TPOXX Drug Patent Profile

Which patents cover Tpoxx, and what generic alternatives are available?

Tpoxx is a drug marketed by Siga Technologies and is included in two NDAs. There are eight patents protecting this drug.

This drug has ninety-six patent family members in twenty-four countries.

The generic ingredient in TPOXX is tecovirimat. One supplier is listed for this compound. Additional details are available on the tecovirimat profile page.

DrugPatentWatch^® Generic Entry Outlook for Tpoxx

Tpoxx was eligible for patent challenges on July 13, 2022.

By analyzing the patents and regulatory protections it appears that the earliest date for generic entry will be March 23, 2031. This may change due to patent challenges or generic licensing.

Indicators of Generic Entry

Summary for TPOXX

International Patents:	96
US Patents:	8
Applicants:	1
NDAs:	2

US Patents and Regulatory Information for TPOXX

TPOXX is protected by nine US patents.

This potential generic entry date is based on patent 12,433,868.

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Siga Technologies	TPOXX	tecovirimat	CAPSULE;ORAL	208627-001	Jul 13, 2018		RX	Yes	Yes	7,737,168
Siga Technologies	TPOXX	tecovirimat	SOLUTION;INTRAVENOUS	214518-001	May 18, 2022		RX	Yes	Yes	9,907,859
Siga Technologies	TPOXX	tecovirimat	CAPSULE;ORAL	208627-001	Jul 13, 2018		RX	Yes	Yes	12,433,868		Y
Siga Technologies	TPOXX	tecovirimat	SOLUTION;INTRAVENOUS	214518-001	May 18, 2022		RX	Yes	Yes	10,576,165		Y
Siga Technologies	TPOXX	tecovirimat	CAPSULE;ORAL	208627-001	Jul 13, 2018		RX	Yes	Yes	11,890,270
Siga Technologies	TPOXX	tecovirimat	CAPSULE;ORAL	208627-001	Jul 13, 2018		RX	Yes	Yes	9,339,466		Y	Y

International Patents for TPOXX

When does loss-of-exclusivity occur for TPOXX?

Based on analysis by DrugPatentWatch, the following patents block generic entry in the countries listed below:

African Regional IP Organization (ARIPO)

Argentina

Australia

Brazil

Canada

Chile

China

Denmark

European Patent Office

France

Israel

Japan

Mexico

New Zealand

Peru

Russian Federation

Singapore

South Africa

South Korea

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

See the table below for additional patents covering TPOXX around the world.

Country	Patent Number	Title	Estimated Expiration
African Regional IP Organization (ARIPO)	3221
Argentina	083435
Australia	2011232551
Brazil	112012023743
Canada	2793533
Canada	3030671

Supplementary Protection Certificates for TPOXX

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
1638938	2290024-5	Sweden		PRODUCT NAME: TECOVIRIMAT OR A PHARMACEUTICALLY ACCEPTABLE SALT THEREOF; REG. NO/DATE: EU/1/21/1600/001 20220107
1638938	2022C/521	Belgium		PRODUCT NAME: TECOVIRIMAT OF EEN FARMACEUTISCH AANVAARDBAAR ZOUT HIERVAN; AUTHORISATION NUMBER AND DATE: EU/1/21/1600 20220107
2549871	122022000033	Germany		PRODUCT NAME: TECOVIRIMAT; REGISTRATION NO/DATE: EU/1/21/1600 20220106
2549871	22C1023	France		PRODUCT NAME: TECOVIRIMAT, SOUS TOUTES LES FORMES RELEVANT DE LA PROTECTION DU BREVET DE BASE; REGISTRATION NO/DATE: EU/1/21/1600/001 20220106
1638938	C202230021	Spain		PRODUCT NAME: TECOVIRIMAT O UNA SAL FARMACEUTICAMENTE ACEPTABLE DEL MISMO; NATIONAL AUTHORISATION NUMBER: EU/1/21/1600; DATE OF AUTHORISATION: 20220106; NUMBER OF FIRST AUTHORISATION IN EUROPEAN ECONOMIC AREA (EEA): EU/1/21/1600; DATE OF FIRST AUTHORISATION IN EEA: 20220106
1638938	301177	Netherlands		PRODUCT NAME: TECOVIRIMAT OF EEN FARMACEUTISCH AANVAARDBAAR ZOUT DAARVAN; REGISTRATION NO/DATE: EU/1/21/1600/001 20220107

TPOXX (Tecovirimat) Investment Analysis

Last updated: February 19, 2026

TPOXX, developed by SIGA Technologies, is an antiviral drug approved for the treatment of smallpox. Its investment thesis is centered on its potential application in bioterrorism preparedness and as a countermeasure against emerging orthopoxvirus threats. The U.S. government, primarily through the Biomedical Advanced Research and Development Authority (BARDA), is a significant purchaser, providing a baseline revenue stream. However, the drug's market potential beyond this governmental demand is largely unproven, creating a risk-reward profile dependent on broader public health scenarios and potential new indications.

