Assessing The Results of One Specific Therapy

Contagion: What do you want to see in terms of patients responding to treatment—timeframe, cultures, follow-ups?

Jones: When assessing clinical response, one of the first things I look at is the white blood cell count—whether it's decreasing. If the patient was febrile initially, are they now afebrile, and have they remained afebrile for more than 24 hours? We aim to get repeat cultures within 24 to 48 hours once they're on appropriate therapy, and ideally, we want to see blood cultures clear within three days. Some guidelines allow up to seven days, but we prefer to see an earlier response, especially in critically ill patients. A major consideration is source control. While it's not always possible, it's essential for effective treatment. We need to determine where the infection originated and if source control interventions can be applied.

Contagion: In the recent literature, the DOTS study, which looked at dalbavancin as an option for treatment of S aureus that demonstrated promising results. Can you talk about the potential benefits for this therapy?

Jones: It's still in peer review right now, but we're hoping for publication by the end of the year. I saw some initial data presented earlier in the year at the Estimate conference, as well as more recently at ID Week in October 2024. Although we're still waiting on the final publication, the preliminary data looks promising.

Currently, dalbavancin has just one indication: acute bacterial skin and skin structure infections, like cellulitis or abscesses. However, its clinical utility is likely highest for off-label uses, such as in cases of bacteremia, endocarditis, and osteomyelitis. This study assessed the desirability of outcomes ranking (DOOR) and included a day-70 secondary outcome, which is a familiar benchmark. It compared dalbavancin against the standard of care, with around 100 patients in each arm, specifically focusing on Staph aureus bacteremia and including some patients with right-sided endocarditis.

Although we're awaiting peer review, the study showed that dalbavancin was non-inferior to standard care in terms of clinical efficacy, with comparable rates of adverse events between groups. This suggests that dalbavancin could be a viable treatment option, potentially encouraging more clinicians to consider it. For many—including myself—this study validates current off-label practices, as around one-third of my dalbavancin use is off-label, mostly for osteomyelitis, and we've seen a rise in its use for Staph aureus bacteremia and endocarditis. Additionally, the study could help standardize dosing, as there is currently some variability in dosing for off-label indications.

The conversation was edited for grammar and clarity.