Sustained treatment success at 12 months for drug-resistant TB patients on concomitant bedaquiline-delamanid

Sustained treatment success at 12 months for drug-resistant TB patients on concomitant bedaquiline-delamanidDear Editor, An estimated 10.6 million people developed TB worldwide in 2022, including 410,000 cases of multidrug-resistant or rifampicin-resistant TB (MDR/ RR-TB), causing 1.3 million deaths. 1 Although the treatment outcomes of bedaquiline (BDQ) and delamanid (DLM) containing regimens for drugresistant TB (DR-TB) are well documented, [2][3][4] there is limited data on long-term post-TB treatment outcomes, including relapse, sequelae and quality of life (QoL).The recurrence of TB after successful treatment presents a significant challenge.A meta-analysis revealed that the pooled incidence rate of recurrent TB was 2.3/100 person-years at risk, with rates of 1.5 in low TB burden and 4.1 in high TB burden settings. 5In a study by Surie et al. in Chennai, India, 9% of MDR-TB patients who achieved treatment success died, with no cases of recurrent TB observed during long-term follow-up. 6In another study in Mumbai, India, the post-treatment case-fatality ratio was 1% at 6 months and 1.7% at 12 months, and the TB recurrence rate was 0.4% at 6 and 0.8% at 12 months. 7A multi-country study estimated a 6-month post-treatment TB-recurrence risk of 7.4/ 1,000 MDR-TB patients, considering deaths as non-recurrences. 8Guidelines for the programmatic management of DR-TB in India recommend posttreatment follow-up for up to 24 months for all successfully treated TB patients.However, systematic follow-up of these patients is still lacking. 9Recently, the WHO has proposed an optional definition of 'sustained treatment success' (alive and TB free) for use in operational research for DR-TB patients assessed at 12-months post-treatment. 10 Mdecins Sans Frontires (MSF) clinic (Govandi East, Mumbai, India) provides free treatment for DR-TB patients with extensive resistance patterns who need the latest drugs and have limited treatment options.The clinic provides BDQ-and DLM-containing regimens with or without carbapenem to DR-TB patients as part of a 'salvage' regimen' for 18-24 months, based on drug susceptibility testing, adverse events and previous drug exposure. 3,4All patients are followed up at 6 months and 12 months to assess sustained treatment success after completion of treatment.During these visits, patients are screened by nurses, examined by a doctor and relevant investigations are advised.Sputum samples from previous pulmonary TB patients are sent for culture.We describe 12-month follow-up outcomes of patients with DR-TB who had failed previous regimens and were successfully treated