Dalbavancin is as effective as vancomycin in acute bacterial infections

by Bruce Sylvester – Findings published on June 4 in the New England Journal of Medicine show that the antibiotic dalbavancin is as effective as vancomycin for treating serious bacterial skin and skin-structure infections. And the study results establish dalbavancin as a therapy for Staphylococcus aureus infections, including methicillin-resistant S. aureus, or MRSA.

“Dalbavancin has a great likelihood of changing our practice in caring for patients with severe skin infections. It will now be possible to treat once a week instead of several times a day and will potentially remove the need for hospital admission and long-term intravenous catheters,” said lead investigator Helen Boucher, M.D., Associate Professor of Medicine at Tufts Medical Center in Boston.

The team completed two Phase 3 clinical trials comparing efficacy of dalbavancin with vancomycin followed by linezolid.  Titled DISCOVER 1 and DISCOVER 2 (Dalbavancin for Infections of the Skin COmpared to Vancomycin at an Early Response), the studies were conducted at 54 and 86 sites. Data from the two DISCOVER trials were pooled for the newly published analysis.

In order to be eligible for DISCOVER, subjects had received a diagnosis of acute bacterial skin and skin-structure infection with cellulitis, a major abscess or a wound infection, all with at least 75 square centimeters of surrounding redness. Other enrollment criteria were elevated body temperature and white blood cell count.

For 10-14 days, patients received either once-weekly intravenous dalbavancin or twice-daily intravenous vancomycin followed by oral linezolid, along with dummy infusions or pills.

The primary endpoint was early clinical response, i.e. cessation of spread of infection-related reddening and inflammation of the skin and the absence of fever at 48 to 72 hours.

Analysis showed that 525 of 659 (79.7 percent) in the dalbavancin group and 521 of 653 (79.8 percent) in the vancomycin-linezolid group had an early clinical response. Among subjects with Staphylococcus aureus, including MRSA, clinical success appeared in 90.6 percent of the dalbavancin-treated patients and 93.8 percent of those treated with vancomycin-linezolid.

Dr. Boucher said, “The patients in our study were very ill: more than 85 percent had fever at entry and more than half had systemic inflammatory response syndrome. In addition, our patients had large infections with median areas of over 300 square centimeters. Our results establish dalbavancin as an effective therapy and prove non-inferiority of dalbavancin to vancomycin in the treatment of these serious infections.”