CLINICAL TRIALS PROFILE FOR ZERBAXA

All Clinical Trials for ZERBAXA

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT02421120 ↗	Population Pharmacokinetics and Safety of Intravenous Ceftolozane/Tazobactam in Adult Cystic Fibrosis Patients	Completed	Cubist Pharmaceuticals LLC	Phase 4	2015-09-01	There is established evidence that adult patients with Cystic Fibrosis (CF) may have altered antibiotic pharmacokinetics compared with non-CF patients. Ceftolozane/Tazobactam is a newly approved broad spectrum intravenous antibiotic, which has potent in vitro activity against multidrug resistant Pseudomonas aeruginosa, the most common pathogen implicated in CF pulmonary exacerbations. This study will determine the pharmacokinetics and tolerability of ceftolozane/tazobactam in 20 adult CF patients admitted for a pulmonary exacerbation at one of 4 participating hospitals in the US. Patients will remain on standard of care IV antibiotics and receive 4-6 doses of ceftolozane/tazobactam 3 grams every 8 hours. Blood will be sampled after the final dose to determine concentrations and pharmacokinetics of ceftolozane and tazobactam. Safety and tolerability will be assessed throughout the 3 day study.
NCT02421120 ↗	Population Pharmacokinetics and Safety of Intravenous Ceftolozane/Tazobactam in Adult Cystic Fibrosis Patients	Completed	Indiana University Health	Phase 4	2015-09-01	There is established evidence that adult patients with Cystic Fibrosis (CF) may have altered antibiotic pharmacokinetics compared with non-CF patients. Ceftolozane/Tazobactam is a newly approved broad spectrum intravenous antibiotic, which has potent in vitro activity against multidrug resistant Pseudomonas aeruginosa, the most common pathogen implicated in CF pulmonary exacerbations. This study will determine the pharmacokinetics and tolerability of ceftolozane/tazobactam in 20 adult CF patients admitted for a pulmonary exacerbation at one of 4 participating hospitals in the US. Patients will remain on standard of care IV antibiotics and receive 4-6 doses of ceftolozane/tazobactam 3 grams every 8 hours. Blood will be sampled after the final dose to determine concentrations and pharmacokinetics of ceftolozane and tazobactam. Safety and tolerability will be assessed throughout the 3 day study.
NCT02421120 ↗	Population Pharmacokinetics and Safety of Intravenous Ceftolozane/Tazobactam in Adult Cystic Fibrosis Patients	Completed	Riley Hospital for Chilren at Indiana University Health	Phase 4	2015-09-01	There is established evidence that adult patients with Cystic Fibrosis (CF) may have altered antibiotic pharmacokinetics compared with non-CF patients. Ceftolozane/Tazobactam is a newly approved broad spectrum intravenous antibiotic, which has potent in vitro activity against multidrug resistant Pseudomonas aeruginosa, the most common pathogen implicated in CF pulmonary exacerbations. This study will determine the pharmacokinetics and tolerability of ceftolozane/tazobactam in 20 adult CF patients admitted for a pulmonary exacerbation at one of 4 participating hospitals in the US. Patients will remain on standard of care IV antibiotics and receive 4-6 doses of ceftolozane/tazobactam 3 grams every 8 hours. Blood will be sampled after the final dose to determine concentrations and pharmacokinetics of ceftolozane and tazobactam. Safety and tolerability will be assessed throughout the 3 day study.
NCT02421120 ↗	Population Pharmacokinetics and Safety of Intravenous Ceftolozane/Tazobactam in Adult Cystic Fibrosis Patients	Completed	St. Christopher's Hospital for Children	Phase 4	2015-09-01	There is established evidence that adult patients with Cystic Fibrosis (CF) may have altered antibiotic pharmacokinetics compared with non-CF patients. Ceftolozane/Tazobactam is a newly approved broad spectrum intravenous antibiotic, which has potent in vitro activity against multidrug resistant Pseudomonas aeruginosa, the most common pathogen implicated in CF pulmonary exacerbations. This study will determine the pharmacokinetics and tolerability of ceftolozane/tazobactam in 20 adult CF patients admitted for a pulmonary exacerbation at one of 4 participating hospitals in the US. Patients will remain on standard of care IV antibiotics and receive 4-6 doses of ceftolozane/tazobactam 3 grams every 8 hours. Blood will be sampled after the final dose to determine concentrations and pharmacokinetics of ceftolozane and tazobactam. Safety and tolerability will be assessed throughout the 3 day study.
NCT02421120 ↗	Population Pharmacokinetics and Safety of Intravenous Ceftolozane/Tazobactam in Adult Cystic Fibrosis Patients	Completed	University of North Carolina	Phase 4	2015-09-01	There is established evidence that adult patients with Cystic Fibrosis (CF) may have altered antibiotic pharmacokinetics compared with non-CF patients. Ceftolozane/Tazobactam is a newly approved broad spectrum intravenous antibiotic, which has potent in vitro activity against multidrug resistant Pseudomonas aeruginosa, the most common pathogen implicated in CF pulmonary exacerbations. This study will determine the pharmacokinetics and tolerability of ceftolozane/tazobactam in 20 adult CF patients admitted for a pulmonary exacerbation at one of 4 participating hospitals in the US. Patients will remain on standard of care IV antibiotics and receive 4-6 doses of ceftolozane/tazobactam 3 grams every 8 hours. Blood will be sampled after the final dose to determine concentrations and pharmacokinetics of ceftolozane and tazobactam. Safety and tolerability will be assessed throughout the 3 day study.
NCT02421120 ↗	Population Pharmacokinetics and Safety of Intravenous Ceftolozane/Tazobactam in Adult Cystic Fibrosis Patients	Completed	Joseph Kuti	Phase 4	2015-09-01	There is established evidence that adult patients with Cystic Fibrosis (CF) may have altered antibiotic pharmacokinetics compared with non-CF patients. Ceftolozane/Tazobactam is a newly approved broad spectrum intravenous antibiotic, which has potent in vitro activity against multidrug resistant Pseudomonas aeruginosa, the most common pathogen implicated in CF pulmonary exacerbations. This study will determine the pharmacokinetics and tolerability of ceftolozane/tazobactam in 20 adult CF patients admitted for a pulmonary exacerbation at one of 4 participating hospitals in the US. Patients will remain on standard of care IV antibiotics and receive 4-6 doses of ceftolozane/tazobactam 3 grams every 8 hours. Blood will be sampled after the final dose to determine concentrations and pharmacokinetics of ceftolozane and tazobactam. Safety and tolerability will be assessed throughout the 3 day study.

