Pegcetacoplan in Combination With Modified FOLFIRINOX for the Treatment of Metastatic Pancreatic Ductal Adenocarcinoma

Inclusion Criteria:

* Histologically or cytologically confirmed metastatic PDAC
* Age ≥ 18 years of age
* Have an Eastern Cooperative Oncology Group (ECOG) performance status of ≤ 1
* Absolute neutrophil count ≥ 1,500/uL
* Platelets ≥ 100,000/uL
* Total bilirubin ≤ 1.5 x institutional upper limit of normal (ULN)
* Aspartate aminotransferase (AST)(serum oxaloacetic transaminase \[SGOT\])/alanine aminotransferase (ALT)(serum glutamic pyruvic transaminase \[SGPT\]) ≤ 3 x institutional ULN or \<=5 ULN in the presence of liver metastasis
* Estimated creatinine clearance ≥ 60 mL/min (Cockcroft-Gault equation)
* Albumin ≥ 3 g/dL
* Have measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria present
* All patients must either have available archival tumor tissue or undergo new tumor biopsy (if presence of a lesion that can be safely biopsied) before treatment initiation for correlative studies
* Willing and able to self-administer pegcetacoplan (administration by caregiver will be allowed)
* Willing to receive vaccination against Neisseria meningitidis and Streptococcus pneumoniae if not already vaccinated
* Participants of child-bearing potential must agree to use adequate contraceptive methods (e.g., hormonal or barrier method of birth control; abstinence) prior to study entry. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately

  * Women of child-bearing potential taking part in this study should continue the use of birth control for 6 months after the last study treatment, and should not donate eggs during that timeframe
  * Male participants taking part in this study should continue the use of birth control for 3 months after the last study treatment, and should not donate sperm during that timeframe
* Participant must understand the investigational nature of this study and sign an independent ethics committee/institutional review board approved written informed consent form prior to receiving any study related procedure

Exclusion Criteria:

* Previous chemotherapy for PDAC. Gemcitabine-based post- or pre-operative therapy is allowed provided that the last dose and or surgical resection was at least 6 months prior to the documentation of metastatic disease, whichever occurred last
* Toxicities from prior treatment grade \> 1 with the exemption of alopecia and fatigue
* Refractory ascites or pleural effusion (requiring para- or thoracentesis weekly or more frequently or use of indwelling catheter for palliation)
* Untreated bowel or gastric outlet obstruction; patients with ≤ 6 weeks from such an event who are adequately palliated are allowed to participate
* Participants with known untreated brain metastases will be excluded from this clinical trial because of their poor prognosis and because they often develop progressive neurologic dysfunction that would confound the evaluation of neurologic and other adverse events
* Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements
* Patients with major arterial thromboembolism (ATE) (coronary, cerebral, extremity or splanchnic) or venous thromboembolism (VTE) (pulmonary embolism or deep venous thrombosis) within 6 months from initiation of study treatment are not eligible for participation
* Pregnant or nursing female participants
* Unwilling or unable to follow protocol requirements
* Any condition which in the investigator's opinion deems the participant an unsuitable candidate to receive study drug