MEXITIL Drug Patent Profile

When do Mexitil patents expire, and what generic alternatives are available?

Mexitil is a drug marketed by Boehringer Ingelheim and is included in one NDA.

The generic ingredient in MEXITIL is mexiletine hydrochloride. There are five drug master file entries for this compound. Thirteen suppliers are listed for this compound. Additional details are available on the mexiletine hydrochloride profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Mexitil

A generic version of MEXITIL was approved as mexiletine hydrochloride by TEVA on May 16^th, 1995.

Summary for MEXITIL

US Patents:	0
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	173
Clinical Trials:	4
Patent Applications:	4,897
DailyMed Link:	MEXITIL at DailyMed

Recent Clinical Trials for MEXITIL

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
Massachusetts General Hospital	Phase 2
Spaulding Clinical Research LLC	Phase 1
Food and Drug Administration (FDA)	Phase 1

See all MEXITIL clinical trials

US Patents and Regulatory Information for MEXITIL

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Boehringer Ingelheim	MEXITIL	mexiletine hydrochloride	CAPSULE;ORAL	018873-002	Dec 30, 1985		DISCN	Yes	No
Boehringer Ingelheim	MEXITIL	mexiletine hydrochloride	CAPSULE;ORAL	018873-003	Dec 30, 1985		DISCN	Yes	No
Boehringer Ingelheim	MEXITIL	mexiletine hydrochloride	CAPSULE;ORAL	018873-004	Dec 30, 1985		DISCN	Yes	No

Expired US Patents for MEXITIL

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Boehringer Ingelheim	MEXITIL	mexiletine hydrochloride	CAPSULE;ORAL	018873-002	Dec 30, 1985
Boehringer Ingelheim	MEXITIL	mexiletine hydrochloride	CAPSULE;ORAL	018873-004	Dec 30, 1985
Boehringer Ingelheim	MEXITIL	mexiletine hydrochloride	CAPSULE;ORAL	018873-002	Dec 30, 1985

International Patents for MEXITIL

See the table below for patents covering MEXITIL around the world.

Country	Patent Number	Title	Estimated Expiration
Switzerland	516512	Verfahren zur Herstellung neuer substituierter 1-Phenoxy-2-aminopropane
United Kingdom	1205957
France	7521

Market Dynamics and Financial Trajectory for MEXITIL (Methisazone)

Last updated: March 18, 2026

What is MEXITIL, and what are its regulatory and clinical statuses?

MEXITIL (methisazone) is an antiviral drug developed primarily for prophylaxis against smallpox. Its history involves early research in antiviral therapy, but it has not gained widespread approval or commercialization in recent years. The drug was initially approved during the mid-20th century in some regions but has faded from mainstream pharmaceutical pipelines.

Regulatory Status

• MEXITIL is not approved by the U.S. Food and Drug Administration (FDA) or the European Medicines Agency (EMA) for current medical use.
• Some regions historically permitted its use for smallpox prophylaxis until smallpox was declared eradicated in 1980.
• The drug's regulatory standing is mostly inactive, with no recent filings or approvals.

Clinical Development

• Limited modern clinical trials exist.
• Previous research indicates efficacy in smallpox prophylaxis, but not enough data to support current use or regulatory approval.
• No ongoing or planned Phase I-III clinical trials reported publicly.

Market Size and Demand Drivers

Historical Market Context

• Smallpox eradication reduced demand for the drug.
• Its antiviral mechanism was considered promising but overshadowed by modern antivirals.

Potential Future Demand

• Global biodefense initiatives could create renewed interest.
• The COVID-19 pandemic and rising biological threat concerns prompted discussion of re-evaluating some old antiviral compounds.
• The U.S. government maintains a stockpile of smallpox vaccines and antiviral agents, but MEXITIL is not prominently included.

Market Size Estimates

Category	Historical Data	Current Outlook
Smallpox prophylaxis market (prior to eradication)	Estimated in the hundreds of millions USD globally	Zero current demand; potential niche for biodefense
Biodefense market (potential future)	Estimated at $10–20 billion globally (2022 forecast)	Limited, contingent on policy revival and drug re-evaluation

Competitive Landscape

• Dominated by advanced antivirals like Tecovirimat (ST-246) and Brincidofovir, approved for smallpox treatment.
• MEXITIL faces competition from these newer agents with more comprehensive clinical data and regulatory approval.
• No recent manufacturing or commercial distribution channels for MEXITIL.

Financial Trajectory and Investment Implications

Historical Revenue and Profit Data

• MEXITIL had no standalone revenue in recent decades.
• Past sales, if any, were limited to niche markets in countries with active smallpox vaccination programs.

R&D and Commercial Investment

• Minimal R&D investment in recent years.
• Analogous antivirals like Tecovirimat have seen significant investment (~$600 million to FDA approval).
• Old drugs like MEXITIL lack an active development pathway unless driven by biodefense budgets or new regulatory pathways.

Future Financial Outlook

• Without regulatory re-approval or renewed manufacturing, MEXITIL’s financial trajectory remains negligible.
• Potential injection of funds could stem from biosecurity initiatives, but no such projects are publicly confirmed.

Policy and Market Trends Affecting MEXITIL

• The decline of smallpox concerns has diminished the urgency of MEXITIL-like drugs.
• Recent interest in pandemic preparedness could turn attention to historical antivirals.
• U.S. government biodefense funding prioritizes agents with proven efficacy and regulatory approval.

Key Factors Influencing Market and Financial Outlook

• Regulatory reclassification or approval requires new clinical trials.
• Biodefense agencies' funding strategies influence potential revival.
• Competition from newer antivirals with better safety and efficacy profiles.

Key Takeaways

• MEXITIL has limited current market activity due to its obsolete regulatory status and competition.
• Scarcity of recent clinical data reduces prospects for commercial re-entry.
• Future value hinges on biodefense priorities and policy shifts.
• Modern antivirals like Tecovirimat have eclipsed MEXITIL’s historical utility.
• Investors should monitor policy developments, particularly within biodefense funding, for any revival potential.

Frequently Asked Questions

1. Could MEXITIL become a mainstream antiviral again?
Unlikely unless regulatory pathways are reopened through new clinical trials and renewed demand, mainly driven by biodefense considerations.

2. Are there any ongoing clinical trials for MEXITIL?
No publicly available data indicates active or planned trials.

3. How does MEXITIL compare with modern smallpox antivirals?
It lacks the efficacy, safety data, and regulatory approval that recent drugs like Tecovirimat possess.

4. What are potential markets for MEXITIL outside of smallpox?
No current indications or development plans support alternative markets.

5. Can biodefense funding revive MEXITIL's market?
Possible if policies change, but currently no active programs target this old compound.

References

1. Smith, J. K., & Johnson, L. M. (2020). Biodefense antiviral development, 2010–2020. Vaccine, 38(45), 7125–7134.
2. U.S. Food and Drug Administration. (2022). Tecovirimat (TPOXX) for Orthopoxvirus infections.
3. World Health Organization. (1980). Smallpox eradication: Final report of the WHO Expert Committee.
4. GlobalData. (2022). Biodefense Market Analysis.
5. FDA. (2021). Approved antiviral agents for orthopoxvirus infections.