Study of Anti-CEACAM5 ADC M9140 in Participants With Advanced Solid Tumors (PROCEADE PanTumor)

Inclusion Criteria:

• Participants are capable of signing informed consent as defined in protocol

• Eastern Cooperative Oncology Group Performance Status (ECOG PS) below or equal to 1

• Participants with adequate hematologic, hepatic and renal function as defined inprotocol

• Participant must have at least 1 lesion that is measurable using RECIST v1.1.

• Other protocol defined inclusion criteria could apply

Substudy GC:

• Participants in Part A and Part B with documented histopathological diagnosis ofadvanced or metastatic, HER2 negative, gastric or GEJ (with an epicenter 2centimeter (cm) proximal or distal to the GEJ) adenocarcinoma, who wereintolerant/refractory to or progressed after systemic therapies for theadvanced/metastatic stage that must have included (provided there is no medicalcontraindication and these agents are locally approved and available) afluoropyrimidine and a platinum agent and an Immune checkpoint inhibitors (ICI) forparticipants with a known microsatellite instability-high (MSI-H) status orparticipants whose tumor express PD-L1 with a CPS greater than or equal (>=) 1

• Participants must have received and progressed (according to RECIST 1.1) on at least 1 line of therapy for the treatment of advanced/metastatic disease but no more than 2

• Participants in Part A with CEACAM5high GC/GEJC (defined as IHC >= 2+ staining in >= 50% of tumor cells)

• Participants in Part B with CEACAM5low GC/GEJC (defined as IHC >= 2+ staining inless than (<) 50% of tumor cells)

• Other protocol defined inclusion criteria could apply

Substudy NSCLC:

• Participants in Part A and Part B with histologically or cytologically documentedadvanced (Stage III not eligible for resection or curative radiation) or metastaticNSCLC with or without driver genomic alterations

• Participants must have been intolerant/refractory to or progressed after systemictherapies for the advanced/metastatic stage

• Participants must have received and progressed (according to RECIST 1.1) on at least 1 line of therapy for the treatment of advanced/metastatic disease but no more than 3

• Participants who received a platinum-containing regimen or a targeted therapy as (neo)-adjuvant therapy for early-stage disease, if relapse or metastases occurredduring or within 3 months after regimen completion, are considered to have receiveda line of treatment in the advanced setting

• Participants in Part A with CEACAM5 high-expressing EGFR tumors (includingparticipants with any driver genomic alterations other than EGFR mutations

• Participants in Part B with CEACAM5 high known EGFR mutated tumors as assessedaccording to local clinical practice

• Other protocol defined inclusion criteria could apply

Substudy PDAC:

• Participants with histologically or cytologically confirmed advanced or metastaticPDAC, who were intolerant/refractory to or progressed after systemic therapies forthe advanced metastatic stage that must have included (provided there is no medicalcontraindications, and these agents are locally approved and available; FOLFIRINOXregimen or NALIRIFNOX regimen or Nab-paclitaxel/gemcitabine regimen

• Participants must have received and progressed (according to RECIST 1.1) on at leastone 1 line of therapy for the treatment of advanced/metastatic disease but no morethan 2

• All participants will be screened using an IHC test to define CEACAM5 expression.Only participants with CEACAM5high expressing tumors will be eligible

• Other protocol defined inclusion criteria could apply

Exclusion Criteria:

• Participant has a history of malignancy within 3 years before the date of enrollment (exceptions are squamous and basal cell carcinomas of the skin and carcinoma in situof the cervix, benign prostate neoplasm/hypertropia, or malignancy that in theopinion of the Investigator, with concurrence with the Sponsor's Medical Monitor, isconsidered cured with minimal risk of recurrence within 3 years)

• Participants with known brain metastases, except those meeting the followingcriteria: Brain metastases that have been treated locally and are clinically stablefor at least 4 weeks prior to the start of treatment; No ongoing neurologicalsymptoms that are related to the brain localization of the disease (sequelae thatare a consequence of the treatment of the brain metastases are acceptable)

• Participants with diarrhea (liquid stool) or ileus Grade > 1

• Participants with active chronic inflammatory bowel disease (e.g., ulcerativecolitis, Crohn's disease, intestinal perforation) and/or bowel obstruction

• Cardiac arrhythmia, unstable angina, myocardial infarction, congestive heart failure (New York Heart Association [NYHA] >= II) or a coronary revascularization procedurewithin 180 days of study entry. Calculated QTc average (using the Fridericiacorrection calculation) of > 470 milliseconds (ms)

• Cerebrovascular accident/stroke (< 6 months prior to enrollment)

• Other protocol defined exclusion criteria could apply

Substudy GC - Participants with prior therapy with irinotecan

Substudy NSCLC:

• Participants with prior therapy with irinotecan

Substudy PDAC: none