PREVYMIS Drug Patent Profile

Which patents cover Prevymis, and when can generic versions of Prevymis launch?

Prevymis is a drug marketed by MSD and Merck Sharp Dohme and is included in three NDAs. There are two patents protecting this drug and two Paragraph IV challenges.

This drug has ninety-eight patent family members in forty-eight countries.

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

DrugPatentWatch^® Generic Entry Outlook for Prevymis

Prevymis was eligible for patent challenges on November 8, 2021.

By analyzing the patents and regulatory protections it appears that the earliest date for generic entry will be August 30, 2031. This may change due to patent challenges or generic licensing.

There has been one patent litigation case involving the patents protecting this drug, indicating strong interest in generic launch. Recent data indicate that 63% of patent challenges are decided in favor of the generic patent challenger and that 54% of successful patent challengers promptly launch generic drugs.

There is one tentative approval for the generic drug (letermovir), which indicates the potential for near-term generic launch.

Indicators of Generic Entry

Summary for PREVYMIS

International Patents:	98
US Patents:	2
Applicants:	2
NDAs:	3
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	48
Clinical Trials:	9
Drug Prices:	Drug price information for PREVYMIS
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for PREVYMIS
What excipients (inactive ingredients) are in PREVYMIS?	PREVYMIS excipients list
DailyMed Link:	PREVYMIS at DailyMed

See drug prices for PREVYMIS

DrugPatentWatch^® Estimated Loss of Exclusivity (LOE) Date for PREVYMIS

Constraining patent/regulatory exclusivity:

PROPHYLAXIS OF CYTOMEGALOVIRUS (CMV) DISEASE IN PEDIATRIC PATIENTS 12 YEARS OF AGE AND OLDER AND WEIGHING AT LEAST 40 KG WHO ARE KIDNEY TRANSPLANT RECIPIENTS AT HIGH RISK (DONOR CMV SEROPOSITIVE/RECIPIENT CMV SERONEGATIVE [D+/R-])

NDA:

209940

Dosage:

SOLUTION;INTRAVENOUS

Constraining patent/regulatory exclusivity:

PROPHYLAXIS OF CYTOMEGALOVIRUS (CMV) DISEASE IN PEDIATRIC PATIENTS 12 YEARS OF AGE AND OLDER AND WEIGHING AT LEAST 40 KG WHO ARE KIDNEY TRANSPLANT RECIPIENTS AT HIGH RISK (DONOR CMV SEROPOSITIVE/RECIPIENT CMV SERONEGATIVE [D+/R-])

NDA:

209939

Dosage:

TABLET;ORAL

Constraining patent/regulatory exclusivity:

PROPHYLAXIS OF CYTOMEGALOVIRUS (CMV) DISEASE IN PEDIATRIC PATIENTS 12 YEARS OF AGE AND OLDER AND WEIGHING AT LEAST 40 KG WHO ARE KIDNEY TRANSPLANT RECIPIENTS AT HIGH RISK (DONOR CMV SEROPOSITIVE/RECIPIENT CMV SERONEGATIVE [D+/R-])

NDA:

219104

Dosage:

PELLETS;ORAL

^*The generic entry opportunity date is the latter of the last compound-claiming patent and the last regulatory exclusivity protection. Many factors can influence early or later generic entry. This date is provided as a rough estimate of generic entry potential and should not be used as an independent source.

Recent Clinical Trials for PREVYMIS

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

Sponsor	Phase
Merck Sharp & Dohme LLC	PHASE1
Jason A Roberts	PHASE1
Royal Brisbane and Women's Hospital	PHASE1

See all PREVYMIS clinical trials

Pharmacology for PREVYMIS

Drug Class	Cytomegalovirus DNA Terminase Complex Inhibitor
Mechanism of Action	Cytochrome P450 2C19 Inducers Cytochrome P450 2C8 Inhibitors Cytochrome P450 2C9 Inducers Cytochrome P450 3A Inhibitors DNA Terminase Complex Inhibitors Organic Anion Transporting Polypeptide 1B1 Inhibitors Organic Anion Transporting Polypeptide 1B3 Inhibitors

Paragraph IV (Patent) Challenges for PREVYMIS

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
PREVYMIS	Intravenous Solution	letermovir	240 mg/12 mL and 480 mg/24 mL	209940	1	2026-03-26
PREVYMIS	Tablets	letermovir	240 mg and 480 mg	209939	1	2024-10-16

US Patents and Regulatory Information for PREVYMIS

PREVYMIS is protected by two US patents and eight FDA Regulatory Exclusivities.

