ABSTRACT
Lefamulin (BC-3781) is a semi-synthetic pleuromutilin antibiotic, approved for the treatment of community-acquired bacterial pneumonia (CABP) by Food and Drug Administration (USA) in August 2019, with the commodity name of Xenleta. It is the first pleuromutilin antibiotics used for systemic treatment of bacterial infections in human. Lefamulin binds to the peptidyl transferase center of the 50S ribosomal subunit to prevent peptide transfer, thus inhibits protein synthesis. Lefamulin displays expanded activity against gram-positive organisms, and also shows high activity against atypical microorganism like Mycoplasma pneumoniae. This review discusses the mechanism, bacterial spectrum of activity, preclinical and clinical data of Lefamulin.
ABSTRACT
The advent and spread of antimicrobial resistance has led to a global public health emergency necessitating development of new antimicrobial drugs. Community acquired bacterial pneumonia (CABP) contributes a major portion of societal burden with increasing morbidity due to evolution of drug resistant strains. Lefamulin is a novel pleuromutilin antibiotic with unique mechanism of action through inhibition of protein synthesis by binding to the peptidyl transferase center of the 50s bacterial ribosome. The drug displays activity against Gram positive and atypical organisms associated with CABP (i.e., Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumonia, Legionella pneumophila, and Chlamydophila pneumoniae), with an expanded Gram-positive spectrum including Staphylococcus aureus (i.e., methicillin-resistant, vancomycin-intermediate, and heterogeneous strains). Lefamulin is available in both intravenous (IV) and per oral (PO) formulation, exhibits high nonlinear plasma protein binding with low unbound concentrations, higher concentrations in lung epithelial lining fluid (ELF) than in plasma, and a half-life of approximately 10 hour. The recommended IV dose is 150 mg twice daily over 1 hour or a PO dose of 600 mg twice daily. Most common adverse drug reactions injection site reactions, hepatic enzyme elevation, nausea, diarrhoea, hypokalemia, insomnia, and headache. Clinical trials for lefamulin have been positive and Phase 3 data suggest similar efficacy when compared to moxifloxacin with or without linezolid in CABP. Also, the documented resistance and cross-resistance with other Gram-positive antibacterials remains low. With Nabrivia Pharmaceuticals having already received US FDA approval in August 2019, lefamulin may soon be a new addition to the mounting armoury of drugs against CABP.