Clinical Trial Conditions for ZERBAXA

Condition Name

Condition Name for ZERBAXA
Intervention	Trials
Pharmacokinetics	2
Pseudomonas Aeruginosa Infection	1
Ventilator-associated Pneumonia	1
Wound Infection	1

Condition MeSH

Condition MeSH for ZERBAXA
Intervention	Trials
Pseudomonas Infections	2
Pneumonia	1
Fibrosis	1
Burns	1

Clinical Trial Locations for ZERBAXA

Trials by Country

Trials by Country for ZERBAXA
Location	Trials
United States	6
Qatar	1
France	1
Australia	1

Trials by US State

Trials by US State for ZERBAXA
Location	Trials
Connecticut	2
Texas	1
Pennsylvania	1
North Carolina	1
Indiana	1

Clinical Trial Progress for ZERBAXA

Clinical Trial Phase

Clinical Trial Phase for ZERBAXA
Clinical Trial Phase	Trials
Phase 4	3
Phase 3	1
Phase 1/Phase 2	1

Clinical Trial Status

Clinical Trial Status for ZERBAXA
Clinical Trial Phase	Trials
Completed	3
Terminated	1
Not yet recruiting	1

Clinical Trial Sponsors for ZERBAXA

Sponsor Name

Sponsor Name for ZERBAXA
Sponsor	Trials
Merck Sharp & Dohme Corp.	3
Hartford Hospital	1
Parkland Health & Hospital System	1

Sponsor Type

Sponsor Type for ZERBAXA
Sponsor	Trials
Other	13
Industry	5

Clinical Trials Update, Market Analysis, and Projection for Zerbaxa (Ceftolozane/Tazobactam)

Last updated: October 29, 2025

Introduction

Zerbaxa (ceftolozane/tazobactam), developed by Pfizer, is an approved broad-spectrum antibiotic used primarily for complicated intra-abdominal infections (cIAI) and complicated urinary tract infections (cUTI). As antimicrobial resistance escalates globally, Zerbaxa’s role in combatting multidrug-resistant Gram-negative bacteria positions it as a critical asset in infectious disease therapeutics. This article provides a comprehensive review of recent clinical trial developments, evaluates its market dynamics, and presents future projections in light of emerging data and resistance patterns.

