Meitheal Pharmaceuticals Receives Approval from the US Food and Drug Administration for CONTEPO™ (fosfomycin) for injection in Patients ≥ 18 Years Having Complicated Urinary Tract Infections (cUTI), Including Acute Pyelonephritis (AP)

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8:53 AM on Tuesday, November 4

The Associated Press

CHICAGO--(BUSINESS WIRE)--Nov 4, 2025--

Meitheal Pharmaceuticals, Inc. (“Meitheal”), a fully integrated biopharmaceutical company based in Chicago and focused on the development and commercialization of generic injectables, fertility, biologic, and branded products, announced approval from the U.S. Food and Drug Administration (FDA) for CONTEPO (fosfomycin) for injection for the treatment of adult patients with complicated urinary tract infections (cUTI), including acute pyelonephritis, caused by susceptible isolates of Escherichia coli and Klebsiella pneumoniae.

CONTEPO, an intravenous (IV) antibiotic that is an injectable epoxide and sole antibiotic class member, has demonstrated activity against gram-negative bacteria including Escherichia coli and Klebsiella pneumoniae that cause cUTIs. 1,2 It has no known cross-resistance to other antibiotic classes. 3,4 Targeting bacteria’s cell wall at an earlier stage than β-lactam antibiotics, CONTEPO’s unique mechanism of action inhibits the first committed step in bacterial cell wall synthesis, eliminating all downstream signaling that is vital to cell survival and leading to the destruction of the bacteria. 2

“The escalating public health issue of antimicrobial resistance and emergence of highly resistant organisms demands immediate attention and innovative therapeutic solutions. The approval of CONTEPO is a major milestone in our company’s evolution and the fight against the ongoing threat of antibiotic resistance,” said Tom Shea, Chief Executive Officer of Meitheal Pharmaceuticals. “We are proud to add a second branded product to our growing portfolio of anti-infectives and antibiotics and look forward to delivering this high-quality and effective antibiotic medicine to patients and providers.”

The FDA approval is supported by data from the pivotal Phase 2/3 ZEUS (ZTI-01) trial which investigated the safety and efficacy of the treatment on hospitalized patients with cUTI, including acute pyelonephritis. The trial showed that intravenous (IV) fosfomycin was noninferior to piperacillin/tazobactam for the primary efficacy endpoint—overall success, defined as clinical cure and microbiologic eradication—at the test-of-cure visit in the microbiological modified intent-to-treat (mMITT) population. Overall success was achieved in 63.5% (108/170) of patients receiving IV fosfomycin and 55.6% (94/169) of those receiving piperacillin/tazobactam, with a treatment difference of 7.9 (95% CI -3.1 to 18.9).

The safety and tolerability profile of CONTEPO was generally well-tolerated. 2 The most commonly reported adverse reactions in ≥2% of CONTEPO patients in the study included transaminase elevations (10.3%), hypokalemia (9.9%), neutropenia (6.4%), nausea (4.3%), diarrhea (3.9%), vomiting (3.9%), hypocalcemia (3.9%), hypernatremia (3.4%), headache (2.6%), and hypophosphatemia (2.1%).

"The rise of multi-drug-resistant pathogens poses a significant threat to our ability to combat infectious diseases, underscoring the continued need for novel therapies that target resistant organisms in patients having cUTIs," said Dr. Keith S. Kaye, MD, MPH Chief, Division of Allergy, Immunology and Infectious Diseases at the Robert Wood Johnson Medical School.

“With an estimated three million cases of cUTIs treated in the hospital setting annually, there is a critical need for a safe and effective treatment option. 5 CONTEPO’s safety, efficacy, and novel mechanism of action makes it a favorable new treatment option,” said Dr. Keith Robinson, Chief Medical Officer of Meitheal Pharmaceuticals.

With this approval, Meitheal’s portfolio has rapidly expanded to over 70 on-market products with additional generic launches expected before the end of the year across its core therapeutic areas of anti-infectives, anesthetics, critical care, fertility, and oncology.

