This study compares two treatment strategies for antibiotic therapy in endocarditis. The aim of the study is to determine which treatment is more effective overall and better tolerated by patients.

The first strategy is standard therapy: treatment with proven antibiotics, which are usually administered initially as an intravenous infusion in the hospital and can be switched to oral therapy with tablets later on for suitable patients.

The second strategy is the study treatment with dalbavancin: This is a long-acting antibiotic. It is administered as a single infusion; for longer treatment durations, a second infusion may be necessary 14 days later.

Inclusion Criteria:

1. ≥ 18 years
2. written informed consent
3. Confirmed left-sided infective endocarditis (mitral and/or aortic valve) involving native (NV) or prosthetic (PV) valves caused by Gram-positive cocci (staphylococci, streptococci, or enterococci) that are susceptible to dalbavancin.

Exclusion Criteria:

1. Hemodynamic instability requiring vasopressor therapy within the last 72 hours prior to randomization

2. Body temperature ≥38.0°C within the 72 hours prior to randomization

3. Evidence of pathogen growth in a blood culture within the 72 hours prior to randomization

4. Presence of a cardiac abscess at the time of randomization

5. Presence of a remaining infected cardiovascular implantable electronic device (CIED), an infected intravascular graft, or an infected TAVI prosthesis ("TAVI endocarditis") at the time of randomization

6. Duration of effective intravenous antibiotic therapy for endocarditis of < 7 days prior to randomization

7. Remaining duration of required antibiotic therapy for the treatment of endocarditis is less than 10 days (i.e., remaining treatment duration must be at least 10 days)

8. Hypersensitivity to dalbavancin, vancomycin, teicoplanin, or other components of the investigational drug

9. Participation in another clinical interventional trial under the German Medicines Act (AMG), Medical Devices Regulation (MDR), or Medical Devices Act (MPDG) without prior consultation and approval by the respective sponsors prior to randomization

10. Continuous renal replacement therapy (e.g., CVVHD, CVVHDF)

11. Child B or C liver cirrhosis

12. Palliative care

13. Secondary infections requiring a longer course of antibiotic therapy than that intended for the treatment of endocarditis

14. Oral antibiotic therapy already initiated to treat the current episode of endocarditis

15. Scheduled cardiac surgery after randomization, within the period designated for antibiotic treatment of endocarditis

16. Intraspinal or brain abscess (> 0.5 cm)

17. Pregnant and breastfeeding women

18. Women of childbearing potential, unless the following criteria are met:

    1. Postmenopausal (12 months of natural amenorrhea or 6 months of amenorrhea with serum FSH > 40 mIU/mL)
    2. Postoperative (6 weeks after bilateral oophorectomy with or without hysterectomy)
    3. Regular and correct use of a contraceptive method with a failure rate < 1% per year (considered reliable contraceptive methods include oral hormonal contraception, dermal hormonal contraception, contraceptive patches, long-acting injectable contraceptives, progesterone-releasing implants (Implanon®), intramuscular progesterone, tubal ligation (female sterilization), hormone-releasing intrauterine device ("hormonal IUD"), dual barrier methods)
    4. sexual abstinence
    5. Vasectomy of the partner