Structure, Detection, and Antibacterial Activity of Metabolites of SQ109, an Anti-Infective Drug Candidate.

SQ109 is a drug candidate for the treatment of tuberculosis (TB). It is thought to target primarily the protein MmpL3 in , but it also inhibits the growth of some other bacteria. SQ109 is metabolized by the liver, and it has been proposed that some of its metabolites might be responsible for its activity against TB.

-Acetylglucosamine-1-Phosphate Transferase, WecA, as a Validated Drug Target in Mycobacterium tuberculosis.

The mycobacterial phosphoglycosyltransferase WecA, which initiates arabinogalactan biosynthesis in , has been proposed as a target of the caprazamycin derivative CPZEN-45, a preclinical drug candidate for the treatment of tuberculosis. In this report, we describe the functional characterization of mycobacterial WecA and confirm the essentiality of its encoding gene in by demonstrating that the transcriptional silencing of is bactericidal and in macrophages. Silencing also conferred hypersensitivity of to the drug tunicamycin, confirming its target selectivity for WecA in whole cells.

Early phase evaluation of SQ109 alone and in combination with rifampicin in pulmonary TB patients.

Objectives: SQ109, an asymmetrical diamine, is a novel anti-TB drug candidate. This first study in patients was done to determine safety, tolerability, pharmacokinetics and bacteriological effect of different doses of SQ109 alone and in combination with rifampicin when administered over 14 days.

Patients And Methods: Smear-positive pulmonary TB patients were randomized into six groups of 15 to receive once-daily oral treatment with 75, 150 or 300 mg of SQ109, rifampicin (10 mg/kg body weight), rifampicin plus 150 mg of SQ109, or rifampicin plus 300 mg of SQ109 for 14 days.

Optimization of a nucleic acid-based reporter system to detect Mycobacterium tuberculosis antibiotic sensitivity.

We previously reported the development of a prototype antibiotic sensitivity assay to detect drug-resistant Mycobacterium tuberculosis using infection by mycobacteriophage to create a novel nucleic acid transcript, a surrogate marker of mycobacterial viability, detected by reverse transcriptase PCR (M. C. Mulvey et al.

Therapeutic efficacy of SQ641-NE against Mycobacterium tuberculosis.

A phospholipid-based nanoemulsion formulation of SQ641 (SQ641-NE) was active against intracellular Mycobacterium tuberculosis in J774A.1 mouse macrophages, although SQ641 by itself was not. Intravenous (i.

Discovery and development of SQ109: a new antitubercular drug with a novel mechanism of action.

Existing drugs have limited efficacy against the rising threat of drug-resistant TB, have significant side effects, and must be given in combinations of four to six drugs for at least 6 months for drug-sensitive TB and up to 24 months for drug-resistant TB. The long treatment duration has led to increased patient noncompliance with therapy. This, in turn, drives the development of additional drug resistance in a spiral that has resulted in some forms of TB being currently untreatable by existing drugs.

Generation of a novel nucleic acid-based reporter system to detect phenotypic susceptibility to antibiotics in Mycobacterium tuberculosis.

Unlabelled: We designed, constructed, and evaluated a prototype novel reporter system comprised of two functional cassettes: (i) the SP6 RNA polymerase gene under transcriptional control of a promoter active in mycobacteria and (ii) the consensus SP6 polymerase promoter that directs expression of an otherwise unexpressed sequence. We incorporated the reporter system into a mycobacteriophage for delivery into viable Mycobacterium tuberculosis, and introduction led to synthesis of an SP6 polymerase-dependent surrogate marker RNA that we detected by reverse transcriptase PCR (RT-PCR). The reporter confirmed the susceptibility profile of both drug-susceptible and drug-resistant M.

SQ109 and PNU-100480 interact to kill Mycobacterium tuberculosis in vitro.

Objectives: To investigate in vitro interaction between two compounds, SQ109 and PNU-100480, currently in development for the treatment of Mycobacterium tuberculosis (MTB).

Methods: The two-drug interactions between SQ109 and PNU-100480 and its major metabolite PNU-101603 were assessed by chequerboard titration, and the rate of killing and intracellular activity were determined in both J774A.1 mouse macrophages and whole blood culture.

Chemical modification of capuramycins to enhance antibacterial activity.

Objectives: To extend capuramycin spectrum of activity beyond mycobacteria and improve intracellular drug activity.

Methods: Three capuramycin analogues (SQ997, SQ922 and SQ641) were conjugated with different natural and unnatural amino acids or decanoic acid (DEC) through an ester bond at one or more available hydroxyl groups. In vitro activity of the modified compounds was determined against Mycobacterium spp.

In vitro antimicrobial activities of capuramycin analogues against non-tuberculous mycobacteria.

Objectives: To determine antibacterial activity of capuramycin analogues SQ997, SQ922, SQ641 and RKS2244 against several non-tuberculous mycobacteria (NTM).

Methods: In vitro antibiotic activities, i.e.

Anti-tuberculosis drug therapy in mice of different inbred strains.

Standard anti-tuberculosis (TB) drug therapy had distinct effects on the bacilli burden in mice of DBA/2, C3H, SWR/J, and C57BL/6 inbred strains. To standardize the TB infection process, susceptible DBA/2 mice were infected with 1/10 of the dose used for relatively resistant C57BL/6 mice, such that the lung CFUs were roughly identical 3 weeks after infection when therapy was initiated. We found that TB treatment was more effective in the susceptible DBA/2 mice than in the relatively resistant C57BL/6 mice.

In vitro interactions between new antitubercular drug candidates SQ109 and TMC207.

