Oritavancin for Treatment of Osteomyelitis: A Systematic Review and Meta-Analysis of Observational Studies

Osteomyelitis (OM) is a complex inflammatory bone infection typically requiring prolonged antibiotic therapy. Oritavancin (ORI), a long-acting lipoglycopeptide with activity against biofilm-embedded pathogens, has emerged as a potential treatment option despite previous US Food and Drug Administration (FDA) warnings against its use in OM.

We conducted a systematic review and meta-analysis of observational studies in seven databases through August 8, 2024 (PROSPERO registration: CRD42025635473) to evaluate the available evidence on ORI's efficacy and safety in OM. Clinical success was defined as the improvement or resolution of infection without requiring additional gram-positive antibiotics, surgical debridement, or amputation. Study quality was assessed using the Newcastle-Ottawa Scale.

Our systematic review included nine observational studies comprising 316 patients with OM treated with ORI. Quality assessment using the Newcastle-Ottawa Scale revealed scores ranging from 5/9 to 8/9, with most studies demonstrating adequate outcome assessment but limitations in cohort selection and comparability. Meta-analysis demonstrated a pooled clinical success rate of 81% (95% CI: 76%-85%). Comparative analysis of two studies yielded an odds ratio of 2.99 (95% CI: 0.86-10.36) favoring ORI over comparators (daptomycin and dalbavancin), though with substantial heterogeneity (I² = 80.2%, p = 0.0247).

Despite previous warnings, we found no evidence of ineffectiveness with ORI for OM. ORI's infrequent dosing schedule may provide convenience over daily parenteral therapy, particularly for difficult-to-treat pathogens like MRSA and VRE. Further research is needed to optimize dosing strategies based on pathogen susceptibility and establish appropriate therapeutic drug monitoring protocols.