Last updated: March 1, 2026
What is NDC 13668-0539?
NDC 13668-0539 refers to a specific pharmaceutical product listed in the U.S. National Drug Code (NDC) database. This product is identified as a proprietary drug, with detailed information including manufacturer, formulation, strength, and packaging, which are critical for analyzing its market position.
According to publicly available data, NDC 13668-0539 corresponds to Amifampridine, marketed under the brand name Firdapse by Catalyst Pharmaceuticals. It is approved for the treatment of Lambert-Eaton Myasthenic Syndrome (LEMS), a rare neuromuscular disorder.
Market Overview
Current Market Size
The global neuromuscular disorder treatment market was valued at approximately $3 billion in 2022, with a compound annual growth rate (CAGR) of 4.7% projected through 2030 [1].
Specifically, for LEMS:
- Estimated patient population in the U.S.: 1,000–2,500 individuals.
- Estimated annual treatment price: $375,000 per patient (based on Firdapse pricing).
Market Drivers
- Increased diagnosis rates due to heightened awareness.
- Off-label use in other neuromuscular disorders.
- Growing availability of orphan drug designations.
Competitive Landscape
| Product |
Manufacturer |
Approval Year |
Price per treatment |
Indications |
| Firdapse |
Catalyst Pharmaceuticals |
2018 |
~$375,000 |
LEMS |
| Bonnelex (related |
Jacobus Pharmaceuticals |
2020 |
~$350,000 |
LEMS (generic alternative) |
| Alternative therapies |
Off-label drugs, experimental treatments |
N/A |
Varies |
Neuromuscular disorders |
Key Factors Influencing Market Size
- Market exclusivity: Catalyst's Orphan Drug status grants exclusivity until 2028.
- Pricing strategies: Catalyst maintains high pricing to recoup R&D and regulatory costs.
- Subscription and insurance coverage: Limited patient access impacts sales volume.
Price Projections
Current Pricing and Revenue
- The current annual treatment cost: $375,000.
- Estimated U.S. patient market: 1,500 (midpoint estimate).
- Estimated U.S. market revenue: $562.5 million annually (1,500 patients x $375,000).
Short-Term Price Trends (Next 2 Years)
- Price stabilization anticipated unless new competitors emerge.
- Catalyst confident in maintaining premium pricing due to lack of direct substitutes.
- Potential for price erosion if biosimilars or generics gain approval post-2028.
Medium- to Long-Term Projections (3–10 Years)
| Scenario |
Assumptions |
Price Estimate |
Revenue Estimate (for 1,500 patients) |
| Best-case |
No biosimilar entry; 5% annual price increase |
$414,000 (2025) |
$621 million |
| Base-case |
Price remains flat; market growth 2% annually |
$375,000 |
$562.5 million |
| Worst-case |
Entry of biosimilars or generics reduces price by 25%; market shrinkage to 1,200 patients |
$281,250 |
$337.5 million |
Influencing Factors
- Patent and regulatory exclusivity expiration (2028) could accelerate biosimilar entry.
- Changes in healthcare policy and pricing reforms.
- Advances in alternative therapies possibly reducing market share.
Regulatory and Policy Impact
- The FDA approved Firdapse in 2018 under orphan drug designation.
- Future policy reforms targeting drug pricing transparency could affect revenue.
- Biosimilar pathway development may lead to increased competition post-2028.
Strategic Recommendations
- Catalyst should prepare for potential biosimilar competition post-2028 by exploring patent extensions.
- Engage with payers to reinforce the drug’s value proposition and justify high pricing.
- Monitor emerging therapies for LEMS and related conditions to adapt to market shifts.
Key Takeaways
- NDC 13668-0539 (Firdapse) commands a high price point, reflective of rare disease status and limited competition.
- The U.S. market revenue estimate approaches $563 million annually, with growth driven by increased diagnosis and treatment adoption.
- Price projections suggest stability until 2028, when biosimilar competition could prompt significant price declines.
- Regulatory exclusivity and orphan drug status are core to current market dominance.
- Long-term success relies on patent management, policy landscape, and competitive differentiation.
FAQs
1. What factors could cause Firdapse’s price to decline?
Introduction of biosimilars or generics after patent expiration, changes in reimbursement policies, and the availability of alternative therapies.
2. How many patients are treated annually with NDC 13668-0539?
Approximately 1,200 to 1,500 patients in the U.S., based on prevalence estimates.
3. What is the main driver of the high drug price?
Rare disease designation grants market exclusivity, allowing the manufacturer to set premium pricing.
4. Are there approved biosimilars for NDC 13668-0539?
As of now, biosimilars are under development but not yet approved; their entry is expected post-2028.
5. How does Catalyst Pharmaceuticals plan to sustain market share?
By extending patent protections, engaging payers for coverage, and expanding indications through clinical trials.
References
[1] MarketWatch. (2022). "Global neuromuscular disorder treatment market size." Retrieved from https://www.marketwatch.com
[2] U.S. Food & Drug Administration. (2018). “FDA approves Firdapse for Lambert-Eaton myasthenic syndrome.”
[3] Catalyst Pharmaceuticals. (2022). Annual Report.
[4] IQVIA. (2022). "Pharmaceutical Market Outlook."
