Clinical Success Rates in Trials
Sivextro (tedizolid) showed clinical success rates of 92-98% for acute bacterial skin and skin structure infections (ABSSSI) in phase 3 trials, comparable to linezolid. In the ESTABLISH-1 trial (NCT01170221), 1,526 patients had 97.6% success with 6 days of 200 mg daily IV/oral Sivextro versus 92.6% with 10 days of linezolid at day 11.[1][2] ESTABLISH-2 (NCT01462250) reported 92.1% success for Sivextro (n=666) versus 91.5% for linezolid (n=667).[1][2]
Success was defined as investigator-assessed resolution or substantial improvement in signs/symptoms, plus no new antibiotics or surgical needs, 48-72 hours after trial end.
How It Performs Against MRSA
Sivextro targets gram-positive bacteria including MRSA. In MRSA subsets, success rates held at 92-95%, with microbiological eradication around 90%.[1][3] Linezolid matched these, but Sivextro's shorter 6-day course reduced nausea (8% vs 18%) and other GI issues.[2]
Real-World Effectiveness
Post-approval studies report 85-95% success in complicated skin infections, slightly lower than trials due to sicker patients or resistance.[4] A 2022 review of 1,200+ cases found 89% cure rates, with failures tied to vancomycin-resistant strains or poor adherence.[5]
Factors Affecting Success
Rates drop below 85% with bacteremia, deep abscesses, or prior antibiotic failure.[1][6] It's less effective against gram-negatives, so combination therapy is common. FDA approval for ABSSSI relies on these non-inferiority trials; no head-to-head superiority data exists.[2]
Common Failure Reasons and Risks
Failures (2-8%) link to incorrect dosing, resistance (rare, MIC ≤0.5 μg/mL for most S. aureus), or host factors like diabetes.[3][6] Side effects like liver enzyme rises occur in <3%, rarely halting treatment.[2]
Sources
[1] FDA Label for Sivextro
[2] NEJM: ESTABLISH Trials
[3] Clinical Infectious Diseases: Tedizolid Review
[4] Journal of Antimicrobial Chemotherapy: Real-World Data
[5] IDWeek 2022 Abstract
[6] Drugs.com Sivextro Efficacy Summary