1624 - Real World Experience with Daptomycin (DAP) and Ceftaroline (CPT) Combination Therapy for Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia

Background: Methicillin-resistant Staphylococcus aureus bacteremia is associated with significant mortality rates up to 30%. Guideline-recommended first-line therapy includes monotherapy with either vancomycin or DAP. Alternative regimens are recommended for persistent MRSA bacteremia of ≥ 7 days or earlier if evident clinical deterioration. The combination of DAP plus CPT has been investigated as salvage therapy due to its synergistic mechanism potential, but real-world data with the combination therapy is limited. The aim of this study was to evaluate the efficacy of DAP plus CPT combination therapy for the treatment of MRSA bacteremia and identify independent predictors of 30-day mortality.

Methods: This was a single center retrospective study of patients receiving DAP-CPT at any point in therapy for the treatment of MRSA bacteremia. Univariable and multivariable analyses were performed to identify independent predictors of 30-day mortality.

Results: Sixty-five unique patients received DAP-CPT with a median time to combination therapy of 7 days. There were no significant independent predictors of 30-day mortality. The most common reason for combination therapy was persistent bacteremia (80%, 52/65). Bacteremia was cleared in 90.8% (59/65) of patients and the 30-day mortality rate was 15.4% (10/65). Median time to bacteremia clearance after combination switch was 3 days. Eleven patients received DAP-CPT within 72 hours of index culture. Median time to bacteremia clearance for patients switched to DAP-CPT within 72 hours versus after 72 hours did not differ (2 vs 3 days; P = 0.526), however the overall median duration of bacteremia was 4 and 11 days (P = 0.018). In a sub analysis, the median time of bacteremia clearance following combination therapy was significantly longer for patients receiving renal replacement therapy (5 vs 2 days; P = 0.04).

Conclusion: There were no independent predictors of 30-day mortality identified. DAP-CPT combination therapy resulted in clearance of persistent bacteremia and may serve as an effective salvage therapy.