ABOUT CONTEPO

CONTEPO (fosfomycin) for injection is a novel, intravenous antibiotic and is the only FDA approved epoxide antibacterial product. Part of a different class of antibiotics known as phosphonics, CONTEPO covalently binds and inhibits phosphoenolpyruvate transferase (MurA) which prevents the formation of cell wall precursors, blocks cell wall synthesis and leads to the destruction of bacteria. It has demonstrated activity against gram-negative bacteria including Escherichia coli and Klebsiella pneumoniae and other antimicrobial resistant pathogens. Efficacy and safety in patients have been demonstrated in adult patients with complicated urinary tract infections (cUTI), including acute pyelonephritis.

INDICATIONS AND USAGE

CONTEPO (fosfomycin) is indicated for the treatment of patients 18 years and older with complicated urinary tract infections (cUTI), including acute pyelonephritis, caused by susceptible isolates of Escherichia coli and Klebsiella pneumoniae.

Usage to Reduce Development of Drug-Resistant Bacteria

To reduce the development of drug-resistant bacteria and maintain the effectiveness of CONTEPO and other antibacterial drugs, CONTEPO should be used only to treat infections that are proven or strongly suspected to be caused by susceptible bacteria.

IMPORTANT SAFETY INFORMATION

Contraindications

CONTEPO is contraindicated in patients with known serious hypersensitivity to fosfomycin, or any of the excipients.

Warning and Precautions

Serum Electrolyte Abnormalities: CONTEPO contains 1,980 mg of sodium in each vial. The high sodium load associated with the use of CONTEPO may result in changes in serum electrolytes, such as increased levels of serum sodium and decreased levels of potassium, calcium, and phosphorous. Electrolyte disturbances, such as hypokalemia and hypocalcemia, may potentiate cardiac effects, including QT prolongation. In a phase 2/3 comparator-controlled clinical trial in patients with cUTI, the following occurred more frequently in CONTEPO-treated patients compared with piperacillin/tazobactam-treated patients: hypokalemia (9.9%), hypernatremia (3.4%), hypophosphatemia (2.1%), and hypocalcemia (3.9%). Monitor serum electrolyte levels and fluid status during treatment with CONTEPO. Electrolyte supplementation may be necessary in some cases. Monitor for signs of edema, particularly in patients who should restrict their sodium intake or are prone to fluid overload.

QT Prolongation: CONTEPO has been shown to prolong the QT interval in some patients. QT prolongation can lead to development of torsade de pointes-type ventricular tachycardia with the risk increasing as the degree of prolongation increases. The risk of QT prolongation may increase in patients with electrolyte abnormalities, or those that have conditions or take medications that may cause an electrolyte imbalance. Avoid CONTEPO in patients with known QT prolongation or ventricular arrhythmias, including a history of torsade de pointes. Monitor electrolytes during treatment with CONTEPO.

Increase Transaminase Levels: In a phase 2/3 clinical trial, increases in transaminases occurred more frequently in CONTEPO-treated patients compared to piperacillin/tazobactam-treated patients. Transaminases (alanine aminotransferase (ALT) or aspartate aminotransferase (AST)) were elevated > 3x upper limit of normal (ULN) in 10.3% of patients receiving CONTEPO and 4.8% of patients receiving piperacillin/tazobactam. Transaminase elevations were asymptomatic and reversible. Monitor hepatic enzymes during CONTEPO treatment.

Hypersensitivity Reactions: Hypersensitivity reactions, such as rash, urticaria, and anaphylaxis have been reported. Before initiating therapy with CONTEPO, it is important to inquire about previous hypersensitivity reactions to oral or parenteral fosfomycin. If an allergic reaction to CONTEPO occurs, discontinue the drug immediately.

Neutropenia Including Agranulocytosis: Neutropenia has been reported in patients receiving IV fosfomycin therapy. Monitor complete blood counts during CONTEPO therapy particularly in patients with pre-existing conditions or patients receiving concomitant drugs that may predispose to bone marrow suppression. Discontinue CONTEPO if neutropenia occurs and consider alternative therapies.

