The purpose of this first-in-human study is to identify a recommend dose(s) for subsequent larger studies (recommended dose(s) for expansion, RDE), examining increasing doses of M0324, primarily looking at safety, but also preliminary signs of efficacy, pharmacokinetics (PK), and pharmacodynamics (PD). Three different treatments with M0324 will be studied, M0324 as a monotherapy(Part 1), M0324 in combination with pembrolizumab (Part 2), and in combination with mFOLFIRINOX (a chemotherapy treatment)(Part 3).

Inclusion Criteria:

Part 1- M0324 Monotherapy:

• Participants with certain advanced/metastatic solid tumor types known to overexpress MUC-1 and who are intolerant or refractory to standard therapy or for which no standard therapy is judged appropriate by the Investigator

Part 2- M0324 Combination with Pembrolizumab:

• Participants with certain advanced/metastatic tumor types known to overexpress MUC-1 and the participants in the combination treatment involving M0324 and pembrolizumab must be intolerant or refractory to standard therapy and no other further standard therapy should be judged appropriate by the Investigator. In addition, the participants must have had prior treatment with immune checkpoint inhibitor(s) (ICIs) and must have experienced documented disease progression on or after ICIs.

Part 3- M0324 Combination with mFOLFIRINOX:

• Participants with previously untreated metastatic pancreatic ductal adenocarcinoma, who are judged by Investigator as eligible for treatment with mFOLFIRINOX. Participants with prior Whipple surgery and/or adjuvant chemotherapy are not permitted
• Other protocol defined inclusion criteria could apply

Exclusion Criteria:

• Has a history of chronic diarrhea greater than or equal to (>=) Grade 2, inflammatory disease of the colon or rectum, or unresolved partial or complete intestinal obstruction
• Participant has a history of malignancy within 3 years before the date of enrollment
• Uncontrolled or poorly controlled arterial hypertension, uncontrolled cardiac arrhythmia, unstable angina, myocardial infarction, congestive heart failure [New York Heart Association (NYHA) >= II] or a coronary revascularization procedure within 180 days of study entry
• Life expectancy of less than 3 months
• Other protocol defined exclusion criteria could apply

We are committed to enhancing public health through responsible sharing of clinical trial data. Following approval of a new product or anew indication for an approved product in both the US and the European Union, the study sponsor and/or its affiliated companies will share study protocols, anonymized patient data and study level data, and redacted clinical study reports with qualified scientific and medical researchers, upon request, as necessary for conducting legitimate research. Further information on how to request data can be found on our website bit.ly/IPD21