New tetracycline antibiotic effective in community-acquired bacterial pneumonia
Dr. Farrin A. Manian
Background: Community-acquired pneumonia (CAP) is a leading cause of hospitalization and death, particularly in the elderly. Omadacycline is a new once-daily tetracycline with in vitro activity against a wide range of CAP pathogens, including Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and atypical organisms, such as Mycoplasma pneumoniae, Legionella pneumophila, and Chlamydia pneumoniae.
Study design: Phase 3 randomized, double-blind, double-dummy, placebo-controlled trial.
Setting: Hospitalized patients (98.8%) in non-ICU settings at 86 sites in Europe, North America, South America, the Middle East, Africa, and Asia.
Synopsis: The trial recruited 774 adults with three or more CAP symptoms (cough, purulent sputum production, dyspnea, or pleuritic chest pain) and at least two abnormal vital signs, one or more clinical signs or laboratory findings associated with CAP, radiologically confirmed pneumonia, and a Pneumonia Severity Index (PSI) of II, III, or IV (with higher class numbers indicating a greater risk of death). Exclusion criteria included having clinically significant liver or renal insufficiency or having an immunocompromised state. The patients were randomized to receive either omadacycline or moxifloxacin intravenously with the option to switch to the oral preparation of the respective drugs after at least 3 days of therapy. Atypical organisms were implicated in 67% of CAPS with known cause, while Streptococcus pneumoniae and Haemophilus influenzae were implicated in 20% and 12%, respectively. Omadacycline was noninferior to moxifloxacin with respect to early clinical response (81.1% vs 82.7%, respectively) and posttreatment clinical response rates (87.6% vs. 85.1%). Mean duration of IV therapy was 5.7 days, and the mean total duration of therapy was 9.6 days in both groups. The frequency of adverse events (primarily gastrointestinal) was similar between the two groups.
Exclusion of the most severe CAP and immunocompromised patients limits generalizability of these results.
Bottom line: Omadacycline provides similar clinical benefit as moxifloxacin in the treatment of selected patients with CAP.
Citation: Stets R et al. Omadacycline for community-acquired bacterial pneumonia. N Eng J Med. 2019;380:517-27.
Dr. Manian is a core educator faculty member in the department of medicine at Massachusetts General Hospital and an associate professor of medicine at Harvard Medical School, Boston.
