Abstract: Objective To investigate the efficacy and safety of chidamide combined with azacitidine in treating relapsed/refractory angioimmunoblastic T⁃cell lymphoma (AITL). Methods The study was a single⁃center prospective clinical trial at Peking Union Medical College. The eligible patients were pathologically confirmed with AITL and met the criteria for relapsed/refractory lymphoma. Treatment included subcutaneous injection of azactidine azacitidine (100 m/d for 7 d) combined with oral chidamide (20 mg/d twice weekly) in a 4 weeks cycle. Results A total of 7 patients were enrolled from March 2021 to August 2022. The median age of disease onset was 53 (range 45-75) years and the median line of previous treatment was 2 (range 1-4) line. After treatment, complete remission (CR) was achieved in 2 cases and partial remission in 3 cases. The objective response rate was 71.4% and the CR rate was 28.6%. As of August 2022, the median follow⁃up time was 14 months (range 4-17 months). 6 patients survived and 1 patient died, and the median progression⁃free survival (PFS), duration of response, and overall survival (OS) of the whole group were not reached. The 1⁃year PFS and OS rates were 51.4% and 100.0%, respectively. Treatment⁃related adverse events were mainly hematological toxicity. The incidence of grade 3-4 neutropenia and thrombocytopenia were 28.6% (2/7) and 14.3% (1/7), respectively. Conclusions Azacitidine combined with chidamide has a high remission rate and safety profile in treating relapsed/refractory AITL, and dual epigenetic regulating drugs may serve as a second⁃line treatment option for patients with AITL.

Key words: Angioimmunoblastic T-cell lymphoma, Epigenetic drug, Chidamide, Azacitidine, Prospective clinical study