Background: FOLFIRINOX remains the standard of care for the first line treatment of patients with locally advanced and metastatic pancreatic adenocarcinoma, however the prognosis remains poor, thus novel treatment options are indicated. Eryaspase, asparaginase (ASNase) encapsulated in red blood cells (RBCs) is an investigational product under development. Following infusion, asparagine and glutamine are actively transported into RBCs where they are hydrolyzed by the encapsulated ASNase. A randomized phase IIb study in patients with advanced pancreatic cancer whose disease progressed following first-line treatment (NCT02195180) was previously conducted. Eryaspase in combination with gemcitabine monotherapy or FOLFOX combination therapy improved overall survival (OS) and progression free survival (PFS). The safety profile of eryaspase was acceptable. A second line pivotal randomized phase III trial (Trybeca-1) is currently enrolling (NCT03665441). We design this phase I study to determine the safety of mFOLFIRINOX combined with Eryaspase in the first line of treatment. Methods: Patients with locally or metastatic biopsy proven pancreatic adenocarcinoma will be treated with the combination of mFOLFIRINOX plus Eryaspase. This will be a standard 3+3 design with 4 possible doing levels. mFOLFIRINOX dosing will include 5-Fluorouracil 2400 mg/m2 over 46 hours, Oxaliplatin 85 mg/m2, Irinotecan 150 mg/m2 plus Eryaspase 75 Units/kg at dose level 0. Eryaspase will be dose escalated up to 100 Units/kg. The study will enroll at three academic centers. Key eligibility criteria include performance status 0 or 1; locally advanced or metastatic tumor disease; adequate organ function. The primary objective is to determine the maximum tolerated dose and safety of this novel combination. Key secondary objectives include objective response rate, progression-free survival, overall survival, pharmacokinetics, pharmacodynamics, and biomarker research. A data safety monitoring committee will review data every 3 months. Clinical trial information: 04292743.