Efficacy and Safety of Intravenous-to-Oral Lascufloxacin Switch Therapy in Community-Onset Pneumonia: A Single-Arm, Open-Label Clinical Trial.

Abstract

Background and objective: For treating community-acquired pneumonia (CAP) in adults, early switching from injectable to oral antimicrobials (switch therapy) is accepted once the clinical course is favorable. Lascufloxacin (LSFX) is a quinolone antibacterial agent, available in intravenous and oral formulations, demonstrating antibacterial activity against a relatively broad spectrum of community-onset pneumonia (COP). No switch therapy using the same drug from injectable to oral antimicrobials has been reported; therefore, we conducted the study to confirm the efficacy and safety of the switch therapy using LSFX.

Method: We conducted an open-label, uncontrolled, multicenter study across 16 hospitals from April 2023 to February 2024 to evaluate the efficacy and safety of LSFX switch therapy against mild-to-moderate COP. Once the switch criteria were fulfilled on days 3-5, switch therapy was initiated. The primary endpoint was the cure rate at the time of test of cure (TOC). Secondary endpoints included the proportion of patients receiving switch therapy, clinical efficacy at the end of treatment (EOT), early clinical response, microbiological response at the EOT, and adverse events. The adverse events were collected from the population for the safety analysis set.

Results: The median age of the participants was 73 years, and the overall switch therapy implementation rate was 114/120 (95%), aligned with approximately 99/104 (95%) of the switch therapy performed by day three after initiating the therapy. The cure or effective rate was 100/104 (96.2%, 95% confidence interval (CI): 90.44-98.94) at TOC, 101/104 (97.1%, 95% CI: 91.80-99.40) at the early clinical efficacy testing, and 103/104 (99.0%, 95% CI: 94.76-99.98) at EOT. Adverse events related to the study drug were reported in 10.0% of the patients, with hepatic dysfunction as the most common adverse effect. Severe LSFX-induced adverse events were not observed, excluding worsening pneumonia.

Conclusion: Switch therapy using LSFX presented high efficacy and acceptable safety profiles against mild-to-moderate severity of COP. This strategy of using the same drug in both intravenous and oral formulations is quite innovative. LSFX may potentially emerge as one of the preferred options for treating COP.