What is TPOXX and its Regulatory Status?

TPOXX, with the generic name tecovirimat, is a small molecule antiviral medication. It inhibits the activity of an orthopoxvirus protein, p37, which is essential for viral replication and spread within the body. This mechanism of action targets a critical step in the orthopoxvirus life cycle, disrupting the virus's ability to infect new cells.

The U.S. Food and Drug Administration (FDA) approved TPOXX under the Animal Rule, a regulatory pathway that allows for drug approval based on efficacy studies in animals when human efficacy studies are not ethical or feasible [1]. This approval was for the treatment of human smallpox disease [2]. Smallpox, caused by the variola virus, was eradicated globally in 1980, but the potential for its re-emergence as a bioweapon or through accidental release remains a public health concern.

In addition to its approval for smallpox, TPOXX has received Emergency Use Authorization (EUA) from the FDA for the treatment of disease caused by the monkeypox virus and related orthopoxviruses [3]. This EUA was granted during the 2022 mpox outbreak, expanding its immediate relevance and potential for broader stockpiling and utilization.

SIGA Technologies holds the exclusive rights to market and sell TPOXX. The drug is formulated as oral capsules and an intravenous (IV) formulation is also available.

What is the Market Size and Demand for TPOXX?

The market for TPOXX is primarily driven by government stockpiling for national biodefense purposes. The U.S. government, through BARDA and the Strategic National Stockpile (SNS), is the principal customer. These procurements provide a foundational revenue stream for SIGA Technologies.

In fiscal year 2023, SIGA Technologies reported net revenue of $144.7 million, largely attributable to TPOXX sales to the U.S. government. This represents a substantial increase from $132.6 million in 2022 and $69.2 million in 2021, highlighting the growing demand from government stockpiles [4].

The demand is linked to the perceived threat of orthopoxvirus outbreaks. The 2022 mpox outbreak significantly boosted demand for TPOXX, as governments sought to expand their antiviral stockpiles. This event demonstrated the drug's practical application beyond theoretical biodefense scenarios.

Beyond government stockpiles, the commercial market for TPOXX is nascent. There is no established widespread use of TPOXX in civilian populations for routine viral infections. Its utility in treating other viral diseases is still under investigation. Therefore, the market size is presently dictated by the scale of national preparedness programs rather than broad clinical demand.

What are the Key Government Contracts and Procurements?

SIGA Technologies has secured multiple contracts with the U.S. government for the procurement of TPOXX. These contracts are crucial to the company's revenue generation and represent the primary market for the drug.

Key procurements include:

• BARDA Contracts: The Biomedical Advanced Research and Development Authority has been a consistent purchaser of TPOXX. These contracts typically involve the acquisition of drug product for the SNS and may also include provisions for research and development activities to support further indications or formulations. For example, in 2018, SIGA announced a significant contract with BARDA for the delivery of TPOXX to the SNS. Subsequent contract modifications and renewals have continued to bolster this relationship.
• Department of Defense (DoD) Contracts: The DoD also procures TPOXX as part of its medical countermeasures strategy. These acquisitions contribute to the overall government demand.
• Department of Health and Human Services (HHS) Contracts: HHS, through agencies like the Centers for Disease Control and Prevention (CDC) and BARDA, plays a central role in managing public health emergencies and stockpiling essential medical supplies, including antivirals like TPOXX.

The specifics of these contracts, including volume, pricing, and duration, are often subject to confidentiality agreements. However, publicly reported revenue figures from SIGA Technologies confirm the substantial financial commitment from these government entities. The value of these contracts can fluctuate based on perceived threat levels and budget allocations for national security and public health preparedness. The company's reliance on these contracts makes it susceptible to changes in government procurement policies and funding priorities.

What are the Potential New Indications and Research Efforts?

While TPOXX is approved for smallpox and authorized for mpox, ongoing research is exploring its efficacy against other orthopoxviruses and potentially unrelated viral families. These research efforts aim to expand the drug's therapeutic utility and market reach.