This potential generic entry date is based on PROPHYLAXIS OF CYTOMEGALOVIRUS (CMV) DISEASE IN PEDIATRIC PATIENTS 12 YEARS OF AGE AND OLDER AND WEIGHING AT LEAST 40 KG WHO ARE KIDNEY TRANSPLANT RECIPIENTS AT HIGH RISK (DONOR CMV SEROPOSITIVE/RECIPIENT CMV SERONEGATIVE [D+/R-]).

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
Merck Sharp Dohme	PREVYMIS	letermovir	TABLET;ORAL	209939-001	Nov 8, 2017		RX	Yes	No
Merck Sharp Dohme	PREVYMIS	letermovir	TABLET;ORAL	209939-001	Nov 8, 2017		RX	Yes	No
Merck Sharp Dohme	PREVYMIS	letermovir	TABLET;ORAL	209939-001	Nov 8, 2017		RX	Yes	No
Msd	PREVYMIS	letermovir	PELLETS;ORAL	219104-001	Aug 30, 2024		RX	Yes	No	RE46791		Y	Y

Expired US Patents for PREVYMIS

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Merck Sharp Dohme	PREVYMIS	letermovir	TABLET;ORAL	209939-001	Nov 8, 2017	8,513,255
Merck Sharp Dohme	PREVYMIS	letermovir	TABLET;ORAL	209939-002	Nov 8, 2017	7,196,086
Merck Sharp Dohme	PREVYMIS	letermovir	SOLUTION;INTRAVENOUS	209940-001	Nov 8, 2017	7,196,086
Merck Sharp Dohme	PREVYMIS	letermovir	SOLUTION;INTRAVENOUS	209940-002	Nov 8, 2017	7,196,086

EU/EMA Drug Approvals for PREVYMIS

Company	Drugname	Inn	Product Number / Indication	Status	Generic	Biosimilar	Orphan	Marketing Authorisation	Marketing Refusal
Merck Sharp & Dohme B.V.	Prevymis	letermovir	EMEA/H/C/004536Prevymis is indicated for prophylaxis of cytomegalovirus (CMV) reactivation and disease in adult CMV-seropositive recipients [R+] of an allogeneic haematopoietic stem cell transplant (HSCT).Consideration should be given to official guidance on the appropriate use of antiviral agents.	Authorised	no	no	yes	2018-01-08

International Patents for PREVYMIS

When does loss-of-exclusivity occur for PREVYMIS?

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

Australia

Brazil

Canada

Chile

China

Colombia

Croatia

Cyprus

Denmark

Eurasian Patent Organization

European Patent Office

Finland

Germany

Hong Kong

Hungary

India

Israel

Japan

Lithuania

Malaysia

Mexico

Montenegro

Morocco

New Zealand

Philippines

Poland

Portugal

San Marino

Serbia

Singapore

Slovenia

South Africa

South Korea

Spain

Tunisia

Ukraine

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 PREVYMIS around the world.

Country	Patent Number	Title	Estimated Expiration
Argentina	044078	DIHIDROQUINAZOLINAS SUSTITUIDAS
Austria	355280
Australia	2004233978	Substituted dihydrochinazolines having antiviral properties
Brazil	PI0410029	dihidroquinazolinas substituìdas

Supplementary Protection Certificates for PREVYMIS

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
1622880	300933	Netherlands		PRODUCT NAME: LETERMOVIR; REGISTRATION NO/DATE: EU/1/17/1245 20180110
1622880	LUC00070	Luxembourg		PRODUCT NAME: LETERMOVIR; AUTHORISATION NUMBER AND DATE: EU71/17/1245 20180110
1622880	2018C/015	Belgium		PRODUCT NAME: LETERMOVIR; AUTHORISATION NUMBER AND DATE: EU/1/17/1245 20180110
1622880	122018000080	Germany		PRODUCT NAME: LETERMOVIR ODER DESSEN SALZ, SOLVAT ODER SOLVAT DES SALZES; REGISTRATION NO/DATE: EU/1/17/1245 20180108

PREVYMIS (letermovir) market dynamics and financial trajectory: pricing, volume drivers, exclusivity timeline, and generic/biosimilar risk

Last updated: June 10, 2026

What is PREVYMIS (letermovir) and where does it fit in the antiviral market?

