Inclusion Criteria:
1. Voluntarily agree to participate by giving signed, dated, and written informed consent prior to any study-specific procedures.
2. ≥ 18 years of age.
3. Histologically confirmed diagnosis of metastatic pancreatic ductal adenocarcinoma.
4. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 (Appendix A).
5. Life expectancy of at least 3 months.
6. Measurable disease on baseline imaging per RECIST 1.1 criteria.
7. \< Grade 2 pre-existing peripheral neuropathy per NCI CTCAE, Version 5.0.
8. Acceptable coagulation status as indicated by an international normalized ratio (INR)
* 1.5 times institutional upper limit of normal (ULN), except patients on anticoagulation who can be included at the discretion of the investigator.
9. Adequate organ function defined as the following laboratory values within 7 days prior to first dose of study drugs, except where noted below:
1. Neutrophils \> 1500/μL (stable off any growth factor within 4 weeks prior to first dose of study drugs).
2. Platelets \> 100 × 103/μL (transfusion to achieve this level is not permitted within 2 weeks prior to first dose of study drugs).
3. Hemoglobin \> 9.0 g/dL (transfusion to achieve this level is not permitted within 2 weeks prior to first dose of study drugs).
4. Creatinine of \< 1.5mg/dL or Creatinine clearance ≥ 45 mL/min (measured or calculated per institutional standards).
5. Aspartate aminotransferase (AST)/ alanine aminotransferase (ALT) \< 3.0 × ULN.
6. Total bilirubin \< 1.25 × ULN (except patients with Gilbert syndrome who must have a total bilirubin level of \< 3.0 × ULN).
7. Serum albumin ≥ 3.0 g/dL (must be confirmed within 3 days prior to first dose of study drugs).
10. Female patients of childbearing potential (WOCBP) must have a negative urine or serum pregnancy test at screening (within 72 hours of first dose of study drugs).
WOCBP must agree to use highly effective contraceptive measures starting with the screening visit through 6 months after the last dose of study drug(s). Highly effective contraception is defined in Appendix B, Guidance on Contraception, or as stipulated in national or local guidelines. Non-childbearing potential is defined as:
1. ≥ 50 years of age and has not had menses for greater than 1 year.
2. Amenorrheic for ≥ 2 years without a hysterectomy and/or bilateral oophorectomy and a follicle-stimulating hormone value in the postmenopausal range upon pre- study (screening) evaluation.
3. Status is post hysterectomy, bilateral oophorectomy, or bilateral tubal ligation.
11. Male patients with a female partner(s) of childbearing potential must agree to use highly effective contraceptive measures throughout the study starting with the screening visit through 6 months after the last dose of study drug(s) is received. Males with pregnant partners must agree to use a condom; no additional method of contraception is required for the pregnant partner.
12. Willing and able to comply with the requirements of the protocol.
Exclusion Criteria:
1. Patients must have received no previous radiotherapy, surgery, chemotherapy, or investigational therapy for the treatment of metastatic disease. Prior treatments in the adjuvant setting with gemcitabine and/or 5-Fluorouracil (5-FU) or gemcitabine administered as a radiation sensitizer are allowed, provided at least 6 months have elapsed since completion of the last dose and development of metastatic disease and no lingering toxicities are present.
2. History of central nervous system (CNS) metastasis.
3. Concurrent malignancy (present during screening) requiring treatment or history of prior malignancy active within 2 years prior to the first dose of study drugs (i.e., patients with a history of prior malignancy are eligible if treatment was completed at least 2 years prior to first dose of study drugs and the patient has no evidence of disease). Patients with history of prior early-stage basal/squamous cell skin cancer or noninvasive or in situ cancers who have undergone definitive treatment at any time are also eligible.
4. QTc Derived From Fridericia's Formula (QTcf) \> 450 ms on electrocardiogram (ECG)
5. Uncontrolled intercurrent illness, including but not limited to clinically significant (i.e., active) cardiovascular disease: cerebral vascular accident/stroke or myocardial infarction within 6 months of enrollment, unstable angina, congestive heart failure (New York Heart Association class ≥ III), or serious uncontrolled cardiac arrhythmia requiring medication. Patients with history of coronary bypass procedure are ineligible.
6. Active, uncontrolled infections, requiring systemic intravenous anti-infective treatment within 2 weeks prior to first dose of study drugs.