Clostridioides difficile-Associated Diarrhea: Clostridioides difficile -associated diarrhea (CDAD) has been reported with use of nearly all systemic antibacterial agents, including CONTEPO, and may range in severity from mild to fatal colitis. Careful medical history is necessary because CDAD has been reported to occur more than 2 months after administration of antibacterial agents. If CDAD is confirmed, discontinue antibacterials not directed against C. difficile, if possible.

Development of Drug-resistant Bacteria: Prescribing CONTEPO in the absence of a proven or strongly suspected bacterial infection indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

Adverse Reactions

The most common adverse reactions occurring in ≥ 2% of patients receiving CONTEPO were transaminase elevations (10.3%), hypokalemia (9.9%), neutropenia (6.4%), nausea (4.3%), diarrhea (3.9%), vomiting (3.9%), hypocalcemia (3.9%), hypernatremia (3.4%), headache (2.6%), and hypophosphatemia (2.1%).

Drug Interactions

Avoid co-administration of CONTEPO with drugs known to prolong the QT interval.

Use in Specific Populations

Lactation: Breastfeeding is not recommended during treatment and 24 hours after the last dose.

Geriatric Use: Because elderly patients are more likely to have decreased cardiac and renal function, care should be taken in dose selection, and electrolytes, fluid status, and renal function should be monitored. Dosage adjustment in elderly patients should take into account renal function.

Renal Impairment: Dosage adjustment is required for patients with estimated CLcr 50 mL/min or less. Monitor estimated CLcr at least daily and adjust the dosage of CONTEPO accordingly. In patients requiring hemodialysis, CONTEPO should be administered after hemodialysis on hemodialysis days.

Hepatic Impairment: Monitor patients with severe hepatic impairment closely for fluid overload and electrolyte abnormalities.

Please click here forFull Prescribing Information.

ABOUT MEITHEAL PHARMACEUTICALS, INC.

Founded in 2017 and based in Chicago, Meitheal is focused on the development and commercialization of generic injectable medications and, as of 2022, has expanded its focus to include fertility, biologic, and branded products. Meitheal currently markets over 70 U.S. FDA-approved products across numerous therapeutic areas including anti-infectives, oncolytics, intensive care, and fertility. As of October 2025, Meitheal, directly or through its partners, has 40 products in the research and development phase, 6 additional products planned for launch in 2025, 4 products in clinical trial phases, and 22 products under review by the FDA. Meitheal’s mission is to provide easy access to fairly priced products through robust manufacturing, consistent supply, and rapid response to our customers’ needs. Ranked regularly as one of Crain’s Fast 50 in Chicago, and in the top 100 of Crain’s Best Places to Work in Chicago from 2022 to 2024, Meitheal emulates the traditional Irish guiding principle we are named for—working together toward a common goal, for the greater good.

Learn more about who we are and what we do at www.meithealpharma.com.

REFERENCES

1.	Raz R. Fosfomycin: an old--new antibiotic. Clinical Microbiology and Infection: The Official Publication of the European Society of Clinical Microbiology and Infectious Diseases. 2012;18(1):4-7.
2.	Kaye KS, Rice LB, Dane AL, et al. Fosfomycin for Injection (ZTI-01) Versus Piperacillin-tazobactam for the Treatment of Complicated Urinary Tract Infection Including Acute Pyelonephritis: ZEUS, A Phase 2/3 Randomized Trial. Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America. 2019;69(12):2045-2056.
3.	Falagas M, Vouloumanou E, Samonis G, et al. Fosfomycin. Clinical Microbiology Reviews 2016;29(2):321-47.
4.	Prescribing Information. CONTEPO (fosfomycin) for injection, for intravenous use. Meitheal Pharmaceuticals. 2025.
5.	Lodise TP, Chopra T, Nathanson BH, Sulham K, Rodriguez M. Epidemiology of Complicated Urinary Tract Infections due to Enterobacterales Among Adult Patients Presenting in Emergency Departments Across the United States. Open Forum Infect Dis. 2022;9(7):ofac315. Published 2022 Jun 24.