Rowlinson, Marie‐Claire

Abstract Background Bedaquiline, pretomanid, and linezolid with or without moxifloxacin (BPaL/M) are recommended oral 6-month treatment regimens for multidrug- or rifampin-resistant (MDR/RR) tuberculosis (TB). Since the US rollout of these regimens in 2019, the US Centers for Disease Control and Prevention (CDC) and partners have identified patients who failed or relapsed on these regimens. Methods Here, we report a case series of US patients with TB treated with BPaL/M-containing regimens, who experienced adverse outcomes during the period 2022‒2024, including drug resistance, relapse, and treatment failure. Results Clinical and public health outcomes were significant for US patients reported. There were 8 patients identified (n = 8). 5 (62.5%) were male, with a median age 57 years, 2 (25%) were previously treated for TB, and 8 (100%) presented with cavitary disease. This included a patient who died from infectious TB with acquired resistance after exposing over 100 healthcare workers, a waitress who was found to have highly infectious TB at the time of her relapse, and a son who contracted Mycobacterium tuberculosis (Mtb) with reduced activity to bedaquiline from his mother in a household transmission event. Conclusions These patients highlight consequences, both for the individual and public health, of relapse and treatment failure in real-life operational settings that may not be readily evident in well-controlled and well-resourced clinical trials. Despite the advent of shorter and better tolerated bedaquiline-based regimens, US clinicians continue to face challenges in managing drug-resistant TB. These data support the need for expert management of these patients beyond routine TB care, as well as the need for close monitoring and follow-up months after treatment completion.

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.

The U.S. Food & Drug Administration (FDA) regulates the marketing of manufacturers’ in vitro diagnostic tests (IVDs), including assays for the detection of SARS-CoV-2.