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Bates, R. H.

Publications and source records attributed to Bates, R. H..

5 recordsLinked to original sources

Next Generation TB Drug Combinations from the Pan-TB Consortium: Combination Efficacy and Contributions of Individual Agents, Evaluated in a BALB/c Mouse TB Model

The Project to Accelerate New Treatments for Tuberculosis (PAN-TB) aims to accelerate development of shorter, simpler and safer pan-TB combinations. We previously identified 3 out of 25 first-generation novel PAN-TB 4-drug combinations, that cured 90% of mice in less than 3 months, at clinically relevant doses in the relapsing mouse model of TB. These regimens include BPa830Sut, BPa286Sut and BQSut286 (B: bedaquiline; Pa: pretomanid; 830: GSK3211830; 286: GSK2556286; Sut: sutezolid; Q: quabodepistat). Here, we assess the efficacy of these combinations where the original candidates are substituted next-generation or more advanced compounds (ganfeborole (656) for 830, sorfequiline, S for B, TBD09 for Sut and TBD11 for 286) and the individual contributions of specific agents. Six novel regimens demonstrated bactericidal activity more rapid than comparators PHMZ (Rifapentine P, Isoniazid H, Moxifloxacin M, Pyrazinamide Z) and BPaMZ. Modelled cure/relapse data showed that SPa286Sut, SPaSut and SPa656Sut cured 90% of mice in about 1 month, while SPa286, SPaQTBD11 and SPaTBD09 in less than 2 months, faster than PHMZ. Consistent with our previous findings, the fastest-curing regimens centered on a diarylquinoline (S), a nitroimidazole (Pa) and an oxazolidinone (TBD09 or Sut) together with an Rv1625c agonist (TBD11 or 286), DprE1 inhibitor (Q) or a LeuRS inhibitor (656). Notably, significant contributions to sterilizing efficacy were demonstrated for S in all combinations and for Pa, Sut, TBD09, Q and TBD11 or 286 in specific S-containing combinations. These findings suggest potential for these novel agents and combinations to improve treatment of both DS-and DR-TB.

pharmacology and toxicology↗

Nonclinical pharmacokinetics and relative efficacy of the first 25 novel tuberculosis drug combinations from the PAN-TB consortium: Use of the BALB/c relapsing mouse model and combination pharmacokinetics within a modeling-based framework

The Project to Accelerate New Treatments for Tuberculosis (PAN-TB) aims to accelerate development of shorter, simpler and safer pan-TB combinations, effective for use in both Drug Susceptible (DS)- and Drug Resistant (DR)- TB patients. Towards this aim, bactericidal and sterilizing activity of 25 priority 4-drug combinations was evaluated at doses targeting clinically relevant exposures, in the BALB/c relapsing mouse model of TB. The combinations comprised 8 PAN-TB drugs and candidates: bedaquiline (B), pretomanid (Pa), delamanid (Del), quabodepistat (Q), sutezolid (Sut), GSK2556286 (286), GSK3211830 (830) and ganfeborole (GSK3036656, (656)). Combination PK studies in infected mice enabled dose selection and a population-PK approach guided dosing so that compounds should achieve mean AUC0-24 within 2-fold of their clinical target exposures during the efficacy studies. All test combinations showed time-dependent bactericidal activity, with six regimens reducing lung bacterial burdens below the limit of detection with 8 weeks treatment, similar to the comparator BPaMZ (M is moxifloxacin and Z as pyrazinamide). Cure/Relapse data were modelled to derive population time to cure 90% mice (T90) values. Fifteen PAN-TB combinations had T90s of less than 5 months, sterilizing mice faster than the standard of care for drug susceptible TB, RHZE/RH. The best-performing PAN-TB combinations, BPa830Sut, BPa286Sut and BQSut286, cured 90% of mice in less than 3 months. These 3 top-ranked 4-drug combinations are all centered on a diarylquinoline (B)/oxazolidinone (Sut) core, together with the nitroimidazole (Pa) or a DprE1 inhibitor (Q) plus a novel agent such as the LeuRS inhibitor (830) or the Rv1625c agonist (286).

