PRIMAXIN Drug Patent Profile

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

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

The generic ingredient in PRIMAXIN is cilastatin sodium; imipenem. 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

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
Merck	PRIMAXIN	cilastatin sodium; imipenem	POWDER;INTRAVENOUS	050587-002	Nov 26, 1985	AP	RX	Yes	Yes
Merck	PRIMAXIN	cilastatin sodium; imipenem	POWDER;INTRAVENOUS	050587-001	Nov 26, 1985		DISCN	Yes	No

International Patents for PRIMAXIN

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

Country	Patent Number	Title	Estimated Expiration
Argentina	244550	PROCEDIMIENTO PARA OBTENER UNA COMPOSICION DE ANTIBIOTICOS DEL TIPO DE LA TIENAMICINA CON INHIBIDORES DE LA DIPEPTIDASA (AN ANTIBACTERIAL COMPOSITION OF THIENAMYCIN-TYPE COMPOUND AND A DIPEPTIDASE INHIBITOR)
Austria	17472
Austria	2299
Austria	24397
Austria	5070
Australia	4893279

Supplementary Protection Certificates for PRIMAXIN

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
2666774	SPC/GB20/031	United Kingdom		PRODUCT NAME: RELEBACTAM OPTIONALLY IN THE FORM OF THE MONOHYDRATE, IMIPENEM AND CILASTATIN, OPTIONALLY IN THE FORM OF THE SODIUM SALT.; REGISTERED: UK EU/1/19/1420 (NI) 20200217; UK PLGB 53095/0053 20200217
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	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	PA2020518	Lithuania		PRODUCT NAME: RELEBAKTAMAS, PASIRINKTINAI MONOHIDRATO PAVIDALU, SU IMIPENEMU IR CILASTATINU, PASIRINKTINAI NATRIO DRUSKOS PAVIDALU; REGISTRATION NO/DATE: EU/1/19/1420 20200213
2666774	202040029	Slovenia		PRODUCT NAME: RELEBACTAM, OPTIONALLY IN THE FORM OF MONOHYDRATE, IMIPENEM AND CILASTATIN, OPTIONALLY IN THE FORM OF SODIUM SALT; NATIONAL AUTHORISATION NUMBER: EU/1/19/1420; DATE OF NATIONAL AUTHORISATION: 20200213; AUTHORITY FOR NATIONAL AUTHORISATION: EU
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

PRIMAXIN (Imipenem and Cilastatin) Investment Scenario, Market Dynamics, and Financial Trajectory

Last updated: February 3, 2026

Executive Summary

PRIMAXIN, a broad-spectrum carbapenem antibiotic combining imipenem and cilastatin, has established itself as a critical therapy against resistant bacterial infections. This report analyzes its current market positioning, investment landscape, and projected financial trajectory, emphasizing key drivers such as antimicrobial resistance, regulatory trends, and competitive dynamics. The assessment provides a comprehensive view for stakeholders contemplating investment opportunities within the antimicrobial therapeutics sector.

---

What Is the Current Market Context for PRIMAXIN?

Market Overview

Aspect	Details
Therapeutic Use	Hospital-acquired, complicated intra-abdominal, urinary tract, pneumonia, and skin infections.
Global Market Size (2022)	Estimated $1.2 billion; expected CAGR of 4.8% from 2023 to 2030.
Leading Manufacturers	Merck & Co. (original developer), Pfizer, Actavis, and other regional players.
Patent Status	U.S. patent expired in 2020; existing formulations under exclusivity for specific indications via orphan or new-use patents.
Off-label Use	Growing due to resistance issues, though off-label use remains unregulated.

Market Drivers

• Rising antimicrobial resistance (AMR) necessitates potent antibiotics like PRIMAXIN.
• Hospital antimicrobial stewardship programs limiting broad-spectrum antibiotic usage.
• Increasing prevalence of multidrug-resistant (MDR) pathogens.
• Aging population with more susceptible infections.

Key Market Trends

Trend	Impact
Generic Entry	Increased price competition post-patent expiry.
Development of Antibiotic Resistance	Spurs demand for novel formulations and combination therapies.
Regulatory Incentives	FDA's Qualified Infectious Disease Product (QIDP) status provides priority review and incentives for new uses.
Rising R&D Investment	Shift toward novel carbapenems and combination solutions.

---

Market Dynamics and Competitive Landscape

Competitors / Alternatives	Market Share (%)	Notable Features
Merck & Co. (Original)	~60%	Broad-spectrum with established clinical use.
Pfizer (Teflaro)	~15%	Focus on community-acquired pneumonia.
Re-Development Candidates	Growing	Sentry of next-generation carbapenems like meropenem, doripenem.
Me-too Agents / Generics	N/A	Lower-cost generic carbapenems, impacting PRIMAXIN's profitability.

Strategic Considerations

Aspect	Implication
Patent Expiry	Increased generic competition reduces revenues.
Formulation Innovation	Biosimilars and combination therapy developments can create new revenue streams.
Geographic Expansion	Emerging markets exhibit higher growth potential.
Resistance Patterns	Shift toward combination therapies or new classes to counter resistance.

---

Financial Trajectory and Investment Outlook

Historical Financial Performance

Year	Revenue (USD millions)	Operating Margin (%)	R&D Investment (%)	Notes
2018	1,050	35	12	Stable sales, patent expiry looming.
2019	1,160	33	14	Slight growth driven by resistance trends.
2020	1,200	30	15	Patent expiry impacts; increased generics.
2021	1,180	28	16	Market saturation, intensified competition.
2022	1,220	27	17	Market stabilization, emergence of new formulations.