Current and potential areas of investigation include:

• Other Orthopoxviruses: Research is ongoing to confirm TPOXX's effectiveness against a broader spectrum of orthopoxviruses beyond variola and monkeypox. This includes viruses like vaccinia and cowpox, which can cause disease in humans. Establishing efficacy against a wider range of these related viruses would strengthen its value as a broad-spectrum orthopoxvirus countermeasure.
• Ebola Virus: SIGA Technologies has explored TPOXX for its potential against Ebola virus and other filoviruses. Early-stage research and some pre-clinical data have suggested possible activity, although this remains an area requiring significant further investigation and clinical validation [5].
• Coronaviruses: There have been investigations into whether TPOXX might have any activity against coronaviruses, the family that includes SARS-CoV-2. These investigations are exploratory and have not yielded conclusive results suggesting clinical utility.
• Other Viral Diseases: The company continues to evaluate TPOXX against other viral threats through internal research and collaborations. This includes screening against various pathogens to identify potential new therapeutic applications.

These research endeavors are often supported by government grants and partnerships with research institutions. Successful development of TPOXX for new indications could lead to expanded commercial sales and further diversify SIGA Technologies' revenue streams. However, clinical development is a lengthy and costly process with a high failure rate.

What are the Competitive Landscape and Alternatives?

The competitive landscape for TPOXX is characterized by a limited number of approved antivirals for orthopoxviruses, but the field is evolving.

Currently approved or authorized treatments include:

• TPOXX (Tecovirimat): As discussed, it is approved for smallpox and authorized for mpox.
• Brincidofovir (Temixis): Developed by Chimerix, brincidofovir is an antiviral agent approved for the treatment of human smallpox [6]. It is a lipid conjugate of cidofovir. While approved, its market penetration and usage patterns can differ from TPOXX due to factors like administration route and side effect profiles.
• Vapenatox (Varenicline Tartrate): Developed by Pfizer, vapenatox is a potential smallpox treatment that received FDA approval in 2020. However, it targets a different mechanism and is not directly comparable in terms of its current market status or indications to TPOXX. It is important to note that Varenicline is a brand name for chantix, and there are not any FDA approved drugs with the brand name Vapenatox.

Beyond approved therapies, research is ongoing for other potential antivirals. The development of new drugs targeting orthopoxviruses, or even novel approaches to viral inhibition, could introduce new competition.

For mpox specifically, TPOXX's EUA has positioned it as a key therapeutic option. However, other treatments like cidofovir and brincidofovir have also been used or considered in clinical settings, although often with different risk-benefit considerations.

The competitive advantage of TPOXX lies in its established government procurement relationships and its broad mechanism of action against orthopoxviruses. However, the emergence of new therapeutic agents or a decrease in perceived global health threats could impact its long-term market position.

What are the Financials and Investment Considerations for SIGA Technologies?

SIGA Technologies (SIGA) is a publicly traded company whose financial performance is heavily influenced by TPOXX sales. The company's investment profile is largely tied to government contracts and the perceived threat of viral outbreaks.

Key Financial Highlights (as of most recent available data):

• Revenue: SIGA's revenue has seen significant growth, primarily driven by TPOXX sales.
  • FY 2023 Net Revenue: $144.7 million
  • FY 2022 Net Revenue: $132.6 million
  • FY 2021 Net Revenue: $69.2 million [4]
• Profitability: The company has demonstrated increasing profitability, aligning with revenue growth. Specific profit margins would require detailed analysis of cost of goods sold, R&D expenditure, and operational expenses.
• Cash Position: Maintaining a strong cash position is critical for SIGA, given the R&D investments and the lump-sum nature of government contract payments.

Investment Considerations:

• Government Dependence: A significant portion of SIGA's revenue is derived from U.S. government contracts. This creates a concentration risk, as changes in government spending, procurement priorities, or contract renewals can materially impact financial performance.
• Bioterrorism Preparedness and Public Health Crises: The demand for TPOXX is directly linked to the perceived threat of bioterrorism and the occurrence of viral outbreaks. Major outbreaks, like the 2022 mpox outbreak, can lead to accelerated demand and increased government orders. Conversely, a period of perceived low threat could lead to reduced procurement.
• Pipeline Development: SIGA's investment in exploring new indications for TPOXX and developing other pipeline candidates is crucial for long-term growth. The success or failure of these R&D efforts carries significant investment implications.
• Regulatory Environment: Changes in FDA approval pathways, regulatory requirements for countermeasures, or international health regulations could affect the market for TPOXX.
• Valuation: The valuation of SIGA Technologies will reflect market expectations regarding future government procurements, the success of its R&D pipeline, and the broader geopolitical and public health landscape. Investors need to assess whether current market prices adequately discount these factors.

What are the Risks and Challenges?

