1553 - Efficacy and Safety of Dalbavancin and Oritavancin in the Treatment of Gram-Positive Infections

Background: Lipoglycopeptides are approved for acute bacterial skin and skin structure infections (ABSSSI), but are often used in other infections, including osteomyelitis (OM) and bloodstream infections (BSI).

Methods: This retrospective cohort study included VA St. Louis Health Care System patients aged ≥18 through ≤89 years treated for ABSSSI, BSI, or OM with lipoglycopeptides.  Patients were excluded if they received ≥72 hours (ABSSSI, BSI) or ≥7 days (OM) of antibiotics prior to lipoglycopeptide administration or other intravenous antibiotics were administered for ≥48 hours after lipoglycopeptide.  The primary efficacy outcome was clinical success in the lipoglycopeptide cohort, defined per infection. Secondary outcomes were a comparison of clinical success in the lipoglycopeptide cohort to historical controls of patients treated at the VA St. Louis for ABSSSI, BSI, or OM.  A multivariate regression was also conducted to find factors in the lipoglycopeptide group independently associated with clinical success.  Safety outcomes compared adverse drug reactions between single- and 2-dose regimens of lipoglycopeptides.

Results: A total of 36 patients were included in the analysis; no patients met inclusion for bloodstream infection.  Twenty-nine patients were treated for ABSSSI and 7 patients met inclusion for OM treatment.  Dalbavancin was the agent used most often for both OM (4/7) and ABSSSI (22/29).  The primary outcome of clinical success occurred in 77.7% (28/36) of the lipoglycopeptide cohort.  There was no difference in clinical success between the lipoglycopeptide cohort and historical controls for ABSSSI (86% [5/29] vs 84% [159/189], p >0.05) or OM (43% [3/7] vs 58% [83/143], p >0.05).  No difference in adverse outcomes between single- and 2-dose regimens of lipoglycopeptide were observed.

Conclusion: Clinical success for patients treated with lipoglycopeptides for ABSSSI and OM in this small cohort were comparable to historical controls.  No difference was identified in the safety between single- and 2-dose regimens of lipoglycopeptides.