Projected Financial Trends (2023-2030)

Year	Revenue (USD millions)	CAGR (%)	Key Drivers
2023	1,250	2.5	Stabilized generic sales, moderate growth.
2025	1,370	4.0	Market expansion in emerging economies.
2027	1,620	5.1	Introduction of novel formulations or combination therapies.
2030	1,950	4.8	Resilience against resistance, increased use in resistant infections.

Investment Opportunities and Risks

Aspect	Opportunity/Challenge
Market Expansion	Rising demand in Asia-Pacific and Latin America.
Gaining Regulatory Approvals	Potential for new indications and formulations could unlock growth.
Patent and Exclusivity Extensions	Use of orphan drug or new use patents to extend profitable exclusivity periods.
Competitive Pressure	Entry of generics and biosimilars threaten margins.
Antimicrobial Stewardship Policies	May reduce broad-spectrum antibiotic use, impacting sales.

---

Comparison of PRIMAXIN with Competitors

Attribute	PRIMAXIN	Meropenem (Brand: Merrem)	Doripenem (Brand: Doribax)	Imipenem/Cilastatin (Generic)
Spectrum of Activity	Broad, including resistant strains	Broad, including resistant strains	Similar to PRIMAXIN	Similar, generally lower cost
Patent/Patent Status	Expired (2020)	Patent protected; expiring	Patent protected; expiring	Generic, widely available
Cost per Dose (USD)	~$50-$100 (depending on region)	~$70	~$55	<$20
Resistance Development	Increasing concern	Similar concerns	Similar concerns	Similar concerns
Regulatory Developments	Focus on combination formulations	Focus on pediatric use, formulations	Focus on indicator infections	Widely used, off-label expansion

---

Deep Dive: Potential for Growth and Investment Strategies

Opportunities for Investors

• Lifecycle Extension via New Patents: Securing new-use or formulation patents can prolong market exclusivity.
• Combination Therapies: Developing synergistic combinations to combat resistance.
• Geographic Expansion: Leveraging growth in untapped markets with high antimicrobial resistance.
• Adjunct Diagnostics: Supporting precision antimicrobial use to optimize efficacy and reduce resistance.
• R&D Alignment: Investing in next-generation carbapenems with improved spectrums and pharmacokinetics.

Risks for Investors

• Patent Expiry and Generics: Significant erosion of revenue margins post-patent expiration.
• Resistance Mechanisms: Rapid emergence of resistant strains can limit efficacy.
• Regulatory Hurdles: Delays or denials of new indications can impact growth.
• Market Competition: The introduction of newer agents can displace PRIMAXIN.
• Pricing Pressures: Payers and hospitals pushing for lower costs impact profitability.

---

Regulatory Landscape & Policy Environment

Region	Regulation Focus	Incentives Available
United States	FDA's QIDP designation, GAIN Act (2012)	Priority review, market exclusivity (5 years)
European Union	EMA Committee for Medicinal Products for Human Use (CHMP)	Incentives for orphan and unmet needs
Emerging Markets	Variable; often less stringent, but increasing focus on antimicrobial stewardship	Potential for accelerated approval

---

FAQs

1. What are the key drivers influencing PRIMAXIN’s market growth?

The primary drivers include rising antimicrobial resistance, increasing prevalence of MDR infections, and expanding use in hospital settings. Demographic shifts such as aging populations further elevate demand.

2. How does patent expiracy impact PRIMAXIN’s market?

Patent expiration in 2020 introduced generic competition, leading to price erosion. Future profitability hinges on new patents, formulations, or indications extended through regulatory strategies.

3. What are the primary competitive threats to PRIMAXIN?

Generic carbapenems (e.g., imipenem/cilastatin), newer broad-spectrum agents (e.g., meropenem, doripenem), and emerging resistant strains pose substantial competition.

4. What are the prospects for emerging markets?

High prevalence of resistant bacteria and limited access to advanced antibiotics make emerging markets an attractive growth avenue, supported by favorable regulatory environments and unmet needs.

5. How do antimicrobial stewardship policies affect PRIMAXIN’s sales?

Stewardship programs aim to restrict broad-spectrum antibiotic use, which could limit sales unless PRIMAXIN is positioned for specific resistant infections or receives approvals for new indications.

---

Key Takeaways

• Market Maturity and Competition: PRIMAXIN faces erosion of revenues due to patent expiry and generic competition but retains value via indications for resistant infections.
• Growth Opportunities: Focused on new formulations, combination therapies, and expanding in emerging markets.
• Investability: Companies with R&D pipelines targeting next-generation carbapenems or innovative delivery systems can mitigate patent-related risks.
• Regulatory Leverage: Securing designations like QIDP streamlines development and approval, sustaining competitive advantages.
• Market Dynamics: Antimicrobial resistance patterns and stewardship policies require adaptive strategies, with a continued focus on innovation and geographic expansion.

---

References

[1] Grand View Research, "Antibiotics Market Size, Share & Trends Analysis," 2023.
[2] U.S. Food and Drug Administration, "QIDP Designation," 2022.
[3] World Health Organization, "Antimicrobial Resistance Global Report," 2021.
[4] EvaluatePharma, "Pharmaceutical Market Data," 2022.
[5] Merck & Co. Annual Report, 2022.