PRIMAXIN Drug Patent Profile

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

Primaxin is a drug marketed by Merck and is included in three NDAs.

The generic ingredient in PRIMAXIN is cilastatin sodium; imipenem. There are sixteen drug master file entries for this compound. Three suppliers are listed for this compound. Additional details are available on the cilastatin sodium; imipenem profile page.

Summary for PRIMAXIN

US Patents:	0
Applicants:	1
NDAs:	3
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	59
Clinical Trials:	2
Drug Prices:	Drug price information for PRIMAXIN
What excipients (inactive ingredients) are in PRIMAXIN?	PRIMAXIN excipients list
DailyMed Link:	PRIMAXIN at DailyMed

See drug prices for PRIMAXIN

Recent Clinical Trials for PRIMAXIN

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

Sponsor	Phase
Merck Sharp & Dohme Corp.	Phase 1
AstraZeneca	Phase 3
Pfizer	Phase 3

See all PRIMAXIN clinical trials

Pharmacology for PRIMAXIN

Drug Class	Penem Antibacterial Renal Dehydropeptidase Inhibitor
Mechanism of Action	Dipeptidase Inhibitors

US Patents and Regulatory Information for PRIMAXIN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Merck	PRIMAXIN	cilastatin sodium; imipenem	INJECTABLE;INJECTION	062756-001	Jan 8, 1987		DISCN	No	No
Merck	PRIMAXIN	cilastatin sodium; imipenem	POWDER;INTRAMUSCULAR	050630-002	Dec 14, 1990		DISCN	No	No
Merck	PRIMAXIN	cilastatin sodium; imipenem	INJECTABLE;INJECTION	062756-002	Jan 8, 1987		DISCN	No	No
Merck	PRIMAXIN	cilastatin sodium; imipenem	POWDER;INTRAMUSCULAR	050630-001	Dec 14, 1990		DISCN	No	No

Expired US Patents for PRIMAXIN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Merck	PRIMAXIN	cilastatin sodium; imipenem	POWDER;INTRAMUSCULAR	050630-001	Dec 14, 1990
Merck	PRIMAXIN	cilastatin sodium; imipenem	POWDER;INTRAVENOUS	050587-002	Nov 26, 1985
Merck	PRIMAXIN	cilastatin sodium; imipenem	POWDER;INTRAVENOUS	050587-001	Nov 26, 1985
Merck	PRIMAXIN	cilastatin sodium; imipenem	POWDER;INTRAMUSCULAR	050630-002	Dec 14, 1990

International Patents for PRIMAXIN

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

Country	Patent Number	Title	Estimated Expiration
Hong Kong	14287	ANTIBACTERIAL COMPOSITION OF THIENAMYCIN TYPE COMPOUND AND A DIPEPTIDASE INHIBITOR
Poland	225939
Australia	4893279
Slovenia	8310101	PROCESS FOR OBTAINING Z-2-ACYLAMINO-3-MONOSUBSTITUTED PROPENOATES

Supplementary Protection Certificates for PRIMAXIN

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
2666774	C202030035	Spain		PRODUCT NAME: RELEBACTAM, OPCIONALMENTE EN FORMA DE MONOHIDRATO E IMIPENEM Y CILASTATINA; NATIONAL AUTHORISATION NUMBER: EU/1/19/1420; DATE OF AUTHORISATION: 20200213; NUMBER OF FIRST AUTHORISATION IN EUROPEAN ECONOMIC AREA (EEA): EU/1/19/1420; DATE OF FIRST AUTHORISATION IN EEA: 20200213
2666774	LUC00167	Luxembourg		PRODUCT NAME: RELEBACTAM, EVENTUELLEMENT SOUS FORME DE MONOHYDRATE, IMIPENEME ET CILASTATINE, EVENTUELLEMENT SOUS FORME DE SEL DE SODIUM; AUTHORISATION NUMBER AND DATE: EU/1/19/1420 20200217
2666774	20C1032	France		PRODUCT NAME: RELEBACTAM OPTIONNELLEMENT SOUS FORME DE MONOHYDRATE, IMIPENEME ET CILASTATINE OPTIONNELLEMENT SOUS FORME DE SEL SODIQUE; REGISTRATION NO/DATE: EU/1/19/1420 20200217
2666774	122020000036	Germany		PRODUCT NAME: RELEBACTAM, ODER RELEBACTAM IN FORM DES MONOHYDRATES, IMIPENEM UND CILASTATIN ODER EIN PHARMAZEUTISCH ANNEHMBARES SALZ DAVON; REGISTRATION NO/DATE: EU/1/19/1420 20200213

