Open-Label Extension Study of De-immunized DI-Leu16-IL2 Immunocytokine Administered in Participants With B-cell NHL

Inclusion Criteria:

1. Participants currently entered on Alopexx Oncology Study AO-101
2. Participants who received 6 cycles of DI-Leu16-IL2 on Study AO-101.
3. Documented clinical benefit following 6th cycle of DI-Leu16-IL2
4. Able to begin extension study within 8 weeks of receiving 6th cycle of DI-Leu16-IL2
5. Participants must have received prior Rituximab-containing therapy.
6. Participants in this extension study are to use adequate birth control measures (abstinence, oral contraceptives, barrier method with spermicide or surgical sterilization) during the study. Females of childbearing potential must have a negative serum pregnancy test on the days of dosing. A female of childbearing potential: 1) has not undergone a hysterectomy or bilateral oophorectomy; or 2) has not been naturally postmenopausal for at least 24 consecutive months (that is, has had menses at any time in the preceding 24 consecutive months.
7. Provide written informed consent prior to any study procedures.

Exclusion Criteria:

1. Pregnant or lactating female
2. An immediate need for palliative radiotherapy or systemic corticosteroid therapy.
3. Actively infected with or chronic carriers of hepatitis B virus (HBV) as demonstrated by positive hepatitis B core antibody (HbcAb) or hepatitis B surface antigen (HbsAg). Participants who are sero-positive only, that is, surface antibody positive \[HbsAb\], are permitted.
4. Other significant active infection
5. Major surgery, chemotherapy, investigational agent, or radiation within 30 days of Day 1
6. Uncontrolled hypertension (diastolic ≥ 100 millimeters of mercury \[mmHg\]) or hypotension (systolic ≤ 90 mmHg)
7. History of prior therapy or a serious, uncontrolled medical disorder that in the Investigator's opinion would impair participation in the study.