Non-Hodgkin Lymphoma Clinical Trials

• Documented informed consent of the participant and/or legally authorized representative.

‣ Assent, when appropriate, will be obtained per institutional guidelines

• Age: ≥ 18 years

• Eastern Cooperative Oncology Group (ECOG) ≤ 2

• Histologically confirmed nodal T-follicular helper (TFH) cell lymphomas or PTCL-not otherwise specified (NOS). Nodal TFH cell lymphomas encompass three subtypes:

‣ Angioimmunoblastic T-cell lymphoma (AITL)(World Health Organization 4th edition revised \[WHO4R\])/follicular helper T-cell lymphoma (TFH lymphoma), angioimmunoblastic type (International Consensus Classification \[ICC\])/nodal TFH cell lymphoma, angioimmunoblastic-type (World Health Organization 5th edition \[WHO5\])

⁃ Nodal PTCL with TFH phenotype (nodal PTCL, TFH)(WHO4R)/TFH lymphoma, NOS (ICC)/nodal TFH cell lymphoma, NOS (WHO5)

⁃ Follicular T-cell lymphoma (FTCL)(WHO4R)/TFH lymphoma, follicular type (ICC)/ nodal TFH cell lymphoma, follicular-type (WHO5)

• Completion of first-line multi-agent chemotherapy with a cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP)-based regimen and documentation of complete response (CR) per Lugano criteria within the previous 6 months prior to enrollment. Prior corticosteroid monotherapy is not considered a line of therapy

• Ineligible for or decline consolidative autologous stem cell transplantation. Ineligibility is defined by:

‣ Patient deemed ineligible for high-dose chemotherapy and ASCT based on physician's assessment

⁃ AND at least one of the following criteria:

• Age ≥ 65 years or

∙ Age ≥ 18 years and Hematopoietic Cell Transplantation-specific Comorbidity Index score ≥ 3

• Recovery to ≤ grade 1 or baseline for any toxicities due to prior treatments, with the exception of peripheral neuropathy (recovery to ≤ grade 2) or alopecia

• Platelets ≥ 25,000/mm\^3

• Hemoglobin ≥ 8 g/dL

• CD4 lymphocyte count ≥ 50/mm\^3 (0.05 × 10\^9/L)

• Total bilirubin ≤ 1.5 × upper limit of normal (ULN) (in patients with Gilbert's Syndrome a bilirubin \> 1.5 × ULN but ≤ 3 × ULN may be allowed with sponsor approval)

• Aspartate aminotransferase (AST)(serum glutamic oxaloacetic transaminase \[SGOT\]) ≤ 2.5 × ULN

• Alanine aminotransferase (ALT) (serum glutamic pyruvic transaminase \[SGPT\]) ≤ 2.5 × ULN

• Serum creatinine ≤ 2.0 × ULN or creatinine clearance ≥ 30 mL/min (estimated by Chronic Kidney Disease Epidemiology Collaboration \[CKD-EPI\] or Cockcroft-Gault equation or measured)

• Seronegative for HIV antigen (Ag)/antibody (Ab) combo, hepatitis C virus (HCV), active hepatitis B virus (HBV) (surface antigen negative) OR patients with presence of hepatitis B core antibody (HBcAb), but absence of hepatitis B surface antigen (HBsAg), are eligible if hepatitis B virus (HBV) deoxyribonucleic acid (DNA) is undetectable (\< 20 IU), and if they are willing to undergo monitoring every 4 weeks for HBV reactivation. Patients positive for HCV antibody are eligible only if polymerase chain reaction (PCR) is negative for HCV ribonucleic acid (RNA)

• Women of childbearing potential (WOCBP): negative serum β-human chorionic gonadotropin (β-hCG) pregnancy test within 1 week before first treatment (WCBP defined as a sexually mature woman who has not undergone surgical sterilization or who has not been naturally postmenopausal for at least 12 consecutive months. Women who are considered not to be of childbearing potential are not required to have a pregnancy test

• Agreement by females and males of reproductive potential (i.e., not surgically sterile or female patients who are not postmenopausal) must be willing to use a highly effective method of contraception for the duration of study treatment and for at least 1 months after the last dose of duvelisib