Zavante Therapeutics announced promising results from the pivotal ZEUS clinical trial, evaluating Zolyd (fosfomycin for injection) for the treatment of complicated urinary tract infections (cUTI), including acute pyelonephritis (AP).

The ZEUS study was a multicenter, randomized, double-blind Phase 2/3 trial evaluating the safety and efficacy of Zolyd vs. piperacillin/tazobactam in 465 hospitalized patients with cUTI or AP. Patients either received infusions of Zolyd 6g three times daily or piperacillin/tazobactam 4.5g three times daily for 7 days (14 days with concurrent bacteremia). Oral step-down therapy was prohibited. The primary efficacy endpoint was overall success, defined as clinical cure plus microbiologic eradication, in the microbiologic-modified intent-to-treat population at the test-of-cure visit (Day 19). 

Related Articles

The study met its primary endpoint, showing that Zolyd was statistically non-inferior to piperacillin/tazobactam, with an overall success rate of 64.7% vs. 54.5%, respectively (treatment difference of 10.2%; 95% CI: -0.4, 20.8). Clinical cure rates were 90.8% in the Zolyd arm compared to 91.6% in the piperacillin/tazobactam arm. Zolyd was found to be safe and generally well-tolerated, mostly with mild and transient treatment emergent adverse events reported (42% with Zolyd vs. 32% with piperacillin/tazobactam). Complete data from the ZEUS study will be presented at an upcoming infectious disease conference.

The Food and Drug Administration (FDA) has previously granted Fast Track and Qualified Infectious Disease Product (QIDP) designations to Zolyd for the treatment of cUTI, hospital-acquired bacterial pneumonia (HABP), ventilator-associated bacterial pneumonia (VABP), acute bacterial skin and skin structure infections (ABSSSI), and complicated intra-abdominal infections (cIAI). Zavante intends to submit a New Drug Application (NDA) to the FDA in early 2018.

Zolyd (also known as ZTI-01) is an investigational, first-in-class injectable epoxide antibiotic with a broad spectrum bactericidal activity in vitro against both Gram-negative and Gram-positive bacteria, including most contemporary MDR strains.

For more information visit