French national cohort of first use of dalbavancin: a high proportion of off-label use

Dalbavancin is a glycopeptide antibiotic with a long half-life, recently marketed in Europe for skin and soft tissue infections (SSTI), but real-life use is not well-known. We aimed to describe all first prescriptions in France over an 18-month period. We performed a retrospective study on all adult patients who received at least one dose of dalbavancin from July 1, 2017 to September 31, 2018. Data were collected thanks to a standard questionnaire. Failure was defined as: persistent or reappearance of signs of infection; and/or switch to suppressive antibiotic treatment; and/or death from infection. We included 75 patients from 29 French hospitals. Main indications were bone and joint infections (BJIs) (64.0%), endocarditis (25.3%), and SSTIs (17.3%). Main bacteria involved were: Staphylococcus aureus (51.4%), including methicillin-resistant S. aureus (MRSA) (19.4%); and coagulase-negative staphylococci (CNS) (44.4%). Median MICs for staphylococci to vancomycin and dalbavancin ranged from 0.875 mg/L to 2.0 mg/L, and 0.040 mg/L to 0.064 mg/L, respectively. Dalbavancin was used after a mean of 2.3 ± 1.2 lines of antimicrobial treatment. Main treatment regimens for dalbavancin were a weekly 2-dose regimen (1500mg each) in 38 (53.2%) cases, and a single-dose regimen (1500mg) in 13 (18.3%) cases. Overall, at the patients\u27 last visit, clinical cure was observed in 54/72 patients, while failure was found in 14/72 patients. First uses of dalbavancin in France were mostly off-label. Most of them were due to BJIs, and often as rescue therapy for severe infections. Even in off-label situations, dalbavancin seems safe and effective