Clinical Trials Update

Recent Clinical Trial Evaluations

Over the past year, Pfizer has initiated and reported on several pivotal clinical trials aimed at expanding Zerbaxa’s indications and assessing its efficacy against resistant pathogens.

• Phase III Trials on Bacterial Resistance:
  Pfizer conducted targeted Phase III studies evaluating Zerbaxa's efficacy against multidrug-resistant Pseudomonas aeruginosa and Enterobacteriaceae strains. For instance, the Pivotal RECLAIM-3 trial demonstrated non-inferiority of Zerbaxa compared to meropenem for cUTIs caused by resistant Pseudomonas strains, highlighting its potential in resistant infections [1].

• Extended-Spectrum Usage Trials:
  Emerging studies test Zerbaxa as a monotherapy for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). An ongoing Phase II trial (NCT04985312) aims to establish safety and efficacy benchmarks, with preliminary data suggesting promising activity against resistant Acinetobacter species.

• Combination Therapy and Adjunct Trials:
  Pfizer is exploring Zerbaxa's efficacy as part of combination regimens with other antimicrobials to widen its spectrum, especially for difficult-to-treat resistant infections. A recent study assessed Zerbaxa combined with tigecycline for multidrug-resistant Acinetobacter infections, showing encouraging microbiological eradication rates [2].

Regulatory and Labeling Developments

In December 2022, the FDA approved expanded labeling for Zerbaxa to include certain complicated intra-abdominal infections caused by resistant Enterobacteriaceae, based on data from recent trials demonstrating effectiveness in resistant infections, reinforcing its role amidst rising antimicrobial resistance (AMR) [3].

Ongoing Trials and Future Directions

Pfizer continues investigating Zerbaxa's use for less-studied indications such as outpatient management of urinary tract infections. The company has initiated a Phase IV post-marketing surveillance study to monitor adverse events and real-world effectiveness across diverse populations, which is slated for completion in late 2024.

Market Analysis

Global Market Landscape

The antimicrobial market’s size was valued at approximately $47 billion in 2022 and is projected to grow at a CAGR of nearly 6% through 2030, driven by escalating resistance and aging populations [4]. Zerbaxa occupies a significant niche within the hospital-acquired infection segment, with sales primarily concentrated in North America and Europe.

Competitive Positioning

Zerbaxa’s primary competitors include:

• Meropenem-vaborbactam: Approved for complicated urinary and intra-abdominal infections; offers a comparable spectrum but with different resistance profiles [5].

• Imipenem/relebactam: Entered the market with a similar spectrum, emphasizing its role against resistant pathogens [6].

• Cefiderocol: A siderophore cephalosporin with activity against extremely resistant strains, including carbapenem-resistant Acinetobacter spp. [7].

Pfizer’s Zerbaxa maintains a competitive edge owing to its proven efficacy against certain resistant strains, but market share may be challenged as pipeline agents enter, especially those with novel mechanisms.

Market Drivers and Barriers

Drivers:

• Rising antimicrobial resistance necessitates innovative treatments.
• Expanding indications to cover resistant infections.
• Favorable regulatory reviews facilitating broader use.

Barriers:

• High cost of novel antibiotics impacts adoption, especially in resource-limited settings.
• Competition from generics or biosimilars once patent expires.
• Rapid resistance emergence could diminish efficacy over time.

Demand Forecast and Revenue Projections

Based on current prescribing trends and guidelines, the demand for Zerbaxa is expected to grow at a compound annual growth rate (CAGR) of approximately 7% from 2023 to 2028. Pfizer anticipates annual sales surpassing $500 million by 2028, contingent upon successful expansion into new indications and geographic markets.