7. Major surgery within 4 weeks prior to signing of informed consent form (ICF).
8. Prior treatment with an immune checkpoint inhibitor.
9. Refractory ascites defined as requiring 2 or more therapeutic paracenteses within the last 4 weeks or ≥ 4 within the last 90 days or ≥ 1 time within the last 2 weeks prior to signing of ICF or requiring diuretics intended to treat ascites within 2 weeks of signing of ICF.
10. Partial or complete bowel obstruction within the last 3 months prior to signing of ICF, signs/symptoms of bowel obstruction, or known radiologic evidence of impending obstruction.
11. Clinically significant gastrointestinal (GI) disorders including:
1. GI perforation or unhealed ulcerations \< 6 months prior to signing of ICF. Patients must have documented evidence (e.g., upper endoscopy, colonoscopy) of completely healed area of prior perforation or ulceration.
2. Clinically significant GI bleeding \< 3 months prior to signing of informed consent.
3. History of active Crohn's disease or ulcerative colitis.
12. Previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection within 10 days for mild or asymptomatic infections or 20 days for severe/critical illness prior to first dose of study drugs.
13. SARS-CoV-2 vaccine \< 7 days prior to first dose of study drugs.
14. Known allergy or hypersensitivity to any of the study drugs or any of the study drug excipients.
15. Symptomatic interstitial lung disease (ILD), history of ILD, or any lung disease which may interfere with detection and management of new immune-related pulmonary t toxicity.
16. History of allogeneic organ transplant.
17. Psychiatric or substance abuse disorders that would interfere with cooperation with the requirements of the study.
18. Patients with a condition requiring systemic treatment with either corticosteroids (\> 10 mg daily prednisone equivalent) within 14 days or another immunosuppressive medication within 30 days prior to the first dose of study drugs. Inhaled or topical steroids, and adrenal replacement steroid doses (≤ 10 mg daily prednisone equivalent), are permitted in the absence of active autoimmune disease.
19. Active autoimmune disease or history of autoimmune disease that required systemic treatment within 2 years prior to first dose of study drugs (i.e., with use of disease- modifying agents or immunosuppressive drugs).
20. Pregnant or breastfeeding patients.
21. Uncontrolled infection with HIV. Patients on stable highly active antiretroviral therapy ( (HAART) therapy with undetectable viral load and normal CD4 (Cluster of differentiation 4) counts for at least 6 months prior to signing ICF. Serological testing for HIV at screening is to be performed at the investigator's discretion based on individual patient's risk factors.
22. Known to be positive for hepatitis B (HBV) surface antigen, or any other positive test for HBV indicating acute or chronic infection. Patients who are or have received anti-HBV therapy are eligible, permitting they have undetectable HBV DNA for at least 6 months prior to signing ICF. Serological testing for HBV at screening is to be performed at the investigator's discretion based on the individual patient's risk factors.
23. Known active hepatitis C (HCV) as determined by positive serology and confirmed by polymerase chain reaction (PCR). Patients on or having received antiretroviral therapy are eligible provided they are virus-free by PCR for at least 6 months prior to signing ICF. Serological testing for HCV at screening is to be performed at the investigator's discretion based on individual patient's risk factors.
24. Dependence on total parenteral nutrition.
25. Patients with concurrent diarrhea \> grade 1 at time of enrollment despite optimal treatment with standard of care pancreatic enzymes.
26. Known active or latent tuberculosis (testing at screening not required).
27. Any condition in the opinion of the principal investigator that might interfere with the patient's participation in the study or in the evaluation of the study results.
28. Unwillingness or inability to comply with procedures required in this protocol.
29. History of coronary artery bypass graft.
30. Patients receiving warfarin or digoxin.
31. Presence of retinal or visual field changes of any etiology. Note: An ophthalmological examination to be performed within the 3 weeks of starting Chloroquine (C1/D1) to include: best corrected distance visual acuity (BCVA), an automated threshold visual field (VF) of the central 10 degrees (with retesting if an abnormality is noted), and spectral domain optical coherence tomography (SD-OCT). All of these parameters should be within normal parameters.
32. Known hypersensitivity to 4-aminoquinoline compounds (chloroquine, hydroxychloroquine, and amodiaquine).
33. Glucose-6-phosphate dehydrogenase (G6PD) deficiency.
34. History of asthma, urticaria, or other allergic-type reactions after taking aspirin or other NSAIDs.
35. Patients who have demonstrated allergic-type reactions to sulfonamides.