The in vitro interactions of two new antitubercular drugs, SQ109 and TMC207, with each other and with rifampin (RIF) were evaluated. The combination of SQ109 with TMC207 (i) improved an already excellent TMC207 MIC for M. tuberculosis H37Rv by 4- to 8-fold, (ii) improved the rate of killing of bacteria over the rate of killing by each single drug, and (iii) enhanced the drug postantibiotic effect by 4 h.

Activity of SQ641, a capuramycin analog, in a murine model of tuberculosis.

New delivery vehicles and routes of delivery were developed for the capuramycin analogue SQ641. While this compound has remarkable in vitro potency against Mycobacterium tuberculosis, it has low solubility in water and poor intracellular activity. We demonstrate here that SQ641 dissolved in the water-soluble vitamin E analogue alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) or incorporated into TPGS-micelles has significant activity in a mouse model of tuberculosis.

Preclinical study of new TB drugs and drug combinations in mouse models.

Tuberculosis (TB) remains one of the leading infectious killers in the world. New anti-TB drugs and more effective drug combinations are urgently needed, particularly given the increasing incidence of drug-resistant TB and HIV-TB co-infection. This review describes the available mouse models of TB and describes their utility in the evaluation of new TB drug candidates and in the evaluation of the efficacy of new TB drug combinations.

In vitro antimycobacterial activities of capuramycin analogues.

Translocase I inhibitor compounds derived from capuramycin demonstrated rapid bactericidal activity against several different mycobacterial species. SQ641 was the most active of the compounds, with a MIC of 0.12 to 8 microg/ml, a postantibiotic effect of 55 h, and interesting synergistic effects with other antitubercular drugs.

PrimaTB STAT-PAK assay, a novel, rapid lateral-flow test for tuberculosis in nonhuman primates.

Tuberculosis (TB) is the most important zoonotic bacterial disease in nonhuman primates (NHP). The current diagnostic method, the intradermal palpebral tuberculin test, has serious shortcomings. We characterized antibody responses in NHP against Mycobacterium tuberculosis to identify immunodominant antigens and develop a rapid serodiagnostic test for TB.

In search of new cures for tuberculosis.

The last 10 years have seen resurgent industry activity in discovery and development of new drugs for the treatment of tuberculosis (TB), a growing widespread and devastating (more than 2 million deaths annually) bacterial infection that is of increasing concern in developing and developed nations alike. This review describes drugs currently being evaluated in the clinic for treatment of uncomplicated and drug resistant pulmonary TB, and updates the literature on 5 new drugs that entered clinical trials in the last 4 years.

Drug therapy of experimental tuberculosis (TB): improved outcome by combining SQ109, a new diamine antibiotic, with existing TB drugs.

Substitution of the new diamine antibiotic SQ109 for ethambutol in a mouse model of chronic tuberculosis (TB) improved efficacy of combination drug therapy with first-line TB drugs rifampin and isoniazid, with or without pyrazinamide: at 8 weeks, lung bacteria were 1.5 log10 lower in SQ109-containing regimens.

Synergistic interactions of SQ109, a new ethylene diamine, with front-line antitubercular drugs in vitro.

Objectives: The purpose of this study was to determine interactions of SQ109, a new asymmetric diamine tuberculosis (TB) drug candidate, with existing antitubercular drugs in vitro and assess its potential to improve combination drug activities against Mycobacterium tuberculosis.

Methods: Two-drug combinations at various concentrations below their MICs were tested for growth inhibition of M. tuberculosis using the BACTEC 460 system in vitro.

Identification of new diamine scaffolds with activity against Mycobacterium tuberculosis.

A diverse 5000-compound library was synthesized from commercially available diamines and screened for activity against Mycobacterium tuberculosis in vitro, revealing 143 hits with minimum inhibitory concentration (MIC) equal to or less than 12.5 microM. New prospective scaffolds with antitubercular activity derived from homo-piperazine, phenyl- and benzyl-substituted piperazines, 4-aminomethylpiperidine, 4-aminophenylethylamine, and 4,4'-methylenebiscyclohexylamine were identified.

Design and optimization of a recombinant system for large-scale production of the MPT64 antigen from Mycobacterium tuberculosis.

Early clinical trials of a potential new tuberculosis (TB) diagnostic, the Patch Test for Active TB (PTAT), used MPB64 protein that was purified from the spent medium of Bacillus Calmette-Guérin (BCG) Tokyo 172 vaccine production. The yield was poor, 0.05 mg/L, and the process for purification of the protein was complex, requiring four chromatographic steps.

Identification of a new antitubercular drug candidate, SQ109, from a combinatorial library of 1,2-ethylenediamines.

Objectives: The aim of this study was to identify a candidate drug for clinical development from a previously synthesized combinatorial library based on the 1,2-ethylenediamine structure of ethambutol.

Methods: Sixty-nine of the most potent hits against Mycobacterium tuberculosis from the original studies were subjected to a sequential set of tests in vitro and in vivo--determination of MIC for M. tuberculosis H37Rv, cytotoxicity, intracellular antimycobacterial activity, permeability evaluation and in vivo efficacy testing.

Rapid, simple in vivo screen for new drugs active against Mycobacterium tuberculosis.

We evaluated the use of a simple and easy-to-obtain potential marker of tuberculosis (TB) drug efficacy, body weight, and correlated weight loss or gain with the number of CFU of Mycobacterium tuberculosis in lungs and spleens of infected mice. C3H mice were infected intravenously with 10(6) CFU of virulent M. tuberculosis H37Rv, and body weight was evaluated for several weeks after infection.

New tuberculosis vaccine development.

Tuberculosis (TB) is a devastating disease that kills more than three million people each year. Of these, 0.9 million are co-infected with HIV and numbers of infections and death continue to rise with the global spread of HIV.