P-67. Safety of Omadacycline Versus Standard-of-Care Oral Antibiotic Treatment for Bone and Joint Infections: Interim Results from an Open-Label, Non- Inferiority, Randomized Controlled Trial

Abstract Background The incidence of bone and joint infections (BJIs) continues to increase, and existing oral BJI antibiotics have limitations. Omadacycline may be a potential treatment option for BJI treatment due to activity against doxycycline-resistant S. aureus and ESBL-producing Enterobacterales for which there are often no viable oral options. However, the safety of omadacycline in this setting is poorly defined. Methods We performed an open label, randomized, controlled clinical trial of adults with BJIs in the outpatient setting. Participants were randomized to omadacycline-containing regimen (omadacycline 300mg po daily) or Standard-of-Care (SOC) antibiotics. Adjunctive antibiotics were permitted in addition to omadacycline. Safety labs were performed at regular intervals. Herein, we report an interim, descriptive analysis of safety data. Results Among the 59 participants enrolled to date, 31 (53%) were randomized to the omadacycline-containing regimen and 28 (47%) to SOC. Median age was 58 years old, 52 (88%) were male, 44 (75%) identified as Hispanic, 8 (14%) as African-American, and 4 (6%) as white. The most common BJIs were diabetic foot infections (52, 88%) and device infections (5, 8%). (Table) Combination therapy was used in 16 (52%) vs. 12 (43%) in the omadacycline-containing vs. SOC arms, and IV only therapy was used in 0 (%) vs. 5 (18%) in the two arms, respectively. Most commonly used SOC regimens included ciprofloxacin (8, 29%), doxycycline (7, 25%), amoxicillin/clavulanate (6, 21%), and levofloxacin (3, 11%). Commonly associated laboratory abnormalities included new or worsening renal insufficiency (2 (6%) in the omadacycline-containing arm vs. 5 (18%) in SOC) and transaminitis (2 (6%) vs. 4 (14%)). Adverse events were similar in the omadacycline-containing vs. SOC arms including nausea (6 (19%) vs. 4 (14%)), vomiting (0 (0%) vs. 4 (14%)), and diarrhea (5 (16%) vs. 2 (7%)). (Table) There was 1 drug-related serious adverse event in the omadacycline-containing arm due to likely hypersensitivity to omadacycline; the event resolved after drug discontinuation. Conclusion In this interim analysis of our ongoing trial, the safety of omadacycline for BJI appears to be similar to the SOC. More robust data on long-term safety is warranted. Disclosures Amy Y. Kang, Pharm.D., BCIDP, Paratek Pharmaceutical: Grant/Research Support Loren G. Miller, MD MPH, Armata: Grant/Research Support|Contrafect: Grant/Research Support|GSK: Grant/Research Support|Merck: Grant/Research Support|Paratek: Grant/Research Support