Clinical Efficacy
Proven efficacy in adults with cUTI, including pyelonephritis
INDICATION AND USAGE
Complicated Urinary Tract Infections, Including Pyelonephritis
ZAYNICH is indicated for the treatment of adult patients with complicated urinary tract infections (cUTI) including pyelonephritis caused by the following susceptible microorganisms: Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter cloacae complex, and Pseudomonas aeruginosa.
Usage to Reduce Development of Drug-Resistant Bacteria
To reduce the development of drug-resistant bacteria and maintain the effectiveness of ZAYNICH and other antibacterial drugs, ZAYNICH should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria.
Study design: In a multinational, double-blind, noninferiority trial, ZAYNICH™ was evaluated versus meropenem in adults with complicated urinary tract infections (cUTI), including pyelonephritis. See additional details below.
ZAYNICH™ demonstrated an 89% composite response at Test of Cure
Composite response was defined as both clinical cure and microbiological response at the Test of Cure (TOC) visit, 10 days after the end of treatment.
Treatment difference: 20.6% (95% CI: 12.3, 29.5)
High rates of clinical cure and microbiological response
At the Test of Cure visit (mMITT population):
| Efficacy outcome | ZAYNICH™ n/N (%) |
Meropenem n/N (%) |
Treatment difference, % (95% CI) |
|---|---|---|---|
| Composite response (clinical cure and microbiological response) | 250/281 (89.0) | 93/136 (68.4) | 20.6 (12.3, 29.5) |
| Clinical cure | 272/281 (96.8) | 129/136 (94.9) | 1.9 (−1.9, 7.3) |
| Microbiological response | 256/281 (91.1) | 96/136 (70.6) | 20.5 (12.6, 29.2) |
CI = confidence interval; mMITT = microbiological modified intent-to-treat.
Clinical cure was defined as complete resolution, or return to premorbid state, of baseline signs and symptoms of cUTI or pyelonephritis present at screening, with no new urinary symptoms or worsening of symptoms.
Microbiological response was defined as reduction of the baseline qualifying pathogen(s) to <103 CFU/mL in urine.
Composite response at Test of Cure by baseline pathogen in cUTI including pyelonephritis
Gram-negative pathogens, mMITT population.
| Gram-negative pathogen | ZAYNICH™ % (n/N) | Meropenem % (n/N) |
|---|---|---|
| Escherichia coli | 92% (162/176) | 69% (60/87) |
| Klebsiella pneumoniae | 79% (41/52) | 63% (15/24) |
| Proteus mirabilis | 88% (22/25) | 86% (6/7) |
| Enterobacter cloacae complex | 85% (11/13) | 57% (4/7) |
| Pseudomonas aeruginosa | 57% (4/7) | 20% (1/5) |
Efficacy in ESBL-screen-positive isolates
Among patients with E. coli, K. pneumoniae, or P. mirabilis isolates with an extended-spectrum beta-lactamase (ESBL)-screen-positive phenotype, composite response at Test of Cure was:
Study design details
A multinational Phase 3 study in adults with cUTI, including pyelonephritis. A total of 530 adults were randomized 2:1 to receive:
ZAYNICH™
2 g cefepime + 1 g zidebactam, IV every 8 hours
Meropenem
1 g IV every 8 hours
Both treatments were infused over 1 hour for 7 to 10 days. Dose adjustments were made for patients with renal impairment. Switching from IV to oral antibacterial therapy was not permitted.
The primary efficacy analysis was conducted in the microbiological modified intent-to-treat (mMITT) population, which included 281 ZAYNICH™-treated patients and 136 meropenem-treated patients.
At baseline, 68% of patients had cUTI and 32% had pyelonephritis. Concomitant bacteremia was identified in 6% of ZAYNICH™-treated patients and 7% of meropenem-treated patients.
Reference: 1. ZAYNICH (cefepime and zidebactam) US Prescribing Information. Wockhardt Bio AG; 2026.