US body Clinical and Laboratory Standards Institute (CLSI) awards high susceptibility breakpoints to Zaynich (Zidebactam/Cefepime- WCK 5222)

In the June 24, 2024 plenary session of Clinical and Laboratory Standards Institute (CLSI), Zaynich (Zidebactam/Cefepime- WCK 5222) has been granted a susceptibility breakpoint of 64 mg/L for around 10 Gram negative pathogens showing high resistance rates. Susceptibility breakpoints guides the doctors about selection of most efficacious antibiotic for treating various infections caused by different pathogens.  

 A high breakpoint of 64 mg/L suggests Zaynich’s (Zidebactam/Cefepime- WCK 5222) strong potential to cover all the clinically important, extreme drug resistant Gram negative pathogens in seriously ill patients. Since the introduction of penicillin in 1928, more than 250 antibiotics have been approved and used clinically, however, this is reportedly the first time ever that an antibiotic has been granted a susceptible breakpoint of as high as  64 mg/L for all the three families of Gram negative pathogens; Enterobacterales, Pseudomonas and Acinetobacter. Pending 

Zaynich’s (Zidebactam/Cefepime- WCK 5222) formal approval, CLSI has designated these breakpoints as Investigational Breakpoints to facilitate clinical trials and compassionate use of this life saving antibiotic. 

 In granting of the breakpoints, more than 8 years of research data on Zaynich (Zidebactam/Cefepime- WCK 5222) was reviewed by three sub-committees of CLSI sequentially, followed by independent rounds of voting by the members at each stage. The final plenary session unanimously approved the investigational breakpoints for Zaynich (Zidebactam/Cefepime- WCK 5222).  

 During more than 1 year, Zaynich (Zidebactam/Cefepime- WCK 5222), has been successfully used to treat 30 patients under compassionate use who were inflicted with infections caused by extreme-drug resistant Gram-negative pathogens, including Pseudomonas, Klebsiella, E. coli, Acinetobacter, and Serratia not amenable to any of the available antibiotics. The high breakpoints assigned to Zaynich are supportive of consistent clinical cure and microbiological eradication demonstrated in these compassionate use patients.  

 Currently, Zaynich (Zidebactam/Cefepime- WCK 5222) is undergoing a multinational Phase 3 study, which is expected to be completed by FY 2025, facilitating its global registration and marketing authorisation.