Abstract
In Mycobacterium tuberculosis (Mtb), persisters are genotypically drug-sensitive bacteria that nonetheless survive antibiotic treatment. Persisters contribute to prolonged TB treatment duration and relapse risk, highlighting the need for new therapeutic strategies to effectively eliminate these tolerant subpopulations. In this study, we screened 2,336 FDA-approved compounds to identify agents that enhance the sterilizing activity of standard anti-TB drugs and prevent the regrowth of persisters. Netupitant (NTP), an FDA-approved antiemetic, emerged as a promising candidate. In combination with isoniazid (INH) and rifampicin (RIF), NTP eliminated viable Mtb cells, achieving a >6-log reduction in colony-forming units (CFUs), compared to the 2.5-log reduction observed with INH-RIF alone. NTP also demonstrated broad-spectrum efficacy, enhancing the activity of multiple TB drugs, including ethambutol, moxifloxacin, amikacin, and bedaquiline. Notably, NTP retained its potency under hypoxic and caseum-mimicking conditions, both of which are known to enrich for non-replicating, drug-tolerant cells. The mammalian target of NTP, the G protein-coupled receptor NK-1, is absent in bacteria, raising the possibility that the NTP target in bacteria is novel. To begin assessing this possibility, we performed transcriptomics and found that NTP significantly upregulates multiple oxidative stress response-associated genes, while downregulating pathways linked to protein synthesis, electron transport chain activities, and ATP synthesis. While further studies are required to decipher mechanisms of action and the resistance profile of NTP, and to assess its in vivo efficacy, these findings underscore its potential as a promising adjunct to existing TB therapies.