The objective of this phase II study is to evaluate the efficacy and safety of BR101801 in patients with peripheral T-cell lymphoma(PTCL).

This phase II study will evaluate the efficacy and safety of single-dose BR101801 once daily in patients with peripheral T-cell lymphoma.

Key Inclusion Criteria:

1. The ECOG performance status ≤ 2.

2. Life expectancy more than 3 months.

3. Patients with relapsed and/or refractory to standard therapy or are intolerance to standard therapy diagnosed with 2022 World Health Organization (WHO) classification

   • Peripheral T-cell lymphoma, not otherwise specified
   • Nodal TFH cell lymphoma, angioimmunoblastic-type
   • Nodal TFH cell lymphoma, follicular-type
   • Nodal TFH cell lymphoma, NOS

4. Patients currently requiring systemic therapy at the investigator's discretion.

5. Patients with a lesion measuring 1.5 cm or more in its longest transverse diameter, as determined by CT, PET/CT or MRI scans according to the 2014 Lugano criteria.

Key Exclusion Criteria:

1. The presence of overt leptomeningeal or active central nervous system (CNS) metastases, or CNS metastases that require local CNS-directed therapy or increasing doses of corticosteroids within the prior 2 weeks.

2. Impaired cardiac function or clinically significant cardiac disease.

3. Patients with interstitial pneumonia or history of drug-induced interstitial pneumonia/pneumonitis.

4. For patients with lymphoma:

   • Systemic antineoplastic therapy (including cytotoxic chemotherapy, alfa-interferon [INF], and toxin immunoconjugates) or any experimental therapy within 3 weeks or 5 half lives, whichever is shorter, before the first dose of study treatment.
   • Therapy with tyrosine kinase inhibitor within 5 half-lives before the first dose of study treatment.
   • Unconjugated monoclonal antibody therapies < 6 weeks before the first dose of study treatment.

5. Patients receiving systemic chronic steroid therapy or any immunosuppressive therapy (>20 mg/day prednisone or equivalent).