Study to Evaluate Efficacy and Safety of HH2853 in Relapsed/Refractory Peripheral T-cell Lymphoma

Inclusion Criteria:

• main inclusion:

1. Tumor types and prior antitumor therapy: Phase Ib:Dose Escalation: All enrolledpatients must have histologically confirmed diagnosis NHL who have received atleast one line of prior systematic treatment (and ≤ 5 lines) and relapses orrefractory. Phase Ib dose expansion part: All enrolled patients must havehistologically confirmed diagnosis of PTCL, including subtypes: PTCL-NOS, AITL,ALK + ALCL, ALK-ALCL, NKTCL, enteropathy associated T-cell lymphoma (EATL),monomorphic epitheliotropic internal T-cell lymphoma (MEITL), HepatosplenicT-cell lymphoma (HSTCL), follicular T-cell lymphoma (FTCL), Nodal peripheralT-cell lymphoma with TFH phenotype (Nodal PTCL-TFH) and other invasive T-cellsources NHL at the investigator and sponsor's discretion (except highlyinvasive). All enrolled patients had relapsed or refractory diseases afterreceiving 1-line systematic treatment (≤ 3 lines). Phase II: All enrolledpatients must have histologically confirmed diagnosis of PTCL, includingsubtypes: PTCL-NOS, AITL, ALK+ALCL, ALK-ALCL, NKTCL, EATL, MEITL, HSTCL, FTCL,Nodal PTCL-TFH et al. Patients must have histologically confirmed diagnosis ofR/R PTCL who have received at least one line of prior systematic combinationchemotherapy and at least one new drug therapy (prior antitumor treatment lines ≤4 lines) : relapse and/or refractory.

2. Availability of qualified tissue samples by patient for pathological diagnosisby the central laboratory.

3. The Eastern cooperative oncology group (ECOG) score 0-1.

4. Life expectancy ≥ 3 months before starting HH2853 treatment.

5. Sufficient bone marrow, liver and renal functions.

Exclusion Criteria:

• main criteria:

1. Previous treatment with EZH2 or EZH1/2 inhibitors.

2. Central nervous system invasion.

3. Any previous history of bone marrow malignancy, including myelodysplasticsyndrome (MDS).

4. Received medications that are known potent CYP3A4 inducers/inhibitors within 1week prior to first dose.