A single-arm, open, multicenter study to investigate the efficacy and safety of YY-20394, an oral small molecular inhibitor of PI3K-delta, in patients with relapsed or refractory peripheral T/NK cell lymphoma.

Inclusion Criteria:

• Males and/or females over age 18.
• Histologically or cytologically confirmed diagnosis of relapsed or refractory peripheral T/NK cell lymphoma.
• Eastern Cooperative Oncology Group performance status of 0 to 1.
• Life expectancy of at least 3 months.
• At least one measurable lesion according to Lugano 2014.
• Adequate organ function.
• Had anti-tumor treatment within 2 weeks prior to the first dose of investigational product (including TKI, Chinese herbal anti-tumor treatment); within 4 weeks prior to the first dose of investigational product (including chemotherapy, radiotherapy, immunotherapy and major surgery); other targeted therapies with 5 half-life period prior to the first dose.
• Men and women of childbearing potential are willing to employ an effective method of contraception for the entire duration of study and 6 months after the last dose.
• Volunteers did not participate in other clinical trials within 1 month prior to study entry.
• Provision of signed and dated, written informed consent prior to any study- specific evaluation.

Exclusion Criteria:

• Previous treatment with any PI3K-delta inhibitors.
• Uncontrolled pleural effusion and ascites.
• The dosage of steroid hormone (prednisone equivalent) was greater than 20mg/day, and lasted for more than 14 days.
• Medical conditions in swallowing difficulty, malabsorption, or other chronic gastrointestinal disease that may hamper compliance and/ or absorption of the investigational agent.
• Drugs that may prolong the QT (such as anti-arrhythmic drugs) could not be interrupted during the study period.
• Evidence of central nervous system involvement of the malignancy, including invasion of brain parenchyma and meninges, or spinal cord compression.
• Have active viral, bacterial, fungal, or other infections that require systematic treatment (e.g., active tuberculosis), excluding nail bed fungal infections.
• Active infection with hepatitis B and C virus (volunteers with HBsAg or HBcAb positive but HBV-DNA negative, or HCV antibody positive but HCV-RNA negative can be enrolled).
• History of immune deficiency (acquired and congenital), or history of organ transplantation, or allogeneic bone marrow or hematopoietic stem cell transplantation; with active autoimmune disease or history of autoimmune disease (e.g., autoimmune enteritis and systemic lupus erythematosus).
• prior autologous hematopoietic stem cell transplantation within 90 days prior to the first dose of study drug.
• Presence of severe or uncontrolled cardiovascular disease.
• Medical history of active bleeding within 2 months prior to study entry, or currently achieved anticoagulant therapy, or susceptible to bleed by the judgement of investigator.
• Presence of concomitant diseases that are seriously endanger the safety of patient or affect the completion of the study by the investigator's judgment (e.g., uncontrolled hypertension, diabetes, thyroid diseases).
• Had received GCSF or blood transfusion treatment within 14 days prior to study entry.
• Female subjects of childbearing potential have a positive pregnancy test at the baseline.
• Medical history of other primary malignant tumors in the past 5 years except for the following: clinically cured cervical or breast carcinoma in situ, local basal cell or squamous cell carcinoma of the skin, thyroid tumor.
• Adverse events occurred during previous anticancer therapy have not been recovered to ≤1 (CTCAE 5.0) except toxicity with no significant risk determined by investigator such as alopecia.
• Live vaccine was administered within 30 days prior to the first dose of the investigational drug, or was scheduled to be administered during the study period.
• Judgment by the investigator that the volunteer should not participate in the study.