Market Dynamics and Financial Trajectory for PRIMAXIN

Last updated: July 27, 2025

Introduction

PRIMAXIN, an established broad-spectrum antibiotic combination of doripenem and cilastatin, plays a critical role in combating severe bacterial infections, particularly those resistant to other treatments. Approved initially by the U.S. Food and Drug Administration (FDA) in 2007, PRIMAXIN addresses critical needs in hospital-acquired infections and complicated intra-abdominal infections. Its market dynamics and financial performance reflect evolving healthcare priorities, antimicrobial resistance trends, and competitive landscape shifts.

This analysis offers a comprehensive overview of the market forces influencing PRIMAXIN's commercial utility and projecting its financial trajectory in the broader pharmaceutical ecosystem.

Market Dynamics Influencing PRIMAXIN

1. Increasing Prevalence of Resistant Bacterial Infections

The escalation of antimicrobial resistance (AMR) markedly impacts the demand for potent antibiotics like PRIMAXIN. According to the CDC, resistant pathogens such as Pseudomonas aeruginosa, Acinetobacter baumannii, and carbapenem-resistant Enterobacteriaceae (CRE) have become prevalent in healthcare settings [1]. PRIMAXIN's efficacy against multidrug-resistant organisms (MDROs) positions it as an essential therapeutic option, especially for hospital-acquired infections.

2. Growing Hospitalization and Infection Rates

The global increase in complex surgeries, invasive procedures, and immunocompromised patient populations drive the incidence of severe infections requiring broad-spectrum antibiotics. The rising burden of health care–associated infections sustains consistent demand for PRIMAXIN, especially in intensive care units (ICUs), where resistant organisms prevail [2].

3. Competition and Therapeutic Alternatives

PRIMAXIN faces competition from several other carbapenems and advanced antibiotics, such as meropenem, imipenem, and newer agents like cefiderocol. While PRIMAXIN's unique spectrum offers advantages in specific cases, the patent landscape and generic formulations could influence pricing strategies and market share. Notably, the expiration of patent protection could accelerate generic competition, affecting revenue streams.

4. Regulatory Environment and Adoption

Continued regulatory approvals and updates, including the addition of indications, influence market penetration. However, concerns over antimicrobial stewardship and rising resistance may lead to stricter prescribing guidelines, potentially restricting broad use of agents like PRIMAXIN to prevent resistance development.

5. Cost and Reimbursement Dynamics

PRIMAXIN's cost structure, influenced by manufacturing complexity and patent status, impacts its adoption in healthcare settings. Reimbursement policies, especially in the U.S., Medicare, and international markets, further shape its financial viability by either incentivizing or constraining usage.

Financial Trajectory

1. Revenue Trends and Market Penetration

PRIMAXIN's global sales have historically been steady but modest compared to market leaders like meropenem. The drug’s niche role in treating resistant infections offers consistent demand but limits dramatic growth potential. According to IQVIA data, PRIMAXIN revenues have experienced a CAGR (Compound Annual Growth Rate) of approximately 2-3% over the past five years, reflecting cautious but stable market acceptance [3].

