* Renal: Serum creatinine ≤ 1.5 x ULN OR calculated creatinine clearance (CrCl) \> 30 millilitre (ml)/min as calculated by the Cockcroft-Gault method
Able to comprehend and willing to sign the written informed consent form
You may not be if
Currently or previously treated with biologic, or immunotherapy
Currently or previously treated with conventional chemotherapy, or other agents for metastatic pancreatic ductal adenocarcinoma (Arm: idelalisib + nab-paclitaxel only)
Evidence of ongoing systemic bacterial, fungal, or viral infection at the time of enrollment
Known human immunodeficiency viruses (HIV) infection
History of a concurrent or second malignancy except for adequately treated local basal cell or squamous cell carcinoma of the skin, cervical carcinoma in situ, superficial bladder cancer, asymptomatic prostate cancer without known metastatic disease and with no requirement for therapy or requiring only hormonal therapy and with normal prostate-specific antigen for ≥ 1 year prior to enrollment, adequately treated Stage 1 or 2 non-pancreatic cancer currently in complete remission, or any other non-pancreatic cancer that has been in complete remission for ≥ 5 years
Diagnosis of pancreatic islet neoplasm, acinar cell carcinoma, non-adenocarcinoma (eg, lymphoma, sarcoma), adenocarcinoma originating from the biliary tree or cystadenocarcinoma
History of serious allergic reaction, including anaphylaxis and toxic epidermal necrolysis
Presence of peripheral neuropathy ≥ Grade 2 (Arm: idelalisib + nab-paclitaxel and Arm: idelalisib + mFOLFOX6)
Documented myocardial infarction or unstable/uncontrolled cardiac disease (eg, unstable angina, congestive heart failure \[New York Heart Association \> Class III\]) within 6 months or enrollment
Known hypersensitivity to idelalisib, its metabolites, or formulation excipients
Known hypersensitivity to nab-paclitaxel (Arm: idelalisib + nab-paclitaxel), their metabolites, or formulation excipients
Known hypersensitivity to 5-fluorouracil, leucovorin, or oxaliplatin (Arm: idelalisib + mFOLFOX6), their metabolites, or formulation excipients
