Last updated: February 16, 2026
What is NDC 23635-0508?
NDC 23635-0508 is a pharmaceutical product identifiable through the National Drug Code (NDC) system. Based on available data, this NDC corresponds to Xyrem (sodium oxybate) oral solution, 500 mg/mL, used primarily for narcolepsy with cataplexy and, in some cases, treatment-resistant depression.
Market Size and Demand Drivers
Indications and Patient Population
Xyrem is approved by the FDA since 2002. Its primary market includes narcolepsy patients with cataplexy, estimated at 135,000 globally, with the U.S. accounting for approximately 62% of this figure ([1]). The drug's off-label expansion for conditions like treatment-resistant depression is nascent but unapproved.
Competitive Landscape
The market contains a limited number of drugs for narcolepsy, mainly modafinil and sodium oxybate. Xyrem’s market exclusivity stems from patent protections and safety profile. Influence from generic versions is minimal due to patent protections until 2024-2027, with some generics introduced in Europe but not yet in the U.S.
Market Trends
- Growing diagnosis rates due to increased awareness.
- Expanded use in sleep disorder clinics.
- Rising off-label use for depression, though not approved.
Current Pricing Structure
List Price
As of Q1 2023, a 30-day supply (assuming 4 grams per night, or 120 mL at 500 mg/mL) costs approximately $28,000. The pricing varies by pharmacy, insurance, and discounts.
Insurance Coverage
Insurance coverage is common but includes significant copays. The drug’s high price points create barriers, impacting adherence.
Reimbursement Trends
Medicare, Medicaid, and private insurers manage coverage. Price negotiations and patient assistance programs mitigate cost barriers.
Price Projections
Factors Influencing Price Trajectory
- Patent expiry: Patents for original formulations expire between 2024 and 2027, risking increased generic competition.
- Manufacturer strategies: Potential price reductions to maintain market share or maintain premium pricing due to safety and efficacy profiles.
- Regulatory changes: Any new approval or additional indications could influence pricing strategies.
Forecast Scenarios
| Scenario |
Timeframe |
Price Change |
Rationale |
| Status Quo Maintained |
2023–2025 |
Stable or slight decrease (~5%) |
No generic competition, established demand |
| Introduction of Generics |
2024–2025 |
Price drop of 20-30% |
Patent expiry permits generics entering the U.S. market |
| Post-Patent Competition |
2026–2027 |
Further decrease (~40%) |
Increased generic presence, price competition |
| Market-Based Premiums |
2024–2027 |
Possible price stabilization (~10%) |
Brand manufacturer applies strategies to preserve margins |
Premium Pricing Justification
Xyrem’s abuse potential mitigation, requiring REMS (Risk Evaluation and Mitigation Strategies), sustains a premium pricing model longer than typical generics.
Risks and Opportunities
-
Risks
- Rapid generic entry post-patent expiry.
- Adverse regulatory decisions or safety concerns.
- Policy changes impacting reimbursement or pricing.
-
Opportunities
- New indications could extend exclusivity or justify premium pricing.
- Development of biosimilars or long-acting formulations.
- International expansion, notably in European markets.
Competitive Pricing Strategies
-
Brand Manufacturer
Maintain high price levels, leverage REMS to limit access, and introduce reformulations to extend exclusivity.
-
Generics
Enter at a lower price point, potentially reducing Xyrem's market share but capturing a segment of cost-sensitive patients.
-
Payers
Push for negotiated discounts, especially as generics enter.
Conclusion
Xyrem (NDC 23635-0508) is positioned as a high-cost drug primarily for narcolepsy. Its current price reflects exclusivity, safety protocols, and limited competition. Projected price declines correlate strongly with patent expiration, expected around 2024–2027. Careful regulatory and market developments will shape the trajectory.
Key Takeaways
- The current average wholesale price for a 30-day supply is approximately $28,000.
- Patent expiration from 2024 to 2027 will likely lead to significant generic price erosion.
- Market demand remains stable, driven by narcolepsy prevalence and off-label use.
- Pricing strategies over the next 2–4 years will depend on competition and regulatory landscape.
- International markets may provide additional revenue streams independent of U.S. patent laws.
FAQs
1. When does patent protection for Xyrem expire?
Patent protections are set to expire between 2024 and 2027, opening the market to generics.
2. How might the entry of generics affect prices?
Prices could decline by 20-30%, reflecting competition but influenced by brand strategies and regulatory factors.
3. Are there any approved alternatives with similar efficacy?
Modafinil and armodafinil are alternatives but serve different indications; sodium oxybate remains the gold standard for narcolepsy with cataplexy.
4. What are the key regulatory considerations?
The REMS program is mandatory for distribution, impacting access and pricing. Any safety concerns could influence market dynamics.
5. Will international markets boost overall revenue?
Yes, especially in Europe and Asia where the drug is approved and less impacted by U.S. patent laws.
References
[1] National Institutes of Health, Narcolepsy Data.
