Written By: Pharmacally Medical News Desk
The US Food and Drug Administration has accepted Wockhardt’s New Drug Application (NDA) for Zaynich, a novel antibiotic combining cefepime and zidebactam. The company says this is the first time in history an Indian pharmaceutical company has filed and received acceptance for an NDA involving a New Chemical Entity (NCE).
The filing was submitted on September 30, 2025, and has now moved into active review under the FDA’s Fast Track program, which is granted to medicines that target serious conditions and address unmet medical needs. Zaynich is also set to receive priority review, which could shorten the evaluation timeline.
Novel mechanism targeting resistant Gram-negative infections
Zaynich pairs cefepime, a fourth-generation cephalosporin, with zidebactam, a first-in-class β-lactam enhancer. Cefepime works by binding to penicillin-binding proteins (PBPs) and disrupting bacterial cell-wall synthesis. Zidebactam reinforces this activity through two mechanisms:
- High-affinity binding to PBP2, directly blocking cell-wall formation
- Inhibition of β-lactamases, protecting cefepime from enzymatic degradation
This dual action is designed to overcome the resistance mechanisms seen in multi-drug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative pathogens, including Pseudomonas, Acinetobacter, Klebsiella, Stenotrophomonas, and Enterobacterales. These organisms are responsible for severe hospital infections such as ventilator-associated pneumonia, bloodstream infections, complicated urinary tract infections, and intra-abdominal infections.
While Zaynich has shown strong activity across these pathogens in clinical trials, Wockhardt noted that the current NDA specifically covers the treatment of complicated urinary tract infections (cUTI), including pyelonephritis.
Robust Phase 3 results form the core of the NDA
The application is supported by data from ENHANCE-1, a global, randomized Phase 3 study that enrolled 530 patients with cUTI across 64 sites in India, Europe, and the United States.
Key findings include:
- 8% clinical cure at the test-of-cure visit (day 7–10 after therapy)
- 0% composite clinical and microbiological cure, compared with 68.4% for meropenem
- The trial met all primary and secondary endpoints aligned with FDA and EMA guidelines
These results demonstrated both non-inferiority and statistical superiority in key measures compared with meropenem, a widely used carbapenem antibiotic.
Additional efficacy in meropenem-resistant infections
Wockhardt also reported that Zaynich showed greater than 97% clinical efficacy in a clinical trial involving patients with confirmed meropenem-resistant infections, including cases of hospital-acquired and ventilator-associated pneumonia, bloodstream infections, intra-abdominal infections, and complicated urinary tract infections.
Separate from the trial environment, the drug has been used under compassionate-use programs in both India and the United States. According to the company, these critically ill patients also demonstrated high response rates, strengthening confidence in the drug’s real-world utility.
The company emphasized that these data further support Zaynich potential role in managing drug-resistant Gram-negative infections but remain supplemental to the NDA, which currently focuses on cUTI.
A milestone for Indian drug innovation
Wockhardt described the NDA acceptance as a significant achievement for India’s pharmaceutical research ecosystem.
“The FDA’s acceptance of the Zaynich NDA is a historic and proud moment for India and Wockhardt. This milestone underscores the strength of our global clinical program and demonstrates what Indian science and innovation can achieve,” the company said.
With Fast Track status and priority review, Zaynich could potentially reach the US market in 2026, subject to FDA approval.
If approved, Zaynich would become one of the few new antibiotics targeting MDR and XDR Gram-negative infections to enter the US market in recent years, and the first NCE from an Indian company to receive such consideration.
Reference
US FDA Accepts Wockhardt’s New Drug Application for Breakthrough Antibiotic Zaynich, 01 December 2025, Wockhardt, https://www.wockhardt.com/wp-content/uploads/2025/12/pr.pdf
Wockhardt submits new drug application to US FDA for zidebactam – cefepime (WCK 5222) for treatment of serious gram – negative infections, 01 October 2025, https://www.wockhardt.com/wp-content/uploads/2025/10/press-release-wck-5222-nda-1-oct-2025.pdf
What is Wockhardt’s New Drug Zidebactam? A groundbreaking beta lactam enhancer in the fight against superbugs, Pharmacally, 08 October 2025, https://pharmacally.com/what-is-wockhardts-new-drug-zidebactam-a-groundbreaking-beta-lactam-enhancer-in-the-fight-against-superbugs/