TQH-3906

This is an open-label, single-arm Phase Ib exploratory study, divided into Cohort 1: moderate to severe active ulcerative colitis, and Cohort 2: moderate to severe active Crohn's disease. Each cohort is divided into two phases. The first phase mainly explores the safety and tolerability of three dose groups of TQH3906 (12mg, 24mg, and 32mg). Based on the findings of the first phase, the second phase of the study will be conducted to select 1-2 dose groups for preliminary efficacy confirmation in ulcerative colitis and Crohn's disease. The subjects will take TQH3906 capsules orally for 8 weeks to evaluate the safety, efficacy, and pharmacokinetic (PK) characteristics of TQH3906 capsules in subjects with moderate to severe active ulcerative colitis or Crohn's disease. The study will include a screening period of up to 4 weeks, an 8-week treatment period, and a 4-week follow-up period after treatment.