In yet another US patient at Houston Methodist Hospital, Texas, Zaynich turned out to be a saviour by successfully clearing a chronic bile duct infection, facilitating liver transplant leading to her discharge from the hospital. As per the treating doctor, patient failed to respond to >6 weeks of treatment with high-end antibiotics available in US such as cefiderocol and eravacycline.

Thus, the treating team was left with no other option but to deploy Zidebactam/Cefepime (WCK 5222) under compassionate use. In the US, the compassionate use approvals are provided by FDA in the form of individual patient-specific expanded-access IND.

The patient, a 73-year-old female with bile duct cancer diagnosed in January 2024, had been undergoing chemotherapy and biliary stent placement. However, developed sepsis and liver abscess as well as cholangitis (an inflammation of the bile ducts) caused by extensively drug resistant Pseudomonas aeruginosa and Klebsiella pneumoniae. She received several broad spectrum antibiotics for >6 weeks but continued to have fever and persistent infection markers precluding liver transplant procedure. 15 days of treatment with Zaynich helped control infectious processes and cleared the way for the transplant in this patient. The pathogens from this patient, Pseudomonas aeruginosa and Klebsiella pneumoniae, were found to possess some of the most challenging resistance mechanisms such as IMP, NDM, and OXA-48 which were effectively neutralized by β-lactam enhancer mechanism of Zaynich.

Till date, 45 patients have benefitted under compassionate use of Zidebactam/Cefepime who were suffering from range of life-threatening Gram negative infections.