Early Directed Oritavancin Therapy in the Emergency Department May Lead to Hospital Avoidance Compared to Standard Treatment for Acute Bacterial Skin and Skin Structure Infections: A Real-World Retrospective Analysis

The Potential Utility of Single-Dose Long-Acting Intravenous Antibiotics for Acute Bacterial Skin and Skin-Structure Infections in the Emergency Department

Acute bacterial skin and skin-structure infections (ABSSSIs) are frequent clinical presentations to emergency departments (EDs) across the nation that can require substantial resources to treat due to several factors. These include an increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) as the causative organism, limited availability of oral antibiotics that treat ABSSSIs secondary to MRSA, absorption and pharmacodynamic concerns with oral therapy, and regimen adherence. In patients who are unable to tolerate oral therapy, or are unable to adhere to prescribed antibiotics, inpatient admission for intravenous (IV) antibiotics may be necessary. Although inpatient IV antibiotics used to treat MRSA, such as vancomycin, are relatively inexpensive, hospital admission itself incurs significant associated costs. The introduction of the long-acting lipoglycopeptides, dalbavancin and oritavancin, has many potential advantages for the treatment of ABSSSIs including one- or two-dose regimens, allowing patients to receive their dose in the ED or infusion center and avoid inpatient admission altogether. Existing data have borne out these results, demonstrating that these agents can significantly reduce the length of hospital stay and the overall treatment cost of ABSSSIs. However, as these agents have nontraditional therapeutic regimens compared with alternative IV and oral agents that require consistent dosing, it is imperative to have decision support tools in place to ensure that this therapy is utilized in appropriate patients with ABSSSIs and that its true benefits can be realized for both the patient and the health care system.

Kimyrsa, An Oritavancin-Containing Product: Clinical Study and Review of Properties

Background

There is a need for improved antibiotic formulations for the treatment of acute bacterial skin and soft structure infection (ABSSSI), especially with the rise of antimicrobial resistance among Gram-positive bacteria. A new formulation of oritavancin was developed to reduce intravenous infusion volume (from 1000 mL to 250 mL), shorten infusion time (from 3 hours to 1 hour), and provide pharmacies with flexibility in oritavancin preparation (from 5% dextrose in sterile water to either normal saline or 5% dextrose in sterile water) compared with the current formulation.

Methods

A total of 102 adult patients with a diagnosis of ABSSSI suspected or confirmed to be caused by a Gram-positive pathogen were randomized 1:1 to receive either the new formulation of oritavancin or the current formulation. After a single 1200-mg intravenous infusion of oritavancin, the relative area-under-the-curve exposure of the new formulation and current formulation groups were compared. Safety and tolerability of the new formulation were assessed for treatment-emergent adverse events, serious adverse events, and changes to laboratory parameters.

Results

The area under the curve for 0 hour to 72 hours postdose was very similar in the new formulation group compared with the current formulation group. No differences in treatment-emergent adverse events were observed between the current and new formulation groups, and all treatment-emergent adverse events were consistent with the known safety profile of the current formulation.

Conclusions

The new formulation of oritavancin with reduced volume and duration of intravenous infusion demonstrates a safety profile and pharmacokinetics similar to that of the original formulation.

Role or oritavancin and dalbavancin in acute bacterial skin and skin structure infections and other potential indications

PURPOSE OF REVIEW

To discuss the currently available evidence about the use oritavancin and dalbavancin for the treatment of acute bacterial skin and skin structure infections (ABSSSI) and for other potential indications.

RECENT FINDINGS

In this review, we briefly summarize the available data on efficacy (from randomized controlled trials) and on effectiveness and cure rates (from observational studies) pertaining to the use of oritavancin and dalbavancin either for ABSSSI or for other indications.

SUMMARY

Oritavancin and dalbavancin are valid options for outpatient therapy and early discharge in patients with ABSSSI, especially when adherence to oral therapy cannot be guaranteed or no oral choices are available. Furthermore, it is worth noting that a non-negligible portion (sometimes the majority) of oritavancin and dalbavancin use in available real-life experiences is for indications other than ABSSSI, especially for Gram-positive osteomyelitis and endocarditis. The number of studies on the use of long-acting lipoglycopeptides for these currently off-label indications is rapidly increasing and will help to further optimize the use of these peculiar antibiotics in the forthcoming future.

Efficacy and safety of oritavancin for the treatment of acute bacterial skin and skin-structure infections: a systematic review and meta-analysis

OBJECTIVES

This study aimed to evaluate the efficacy and safety of oritavancin (ORI) versus comparators for the treatment of acute bacterial skin and skin-structure infections (ABSSSIs) based on available clinical studies.

METHODS

PubMed, Cochrane Library and Embase were searched from database inception to 28 July 2020 to identify clinical studies assessing the efficacy and safety of ORI and comparator antibiotics for the treatment of ABSSSIs. Primary efficacy outcome, investigator-assessed clinical cure, lesion size reduction ≥20%, additional post-treatment antibiotics, and 30-day emergency room (ER) visits and readmission were assessed as efficacy outcomes. Adverse events (AEs) and mortality were assessed as safety outcomes. I² statistic was calculated for heterogeneity, and a fixed-effects or random-effects model was used for estimation of the risk ratio (RR).

RESULTS

A total of 9213 patients from two randomised clinical trials (RCTs) and four cohort studies were included in this meta-analysis. ORI was statistically non-inferior to control agents in all efficacy and safety outcomes. Moreover, ORI significantly reduced the occurrence of 30-day readmission (RR = 0.42; P = 0.0004) and drug-related AEs (RR = 0.78; P = 0.002). In the subgroup analysis, ORI also had a lower rate of 30-day ER visits in the outpatient setting (RR = 0.34; P < 0.00001).

CONCLUSION

ORI was not inferior to comparators for the treatment of ABSSSIs. Meanwhile, it showed advantages in reducing the rate of readmission and drug-related AEs. More high-quality and large-scale RCTs are required to further confirm the efficacy and safety of ORI. [Trial registration: PROSPERO ID: CRD42020201942].

Real-World Evidence Studies of Oritavancin Use in Gram-Positive Infections Augment Randomized Controlled Trials to Address Clinical and Economic Outcomes

Randomized controlled trials (RCTs) sponsored by pharmaceutical manufacturers for regulatory approval are conducted with restrictive criteria in an effort to definitively demonstrate the safety and efficacy of a drug or biologic. Unfortunately, the strict enrollment criteria in RCTs may exclude patients likely to receive the medication in a real-world clinical practice. Antibiotic RCTs for registration are designed to show noninferiority against standard of care or best available therapy, often minimizing clinical differentiation needed by clinicians to select the optimal agent for their patients. Lastly, RCTs do not include pharmacoeconomic data that would add a cost basis for determining the value of one product over another. Real-world studies may add support to the safety and efficacy demonstrated from RCTs and address patient populations excluded from clinical development programs. This supplement presents several real-world studies demonstrating the clinical and economic outcomes of various uses of oritavancin to augment the evidence published from RCTs. Clinicians may decide how to use this information in their own practice settings.