Previously Untreated Peripheral T-cell Lymphoma

The goal of this clinical study is to find the best way to combine the study drug BEBT-908 (ifupinostat hydrochloride for injection) with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) for treating previously untreated peripheral T-cell lymphoma, and to find out whether this best combination is better than standard CHOP treatment alone. The main questions this study will try to answer are: What percentage of participants will respond well to treatment with BEBT-908 plus CHOP? Is BEBT-908 plus CHOP better than standard CHOP treatment? What medical problems will participants have while receiving this combination treatment? This study includes an Exploration Phase and an Expansion Phase. The Exploration Phase has 3 cohorts. All participants receive both BEBT-908 and CHOP, but the dosing arrangements differ across cohorts: the dose of BEBT-908 differs, the sequencing of administration differs, and whether participants continue with CHOP or transition to BEBT-908 depends on their tolerability to CHOP. Eligible participants will receive the combination treatment for their assigned cohort. After that, based on the results from all 3 cohorts in the Exploration Phase, one optimal cohort will be selected to proceed into the Expansion Phase. In the Expansion Phase, eligible participants will be randomly assigned (like flipping a coin) in a 1:1 ratio to either the treatment group, receiving the optimal combination regimen identified in the Exploration Phase, or the control group, receiving 6 cycles of CHOP. This study design will help investigators find the best way to combine BEBT-908 and CHOP for treating previously untreated peripheral T-cell lymphoma, and check whether this optimal combination regimen is better than standard CHOP treatment.