0292?
NDC 51991-0292 is a drug marketed under the brand name Firdapse (amifampridine). It is an approved treatment for Lambert-Eaton Myasthenic Syndrome (LEMS), a rare autoimmune disorder affecting neuromuscular transmission.
Market Overview
Patient Population Size
- LEMS prevalence: approximately 3 to 4 cases per million globally.
- Estimated U.S. patient count: 1,000 to 2,000 individuals.
- Pediatric cases are rare; predominantly adult patients.
Competitive Landscape
- Only one FDA-approved drug: Firdapse (amifampridine).
- Off-label treatments include immunosuppressants and muscle-strengthening agents.
- Generic market entry unlikely soon due to patent protections and exclusivity.
Key Players
- Catalyst Pharmaceuticals is the sole manufacturer and marketer.
- No direct competitors with approved drugs for LEMS.
Pricing Data and Historical Trends
Current Wholesale Acquisition Cost (WAC)
- As of 2023, retail price per 30-count tablet (10 mg): approximately $900.
- Monthly treatment cost (~90 tablets): roughly $27,000.
- Annual cost: approximately $324,000 per patient.
Price Trends
- Price increases observed over the past five years.
- Price adjustments driven by manufacturing costs, rarity of indication, and limited competition.
Market Penetration
- Estimated U.S. prescriptions per year: 1,200 to 1,500.
- Market share: Catalyst holds near 100% due to sole approval.
Revenue Projections and Growth
| Year |
Estimated Patients |
Revenue (USD) |
Notes |
| 2023 |
1,200 |
388.8 million |
Based on $324,000 per patient/year |
| 2024 |
1,250 |
405 million |
Slight increase in prescriptions |
| 2025 |
1,300 |
422.4 million |
Continued growth expected |
| 2026 |
1,350 |
438.6 million |
Market stabilization |
Assumptions
- No significant price reduction.
- No new competitors or generics.
- Prescriptions sustain growth at 4-5% annually.
Regulatory and Patent Considerations
- Patent protection until at least 2025; no current expirations.
- Orphan drug designation confers seven years of market exclusivity post-approval.
- Potential for new formulations or delivery methods to extend exclusivity.
Price Projections Outlook
- Near-term (1-2 years): Prices remain stable at ~$900 per tablet.
- Mid-term (3-5 years): Potential for slight increases (~3-5% annually) driven by inflation and manufacturing costs.
- Long-term (5+ years): Price reductions unlikely without significant patent expiration or biosimilar entry due to market exclusivity.
Key Drivers of Market Dynamics
- Rare disease exclusivity maintains high pricing.
- Limited competition sustains current price points.
- Growth driven by increased diagnosis and awareness.
Risks and Challenges
- Patent expiration could lead to generic entries and price erosion.
- Regulatory changes affecting orphan drug status.
- Market saturation if diagnosis rates plateau.
Key Takeaways
- NDC 51991-0292 (Firdapse) currently commands high prices due to market exclusivity and limited competition.
- The patient base remains small but consistent, with upticks driven by better diagnosis.
- Revenue projections rely on stable pricing and growing prescription volumes.
- Price reductions are unlikely without patent expiration or regulatory changes.
- Future market growth depends on patient access, disease awareness, and potential pipeline developments.
FAQs
Q1: What is the typical treatment cost for a patient using NDC 51991-0292?
A: Approximately $324,000 annually, based on current wholesale prices.
Q2: Are generic versions of Firdapse available?
A: No. Patent protections and orphan drug exclusivity prevent generics until at least 2025.
Q3: How many patients are treated with this drug in the U.S.?
A: Estimated 1,200 to 1,500 patients annually.
Q4: What are the main factors influencing price stability?
A: Market exclusivity, limited competition, and high treatment costs for a rare disease.
Q5: What are the prospects for price declines in the next five years?
A: Limited, unless patent protections expire or regulatory changes occur.
References
[1] FDA. (2021). Firdapse (amifampridine) drug approval information.
[2] Catalyst Pharmaceuticals. (2023). Annual financial report.
[3] SSR Health. (2023). Brand drug pricing data.
[4] Orphan Drug Database. (2023). Market exclusivity and patent coverage details.
[5] Global Rare Disease Data. (2022). Epidemiology and patient demographics.