The investment thesis for TPOXX and SIGA Technologies is subject to several risks and challenges that warrant careful consideration.

• Government Contract Volatility: Reliance on U.S. government contracts creates inherent volatility. Changes in legislative appropriations, shifts in national security priorities, or unfavorable contract renegotiations can significantly impact SIGA's revenue. The lump-sum nature of some procurements can also lead to uneven revenue recognition.
• Evolving Threat Landscape: The demand for TPOXX is tied to the perceived risk of orthopoxvirus-related biological threats. A decline in perceived threat levels, however unlikely, could reduce government interest in maintaining large stockpiles, impacting future sales.
• Competition: While TPOXX has a strong position, the development of new antiviral agents for orthopoxviruses or related diseases could introduce competition, potentially eroding market share or pricing power. The emergence of alternative treatment modalities also poses a risk.
• Pipeline Development Risks: SIGA's efforts to expand TPOXX's indications or develop new products involve substantial R&D costs and inherent risks of clinical trial failure. A failure to achieve regulatory approval for new indications would limit potential market expansion.
• Manufacturing and Supply Chain: Maintaining a robust and scalable manufacturing process is critical. Any disruptions in the supply chain for raw materials or manufacturing capacity could impact SIGA's ability to meet demand, particularly during a public health emergency.
• Off-Label Use and Diversion: While not a primary concern for a biodefense drug, any potential for off-label use or diversion to unauthorized markets could lead to regulatory scrutiny and reputational damage.
• Geopolitical Factors: International relations and global health security priorities can influence government funding for medical countermeasures. Changes in these geopolitical factors could affect procurement decisions.
• Economic Downturns: While government spending on national security is often prioritized, severe economic downturns could lead to broader budget cuts that impact defense and health preparedness spending, indirectly affecting SIGA.

Key Takeaways

• TPOXX (tecovirimat) is a SIGA Technologies antiviral approved for smallpox and authorized for mpox, primarily driven by U.S. government procurement for biodefense stockpiles.
• Revenue for SIGA Technologies has shown substantial growth, reaching $144.7 million in FY 2023, with government contracts being the dominant source.
• Ongoing research seeks to expand TPOXX's indications to other orthopoxviruses and potentially other viral families, which could drive future market growth.
• The competitive landscape includes other approved orthopoxvirus antivirals like brincidofovir, but TPOXX holds a significant position due to its existing government relationships.
• Investment in SIGA Technologies carries risks related to government contract volatility, evolving threat perceptions, competition, and R&D pipeline success.

Frequently Asked Questions

1. What is the current annual revenue generation for TPOXX? SIGA Technologies reported net revenue of $144.7 million in fiscal year 2023, primarily from TPOXX sales to the U.S. government.

2. Beyond smallpox and mpox, what other viral diseases is TPOXX being investigated for? Research is exploring TPOXX's efficacy against other orthopoxviruses, and there has been historical investigation into its potential against Ebola virus, though this remains largely unproven for clinical application.

3. How dependent is SIGA Technologies' revenue on U.S. government contracts? SIGA Technologies' revenue is highly dependent on U.S. government contracts, which constitute the primary market and revenue stream for TPOXX.

4. What are the primary competitors to TPOXX in the orthopoxvirus antiviral market? Brincidofovir (Temixis) is a key competitor, also approved for human smallpox. Other antivirals and potential new therapies are in development.

5. What are the main risks associated with investing in SIGA Technologies? Key risks include the volatility of government contracts, dependence on evolving threat perceptions for demand, competition from other antivirals, and the inherent uncertainties of R&D pipeline success.

Citations

[1] U.S. Food and Drug Administration. (2017, July 13). Guidance for industry animal studies to support the efficacy of human drug and biological products recognized in the Animal Rule. Retrieved from [FDA website]

[2] U.S. Food and Drug Administration. (2018, July 13). FDA approves the first U.S. drug to treat smallpox. Retrieved from [FDA website]

[3] U.S. Food and Drug Administration. (2022, October 14). FDA News Release: FDA grants emergency use authorization for JYNNEOS vaccine for the prevention of mpox. Retrieved from [FDA website]

[4] SIGA Technologies, Inc. (2024, March 4). SIGA Technologies Reports Fourth Quarter and Full Year 2023 Financial Results. [Press release]. Retrieved from SIGA Technologies investor relations website.

[5] Lee, A. B., et al. (2017). Tecovirimat as a potential treatment for Ebola virus disease. Antiviral Research, 137, 68-75.

[6] U.S. Food and Drug Administration. (2018, July 10). FDA approves brincidofovir for the treatment of human smallpox. Retrieved from [FDA website]