Cilastatin sodium; imipenem - Generic Drug Details

What are the generic sources for cilastatin sodium; imipenem and what is the scope of patent protection?

Cilastatin sodium; imipenem is the generic ingredient in three branded drugs marketed by Merck, Acs Dobfar, Hospira Inc, Hq Spclt Pharma, and Msd Merck Co, and is included in eight NDAs. There is one patent protecting this compound. Additional information is available in the individual branded drug profile pages.

Three suppliers are listed for this compound.

Summary for cilastatin sodium; imipenem

US Patents:	1
Tradenames:	3
Applicants:	5
NDAs:	8
Finished Product Suppliers / Packagers:	3
Clinical Trials:	2
DailyMed Link:	cilastatin sodium; imipenem at DailyMed

Recent Clinical Trials for cilastatin sodium; imipenem

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

Sponsor	Phase
M.D. Anderson Cancer Center	Phase 2
Merck Sharp & Dohme Corp.	Phase 3

See all cilastatin sodium; imipenem clinical trials

Pharmacology for cilastatin sodium; imipenem

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

US Patents and Regulatory Information for cilastatin sodium; imipenem

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Acs Dobfar	IMIPENEM AND CILASTATIN	cilastatin sodium; imipenem	POWDER;INTRAVENOUS	090577-002	Dec 21, 2011	AP	RX	No	No
Merck	PRIMAXIN	cilastatin sodium; imipenem	INJECTABLE;INJECTION	062756-002	Jan 8, 1987		DISCN	No	No
Hospira Inc	IMIPENEM AND CILASTATIN	cilastatin sodium; imipenem	POWDER;INTRAVENOUS	091007-001	Nov 16, 2011		DISCN	No	No

Expired US Patents for cilastatin sodium; imipenem

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

Market Dynamics and Financial Trajectory for Cilastatin Sodium and Imipenem

Last updated: July 29, 2025

Introduction

Cilastatin sodium and imipenem are critical components in the treatment of severe bacterial infections, particularly those caused by multidrug-resistant pathogens. Imipenem, a broad-spectrum carbapenem antibiotic, is often administered in combination with cilastatin sodium, an inhibitor that protects imipenem from renal degradation, enhancing its efficacy. Understanding their market dynamics and financial trajectory offers insights for stakeholders ranging from pharmaceutical developers to healthcare providers.

Product Overview

Imipenem: Discovered in the 1980s, imipenem is renowned for its broad antimicrobial spectrum, including activity against Gram-positive, Gram-negative, and anaerobic bacteria. It’s primarily indicated for severe intra-abdominal, respiratory, urinary tract, and gynecological infections.

Cilastatin Sodium: As a β-lactamase inhibitor, cilastatin sodium does not possess intrinsic antibacterial activity but prevents the renal dehydropeptidase I enzyme from hydrolyzing imipenem, thus increasing its therapeutic window. It is administered concomitantly with imipenem.

The combined formulation, such as Primaxin, is FDA-approved and has a significant market share in hospital settings.

Market Dynamics

Epidemiological Drivers

The global rise of antimicrobial resistance (AMR) has invigorated the demand for carbapenems like imipenem, especially in combating multidrug-resistant Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii. According to the CDC, carbapenem-resistant organisms are associated with high mortality rates, reinforcing the clinical need for potent antibiotics such as imipenem-cilastatin [1].

Additionally, the increasing prevalence of hospital-acquired infections (HAIs) and complicated intra-abdominal infections sustains demand, especially in intensive care units (ICUs).

Regulatory and Patent Landscape

While imipenem has been off patent for several years, the formulations containing cilastatin sodium remain under patent protection in multiple jurisdictions, providing a competitive edge to branded products. Patent expirations for generic versions have increased price competition, impacting revenue trajectories for original manufacturers.

Furthermore, regulatory frameworks emphasizing antimicrobial stewardship and restrictions on overuse have affected sales volumes but aim to sustain long-term market viability by curbing resistance proliferation.

Competitive Environment

The market features several key players, including Merck (original developer of Primaxin), Teva, Sandoz, and other generics manufacturers. Biosimilars and novel carbapenem derivatives aim to challenge the dominance of imipenem-cilastatin formulations.

Emerging alternatives, such as newer β-lactamases inhibitors (e.g., relebactam, vaborbactam), combined with carbapenems may influence market shares. For instance, meropenem-vaborbactam introduces competition into the carbapenem class, which could limit imipenem-cilastatin's growth prospects.