microbiology↗

Design and development of lysyl tRNA synthetase inhibitors, for the treatment of tuberculosis

There is currently a public health crisis due to the rise of multi-drug-resistant tuberculosis cases, as well as the rise in number of deaths from tuberculosis. To achieve the United Nations Sustainable Development Goal of ending the tuberculosis epidemic by 2030, new treatments are urgently required. We previously reported the discovery of 49, a pre-clinical candidate that acted through inhibition of the Mycobacterium tuberculosis lysyl-tRNA synthetase (LysRS). In this report, the full medicinal chemistry program is reviewed from the original hit through to the optimised lead. The work was guided by the first crystal structure of M. tuberculosis LysRS. The physicochemical and pharmacokinetic properties were optimised to afford compounds suitable for evaluation in mouse efficacy models of tuberculosis and with the potential for clinical development.

microbiology↗

Sanfetrinem, an oral beta-lactam antibiotic repurposed for the treatment of tuberculosis

Tuberculosis (TB) is historically the worlds deadliest infectious disease. New TB drugs that can avoid pre-existing resistance are desperately needed. The {beta}-lactams are the oldest and most widely used class of antibiotics to treat bacterial infections but, for a variety of reasons, they were largely ignored until recently as a potential treatment option for TB. Recently, a growing body of evidence indicates that later-generation carbapenems in the presence of {beta}-lactamase inhibitors could play a role in TB treatment. However, most of these drugs can only be administered intravenously in the clinic. We performed a screening of {beta}-lactams against intracellular Mycobacterium tuberculosis (Mtb) and identified sanfetrinem cilexetil as a promising oral {beta}-lactam candidate. Preclinical in vitro and in vivo studies demonstrated that: (i) media composition impacts the activity of sanfetrinem against Mtb, being more potent in the presence of physiologically relevant cholesterol as the only carbon source, compared to the standard broth media; (ii) sanfetrinem shows broad spectrum activity against Mtb clinical isolates, including MDR/XDR strains; (iii) sanfetrinem is rapidly bactericidal in vitro against Mtb despite being poorly stable in the assay media; (iv) there are strong in vitro synergistic interactions with amoxicillin, ethambutol, rifampicin and rifapentine and, (v) sanfetrinem cilexetil is active in an in vivo model of infection. These data, together with robust pre-clinical and clinical studies of broad-spectrum carbapenem antibiotics carried out in the 1990s by GSK, identified sanfetrinem as having potential for treating TB and catalyzed a repurposing proof-of-concept Phase 2a clinical study (NCT05388448) currently underway in South Africa.

microbiology↗

GSK2556286 is a novel antitubercular drug candidate effective in vivo with the potential to shorten tuberculosis treatment

As a result of a high-throughput compound screening campaign of Mycobacterium tuberculosis infected macrophages, a new preclinical drug candidate for the treatment of tuberculosis has been identified. GSK2556286 inhibits growth within human macrophages (IC50 = 0.07 {micro}M), is active against extracellular bacteria in cholesterol-containing culture media and exhibits no cross-resistance with known antitubercular drugs. In addition, it has shown efficacy in different mouse models of tuberculosis (TB) and has an adequate safety profile in two preclinical species. These features indicate a compound with a novel mode of action, although still not fully defined, that is effective against both multidrug or extensively-resistant (M/XDR) and drug-sensitive (DS) M. tuberculosis with the potential to shorten the duration of treatment in novel combination drug regimens. One Sentence SummaryGSK2556286 is a novel preclinical drug candidate for the treatment of tuberculosis with a new mode of action potentially able to contribute to the shortening of TB chemotherapy.

pharmacology and toxicology↗