Molina, Kyle C.

ABSTRACT Infections due to nontuberculous mycobacteria (NTM) continue to increase in prevalence, leading to problematic clinical outcomes. Omadacycline (OMC) is an aminomethylcycline antibiotic with FDA orphan drug and fast-track designations for pulmonary NTM infections, including Mycobacteroides abscessus (MAB). This multicenter retrospective study across 16 U.S. medical institutions from January 2020 to March 2023 examined the long-term clinical success, safety, and tolerability of OMC for NTM infections. The cohort included patients aged ≥18 yr, who were clinically evaluable, and` had been treated with OMC for ≥3 mo without a previous diagnosis of cystic fibrosis. The primary outcome was 3 mo clinical success, with secondary outcomes including clinical improvement and mortality at 6- and 12 mo, persistence or reemergence of infection, adverse effects, and reasons for OMC utilization. Seventy-five patients were included in this analysis. Most patients were female (48/75, 64.0%) or Caucasian (58/75, 77.3%), with a median (IQR) age of 59 yr (49–67). Most had NTM pulmonary disease (33/75, 44.0%), skin and soft tissue disease (19/75, 25.3%), or osteomyelitis (10/75, 13.3%), and Mycobacterium abscessus (60/75, 80%) was the most commonly isolated NTM pathogen. The median (IQR) treatment duration was 6 mo ( 4 – 14 ), and the most commonly co-administered antibiotic was azithromycin (33/70, 47.1%). Three-month clinical success was observed in 80.0% (60/75) of patients, and AEs attributable to OMC occurred in 32.0% (24/75) of patients, leading to drug discontinuation in 9.3% (7/75).

Abstract Background Multi-drug resistant (MDR) pathogens are a continuously evolving threat for which there are limited effective treatment modalities. Omadacycline (OMC) is a novel oral and intravenously administered aminomethylcycline with potent in-vitro activity against MDR gram-negative and gram-positive pathogens. Post-marketing data investigating its potential place in the antibiotic armamentarium is limited. This study aimed at describing the clinical success and tolerability of patients receiving OMC for various infections. Methods This was a multicenter, retrospective, observational study conducted from January 2020 to March 30, 2022. We included all patients ≥ 18 years of age that received OMC for any infection not related to Mycobacterium spp. for ≥72 hours. The primary outcome was clinical success at 30 days, defined as survival, the absence of persistence or re-emergence of infection during or after therapy, and the absence of escalation or alteration of OMC. Incidence of adverse effects while on OMC and reasons for OMC utilization were also analyzed. Results This analysis included 19 patients from 10 distinct academic centers. The median age was 50 years (IQR, 37-63), 58% were male, 63% were Caucasian, and the median APACHE II, Charlson and SOFA scores were 10 (IQR 5-12.5), 4 (IQR 2-6.3), and 1 (IQR 0 – 2.25), respectively. Most patients had a bone and joint (8/19, 42.1%) or intra-abdominal infections (4/19, 21.1%), all with positive cultures. Eight patients (44.1%) had a polymicrobial infection and 4 (22.2%) had bacteremia. The most common pathogens encountered were Carbapenem-resistant A. baumannii (5/19, 27.8%), E. coli (5/19, 27.8%), Vancomycin-resistant Enterococcus spp. (4/19, 22.2%), and K. pneumoniae (3/19, 16.7%). Clinical success was observed in 14 patients (74%) and 7 (36.8%) received combination therapy. Adverse drug reactions were reported in 3 patients (15.8%) and of those patients, none discontinued therapy. Reasons for prescribing OMC were mostly attributed to oral availability (12/14, 85.7%) and resistance to other agents (7/14, 50%). Conclusion OMC demonstrated clinical effectiveness and safety against a large number of MDR pathogens. More robust, prospective, comparative studies are needed to confirm our preliminary findings. Disclosures P. Brandon Bookstaver, PharmD, Spero Therapeutics: Advisor/Consultant.

Abstract Background The survival benefit of combination antifungal therapy for invasive mucormycosis (IM) in patients with hematologic malignancy (HM) and hematopoietic cell transplant (HCT) is not well defined. Methods This multicenter, retrospective study included HM and HCT recipients with proven or probable IM between January 1, 2007 and December 31, 2017 from 10 transplant centers across North America. Results Sixty-four patients with proven (n = 47) or probable (n = 17) IM defined by 2008 European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) consensus definitions were included. Thirty-nine (61%) were HCT recipients (95% allogeneic). Sites of infection included rhino-orbital-cerebral (33), pulmonary (30%), disseminated (19%), gastrointestinal (3%), and cutaneous (3%). Surgical debridement was performed in 66%. Initial antifungal treatment consisted of the following: lipid formulation of amphotericin B (AmB) alone (44%), AmB + posaconazole (25%), AmB + echinocandin (13%), AmB + isavuconazole (8%), posaconazole alone (5%), and isavuconazole alone (3%). All-cause mortality at 30 days and 1 year were 38% and 66%, respectively. Initial treatment with AmB plus posaconazole or isavuconazole (n = 28) was associated with a trend toward lower treatment failure compared with AmB (n = 21) (42% vs 64%, P = .136). Conclusions Long-term survival with IM among HM and HCT populations remains poor. However, initial use of AmB + azole in conjunction with surgery may result in less treatment failure. More evidence from prospective controlled studies is needed to confirm this observation.