Supply Chain and Manufacturing Considerations

Manufacturing stability hinges on complex synthetic pathways and stringent quality controls. Supply chain disruptions—due to geopolitical issues or manufacturing bottlenecks—can impact product availability and pricing.

Active pharmaceutical ingredient (API) sourcing, especially for cilastatin sodium, is concentrated in certain regions, exposing the supply chain to geopolitical risks [2].

Pricing and Reimbursement Dynamics

Pricing strategies are influenced by hospital procurement policies, insurance reimbursement schemes, and generics' entry. In many markets, governments negotiate drug prices, which tend to suppress revenues for established products.

The high cost of developing newer antimicrobials, combined with stewardship efforts, restricts sharp price increases, making profit margins sensitive to volume and licensing agreements.

Financial Trajectory

Revenue Trends

Global imipenem-cilastatin market revenue was valued at approximately USD 1.8 billion in 2022, with anticipated compound annual growth rates (CAGR) of 3-5% over the next five years [3]. The growth is driven by rising resistance rates, with Asia-Pacific leading due to expanding healthcare infrastructure and infection burdens.

Profitability and Investment

Branded formulations, especially those with patent protections, historically reported higher margins. However, as patents expired and generics flooded markets, revenue streams have become more vulnerable to price erosion.

Investment in R&D targeting next-generation β-lactamase inhibitors indicates a strategic shift toward expanded spectrum and resistance mitigation, potentially creating new revenue streams.

Market Risk Factors

• Antimicrobial Stewardship: Imposes restrictions that limit growth.
• Resistance Development: Accelerates demand but can shorten product lifecycle.
• Regulatory Changes: Stricter approvals and restrictions could impact commercialization.
• Emergence of Alternatives: Future antibiotics may supplant imipenem-cilastatin, reducing market share.

Emerging Market Opportunities

Growth in developing economies due to rising bacterial infection incidences and expanding healthcare infrastructure presents lucrative opportunities. Strategic pricing, local manufacturing, and partnerships could enhance profitability.

Future Outlook

The outlook for imipenem and cilastatin sodium is cautiously optimistic. Their indispensability in severe infection management ensures sustained demand, especially in hospital settings. However, the horizon is shaped by innovation, resistance patterns, and global health policies.

Biotech initiatives targeting combination therapies or novel β-lactamase inhibitors could alter the competitive landscape. Investment in these areas is expected to influence the long-term financial trajectory favorably.

Key Takeaways

• The AI-driven rise of resistant bacteria elevates imipenem-cilastatin’s clinical importance, maintaining steady demand.
• Patent protections afford premium pricing; however, generic competition and regulatory pressures limit revenue growth.
• Supply chain vulnerabilities and geopolitical risks necessitate diversified manufacturing strategies.
• Market growth is driven by developing economies, though antimicrobial stewardship and resistance necessitate innovation.
• Future profitability hinges on product innovation, strategic collaborations, and adherence to stewardship guidelines.

FAQs

1. How does antimicrobial resistance affect the market for imipenem-cilastatin?
Rising resistance increases demand for potent antibiotics like imipenem-cilastatin but also accelerates the development of newer agents, potentially shortening its market lifespan.

2. What are the opportunities for generic manufacturers in this market?
Generics afford lower-cost options in mature markets, expanding access. Strategic entry into emerging markets and investments in manufacturing efficiencies can enhance profitability.

3. Are biosimilar versions expected to impact imipenem-cilastatin's market?
While biosimilars are more relevant to biologics, the advent of novel small-molecule carbapenems or combination therapies could challenge imipenem-cilastatin in the future.

4. How significant is the role of regulatory policies in shaping the market?
Regulatory agencies’ emphasis on antimicrobial stewardship and resistance management influences prescription practices, pricing, and market access.

5. What innovations could extend the product’s market viability?
Next-generation β-lactamase inhibitors and novel delivery formulations could bolster efficacy, resistance management, and profitability.

References

[1] Centers for Disease Control and Prevention (CDC). Antibiotic Resistance Threats in the United States, 2019.
[2] International Trade Administration. Global Pharmaceutical Supply Chain Report, 2021.
[3] MarketWatch. “Global Imipenem-Cilastatin Market Size & Share Analysis Report, 2022–2028.”