A pooled safety analysis of omadacycline (OMC) was based on 2150 subjects from 3 phase 3 trials: OASIS-1 (N = 645) and OASIS-2 (N = 735) in acute bacterial skin and skin structure infections (ABSSSIs), and OPTIC (N = 770) in community-acquired bacterial pneumonia (CABP). A total of 705 subjects received the combined intravenous (IV) and oral regimens for the treatment of ABSSSI (n = 323) and CABP (n = 382) in the OASIS-1 and OPTIC studies, respectively. A total of 368 subjects received the oral-only OMC regimen for the treatment of ABSSSI. Comparators were linezolid (LZD) 600 mg IV then oral in ABSSSI (n = 367) and moxifloxacin (MOX) 400 mg IV then oral in CABP (n = 388). Safety parameters included treatment-emergent adverse events (TEAEs), laboratory evaluations, vital signs, and electrocardiogram (ECG) findings.
Overall, 60.6% of the subjects were male and 91.6% were white; mean age ranges were 44.7 to 45.1 years and 60.9 to 62.1 years in the ABSSSI and CABP studies, respectively. TEAEs were observed in 47.5% of patients treated with OMC, 41.2% treated with LZD, and 48.5% treated with MOX, with gastrointestinal events the most common TEAEs. Rates of serious TEAEs were low (3.6%, OMC; 1.9%, LZD; 6.7%, MOX). Nausea (14.9%, OMC; 8.7%, LZD; 5.4%, MOX) and vomiting (8.3%, OMC; 3.9%, LZD; 1.5%, MOX) were the most frequently reported TEAEs. Diarrhea was observed in 2.4% of OMC-treated patients, 2.9% of LZD-treated patients, and 8.0% of MOX-treated patients, with no cases of Clostridium difficile in OMC-treated subjects. Most TEAEs were mild to moderate and did not result in study drug discontinuation (3.1%, OMC; 1.5%, LZD; 7.0%, MOX); 4 OMC, 1 LZD, and 0 MOX subjects discontinued for nausea and vomiting. Frequency of hepatic TEAEs was similar among the 3 groups, with 4.3% of OMC-treated subjects, 4.1% of LZD-treated subjects, and 4.5% of MOX-treated subjects having postbaseline alanine aminotransferase >3 times the upper limit of normal. Vital signs and ECGs were comparable postbaseline in each treatment group. Known tetracycline class adverse events, such as fungal infections, were similar in all groups.
Omadacycline demonstrates a favorable safety profile, consistent with its tetracycline heritage, is generally well-tolerated in subjects with ABSSSIs and CABP, and has infrequent discontinuations because of adverse events.
Source: Opal S, et al. IDWeek 2018. Abstract 1374.