The purpose of this study is to evaluate the safety and clinical activity of plerixafor in combination with cemiplimab in patients with metastatic pancreatic cancer.

Inclusion Criteria:

Age ≥18 years.

• Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1
• Have histologically or cytologically-proven ductal pancreatic cancer.
• Have metastatic disease.
• Have documented radiographic disease progression after previous systemic chemotherapy given in a neoadjuvant, adjuvant, locally advanced or metastatic setting.
• Patients with the presence of at least one measurable lesion.
• Willing to have to a tumor biopsy.
• Life expectancy of greater than 3 months.
• Patients must have adequate organ and marrow function defined by study - specified laboratory tests.
• Woman of childbearing potential must have a negative pregnancy test and follow contraceptive guidelines as defined per protocol.
• Men must use acceptable form of birth control while on study.
• Ability to understand and willingness to sign a written informed consent document.

Exclusion Criteria:

• Known history or evidence of brain metastases.
• Had chemotherapy, radiation, or steroids within 14 days prior to study treatment.
• Have received any investigational drugs, a live vaccine, any allergen hyposensitization therapy, growth factors or major surgery within 28 days prior to study treatment.
• Require any antineoplastic therapy.
• Had surgery within 28 days of dosing of investigational agent.
• Has received any prophylactic vaccine within 14 days of first dose of study drug.
• History of prior treatment with anti-CXCR4.
• Have used any systemic steroids within 14 days of study treatment.
• Patients receiving growth factors including, but not limited to, granulocyte-colony stimulating factor (G-CSF), Granulocyte-macrophage colony-stimulating factor (GM-CSF), erythropoietin, within 14 days of study drug administration.
• Hypersensitivity reaction to any monoclonal antibody.
• Evidence of clinical or radiographic ascites.
• Have clinically significant and/or malignant pleural effusion.
• Patient with uncontrolled intercurrent illness including, but not limited to, uncontrolled infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.
• Has an active known or suspected autoimmune disease.
• Prior tissue or organ allograft or allogeneic bone marrow transplantation.
• All toxicities attributed to prior anti-cancer therapy other than alopecia and fatigue must have resolved to grade 1 (National Cancer Institute Common Terminology Criteria for Adverse Events [CTCAE], version 5) or baseline before administration of study drug.
• Infection with HIV or hepatitis B or C at screening.
• Patient has a pulse oximetry of <92% on room air.
• Patient is on supplemental home oxygen.
• Has uncontrolled intercurrent acute or chronic medical illness or any use of illicit drugs or substance abuse.
• Patient is unwilling or unable to follow the study schedule for any reason.
• Woman who are pregnant or breastfeeding.
• Have rapidly progressing disease, as judged by the investigator.
• History of significant, recurrent, unexplained postural hypotension in the last 6 months.

4 participants were excluded from analysis because they did not receive at least one dose of study drug.

Up to 17 months

Serious and Other (Not Including Serious) Adverse Events were evaluated for up to 13 months. All-cause mortality was evaluated for up to 17 months.