Chidamide in Patients With Recurrent and Refractory Diffuse Large b

Chidamide tablets: 20mg orally, twice a week (at least 3 days between doses

Lenalidomide capsule: 25mg orally, once before going to bed every night, from day 1 to day 21 of each cycle

Rituximab injection: 375mg/m2 intravenously, once every 4 weeks (Q4w), on the first day of each cycle