In vitro activity for ZERBAXA® (ceftolozane and tazobactam)
ZERBAXA demonstrated potent in vitro activity
- Culture and susceptibility information and local epidemiology should be considered in modifying antibacterial therapy
- The clinical significance of in vitro data is unknown
Susceptibility rates for select ICU respiratory tract isolates in surveillance data (2019-2020)1,a
The Study for Monitoring Antimicrobial Resistance Trends (SMART) was initiated by Merck in 2002 to monitor the in vitro susceptibility of clinical bacterial Gram-negative isolates to various antimicrobials in intra-abdominal, respiratory, and urinary tract infections. Collection of isolates from respiratory tract infections (RTI) started in 2015. This collection of isolates started in 2019 and was completed in 2020.
Minimum inhibitory concentration (MIC) values for ceftolozane/tazobactam and comparator agents were determined using the broth microdilution methodology recommended by the Clinical and Laboratory Standards Institute (CLSI) that was current in the year the data was collected. The following breakpoints were used to test for the susceptibility of P. aeruginosa for ZERBAXA (MICs [mcg/mL]): ≤4/4 (susceptible), and of K. pneumonia: ≤2 (susceptible).
The limitations of SMART surveillance include the small number of sites per country, changes over time in the sites participating in SMART, and the relatively small number of isolates tested each year, n=250 per site. In addition, the lack of clinical information does not allow for confirmation of isolates as being “community-acquired” vs “hospital-acquired.”
- Data available on request from Merck &Co., Inc., Professional Services DAP, WP1-27, PO Box 4, West Point, PA 19846-0004. Please specify information package US-ZER-01502.