PREVYMIS is letermovir, an oral inhibitor of the viral terminase complex used to prevent cytomegalovirus (CMV) infection and disease in adult recipients of an allogeneic hematopoietic stem cell transplant (HSCT) who are CMV-seropositive. Commercial positioning is strongly tied to HSCT incident volume, prophylaxis penetration, and adherence to the drug’s labeled use in post-transplant windows.

Core commercial use case

• Target population: adult allogeneic HSCT recipients at risk for CMV reactivation and CMV disease
• Primary treatment model: prophylaxis/maintenance-style use in transplant aftercare rather than acute-course therapy

Competitive set: where PREVYMIS fights for share

In CMV prevention for transplant patients, the competitive landscape is shaped by:

• Comparator prophylaxis strategies (historically includes antivirals such as valganciclovir and ganciclovir, with center-specific protocols)
• Therapeutic shifts driven by toxicity profiles, monitoring intensity, and patient management logistics
• The degree to which institutions adopt prophylaxis rather than pre-emptive strategies

Why do market dynamics matter for PREVYMIS revenue growth or decline?

PREVYMIS revenue trajectory is typically driven by a small number of structural variables, each with pricing and contracting implications.

1) HSCT volumes and risk-window sizing

• Higher HSCT incidence lifts total addressable prophylaxis starts.
• Because PREVYMIS is used for a defined post-transplant prophylaxis period, “number of patients × treatment duration adherence” is the direct revenue engine.

2) Adoption curves at major transplant centers

• Hospital formularies and transplant program protocols control initial penetration.
• Switching costs are low for an individual patient but high for system-wide protocol changes because of CMV monitoring workflow redesign and staff training.

3) Payer access and rebate pressure

• Specialized oncology/transplant pharmacy contracts and PBM formulary placement influence net price.
• Revenue can compress quickly if competitors (or generics of older comparators) change the payer’s preferred prophylaxis.

4) Drug-drug interaction management

Letermovir’s interaction profile affects utilization through co-medication constraints (notably calcineurin inhibitors in transplant regimens). Operational friction can slow uptake, while optimized co-therapy protocols can increase persistence.

What is the financial trajectory of PREVYMIS and how do net sales typically behave?

PREVYMIS is marketed by Merck (MSD) in the U.S. and is commercially tracked as a specialty antiviral franchise product with pricing and volume drivers tied to transplant care patterns.

Revenue behavior to expect (commercial mechanism)

• Net sales rise when HSCT prophylaxis penetration increases and patients stay on therapy through labeled duration.
• Net sales soften when:
  • center adoption stalls,
  • payer contracting tightens, or
  • clinicians revert to alternative prophylaxis strategies during periods of formulary pressure.

What to watch in financial reporting

For PREVYMIS, the most predictive forward indicators tend to be:

• Specialty pharmacy fill volume trends (starts and days supply)
• net price and rebates dynamics (management commentary and payer contracting updates)
• channel mix and international scaling (if growth is driven by ex-U.S. adoption)

How does exclusivity timing affect PREVYMIS market risk?

PREVYMIS’s market risk schedule is determined by a layered exclusivity stack:

• regulatory exclusivity periods (data exclusivity)
• patent expiry timelines (composition, formulations, and method-of-use claims)
• any approved follow-on products that could extend exclusivity
• Paragraph IV litigation risk for generic letermovir tablets (if an ANDA is pursued for oral solid dosing)

Practical effect

• In mature antiviral franchises, loss of exclusivity typically does not cause instantaneous price collapse; it depends on:
  • remaining “secondary” patents on use/formulation
  • whether an ANDA filer can fully design around
  • whether settlements delay entry

What patents protect PREVYMIS and what does that imply for generic entry timing?

A complete, decision-grade patent landscape requires verified Orange Book listings and published patent data with expiration dates. That information is not provided in the prompt, and no drug-specific patent numbers or assignee details can be asserted without a sourced record.

Because a partial or unsourced patent summary would be inaccurate, no patent-expiration or Paragraph IV entry timeline is provided here.

What is the Orange Book status of PREVYMIS, and is it listed for U.S. generic competition?

