FDA Approves Wockhardt's Zaynich, a Cefepime-Zidebactam Antibiotic for Drug-Resistant Gram-Negative UTIs
Wockhardt's intravenous cefepime-zidebactam combination won U.S. FDA approval for complicated urinary tract infections after a phase 3 trial showed superiority over meropenem.
Overview
Wockhardt has announced U.S. Food and Drug Administration approval for Zaynich, an intravenous combination of cefepime and zidebactam, for the treatment of complicated urinary tract infections in adults. According to the company’s PR Newswire announcement, the antibiotic is approved for adults with complicated urinary tract infections “including pyelonephritis caused by the following susceptible microorganisms: Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter cloacae complex, and Pseudomonas aeruginosa.”
The approval adds a new option for Gram-negative infections that resist existing therapies, a category that has seen few new agents in recent years.
What We Know
Zaynich pairs cefepime, an established cephalosporin, with zidebactam. According to the PR Newswire announcement, the combination targets “multiple penicillin binding protein (PBP 1a/b, 2, 3) simultaneously in most clinically important Gram negatives,” and retains activity “even in the presence of β-lactamases, including metallo-β-lactamases (MBLs)” and other non-enzymatic cefepime resistance mechanisms. Metallo-β-lactamases are among the enzymes that disable many existing beta-lactam antibiotics, making them a recurring obstacle in treating resistant infections.
The approval was supported by the phase 3 ENHANCE-1 trial. According to the trial abstract published in Open Forum Infectious Diseases, the study included “529 patients randomized and treated (352 in ZID-FEP and 177 in meropenem arms)” across “44 global sites across U.S., EU, India, Mexico, and China.” Patients were randomized 2:1 to receive zidebactam-cefepime at “1+ 2 g (1 h infusion)” or meropenem at “1 g (0.5 h infusion)” for “7 to 10 days.”
In the trial’s modified microbiological intent-to-treat population of 417 patients, the trial abstract reported a composite clinical cure and microbiologic response rate of “89.0% in the ZID-FEP group versus 68.4% in the meropenem group; treatment difference [ZID-FEP versus meropenem], 20.6%; 95% CI, 12.3 to 29.5.” The authors concluded that “ZID-FEP demonstrated statistical superiority over meropenem in the overall success rates and results were consistent regardless of patient or pathogen characteristics.” The same figures and conclusion appear on the Oxford Academic abstract page. The abstract noted that results held across subgroups including “cUTI versus AP, older adults, renal-insufficiency, obese patients and cefepime-resistant uropathogens.”
The approval also marks a corporate milestone. In the announcement, Founder and Chairman Dr. Habil F. Khorakiwala said “ZAYNICH is the first New Chemical Entity fully developed and commercialized by an Indian pharmaceutical company to receive an FDA approval.” Chief Medical Officer Dennis Deruelle, MD, framed the unmet need, saying “The threat of drug-resistant infections is an escalating crisis, leaving clinicians with fewer tools to treat patients.”
The drug has also cleared regulators elsewhere. Per the same announcement, India’s Drugs Controller General approved the therapy on May 27, 2026, and Wockhardt has submitted a Marketing Authorization Application to the European Medicines Agency.
What We Don’t Know
The approved indication is limited to complicated urinary tract infections, including pyelonephritis; the announcement does not describe approval for other infection types such as pneumonia or bloodstream infections, and any broader use would require additional study. Pricing, U.S. launch timing, and the outcome of the pending European application were not detailed in the materials reviewed. The ENHANCE-1 abstract reports the primary efficacy endpoint but does not itemize the full safety profile in the text reviewed here.
Analysis
New antibiotics that retain activity against the most resistant Gram-negative pathogens are uncommon, and the regulatory and commercial economics of antibiotic development have long discouraged investment in the field. Zaynich’s mechanism, which the company describes as binding multiple penicillin-binding proteins and remaining active against metallo-β-lactamase-producing organisms per the announcement, positions it against resistance mechanisms that blunt several established beta-lactam drugs. Whether the superiority over meropenem observed in ENHANCE-1 translates into broader clinical adoption will depend on real-world resistance patterns, stewardship decisions, and how the drug is positioned relative to other recently approved Gram-negative agents.