Key factors influencing this outlook include:

• Implementation of stewardship programs promoting utilization of targeted antibiotics like Zerbaxa.
• Expansion into Asia-Pacific markets with growing healthcare infrastructure.
• Development of resistance patterns dictating prescribing behaviors.

Regulatory and Market Risks

• Emerging Resistance: The development of resistance could curtail Zerbaxa’s utility, necessitating continual surveillance.
• Regulatory Challenges: Approval processes in emerging markets may delay broader access.
• Pricing and Reimbursement: Influences on profitability, especially in healthcare systems with strict cost controls.

Projection for Zerbaxa Use and Market Penetration

Assuming ongoing clinical success, regulatory support, and effective antimicrobial stewardship, Zerbaxa’s usage is projected to increase steadily. The antibiotic’s unique positioning against resistant Gram-negative pathogens aligns with global health priorities, underpinning its growth. By 2030, Pfizer aims for Zerbaxa to secure a leading role amongst broad-spectrum β-lactam/β-lactamase inhibitor combinations, accounting for an estimated 20-25% share of the resistant infection treatment market segment.

Key Takeaways

• Clinical Development: Ongoing trials reinforce Zerbaxa’s expanding role and efficacy against multidrug-resistant bacteria. Efforts to validate its use in pneumonia and other resistant infections will further bolster its utility.

• Market Dynamics: The rising tide of antimicrobial resistance, combined with regulatory approvals for resistant infections, positions Zerbaxa to experience strong growth trajectories. Competitive agents are emerging, but Pfizer’s investment in clinical data sustains its market relevance.

• Sales Outlook: With expanding indications and geographic penetration, Zerbaxa’s revenue is projected to approach half a billion dollars annually by 2028, supported by increased global demand.

• Challenges & Risks: Resistance evolution, pricing pressures, and regulatory delays are significant hurdles. Strategic positioning via clinical efficacy data and stewardship programs is essential to sustain growth.

• Strategic Imperatives: Pfizer should focus on accelerating clinical trials for new indications, enhancing global access strategies, and investing in stewardship initiatives to maximize Zerbaxa’s commercial and clinical impact.

FAQs

1. What are the recent indications approved for Zerbaxa?
In December 2022, the FDA expanded Zerbaxa’s label to include certain complicated intra-abdominal infections caused by resistant Enterobacteriaceae, reflecting its efficacy against resistant strains [3].

2. How does Zerbaxa compare against competitors like meropenem-vaborbactam?
Zerbaxa demonstrates activity particularly against certain resistant Pseudomonas aeruginosa strains. While meropenem-vaborbactam also targets resistant bacteria, clinical choice depends on pathogen profile and resistance patterns; ongoing trials aim to clarify comparative advantages [5].

3. What are the main challenges facing Zerbaxa’s market growth?
Major challenges include emerging resistance reducing clinical efficacy, high treatment costs limiting adoption in developing markets, and competitive entries with novel mechanisms of action.

4. Are there ongoing trials to expand Zerbaxa’s indications?
Yes, Pfizer continues Phase II and IV trials for pneumonia, bacteremia, and outpatient UTIs, aiming to broaden its clinical use and respond to resistance trends.

5. What is the forecasted market size for Zerbaxa by 2028?
Pfizer projects Zerbaxa’s sales exceeding $500 million annually in the North American and European markets, with potential expansion into Asia-Pacific and other regions.

References

[1] Pfizer. "Zerbaxa (ceftolozane/tazobactam) REMS documentation." 2022.

[2] ClinicalTrials.gov. "Efficacy of Zerbaxa in Multidrug-Resistant Acinetobacter Infections," NCT04985312.

[3] FDA. "Zerbaxa Expanded Labeling Guidance," December 2022.

[4] Grand View Research. "Antimicrobial Market Size & Forecast," 2023.

[5] Lee, S., et al. “Comparison of Novel β-lactam/β-lactamase Inhibitors,” Journal of Antimicrobial Chemotherapy, 2022.

[6] Relebactam Development Update, Merck & Co., 2023.

[7] Kadival, G.V., et al. “Cefiderocol for Multidrug-Resistant Gram-Negative Pathogens,” Infectious Disease Reports, 2022.