Study of Pegilodecakin (LY3500518) With FOLFOX Compared to FOLFOX Alone Second-line Tx in Participants With Metastatic Pancreatic Cancer

To compare the efficacy of pegilodecakin in combination with FOLFOX versus FOLFOX alone in participants with metastatic pancreatic cancer as measured by overall survival.

This is an open-label, multi-center, randomized, Phase 3 study designed to compare the efficacy and safety of pegilodecakin in combination with FOLFOX versus FOLFOX alone in participants with metastatic adenocarcinoma of the pancreas who have progressed on one prior gemcitabine containing regimen.

Biological: Pegilodecakin. Pegilodecakin plus FOLFOX

Drug: FOLFOX. FOLFOX Alone

Pegilodecakin + FOLFOX (experimental): Pegilodecakin 5 microgram per kilogram (μg/kg) dosed as one of the following 2 fixed doses: 0.4 milligram (mg) for participants weighing ≤80 kg or 0.8 mg for participants weighing\>80 kg on Days 1-5 and Days 8-12 subcutaneously (SC) plus FOLFOX \[dl-Leucovorin (dl-LV) 400 milligram per meter square (mg/m2) and oxaliplatin 85 mg/m2 followed by bolus 5-fluorouracil (5-FU) 400 mg/m2 and a 46 to 48 hour infusion of 5- FU 2400 mg/m2\] initiated on Day 1 of a 14-day cycles for up to 12 cycles or until disease progression. After discontinuation of FOLFOX in the absence of tumor progression \[that is (i.e., completion of the planned 12 cycles or unacceptable FOLFOX related toxicity\], Pegilodecakin 10µg/kg maintenance treatment administered as one of the 2 fixed doses, either 0.8 mg for participants weighing ≤80 kg or 1.6 mg for participants weighing\>80 kg.

FOLFOX (active comparator): FOLFOX (dl-LV 400 mg/m2 and oxaliplatin 85 mg/m2 followed by bolus 5-FU 400 mg/m2 and a 46-hour infusion of 5-FU 2400 mg/m2) initiated on Day 1 of a 14-day cycles for up to 12 cycles or until disease progression.

Overall Survival. Overall survival is defined as the time from date of randomization to the date of death (due to any cause). For participants whose last known status is alive at the data cutoff date for the analysis, time will be censored as the last contact date prior to the data cutoff date. Time frame: Randomization to date of death from any cause (Up To 30 Months).

Progression Free Survival. Time frame: Randomization to Progressive Disease (PD) or Date of Death (Up To 30 Months).

Percentage of Participants Achieving Complete Response (CR) or Partial Response (PR) [Objective Response Rate (ORR)] That Assessed by Investigator. Time frame: Randomization to PD (Up To 30 Months).

Percentage of Participants With a Best Overall Response of Complete Response (CR), Partial Response (PR) or Stable Disease (SD): Disease Control Rate (DCR). Time frame: Randomization to Objective Progressive Disease or Start of New Anti-Cancer Therapy (Up To 30 Months).

Duration of Response (DOR). Time frame: Randomization to Progressive Disease (PD) or Date of Death (Up To 30 Months).

Percentage of Participants Alive at 1 Year (12-Month Survival Rate). Time frame: From randomization to until the date of first documented date of death from any cause within 12 months.

Inclusion Criteria: 1. The presence of metastatic pancreatic adenocarcinoma 2. Measurable disease per RECIST v.1.1 3. Participant must have documented tumor progression during or following a gemcitabine containing regimen to treat metastatic disease as established by CT or MRI scan 4. Eastern Cooperative Oncology Group Performance Status of 0 - 1 5. Participant must have completed prior chemotherapy at least 2 weeks (washout period) prior to randomization and recovered from toxicity to Grade 1 or baseline 6. Participants must not have received previous radiation therapy or investigational therapy for the treatment of advanced metastatic disease. 7. Participants having received cytotoxic doses of gemcitabine or any other chemotherapy in the adjuvant setting are not eligible for this study 8. No peripheral neuropathy 9. No known history of dihydropyrimidine dehydrogenase deficiency Exclusion Criteria: 1. Diagnosis of pancreatic islet neoplasm, acinar cell carcinoma, non- adenocarcinoma (i.e., lymphoma, sarcoma), adenocarcinoma originating from the biliary tree, or cystadenocarcinoma 2. Participant on Coumadin and not willing to change to LMWH or oral Factor II or Xa inhibitor with half-life of less than 24 hours. 3. Participant has received prior treatment with pegilodecakin or fluoropyrimidine/platinum containing regimen 4. Participants who were intolerant of a gemcitabine containing regimen. 5. History of positivity for human immunodeficiency virus 6. Chronic active or active viral hepatitis A, B, or C infection 7. Clinically significant bleeding within two weeks prior to randomization (e.g., gastrointestinal (GI) bleeding, intracranial hemorrhage) 8. Pregnant or lactating women 9. Participants with a history of immune-mediated neurological disorders such as multiple sclerosis, Guillain-Barré or inflammatory CNS/PNS disorders 10. Clinically significant ascites defined as requiring ≥ 1 paracentesis every 2- weeks 11. Major surgery, defined as any surgical procedure that involves general anesthesia and a significant incision (i.e., larger than what is required for placement of central venous access, percutaneous feeding tube, or biopsy),within 28 days prior to randomization or anticipated surgery during the study period 12. Prior history of receiving immune modulators including, but not limited to, anti-CTLA4, anti-PD1, anti-PD-L1

Enrollment: 567 participants (actual).