The study is evaluating the efficacy, and safety of SHR1459 combined with YY-20394 for Recurrent and refractory B-cell non-Hodgkin's lymphoma in adults.

Inclusion Criteria:

1. Histologically confirmed diagnosis of B-cell NHL such as DLBCL, FL and MCL
2. Patients received at least 2 lines of systemic therapy
3. Previously received anti- CD20 treatment
4. Patients in stage II should also be unsuitable or unwilling to receive allogeneic hematopoietic stem cell transplantation
5. Patients must have an acceptable organ function

Exclusion Criteria:

1. Previously treated with PI3K inhibitors or BTK inhibitors
2. Unresolved toxicity of CTCAE grade > 1 from prior anti-lymphoma therapy
3. Chemotherapy or other investigational therapy within 28 days (or 5 times the half-life time, whichever is shorter) before starting cycle 1
4. Significant concurrent medical disease or condition which according to the investigators' judgement
5. Active hepatitis B, C or HIV infection
6. Infection requiring treatment 2 weeks prior to the first dosing