Comparison of Delafloxacin and Vancomycin by Age and Gender in Two Phase 3 Trials in the Treatment of Acute Bacterial Skin and Skin Structure Infections

Abstract

Background. Delafloxacin (DLX) is a novel investigational anionic fluoroquinolone being developed for oral or intravenous (IV) administration for infections caused by Gram‐positive organisms (including methicillin‐resistant Staphylococcus aureus [MRSA]), Gram‐negative organisms, atypical organisms, and anaerobes. Methods. Data on age and gender were reviewed from 2 randomized, doubleblind trials of adults with acute bacterial skin and skin structure infection (ABSSSI). At baseline, patients had a lesion size ≥75 cm2 with ≥2 signs of systemic infection. Patients received 5‐14 days BID DLX 300 mg IV/450 mg oral, or vancomycin (VAN) 15 mg/kg (based on the actual body weight) with aztreonam (AZ). Both studies included endpoints for objective response at 48‐72 hrs based on ≥20% reduction of lesion size and investigator‐assessed‐response rates based on complete resolution of signs and symptoms (Cure) at Follow up (FU; Day 14) and Late Follow up (LFU; Day 21‐28). Results. In the combined patient pool, 1510 patients (754 DLX, 756 VAN) in the Intent to Treat (ITT) had a mean age of 49.0 yrs for DLX and 48.1 yrs for VAN (1314 were <65 yrs, 196 >65 yrs), and were majority male (62% DLX, 64% VAN). At baseline, digital mean lesion size was similar between both arms (321.1 cm2 DLX, 344.7 cm2 VAN). Infection types included cellulitis (44.0%), wound infection (30.1%), major cutaneous abscess (25.1%) and burn infection (0.8%). Below is the comparison of DLX and VAN objective response at 48‐72 hours in the ITT population: Investigator‐assessed cure rates for all subjects at FU (55.2% DLX, 55.7% VAN) and LFU (69.0% DLX, 69.0% VAN) were similar. Overall, DLX had similar rates of related TEAEs between treatment groups regardless of age and gender. The most common AEs that were related to treatment were nausea (6.1% DLX, 4.3% VAN), pruritus (0.4% DLX, 2.3% VAN), and diarrhea (6.1% DLX, 2.0% VAN). Conclusion. In a pooled analysis based on age and gender, DLX had comparable outcomes to VAN for the objective response at 48‐72 hours. DLX was also well tolerated regardless of age or gender. .