Comparison of dalbavancin with standard of care in the management of infective endocarditis: efficacy, safety, and cost analysis

Dalbavancin as consolidation antibiotic treatment in infective endocarditis, cardiac implantable electronic devices infection and bacteremia: Clinical experience of 7 years

INTRODUCTION

Dalbavancin (DBV), a novel lipoglycopeptide with activity against Gram-positive bacterial infections, is approved for the treatment of acute bacterial skin and skin structure infections (ABSSSIs). It has linear dose-related pharmacokinetics allowing a prolonged interval between doses. It would be a good option for the treatment of patients with Gram-positive cardiovascular infections.

METHODS

Retrospective analysis of patients with cardiovascular infection (infective endocarditis, bacteremia, implantable electronic device infection) treated with DBV at Hospital Clínico San Carlos (Madrid) for 7 years (2016-2022). Patients were divided in two study groups: 1) Infective endocarditis (IE), 2) Bacteremia. Epidemiological, clinical, microbiological and therapeutic data were analyzed.

RESULTS

A total of 25 patients were treated with DBV for cardiovascular infection. IE was the most common indication (68%), followed by bacteremia (32%) with male predominance in both groups (64% vs 62%) and median age of 67,7 and 57,5 years, respectively. 100% of blood cultures were positive to Gram-positive microorganisms (Staphylococcus spp., Streptococcus spp. or Enterococcus spp.) in both study groups. Previously to DBV, all patients received other antibiotic therapy, both in the group of IE (median: 80 days) as in bacteremia (14,8 days). The main reason for the administration of DBV was to continue intravenous antimicrobial therapy outside the hospital in both the EI group (n = 15) and the bacteremia group (n = 8). DBV was used as consolidation therapy in a once- or twice-weekly regimen. Microbiological and clinical successes were reached in 84% of cases (n = 21), 76,4% in IE group and 100% in bacteremia group. No patient documented adverse effects during long-term dalbavancin treatment.

CONCLUSION

DBV is an effective and safety treatment as consolidation antibiotic therapy in IE and bacteremia produced by Gram-positive microorganisms.

Therapeutic Drug Monitoring of Dalbavancin in Real Life: A Two-Year Experience

Dalbavancin is a long-acting lipoglycopeptide that is registered for the treatment of acute bacterial skin and skin structure infections, and it is also increasingly used for infections that require prolonged antibiotic treatment. Here, we present the results from the first 2 years of a service set up in December 2021 for the therapeutic drug monitoring (TDM) of dalbavancin in clinical settings. In particular, we compared the trough concentration (Cmin) to maximum concentration (Cmax) in patients with osteoarticular infections receiving prolonged treatment with dalbavancin. Log-linear regression models were used to estimate the timing of dalbavancin administration with the goal of maintaining Cmin concentrations of >8 mg/L in the two TDM-based strategies. From December 2021 to November 2023, 366 TDMs of dalbavancin from 81 patients were performed. The Cmin and Cmax concentrations of dalbavancin ranged from 4.1 to 70.5 mg/L and from 74.9 to 995.6 mg/L, respectively. With log-linear regression models, we estimated that each injection should be administered every 42-48 days to maintain the Cmin concentrations. Out of the 81 patients, 37 received at least three doses of dalbavancin for the treatment of osteoarticular infections. Despite there being no significant differences in the days of dalbavancin treatment (130 ± 97 versus 106 ± 102 days), the patients in the Cmax-based TDM group received a significantly lower number of dalbavancin injections (5.2 ± 1.8 versus 7.3 ± 2.6 injections, p = 0.005), and they were administered over a longer period of time (40 ± 10 versus 29 ± 14 days, p = 0.013) than in the Cmin-based TDM group. In conclusion, Cmax-based TDM was associated with a significant reduction in the inter-individual variability of dalbavancin concentrations and lower drug dosing frequency than those of Cmin-based TDM. This approach could, therefore, favor a more rational and targeted use of dalbavancin in patients requiring prolonged treatment.

Long-Term Suppressive Therapeutic-Drug-Monitoring-Guided Dalbavancin Therapy for Cardiovascular Prosthetic Infections

Dalbavancin represents a promising treatment for cardiovascular prosthetic infections due to its prolonged half-life, bactericidal activity, large spectrum of activity, and excellent biofilm penetration. However, the use of dalbavancin in this setting is limited, and only a few cases have performed therapeutic drug monitoring (TDM) analysis to optimize dosage in suppressive treatments longer than 4 weeks. Our retrospective case series reports the use of dalbavancin in a small cohort of patients with cardiovascular prosthetic infections (cardiac implantable electronic device infections (CEDIs), prosthetic valve endocarditis (PVE), prosthetic vascular graft infections (PVGIs)) treated with dalbavancin as sequential therapy. From May 2019 to May 2023, 14 patients were included: eight cases of PVE (57.1%), seven cases of PVGI (50%), three cases of CEDI (21.4%), and four cases with overlap of infection sites (28.6%). The main pathogen was Staphylococcus aureus (35.7%). Prosthesis replacement was obtained in four patients (28.6%). The median time between symptom onset and the end of treatment was 15 weeks (IQR 7-53), with a median duration of dalbavancin therapy of 8 weeks (IQR 1 to 45 weeks) and 3.5 doses per patient. Among patients managed with TDM-guided strategy, dalbavancin infusion intervals ranged from 4 to 9 weeks. The median length of follow-up was 65 weeks (IQR 23 to 144 weeks). Clinical success was achieved in 10 cases (76.9%); all clinical failures occurred in patients with the implant retained. Among patients monitored by TDM, clinical success was 87.5% vs. 60% in patients treated without TDM. Because of pharmacokinetic individual variability, dalbavancin TDM-guided administration could improve clinical outcomes by individualizing dosing and selecting dosing intervals. This case series seems to suggest a promising role of long-term suppressive dalbavancin treatment for difficult-to-treat cardiovascular prosthesis infection, also with limited surgical indications.