Ceftazidime-avibactam (CZA) was introduced in South Korea in July 2023, but regional data on its clinical efficacy, treatment outcomes, and microbiological characteristics of bloodstream infections (BSIs) caused by Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacterales remain limited. This study evaluated the effectiveness of CZA compared with conventional therapies targeting KPC-producing Enterobacterales BSIs. A retrospective observational study of adult patients with KPC-producing Enterobacterales BSIs was conducted at a tertiary care center in Seoul, Republic of Korea. Patients treated with CZA between July 2023 and November 2024 were compared with a historical cohort treated with best available agents (conventional therapy) from December 2021 to June 2023. The primary endpoint was 30-day all-cause mortality. Secondary endpoints included BSI persistence, BSI recurrence, and emergence of resistance. A total of 106 patients received CZA and 156 received best available agents. The 30-day mortality rate was significantly lower in the CZA group compared with the comparator group (15.1% vs 28.2%, P = 0.02). Persistent BSI was also significantly reduced in the CZA group (5.0% vs 34.2%, P P = 0.014), and CZA resistance emerged in three patients (2.8%, 3/106). In this Korean cohort, CZA therapy was associated with significantly lower 30-day mortality and persistent BSI rates in patients with KPC-producing Enterobacterales BSIs, compared with best available agents.IMPORTANCEBloodstream infections caused by Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacterales carry high mortality rates and offer few treatment options, representing an urgent public health threat. Ceftazidime-avibactam (CZA) has emerged as a key therapy for these infections globally, yet real-world clinical data from South Korea have been absent since its recent introduction. This study presents the first comprehensive evaluation of CZA for treating KPC-producing Enterobacterales bloodstream infections in a Korean tertiary-care hospital. Through direct comparison with conventional combination regimens, we show that CZA substantially reduces 30-day mortality and persistent bacteremia. These findings provide important evidence for CZA as an effective first-line treatment, especially in settings where KPC-producing organisms are highly prevalent. Our results emphasize the value of timely access to novel β-lactam/β-lactamase inhibitors and point to the ongoing need for resistance surveillance.
KWON et al. (Thu,) studied this question.