P-1499. Patient Characteristics and Clinical Outcomes Associated with Meropenem/Vaborbactam Treatment in Carbapenem-Resistant <i>Enterobacterales</i> Pneumonia

Abstract Background Carbapenem-resistant Enterobacterales (CRE) are a major public health threat due to increasing prevalence and limited effective treatment options. Meropenem/vaborbactam (M/V) is a beta-lactam/beta-lactamase inhibitor agent designed to treat CRE. There is a paucity of data related to patient characteristics and associated outcomes with the utilization of M/V in pneumonia due to CRE. The objective of this study was to describe real-world experience with M/V in this setting. Methods This is a retrospective, observational, multicenter, cross-sectional study of patients ≥ 18 years old who received M/V for ≥ 72 hours for clinically-diagnosed hospital-acquired (HAP) or ventilator-associated pneumonia (VAP) due to CRE between 6/2020-2/2024. The primary outcome was clinical success, defined as resolution or improvement in signs/symptoms of infection and without the need for additional therapy. The secondary outcomes included 30-day mortality, 30-day microbiologic recurrence, 30-day symptomatic recurrence and adverse drug reaction(s). Results Sixty-two patients were included from six U.S. medical centers. The mean age (standard deviation [SD]) was 58.2 (15.4) years; patients were predominantly male (71.0%) and Caucasian (58.1%). At time of culture collection, the mean (SD) APACHE II score was 22.1 (7.8) and most patients (78.0%) were admitted to the intensive care unit. Klebsiella pneumoniae was the predominant species isolated in culture (43.5%). Notably, 65.6% were diagnosed with VAP, 32.3% had a COVID-19-related hospitalization and 29.0% developed secondary bacteremia. Patients received a median (interquartile range [IQR]) of 7.2 (6.1-12.0) days of M/V, with 21.0% receiving systemic combination therapy. Clinical success was achieved in 69.4% of patients and 30-day mortality occurred in 33.9%. Microbiologic and symptomatic recurrence occurred in 11.2% and 8.1% of cases, respectively. One patient experienced Clostridioides difficile infection attributed to the use of M/V. Conclusion Our study demonstrates promising clinical success with the use of M/V for treatment of pneumonia. Larger, comparative studies are needed in this population to identify patient factors associated with clinical success and assess M/V’s efficacy compared to other available therapies. Disclosures Kaylee E. Caniff, PharmD, BCIDP, T2Biosystems: Honoraria Kevin W. Garey, PharmD, MS, Acurx: Grant/Research Support Tamara Krekel, PharmD, BCPS, BCIDP, Merck Inc: Honoraria Wesley D. Kufel, Pharm.D., BCPS, BCIDP, Merck &amp; Co.: Grant/Research Support|Shionogi, Inc: Grant/Research Support Michael J. Rybak, PharmD, PhD, MPH, Abbvie, Melinta, Sionogi, Merck, T2Biosystems: Advisor/Consultant|Abbvie, Melinta, Sionogi, Merck, T2Biosystems: Grant/Research Support|Abbvie, Melinta, Sionogi, Merck, T2Biosystems: Speaker