Orange Book status is a direct gate to generic and biosimilar risk. A correct answer requires:

• Orange Book drug products list
• listed patents and their expiration dates
• any “marketing exclusivity” tags

This prompt does not include Orange Book dataset details, and no definitive listing can be produced without verified, drug-specific listings.

Is there generic or biosimilar risk for PREVYMIS?

PREVYMIS is a small-molecule drug (letermovir), so biosimilar frameworks are not the primary risk vector. The primary generic risk is an ANDA for letermovir.

A decision-grade generic risk assessment requires:

• whether ANDAs are filed
• whether Paragraph IV certifications were made
• whether litigation is ongoing or settled
• whether launch is scheduled and delayed

No litigation or ANDA filing specifics are included in the prompt, so no entry-risk staging can be stated.

How does PREVYMIS compete commercially versus alternative CMV prophylaxis?

PREVYMIS’s commercial value proposition is less about viral clearance efficacy headlines and more about transplant workflow fit: prophylaxis reliability, tolerability profile, and reduced monitoring burden relative to some alternatives.

Adoption drivers in real-world protocols

• transplant center experience with CMV management
• clinician confidence with prophylaxis-to-preemptive transitions
• compatibility with concurrent immunosuppressive regimens
• formulary and procurement logistics

Competitive pricing dynamics

Net pricing for specialty antivirals can compress if:

• alternative prophylaxis regimens become the payer-preferred pathway
• bundled transplant drug formularies are negotiated with a single preferred agent
• generic pressure impacts comparators in the same care pathway

What litigation or settlements affect PREVYMIS market access?

Patent litigation materially affects time-to-launch for generics. A correct litigation summary requires docket-level filings or public court records tied to specific Orange Book patents.

No litigation data is provided in the prompt, so no settlement or case timeline is reported.

What regulatory status issues shape the PREVYMIS commercialization curve?

Regulatory status determines:

• labeling scope and eligible patient populations
• restrictions on drug-drug co-therapy
• post-marketing obligations and potential label updates

A complete regulatory and label evolution map requires FDA labeling versions and any Safety Communications. None are provided in the prompt.

What manufacturing and IP barriers would constrain a generic letermovir tablet?

For oral small-molecule antivirals, barriers often include:

• crystallization/formulation IP
• process IP for manufacturing
• stability and bioavailability tied to formulation
• interaction with drug substances in combination regimens (indirect, via labeling)

A precise barrier assessment requires the formulation and process patent claims tied to PREVYMIS. Patent claims are not supplied in the prompt.

How does PREVYMIS compare with other CMV antivirals on market dynamics?

Without a sourced list of competing product net sales, pricing, and utilization trends, this section would risk factual inaccuracy. A structured comparison (price per treatment day, persistence, and center penetration) is not possible without product-level financial and utilization inputs.

What revenue exposure scenarios exist if exclusivity is challenged?

A realistic scenario tree depends on:

• date of first patent expiry,
• whether ANDA filers can design around remaining patents,
• whether settlements delay launch,
• whether label carve-outs allow earlier entry on narrow grounds.

Because no patent expiry or litigation posture is provided, no entry-scenario revenue impact can be calculated.

Key Takeaways

• PREVYMIS revenue is driven by HSCT-related prophylaxis starts, treatment persistence through the labeled risk window, and transplant-center adoption.
• Net sales behavior depends on net price and rebate contracting, payer preferred-pathway shifts, and the operational fit of letermovir within post-transplant regimens.
• Decision-grade generic entry and revenue risk require verified Orange Book patent listings, ANDA/Paragraph IV filings, and litigation/settlement dates. Those data are not included here, so exclusivity and challenge timelines are not stated.

FAQs

1) Does PREVYMIS pricing depend more on wholesale acquisition cost or net contract price?
2) What drives PREVYMIS demand most: HSCT incidence, prophylaxis penetration, or treatment duration adherence?
3) What patient management factors can slow PREVYMIS adoption at transplant centers?
4) If an ANDA for letermovir is filed, what certification type would typically govern launch timing?
5) How do payer formulary designs in transplant medicine affect specialty antiviral utilization?

References

1. (No sources provided in the prompt.)

DrugChatter Q&A for PREVYMIS

Prevymis prescribing information?
Prevymis medication guide?