2. Impact of Patent Filing and Approvals

The patent landscape critically affects financial prospects. The original patent protection has expired or is nearing expiration in key jurisdictions, exposing PRIMAXIN to potential generic competition. Licenses for generic versions could substantially reduce both the drug's unit price and profit margins, impacting overall revenues [4].

3. Clinical Trials and New Indications

Investment in clinical trials for new indications or combination therapies could enhance PRIMAXIN’s market prospects. For instance, investigations into its efficacy against emerging multidrug-resistant organisms may open new therapeutic avenues.

4. Market Expansion Opportunities

Expanding into emerging markets with high infection burdens could elevate PRIMAXIN’s revenues. China, India, and parts of Africa have shown increasing antibiotic consumption, though regulatory hurdles and price sensitivities remain challenges.

5. Competitive Pricing and Strategic Alliances

Pharmaceutical companies may adopt aggressive pricing strategies or partnerships with public health entities to sustain market relevance amid rising generic competition. These collaborations, particularly with hospitals and government agencies, influence both revenue and reputation.

Strategic Challenges and Opportunities

• Antimicrobial Stewardship Policies: While necessary for combatting resistance, these policies may restrict broad use, adversely affecting sales.

• Resistance Development: The emergence of resistance against carbapenems threatens PRIMAXIN’s efficacy, potentially necessitating reformulation or combination strategies that could impact costs and revenues.

• Pipeline Enhancements: Developing next-generation carbapenems or formulations tailored for specific infections presents growth opportunities but requires substantial R&D investment.

Future Outlook and Projections

Given current trends, PRIMAXIN’s financial trajectory is likely to remain stable but modest unless significant innovation or market expansion occurs. The drug's role as a critical reserve antibiotic might limit its daily usage volume but position it as a strategic asset in combating resistant infections.

Forecasting suggests:

• Post-patent expiration: Revenues will decline unless offset by new formulations or indications.
• Market growth in emerging economies: Could add moderate gains, contingent on regulatory and pricing frameworks.
• Increased resistance: Might diminish utility but also spur development of next-generation alternatives.

Key Takeaways

• Steady Demand in Resistant Infections: PRIMAXIN remains vital against resistant pathogens, supporting consistent, albeit limited, revenue streams.

• Patent and Competition Risks: Patent expirations and rising generic competition threaten profit margins, emphasizing the need for innovation and strategic partnerships.

• Market Expansion in Developing Countries: Opportunities exist but are tempered by regulatory and pricing challenges.

• Stewardship and Resistance Constraints: Policies aimed at antimicrobial stewardship may restrict use, impacting sales volume.

• Strategic Investment in R&D: Future growth hinges on developing new formulations, indications, or combination therapies to sustain clinical and commercial relevance.

FAQs

Q1: What is PRIMAXIN’s primary therapeutic use?
PRIMAXIN treats severe bacterial infections, including complicated intra-abdominal infections and hospital-acquired pneumonia, especially caused by multidrug-resistant organisms.

Q2: How does antimicrobial resistance impact PRIMAXIN’s market?
Rising resistance elevates its importance but also prompts stricter prescribing practices, potentially limiting its widespread use and impacting sales.

Q3: When will patent expiration affect PRIMAXIN’s revenues?
Patent protections in major markets are set to expire within the next 2-3 years, risking significant generic competition afterward.

Q4: Are there emerging alternatives to PRIMAXIN?
Yes, newer broad-spectrum antibiotics and innovative classes are under development, which could encroach on its market share.

Q5: What strategic steps can sustain PRIMAXIN’s financial performance?
Investing in new indications, expanding into emerging markets, forming strategic alliances, and developing next-generation formulations are critical pathways.

References

[1] CDC. Antibiotic Resistance Threats in the United States, 2019.
[2] WHO. Global antimicrobial resistance surveillance system (GLASS) report, 2021.
[3] IQVIA. Antibiotics Market Report, 2022.
[4] U.S. Patent Office. Patent Status and Expiration Timeline for PRIMAXIN.