Efficacy and Safety of a Novel Broad-Spectrum Anti-MRSA Agent Levonadifloxacin Compared with Linezolid for Acute Bacterial Skin and Skin Structure Infections: A Phase 3, Openlabel, Randomized Study.

BACKGROUND

Levonadifloxacin is a novel broad-spectrum anti-MRSA agents belonging to the benzoquinolizine subclass of quinolone. It is developed for oral or intravenous administration for the treatment of infections caused by Gram-positive organisms including methicillin-resistant Staphylococcus aureus (MRSA).

OBJECTIVES

To establish the non-inferiority of levonadifloxacin compared with linezolid for the treatment of acute bacterial skin and skin structure infections (ABSSSI) and to compare the safety of the two antimicrobials.

SUBJECTS AND METHODS

This was a Phase 3, multicentre, randomized, open-label, active- comparator study with 500 subjects. Oral levonadifloxacin 1000 mg was compared with oral linezolid 600 mg whereas IV levonadifloxacin 800mg was compared with IV linezolid 600 mg, each treatment was administered twice daily for 7-10 days. Non-inferiority was evaluated by comparing oral levonadifloxacin to oral linezolid and IV levonadifloxacin to IV linezolid for overall clinical response at TOC (Test of Cure) Visit.

RESULTS

The clinical cure rates observed at the TOC in the mITT (modified Intent to treat) populations for levonadifloxacin was numerically higher compared to linezolid in the IV sub-group [(91.0% verses 87.8%); treatment difference of 3.2% (95%CI, -4.5 to 10.9)] and in the oral sub-group (95.2% versus 93.6%); treatment difference of 1.6 % [95%CI, -4.2 to 7.3]). As the lowerbound of the 95% CI around the treatment difference was greater than -15% for both subgroups, the primary objective of the study was met. Therefore, both IV levonadifloxacin and oral levonadifloxacin were non-inferior to IV linezolid and oral linezolid, respectively. The majority of subjects in the micro-ITT population had a baseline infection caused by S. aureus with approximately 30% of subjects having MRSA. Levonadifloxacin (IV and oral) had a higher clinical cure rate at TOC for MRSA patients compared with linezolid (IV and oral), (95.0% vs. 89.3% respectively). Levonadifloxacin showed evidence of favourable clinical and microbiological efficacy in subjects with concurrent bacteraemia as well as in subjects with diabetes including diabetic foot infections caused by Gram-positive pathogens including MRSA. Pharmacokinetic analysis showed that bioavailability of oral levonadifloxacin was 90% and similar pharmacokinetic profile of levonadifloxacin by both routes provide an option for IV to oral switch for the treatment of subjects. Incidences of treatment-emergent adverse events (TEAEs) were similar between treatment groups and between IV (20.8% vs. 22.4%, for levonadifloxacin and linezolid, respectively) and oral therapy (16.0% vs. 13.5%, respectively), There were no SAEs or deaths related to study drug and the majority of the AEs observed were mild in nature. Overall, the administration of both IV and oral levonadifloxacin was well-tolerated in subjects with ABSSSI.

CONCLUSIONS

The results demonstrate that IV and oral levonadifloxacin therapy has excellent clinical activity against MRSA and offers advantage compared to other quinolones which generally lack MRSA coverage. Levonadifloxacin is safe and well tolerated in the treatment of ABSSSI caused by Gram -positive pathogens including MRSA as well as non-inferior to IV and oral linezolid, respectively. Similar pharmacokinetic profile of IV and oral levonadifloxacin provides an option for IV to oral switch for the treatment of subjects. Both oral and IV levonadifloxacin have recently been granted approval in India for the treatment of ABSSSI including diabetic foot infections and concurrent bacteraemia in adults (18 years of age or older). ClinicalTrials.gov Registration: NCT03405064. CTRI No.: CTRI/2017/06/008843.