614 - Long-Acting Lipoglycopeptides for the Treatment of Bone and Joint Infections and Bacteremia in Infectious Disease Outpatient Infusion Clinics

Background: Long-acting lipoglycopeptides (LGPs) are approved for the treatment of acute bacterial skin and skin-structure infections. Broad Gram-positive coverage and weekly dosing regimens are useful for other diagnoses, but real-world data supporting such use are sparse. We review our experience of dalbavancin and oritavancin for the treatment of bone and joint infection (BJI) and bacteremia (BAC) in outpatient infusion clinics (OICs).

Methods: We conducted a multicenter, retrospective, observational cohort study of patients (pts) receiving long-acting LGPs in OICs over 2 yrs from 2018-2019 for BJI and BAC. Data collected included demographics, diagnosis, dosing regimen, microbiology, clinical outcomes, and adverse events (AEs). Clinical success, defined as resolution of infection with continued oral antibiotics allowed, was assessed at the next follow-up visit. Worsening infection, the need for additional intravenous therapy, and discontinuations during therapy were deemed non-successful.

Results: We identified 70 pts (mean age: 64±16 years, 53% male) from 25 OICs, who received dalbavancin (n=50), oritavancin (n=19) and both (n=1).  BJI accounted for 55 (79%) with 31 osteomyelitis, 9 bursitis, 7 prosthetic joint, 7 septic arthritis and 1 tenosynovitis. BAC was the primary diagnosis in 15 (21%) and sources were 6 device, 2 lower respiratory tract, 2 urinary tract and 5 unknown. 46% of pts were treated in the OIC without prior hospitalization. 72 Gram-positive isolates were obtained from 67 pts, with Staphylococcus aureus predominant (42/72, 58%), including methicillin-resistant (26/72, 36%) and  methicillin-susceptible isolates (16/72, 22%).  Median number of doses administered were 2 [IQR 1-2] in BJI and 1 in BAC [IQR 1-2].  Overall clinical success was 86% (57/66), with 4 non-evaluable.  BJI had 85% success (44/52), with 90% in osteomyelitis (28/31), 50% in prosthetic joint (3/6) and 87% (13/15) in the others.  Clinical success was 93% (13/14) in BAC. Three pts (4%) on dalbavancin experienced mild AEs, none resulting in discontinuation of therapy.

Conclusion: This multicenter real-world study of long-acting LGPs demonstrates safety and high clinical success rates in BJI and BAC.  Our experience suggests a role for use of these agents in treatment of BJI and BAC in the outpatient setting.