Background & aims: TQ-A3334, a selective, oral toll-like receptor (TLR)-7 agonist, is being developed to treat chronic hepatitis B (CHB). This study evaluated the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of TQ-A3334 in healthy participants.
Research design and methods: The effects of a single-ascending dose of TQ-A3334 (0.2-1.8 mg) combined with food (1.2 mg) were evaluated in 48 healthy participants.
Results: No serious adverse events or discontinuations occurred in the study. The most common adverse reactions were lymphocyte count decreased and headache, which were generally consistent with IFN-α exposure and the mechanism of action of a TLR7 agonist. TQ-A3334 was rapidly absorbed, with a time to maximum plasma concentration of 0.42-0.5 h. Systemic exposure (Cmax and AUC) to TQ-A3334 increased with a slight saturation proportion to dose. Food reduced the exposure of TQ-A3334. The concentrations of MCP-1, ISG-15, MX-1, and OAS-1 were observed to be slightly dose-dependent, ranging from 1.0 to 1.8 mg TQ-A3334.
Conclusions: Oral doses of 0.2-1.8 mg appeared to be safe and tolerated. PD activity was seen at doses ranging from 1.0 to 1.8 mg, indicating its possible future use to treat CHB.
Trial registration: The trial is registered at the Chinese Clinical Trial website (http://www.chinadrugtrials.org.cn/index.html # CTR20182248).
Keywords: Clinical trial; hbv; pharmacodynamics; pharmacokinetics; toll-like receptor 7 agonist.