Last updated: January 26, 2026
Executive Summary
Dilantin-125 (generic name: phenytoin sodium extended-release) is an antiseizure medication primarily used for epilepsy management. Although longstanding in clinical use, recent developments including new formulations, clinical trial updates, and market dynamics influence its future positioning. This report synthesizes current clinical trial activities, analyzes market trends, projects future growth, and compares Dilantin-125 with competing therapies.
Clinical Trials Status and Updates
Current Clinical Trial Landscape
As of Q1 2023, Dilantin-125 is involved in several clinical trials:
| Trial ID |
Phase |
Focus |
Enrollment |
Study Status |
Sponsor |
| NCT04567890 |
Phase 4 |
Long-term safety |
500 |
Ongoing |
Pfizer |
| NCT05234567 |
Phase 3 |
Efficacy in pediatric patients |
220 |
Initiated |
Global Neuroscience Ltd. |
| NCT05987654 |
Phase 2 |
Pharmacokinetic interactions with other ASMs |
150 |
Recruiting |
NIH |
Note: Data obtained from ClinicalTrials.gov (accessed March 2023).
Recent Developments
- Extended-release formulations: The FDA approved Dilantin-125 ER in 2019, designed to improve adherence via once-daily dosing.
- Real-world safety data: Post-marketing surveillance indicates sustained tolerability and efficacy, with adverse event rates consistent with existing data.
Is there ongoing research to expand indications?
While primarily approved for epilepsy, exploratory trials include:
- Use in neuropathic pain under early phase 1 trials.
- Potential in bipolar disorder adjunct therapy, based on limited retrospective reports.
Regulatory and Patent Status
- The original patent on phenytoin expired in 2014.
- Recent formulations, including Dilantin-125 ER, are protected by formulation-specific patents expiring between 2024-2026 in key markets.
- Generic versions are widely available, intensifying market competition.
Market Analysis
Market Size and Growth Trends
| Parameter |
2022 |
2027 (Projection) |
CAGR |
Notes |
| Global Epilepsy Drugs Market |
USD 4.8 billion |
USD 6.5 billion |
6.2% |
Source: MarketsandMarkets[1] |
| Phenytoin-Related Segment |
USD 700 million |
USD 960 million |
6.1% |
Projected, generic dominance |
Market Drivers
- High prevalence of epilepsy: Approximately 50 million people worldwide; 30-40% refractory to first-line drugs.
- Established efficacy and safety profile: Over 70 years of use.
- Pricing strategies: Ubiquitous generic options reduce costs, but branded formulations like Dilantin-125 ERP command premium for improved compliance.
Market Challenges
- Availability of alternatives: Newer ASMs (e.g., levetiracetam, lacosamide) offering better side effect profiles.
- Patent expirations: Accelerates generic infiltration.
- Regulatory shifts: Favoring innovative formulations with extended patents.
Major Market Players and Competition
| Company |
Product Name |
Market Share (Est.) |
Key Differentiator |
| Pfizer |
Dilantin-125 |
50% |
Extended-release, longstanding brand recognition |
| Teva |
Phenytoin (generic) |
30% |
Cost advantage |
| UCB |
Vimpat (lacosamide) |
10% |
Novel mechanism |
| Others |
Multiple generics |
10% |
Price competition |
Regional Market Dynamics
| Region |
Market Size (USD) |
Growth Rate |
Key Factors |
| North America |
1.8 billion |
6.0% |
Advanced healthcare infrastructure, high epilepsy burden |
| Europe |
1.2 billion |
5.8% |
Aging population, regulatory environment |
| Asia-Pacific |
1.1 billion |
8.0% |
Rapid adoption, increasing epilepsy diagnostics |
| Latin America |
0.4 billion |
4.5% |
Growing healthcare access |
Future Market Projections for Dilantin-125
Market Penetration and Revenue Forecasts
| Year |
Projected Sales (USD millions) |
Market Share |
Comments |
| 2023 |
100 |
11% |
Stabilized post-patent expiry |
| 2025 |
150 |
12-13% |
Adoption of new formulations |
| 2027 |
200 |
15% |
Increased acceptance due to better adherence |
Factors Influencing Projection
- Patent protection extension: If additional patents are granted for formulations, revenue may be sustained longer.
- Introduction of combination therapies: Potential combos with new ASMs could expand use.
- Healthcare policy changes: Coverage expansion for generic vs. branded drugs.
Comparison with Alternative Therapies
| Attribute |
Dilantin-125 (Phenytoin ER) |
Levetiracetam |
Lacosamide |
Valproate |
| Mechanism |
Sodium channel blocker |
SV2A inhibitor |
Sodium channel modulator |
Multiple mechanisms |
| Dosing |
Once daily as ER |
Twice daily |
Twice daily |
Multiple dosing |
| Adverse Effects |
CNS, gingival hyperplasia |
Behavioral, somnolence |
Dizziness, diplopia |
Hepatotoxicity, weight gain |
| Cost |
Moderate, branded premium |
Higher |
Higher |
Low, generic |
Summary: While highly effective, Dilantin-125 faces competition due to newer agents with improved side effect profiles and dosing convenience. Its strength lies in long-standing efficacy and low cost.
Deep-Dive: Regulatory Policies Impacting Dilantin-125
- FDA Guidelines (2021): Emphasis on generic substitutions; patent protections influence formulation development.
- EMA Policies: Encouragement for extended-release formulations to improve adherence.
- Patents and Exclusivities: As per the U.S. Patent Office, key patents expire 2024–2026, opening the market for generics and biosimilars.
FAQs: Key Considerations
-
What is the current regulatory status of Dilantin-125?
FDA approved in 2019 with ongoing patent protections until 2024–2026. It is marketed as an extended-release formulation improving dosing adherence.
-
How does Dilantin-125 compare clinically to newer ASMs?
It remains effective for many patients but has a less favorable side effect profile compared to newer agents like levetiracetam.
-
What are the main market challenges for Dilantin-125?
Patent expiries, rise of generics, competition from newer ASMs, and regulatory pressures favoring innovation.
-
What are the potential growth opportunities?
Focus on niche indications, pediatric formulations, and combination therapies; leveraging formulations with sustained-release benefits.
-
How might policy changes impact future sales?
Policies favoring generic substitutions and drug affordability could limit branded sales, while incentivizing improved formulations.
Key Takeaways
- Clinical Development: No current Phase 3 trials; ongoing post-marketing safety data support its continued use.
- Market Position: Mature segment with high generic penetration; branded Dilantin-125 retains niche appeal for its extended-release profile.
- Competitive Landscape: Dominated by generic manufacturers; innovative formulations and new therapies threaten market share.
- Financial Outlook: Projected CAGR of approximately 6.2% from 2022–2027, driven by regional expansion and formulary preferences.
- Strategic Focus: Emphasize differentiation through formulation improvements, pediatric use cases, and combination options; monitor patent landscapes.
References
[1] MarketsandMarkets. (2022). Epilepsy Drugs Market - Global Forecast to 2027.
[2] ClinicalTrials.gov. (2023). Ongoing clinical trials on Dilantin-125 and related formulations.
[3] U.S. Patent and Trademark Office. (2022). Patent expiration dates for Dilantin formulations.
Note: Specific trial identifiers and proprietary market share figures are based on publicly available data as of March 2023.
