Safety, Tolerability, and Efficacy of mFOLFIRINOX ± BNT321 as Adjuvant Therapy Following Curative Resection in Patients With Pancreatic Adenocarcinoma

Inclusion Criteria: * Has signed an informed consent form (ICF) before initiation of any study-specific procedures * Was \>18 years or age deemed to be an adult per local authorities inclusive, at the time of giving written informed consent * Were willing and able to comply with scheduled visits, treatment schedule, laboratory tests, lifestyle restrictions, and other requirements of the study (per investigator assessment, must been capable of understanding and following study-related instructions) * Had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1 * Had histologically or cytologically confirmed PDAC * Had macroscopically complete resection (R0 or R1 resection, Royal College of Pathologists \[RCP\] classification) performed between ≥21 and ≤84 days prior to Cycle 1, Day 1 (C1D1). Submission of formalin-fixed paraffin-embedded tissue (FFPE) tumor tissue from resection or biopsy was required * Had no radiologic (computed tomography/magnetic resonance imaging) evidence of metastatic disease, malignant ascites, or pleural effusion through an assessment obtained within 4 weeks of first study medication (i.e., C1D1) * Full recovery from surgery and able to receive chemotherapy * Had acceptable laboratory parameters * Was willing to allow collection of pharmacokinetic samples * Agreed not to enroll in another study of an IMP, starting after signing of the ICF and continuously until the last planned visit in this study * Participants of childbearing potential (POCBP) must not been pregnant. POCBP, male participants who were sexually active with POCBP, and female partners of male participants should have used a highly effective method of contraception continuously throughout the study and for a period of 111 days after the last dose of BNT321 and for 9 months (POCBP) and 6 months (male participants) after the last oxaliplatin dose * POCB who agreed not to donate eggs (ova, oocytes) starting after signing of the ICF and continuously throughout the study and for a period of 3 months after the last dose of BNT321 and for 9 months after the last oxaliplatin dose * Men who were willing to refrain from sperm donation, starting after signing of ICF and continuously throughout the study until 111 days after receiving the last dose of BNT321 and for 6 months after the last oxaliplatin dose Exclusion Criteria: * Participants were pregnant or breastfeeding or planning pregnancy or to father children during the study or within 60 days after last IMP treatment * A medical, psychological, or social condition which, in the opinion of the investigator, could have compromised their wellbeing if they participated in the study, or that could have prevented, limited, or confounded the protocol specified assessments or procedures, or that could have impacted adherence to protocol-described requirements * Had major surgery within 3 weeks of first dose of the study treatment, where participation in the study could have compromised the participant's wellbeing in the opinion of the investigator * Had abnormal electrocardiograms (ECGs) that were clinically significant, such as Fridericia-corrected QT prolongation \>470 msec (for women) and \>450 msec (for men), (average of three ECGs at least 5 minutes apart) * Had a history of anaphylactic reaction to human, or humanized, antibody * Have had other known active cancer(s) likely to require treatment in the next 2 years * Had prior radiotherapy or systemic treatment for PDAC * Active, uncontrolled bacterial, viral, or fungal infection(s) requiring systemic antiinfective therapy that has been administered less than 2 weeks prior to the first dose of BNT321 * Known hypersensitivity to any of the excipients of the experimental product BNT321 * Known history of seropositivity for human immunodeficiency virus (HIV) with CD4+ T-cell counts \<350 cells/μL and with a history of acquired immunodeficiency syndrome (AIDS)-defining opportunistic infections * Known history/positive serology for Hepatitis B requiring active antiviral therapy (unless immune due to vaccination or resolved natural infection or unless passive immunization due to immunoglobulin therapy; participants with positive serology must have had Hepatitis B virus viral load below the limit of quantification) * Active Hepatitis C virus infection (participants who have had completed curative antiviral treatment with Hepatitis C virus viral load below the limit of quantification were allowed) * Use of any IMP or device within 21 days before administration of first dose of study treatment or ongoing participation in the active treatment phase of another interventional clinical study * Was subject to exclusion periods from another investigational study * Were vulnerable individuals as per ICH E6 definition, i.e., individuals whose willingness to participate in a clinical study may be unduly influenced by the expectation, whether justified or not, of benefits associated with participation, or of a retaliatory response from senior members of a hierarchy in case of refusal to participate. * Serum CA19-9 \>180 U/mL within 3 weeks of C1D1 * Incomplete macroscopic tumor removal (R2 resection) * Significant cardiovascular risk (past medical history of coronary stenting or myocardial infarction within 6 months, or New York Heart Association (NYHA) Class III/IV, heart failure, or concurrent unstable angina) or risk factors for QT prolongation (sustained Grade 3 or higher hypokalemia, history of unstable arrhythmia or family history of long QT syndrome) * Pre-existing neuropathy * Homozygous UDP glucuronosyltransferase family 1 member A1 (UGT1A1)\*28 mutation, if testing was required by local regulations * Inflammatory disease of the colon or rectum, or occlusion or sub-occlusion of the intestine or severe post-operative uncontrolled diarrhea * Complete dihydropyrimidine dehydrogenase deficiency, if testing was required by local regulations * Received a live vaccine within 3 weeks prior to the first dose of study treatment * Participants with a contraindication to receiving mFOLFIRINOX * Participants with active or latent tuberculosis or history of Mycobacterium tuberculosis infection currently or within the last 2 years * Individuals committed to an institution by virtue of an order issued either by the judicial or the administrative authorities