Community-acquired pneumonia (CAP) refers to infectious parenchymal lung inflammation acquired outside hospital settings. In China, its incidence is 7.13 per 1000 person-years, with over 10 million new cases annually. Elderly CAP patients carry a higher mortality risk. The predominant pathogens of CAP in China are Mycoplasma pneumoniae and Streptococcus pneumoniae, followed by Haemophilus influenzae, Staphylococcus aureus and other pathogens.

Commonly used antibacterial agents include macrolides, penicillins, cephalosporins, respiratory quinolones and tetracyclines. Nevertheless, drug resistance is prevalent nationwide. Specifically, the resistance rate of Mycoplasma pneumoniae to macrolides ranges from 54.9% to 71.7%, while that of Streptococcus pneumoniae reaches as high as 77.2% to 93.8%. Therefore, novel antibacterial agents covering common pathogens with low cross-resistance are urgently needed.

Lefamulin is the first systemic pleuromutilin antibacterial agent for human use. It binds to the peptidyl transferase center of bacterial 50S ribosomal subunit via dual A/P sites to inhibit bacterial protein synthesis. It features low cross-resistance and low potential to induce drug resistance, and exerts broad-spectrum antibacterial activity against common typical and atypical pathogens (including multi-drug resistant strains) causing CAP.

Multiple Phase III randomized controlled trials have verified that lefamulin achieves favorable early clinical response (ECR) and investigator-assessed clinical response (IACR) in CAP patients, providing solid evidence-based support for its clinical application. As a safer and more effective therapeutic option for CAP, lefamulin has been recommended by domestic and international clinical guidelines and expert consensus.

This study aims to evaluate the safety and efficacy of lefamulin in real-world clinical treatment among Chinese patients with CAP.

Inclusion Criteria:

1. Signed informed consent form
2. Clinical diagnosis of community-acquired pneumonia (CAP) by treating physicians
3. Currently receiving lefamulin treatment or prescribed and agreed to initiate lefamulin therapy as determined by the treating physician

Exclusion Criteria:

1. Patients with contraindications to lefamulin according to the approved prescribing information (e.g., known hypersensitivity to lefamulin or pleuromutilin class antibiotics)
2. Pulmonary infiltrates caused by non-infectious factors (e.g., pulmonary embolism, aspiration chemical pneumonitis, hypersensitivity pneumonitis, congestive heart failure, bronchial obstruction, lung cancer, cystic fibrosis)
3. Confirmed or suspected empyema via chest X-ray or CT examination
4. Participation in any other ongoing interventional clinical trial

A total of 1000 patients with CAP are planned to be enrolled in this study. All enrolled patients have been prescribed and scheduled to start lefamulin treatment or are already receiving lefamulin therapy. The decision to initiate lefamulin treatment is independent of this study.