A Phase IIa Study Evaluating the Pharmacokinetics, Safety and Efficacy of APG-115 as a Single Agent or in Combination With APG-2575 in Subjects With Relapsed/Refractory T-Cell Prolymphocytic Leukemia (R/R T-PLL) or Non-Hodgkin's Lymphoma (NHL).

Inclusion Criteria: 1. Age ≥ 18 years old 2. Patients with relapsed/refractory T-PLL who have active disease and have received at least one prior therapy; Patients with histologically confirmed diagnosis of NHL, NHL Patients must be either relapsed, refractory, intolerant, or are considered ineligible for therapies known to provide clinical benefit; 3. Patients must not have had chemotherapy or antibody therapy for 7 days prior to starting APG-115 and/or APG-2575. However, patients with rapidly proliferative disease may receive hydroxyurea or decadron until 24 hours prior to starting therapy on this protocol. 4. Absolute neutrophil count (ANC) ≥ 500/mm˄3; hemoglobin ≥ 60 g/L; platelet count ≥ 30,000/mm˄3 5. Patients with adequate organ function; 6. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2; 7. Patient must have the ability to understand the requirements of the study and signed informed consent. A signed informed consent by the patient or his/her legally authorized representative is required prior to their enrollment on the protocol. Exclusion Criteria: 1. Patient previously treated with a murine double minute 2 (MDM2) inhibitor. 2. Known active, uncontrolled central nervous system (CNS) malignancy 3. Patients require graft versus host therapy, or require continued treatment with systemic immunosuppressive agents (calcineurin inhibitors within 4 weeks prior to the first dose of study drug). 4. Patients who have any conditions or illness that, according to the opinions of the Investigators or the medical monitor, would compromise patient safety or interfere with the evaluation of safety and efficacy to the study drug(s). 5. Patients who have used strong CYP2C8 inhibitors, or moderate or strong CYP3A4 inhibitors or inducers within washout period of 14 days or 7 half-lives before the first administration of study drugs, whichever is longer.