Early oral switch therapy in low-risk Staphylococcus aureus bloodstream infection. Acronym: SABATO (Staphylococcus aureus Bacteremia Antibiotic Treatment Options)

• Applicant: Professor Dr. Achim Kaasch
• Subject Area: Public Health, Healthcare Research, Social and Occupational Medicine
• Term: from 2012 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 217917502

About 25,000 cases of Staphylococcus aureus bloodstream infections (SAB) occur annually in Germany. The standard antimicrobial therapy for uncomplicated SAB is at least 14 days of intravenously administered antimicrobials. Intravenous administration is thought to prevent SABrelated complications that result from dissemination to distant sites through the bloodstream. However, there is insufficient evidence that antimicrobial therapy needs to be administered intravenously. Patients with a very low risk for SAB-related complications may benefit from an early switch to oral antimicrobial therapy. Potential benefits are an earlier hospital discharge, fewer adverse reactions associated with intravenous therapy, increased quality of life, and cost savings.The SABATO study is a multicenter, open-label, randomized, controlled trial designed to demonstrate that an early switch from intravenous to oral antimicrobial administration is non-inferior to a conventional course of intravenous therapy. The primary endpoint is the rate of SAB-related complications (recurrent SAB or any culture confirmed deep-seated S. aureus infection) within 90 days in the per-protocol population. Secondary endpoints include clinical response to treatment, mortality, and length of hospitalization.The first patient was enrolled in Dec 2013. Until 31 January 2018, 3519 patients were screened in 36 study centers and 132 patients were enrolled into the trial. Despite considerable efforts, recruitment is behind schedule and obtaining the full sample size (430 patients) within an acceptable time period is out of reach. Therefore, we propose to stop recruitment in July 2019 when at least 50% of the full sample size (i.e. 215 patients) is enrolled. This adaptation has already been considered in the initial study protocol. The sample size will be sufficient to support a non-inferiority margin of 10%. This strategy will allow us to successfully complete the trial by December 2019.

• DFG Programme: Clinical Trials