Anti-CEACAM5 ADC M9140 in Advanced Solid Tumors (PROCEADE-CRC-01)

The purpose of this first in-human study is to evaluate the safety, tolerability, pharmacokinetics, and preliminary clinical activity of M9140 in advanced solid tumors. This study contains 2 parts: Dose escalation (Part 1) and dose expansion (Part 2) Study details include: * Study Duration per participant: Approximately 4 months for Part 1 and 8 months for Part 2 * M9140 is not available through an expanded access program

Inclusion Criteria: * Participants with documented histopathological diagnosis of locally advanced or metastatic colorectal cancer (CRC), who were intolerant/refractory to or progressed after standard systemic therapies for the advanced/metastatic stage, if locally indicated and available to the participant. Participants with a known microsatellite instability high (MSI-H) status must have received treatment with an immune checkpoint inhibitor (if locally indicated and available) unless contraindicated. * Eastern Cooperative Oncology Group Performance Status (ECOG PS) below or equal to 1 * Participants with adequate hematologic, hepatic and renal function as defined in protocol * 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 situ of the cervix, benign prostate neoplasm/hypertropia, or malignancy that in the opinion of the Investigator, with concurrence with the Sponsor's Medical Monitor, is considered cured with minimal risk of recurrence within 3 years) * Participants with known brain metastases, except those meeting the following criteria: Brain metastases that have been treated locally and are clinically stable for at least 4 weeks prior to the start of treatment; No ongoing neurological symptoms that are related to the brain localization of the disease (sequelae that are 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., ulcerative colitis, Crohn's disease, intestinal perforation) and/or bowel obstruction * Unstable angina, myocardial infarction, congestive heart failure (New York Heart Association \[NYHA\] \>= II) or a coronary revascularization procedure within 180 days of study entry. Calculated QTc average (using the Fridericia correction calculation) of \> 470 milliseconds (ms) * Cerebrovascular accident/stroke (\< 6 months prior to enrollment) * Other protocol defined exclusion criteria could apply