Safety, Tolerability, Pharmacokinetics, and Metabolism of Telacebec (Q203) for the Treatment of Tuberculosis: a Randomized, Placebo-Controlled, Multiple Ascending Dose Phase 1B Trial

Abstract

A phase 1b, randomized, placebo-controlled, double-blind, multiple ascending dose study (NCT02858973) was conducted to assess the safety, tolerability, and pharmacokinetics of the new antituberculosis agent telacebec (Q203). A total of 47 healthy adult subjects entered the study; 36 received telacebec, and 11 received placebo. Telacebec at doses of 20, 50, 100, 160, 250, and 320 mg was orally administered once daily with a standard meal for 14 days. Multiple oral doses of telacebec up to 320 mg daily for 14 days appeared to be safe and well tolerated by healthy adult subjects in this study. There were no deaths, serious adverse events, or subject discontinuations due to adverse events. Following oral doses of telacebec, the overall extent (AUC_τ) and peak (C_max) exposures of telacebec increased from 538.94 to 10,098.47 ng·h/mL and from 76.43 to 1502.33 ng/mL, respectively, with increasing telacebec doses from 20 mg to 320 mg. A steady state was achieved for plasma telacebec by day 12, and there was 1.9- to 3.1-fold accumulation in the extent of telacebec exposure after daily doses for 14 days. Analysis of plasma samples from the participants indicated that telacebec was the primary circulating entity with no significant metabolites. Three potential metabolites of telacebec have been identified, which may be relatively minimal compared to the parent drug. Consistent with findings from preclinical and previous single-dose clinical studies, these results also support the potential of telacebec for further development as a safe and effective agent for the treatment of tuberculosis.

Keywords: antituberculosis; metabolism; multiple ascending doses; pharmacokinetics; safety; telacebec.

FIG 1

Average plasma concentrations of telacebec versus time profiles after (A) the first dose on day 1, (B) the last dose on day 14, and (C) trough concentrations (C_trough) following oral doses of telacebec at 20 – 320 mg once daily for 14 days in healthy adult subjects (mean ± SD, n = 6).

FIG 2

Dose proportionality of telacebec with respect to (A) C_max on day 1, (B) C_max on day 14, (C) AUC_τ on day 1, and (D) AUC_τ on day 14. Closed symbols represent the mean and open symbols represent the individual data (n = 6).