Lefamulin Post-Market Surveillance Study

A Multicenter, Single-arm, Real-world Study to Evaluate the Safety and Efficacy of Lefamulin in Patients With Community-acquired Pneumonia

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Community-Acquired Pneumonia (CAP)
• Intervention / Treatment: Other: This is a multicenter, single-arm, non-interventional study. No interventional measures will be adopted.

• Study Type: Observational
• Enrollment (Estimated): 1000

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

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.

Description

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

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To evaluate the safety of lefamulin in the real-world treatment of patients with CAP	Treatment-emergent adverse events (TEAEs) will be collected from medical records, patient interviews, and laboratory findings. Events will be coded using MedDRA (or CTCAE v5.0 where applicable), and assessed for severity, seriousness, and causality to lefamulin by the investigator. Data will be summarized as: Number and percentage of participants with any TEAE, drug-related TEAE, serious adverse events (SAEs), and TEAEs leading to treatment discontinuation. Incidence by severity (mild, moderate, severe), system organ class, and preferred term.	Visit 1 (Day 1: baseline, date of initial lefamulin administration) through Visit 4 (Days 27-33 post-administration)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of participants achieving Early Clinical Response (ECR).	Early Clinical Response (ECR) is assessed at Visit 2 as the proportion of participants with improvement in at least two of the four cardinal symptoms of CAP (cough, sputum production, dyspnea, chest pain) without worsening of any symptom. Data will be summarized as number and percentage of participants achieving ECR in the intention-to-treat (ITT) population, with 95% confidence intervals.	Visit 2 (Days 4-6 after lefamulin administration)
Proportion of participants achieving Investigator-Assessed Clinical Response (IACR) at Test-of-Cure (TOC)	Investigator-Assessed Clinical Response (IACR) is defined as complete or partial resolution of signs and symptoms of community-acquired pneumonia. Assessments will be performed at end of treatment (Visit 3) and 5-10 days after TOC (Visit 4, retrospective). Data will be summarized as the number and percentage of participants achieving IACR at each time point in the clinically evaluable and modified ITT populations, with 95% confidence intervals.	Visit 3 (within 2 days after end of treatment) and Visit 4 (5-10 days post-TOC, retrospective assessment)
Health outcomes including hospital readmission/re-visit rate and change in EQ-5D-5L score	This measure includes: Rate of all-cause hospital readmission or pneumonia-related re-visit within 30 days. Change in health-related quality of life as measured by the EQ-5D-5L questionnaire from baseline (Visit 1) to Visit 4. EQ-5D-5L will be scored using the standard index value (0-1 scale, where 1 = full health). Data will be summarized as: Number and percentage of participants with hospital readmission/re-visit. Mean change in EQ-5D-5L index score from baseline, with standard deviation.	Up to Visit 4 (Days 27-33 after lefamulin administration)

Collaborators and Investigators

• Sponsor: Marubeni Pharmaceuticals (Suzhou) Co., Ltd.
• Collaborators: China-Japan Friendship Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): June 30, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: June 17, 2026
• First Submitted That Met QC Criteria: July 6, 2026
• First Posted (Actual): July 13, 2026

Study Record Updates

• Last Update Posted (Actual): July 13, 2026
• Last Update Submitted That Met QC Criteria: July 6, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: antibiotic; post-marketing; community-acquired bacterial pneumonia; real-world study; pleuromutilin; lefamulin
• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Respiratory Tract Diseases; Pneumonia; Community-Acquired Infections; Community-Acquired Pneumonia
• Other Study ID Numbers: MPCN-LEF-2025-001

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No