Fiske, Christina T.

Abstract Background Mycobacterium abscessus complex (MABC) is a difficult-to-treat infection due to antibiotic resistance. Our study aimed to assess omadacycline’s (OMC) clinical and microbiological outcomes for the treatment of pulmonary MABC. Methods A retrospective study was carried out across 12 US medical institutions from 1/2018-4/2023 to examine the clinical outcomes, and tolerability of OMC treatment for pulmonary MABC. Patients aged ≥ 18 years who were treated with OMC for ≥ 3 months were included. The primary outcome was clinical success at 3, 6, and 12 months. The secondary outcomes were sputum culture conversion rate, adverse effects, and clinical success by subspecies and macrolide susceptibility. Results Thirty-five patients were included in this analysis. Most patients were female (74.3%) and Caucasian (74.3%), with a median (IQR) age of 61 years (51–70). Subspeciation was performed for 22 isolates with predominant M. abscessus subspecies (77.3%). Moreover, coinfection with other NTM species was present in 28.6% of cases where Mycobacterium avium complex was present in 8 cultures. Sixty-eight percent of the MABC isolates were confirmed to be macrolide resistance; half (12/24, 50.0%) were evident by the presence of functional erm gene, while the other half by antimicrobial susceptibility (Table 3). Of the remaining isolates, 14% were macrolide-susceptible, while no information was reported in 17%. The median (IQR) treatment duration of OMC was 8 months (3.9 – 15.7). The most commonly co-administered antibiotics were intravenous amikacin, imipenem/cilastatin, inhaled amikacin and clofazimine with the same percentage (42.9%) (Table 1). Overall, MABC clinical success was observed in 71.4%, 89.7%, and 90.9% in 3-, 6- and 12 months, respectively (Table 3). Adverse effects reported in 34.3%. The most common side effects were gastrointestinal intolerance (25.7%) and hepatoxicity (11.4%), which led to drug discontinuation in 22.9%. Conclusion OMC treatment showed clinical success in > 70% of patients with pulmonary MABC including patients with macrolide resistant strains for more than 3 months. However, larger studies are needed to validate the outcomes beyond 12 months. Disclosures Kaylee E. Caniff, PharmD, BCIDP, T2Biosystems: Honoraria Michael J. Rybak, PharmD, PhD, MPH, Abbvie, Melinta, Sionogi, Merck, T2Biosystems: Advisor/Consultant|Abbvie, Melinta, Sionogi, Merck, T2Biosystems: Grant/Research Support|Abbvie, Melinta, Sionogi, Merck, T2Biosystems: Speaker

Abstract The Infectious Diseases Society of America Training Program Directors Committee met in October 2022 and discussed an observed increase in clinical volume and acuity on infectious diseases (ID) services, and its impact on fellow education. Committee members sought to develop specific goals and strategies related to improving training program culture, preserving quality education on inpatient consult services and in the clinic, and negotiating change at the annual IDWeek Training Program Director meeting. This paper outlines a presentation of ideas brought forth at the meeting and is meant to serve as a reference document for infectious diseases training program directors seeking guidance in this area.

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 Rifampin-resistant tuberculosis is a leading cause of morbidity worldwide; only one-third of persons start treatment, and outcomes are often inadequate. Several trials demonstrate 90% efficacy using an all-oral, 6-month regimen of bedaquiline, pretomanid, and linezolid (BPaL), but significant toxicity occurred using 1200-mg linezolid. After US Food and Drug Administration approval in 2019, some US clinicians rapidly implemented BPaL using an initial 600-mg linezolid dose adjusted by serum drug concentrations and clinical monitoring. Methods Data from US patients treated with BPaL between 14 October 2019 and 30 April 2022 were compiled and analyzed by the BPaL Implementation Group (BIG), including baseline examination and laboratory, electrocardiographic, and clinical monitoring throughout treatment and follow-up. Linezolid dosing and clinical management was provider driven, and most patients had linezolid adjusted by therapeutic drug monitoring. Results Of 70 patients starting BPaL, 2 changed to rifampin-based therapy, 68 (97.1%) completed BPaL, and 2 of the 68 (2.9%) experienced relapse after completion. Using an initial 600-mg linezolid dose daily adjusted by therapeutic drug monitoring and careful clinical and laboratory monitoring for adverse effects, supportive care, and expert consultation throughout BPaL treatment, 3 patients (4.4%) with hematologic toxicity and 4 (5.9%) with neurotoxicity required a change in linezolid dose or frequency. The median BPaL duration was 6 months. Conclusions BPaL has transformed treatment for rifampin-resistant or intolerant tuberculosis. In this cohort, effective treatment required less than half the duration recommended in 2019 US guidelines for drug-resistant tuberculosis. Use of individualized linezolid dosing and monitoring likely enhanced safety and treatment completion. The BIG cohort demonstrates that early implementation of new tuberculosis treatments in the United States is feasible.