Safety and efficacy of exposure to bedaquiline-delamanid in multidrug-resistant tuberculosis : A case series from France and Latvia

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Is bedaquiline as effective as fluoroquinolones in the treatment of multidrug-resistant tuberculosis?

The MDR-TB Management Group of the French National Reference Center for Mycobacteria and the Physicians of the French MDR-TB CohortInternational audienceBedaquiline (Bdq) is approved for the treatment of multidrug-resistant (MDR) tuberculosis (TB). In a phase IIb trial, Bdq allowed a significant reduction in time to culture conversion and improved outcome in MDR-TB patients [1, 2]. Preliminary reports of Bdq compassionate use have shown promising results [3–5]. However, in an early bactericidal activity (EBA) study, the association of moxifloxacin (Mfx) with PA-824 and pyrazinamide showed better activity than Bdq-based associations [6]. In addition, resistance to fluoroquinolones (Fq) has been associated with poorer outcome in MDR-TB before Bdq use [7]. These data reinforce the pivotal role of Fq. Comparing Bdq to Fq in interventional studies is challenging. Indeed, the paucity of drugs available for MDR-TB treatment, and the need for combination therapy, often impose the need to use all available drugs

Long-term outcome and safety of prolonged bedaquiline treatment for multidrug-resistant tuberculosis

for the French MDR-TB Management Group9International audienceBedaquiline, a recently approved drug for the treatment of multidrug-resistant tuberculosis (MDR-TB), is recommended for a duration of 24 weeks. There are scarce data on patients treated with this drug outside clinical trials.All MDR-TB patients who started treatment from January 1, 2011 to December 31, 2013 and received ≥30 days of bedaquiline were included in a multicentre observational cohort.Among 45 MDR-TB patients, 53% harboured isolates resistant to both fluoroquinolones and second-line injectables, and 38% harboured isolates resistant to one of these drug classes. Median bedaquiline treatment duration was 361 days and 33 patients (73%) received prolonged (>190 days) bedaquiline treatment. Overall, 36 patients (80%) had favourable outcome, five were lost to follow-up, three died, and one failed and acquired bedaquiline resistance. No cases of recurrence were reported. Severe and serious adverse events were recorded in 60% and 18% of patients, respectively. Values of Fridericia-corrected QT interval (QTcF) >500 ms were recorded in 11% of patients, but neither arrhythmias nor symptomatic cardiac side-effects occurred. Bedaquiline was discontinued in three patients following QTcF prolongation. No significant differences in outcomes or adverse events rates were observed between patients receiving standard and prolonged bedaquiline treatment.Bedaquiline-containing regimens achieved favourable outcomes in a large proportion of patients. Prolonged bedaquiline treatment was overall well tolerated in this cohort

Rapid emergence of Mycobacterium tuberculosis bedaquiline resistance: lessons not to repeat past errors

On behalf of the CNR MyRMA and the Tuberculosis Consilium of the CNR MyRMAInternational audienceBedaquiline (BDQ) has demonstrated potent clinical activity against multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis complex strains [1–3]. It has now been used in >50 countries, and it is estimated that ∼2500 patients had been treated with BDQ by the end of 2015. In spite of its recent clinical use, there are few reports of BDQ-resistant strains [4, 5]. Mutations in the rv0678 gene encoding the MmpL5 efflux pump repressor generate low-level BDQ resistance and clofazimine (CFZ) cross-resistance [6]. To our knowledge, this is the sole mechanism of BDQ resistance described in clinical strains [4, 5]. Despite its introduction in France in 2011 for XDR- and MDR-tuberculosis (TB) treatment, we report herein four BDQ-resistant cases, and discuss strategies to avoid a surge of BDQ resistance

Increased linezolid plasma concentrations are associated with the development of severe toxicity in MDR-TB treatment.

Auteurs : the LZDM groupInternational audienceAbstract Background Treatment of multidrug-resistant (MDR) tuberculosis with linezolid is characterized by high rates of adverse events. Evidence on therapeutic drug monitoring to predict drug toxicity is scarce. This study aimed to evaluate the association of linezolid trough concentrations with severe toxicity. Methods We retrospectively assessed consecutive patients started on linezolid for MDR tuberculosis between 2011 and 2017. The primary outcome was severe mitochondrial toxicity (SMT) due to linezolid, defined as neurotoxicity or myelotoxicity leading to drug discontinuation. The impact of plasma linezolid trough concentrations >2 mg/L was assessed in multivariate Cox proportional hazards models including time-varying covariates. Results SMT occurred in 57 of 146 included patients (39%) at an incidence rate of 0.38 per person-year (95% confidence interval, .30–.49). A maximum linezolid trough concentration >2 mg/L was detected in 52 patients (35.6%), while the mean trough concentration was >2 mg/L in 22 (15%). The adjusted hazard ratio for SMT was 2.35 (95% confidence interval, 1.26–4.38; P = .01) in patients with a mean trough concentration >2 mg/L and 2.63 (1.55–4.47; P < .01) for SMT after the first detection of a trough concentration >2 mg/L. In an exploratory analysis, higher maximum trough concentrations were dose-dependently associated with toxicity, while lowering elevated trough concentrations did not restore baseline risk. Conclusions Linezolid trough concentrations >2 mg/L are strongly associated with the development of severe treatment-emergent toxicity in patients treated for MDR tuberculosis. Pending further prospective evidence, an individual risk-benefit assessment on the continuation of linezolid treatment is warranted in any patient with trough concentrations >2 mg/L

Clinical Features and Outcome of Multidrug-Resistant Osteoarticular Tuberculosis: A 12-Year Case Series from France.

International audienceThe optimal treatment for osteoarticular infection due to multidrug-resistant tuberculosis strains (MDR-OATB) remains unclear. This study aims to evaluate the diagnosis, management and outcome of MDR-OATB in France. We present a case series of MDR-OATB patients reviewed at the French National Reference Center for Mycobacteria between 2007 and 2018. Medical history and clinical, microbiological, treatment and outcome data were collected. Twenty-three MDR-OATB cases were reported, representing 3% of all concurrent MDR-TB cases in France. Overall, 17 were male, and the median age was 32 years. Six patients were previously treated for TB, including four with first-line drugs. The most frequently affected site was the spine (n = 16). Bone and joint surgery were required in 12 patients. Twenty-one patients (91%) successfully completed the treatment with a regimen containing a mean of four drugs (range, 2-6) for a mean duration of 20 months (range, 13-27). Overall, high rates of treatment success were achieved following WHO MDR-TB treatment guidelines and individualized patient management recommendations by the French National TB Consilium. However, the optimal combination of drugs, duration of treatment and role of surgery in the management of MDR-OATB remains to be determined