Q203 (IAP6) is a midazopyridine amide compound. Q203 is active against Mycobacterium tuberculosis H37Rv with an MIC50 of 2.7 nM in culture broth medium.
Imidazopyridine amide (IPA) compounds block Mycobacterium tuberculosis growth by targeting the respiratory cytochrome bc1 complex. The optimized IPA compound Q203 inhibits the growth of MDR and XDR Mycobacterium tuberculosis clinical isolates in culture broth medium in the low nanomolar range. Q203 is active against the reference strain Mycobacterium tuberculosis H37Rv with MIC50s of 2.7 nM in culture broth medium and 0.28 nM inside macrophages[1].
Q203 is efficacious in a mouse model of tuberculosis at a dose less than 1 mg per kg body weight. Q203 displays pharmacokinetic and safety profiles compatible with once-daily dosing. Q203 has a bioavailability of 90% and a terminal half-life of 23.4 h. The volume of distribution is moderate (5.27 l per kg body weight), and the systemic clearance is low (4.03 mL/min per kg). After 4 weeks of treatment, reductions of 90%, 99% and 99.9% in M. tuberculosis H37Rv bacterial load is observed in the groups treated with Q203 at 0.4, 2 and 10 mg per kg body weight, respectively[1].
References:
[1]. Pethe K, et al. Discovery of Q203, a potent clinical candidate for the treatment of tuberculosis. Nat Med. 2013 Sep;19(9):1157-60.