DISCOVER 1 and DISCOVER 2—identically designed phase 3 double-blind international trials—demonstrated that dalbavancin was noninferior to vancomycin or linezolid in the treatment of acute bacterial skin and skin structure infections (ABSSSIs) [Boucher HW et al. N Engl J Med. 2014]. Sailaja Puttagunta, MD, Durata Therapeutics, Branford, Connecticut, USA, presented a poster of a substudy of DISCOVER showing that the efficacy of dalbavancin extends to those who have obesity.

Dalbavancin is a lipoglycopeptide antibiotic agent that is active against gram-positive pathogens and has a long plasma half-life that allows for once-weekly dosing. DISCOVER 1 and DISCOVER 2 included adults with ABSSSIs (cellulitis, major abscesses, wound infection) with erythema > 75 cm² and 1 of the following: a fever, an elevated white blood count (> 12 000 white blood cells/mm³), or > 10% band forms on the white cell differential count.

Other eligibility requirements, in addition to erythema, were at least 2 of the following: purulent drainage or discharge, fluctuance, heat or localized warmth, tenderness on palpation, and swelling or induration. Patients who received antibiotic treatment within 14 days of randomization were excluded.

Participants aged 18 to 85 years were randomly assigned to receive either of the following:

• 1 g of intravenous dalbavancin over a period of 30 minutes on day 1, followed by 500 mg intravenously over a period of 30 minutes on day 8, or

• 1 g (or 15 mg/kg of body weight) of intravenous vancomycin over a period of 120 minutes every 12 hours for at least 3 days, with an option to switch to 600 mg of oral linezolid every 12 hours to complete 10 to 14 days of therapy.

The primary end point was the cessation of the spread of infection-related erythema of the lesion at 48 to 72 hours and the absence of fever at 3 consecutive recordings every 6 hours in the intention-to-treat population.

The objective of the subgroup analysis was to evaluate the clinical effectiveness of dalbavancin for the treatment of ABSSSIs in patients who were obese (body mass index [BMI] ≥ 30 kg/m²) relative to those who were overweight (BMI, 25 to 29.9 kg/m²) and normal weight (BMI < 25 kg/m²).

Efficacy of dalbavancin was assessed in the 3 weight groups by a categorical analysis of subgroups of patients stratified by weight bands or as part of a covariance analysis examining BMI as a continuous and categorical variable. Baseline demographics were similar in the three groups. Clinical outcomes by BMI are shown in Table 1.

Clinical success rates were similar in all 3 weight groups, suggesting that dalbavancin was an effective treatment option for patients who have skin infections and are obese, overweight, or normal weight.