Dalbavancin as Suppressive Therapy for Implant-Associated Osteoarticular Infections

<b>Introduction</b>: Suppressive antibiotic therapy (SAT) is a therapeutic alternative for complex infections where a cure is considered unlikely or impossible. SAT involves the prolonged, often indefinite, administration of antibiotics, typically given orally, to control symptoms. However, the increasing incidence of multidrug-resistant microorganisms limits the availability of oral options. Dalbavancin is a parenteral antibiotic with broad coverage against Gram-positive bacteria that offers the advantage of an extended dosing interval. The aim of this study was to describe the characteristics and clinical outcomes of patients with implant-associated osteoarticular infections receiving dalbavancin as SAT. A secondary objective was to identify factors associated with SAT failure with dalbavancin. <b>Materials and Methods</b>: We conducted a multicentre, observational study with retrospective recruitment of patients treated with dalbavancin as (SAT) for complex implant-associated osteoarticular infections, in which curative surgery was either not feasible or insufficient. Cohort characteristics were described, and variables associated with SAT failure under dalbavancin treatment were analysed. <b>Results</b>: A total of 43 patients received dalbavancin as SAT. The most frequent indication was prosthetic joint infection (38 [88.4%]). A total of 28 patients (65.1%) had chronic infections; the remaining cases were acute infections that had failed conservative management. Nine different dosing regimens of dalbavancin were used. Dalbavancin provided adequate symptomatic control in 32 patients (74.4%) over a follow-up period of 836.5 days (IQR 402-1288.5). The antibiotic was well tolerated; only one adverse effect was reported in a patient. Three patients developed resistance during treatment, which accounted for SAT failure. <b>Conclusions</b>: Dalbavancin is shown to be a safe and convenient alternative for SAT for orthopaedic implant infection. Although the development of resistance was infrequent, it can occur and should be monitored.