A Study to Evaluate the Safety, Pharmacokinetics, and Anti-Tumor Activity of VVD-133214 as Monotherapy and in Combination With Pembrolizumab in Participants With Advanced Solid Tumors

Inclusion Criteria:

• Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1

• Have a microsatellite instability (MSI) and/or deficient mismatch repair (dMMR),histologically or cytologically documented advanced (unresectable and/or metastatic)solid tumor; for the combination with pembrolizumab only: Histologically confirmedlocally advanced, or metastatic colorectal adenocarcinoma (CRC) with no priorsystemic treatment for metastatic disease and not amenable to surgery

• Have received and then progressed following, or are intolerant to, standard therapyin the advanced setting

• Presence of measurable disease according to Response Evaluation Criteria in SolidTumors (RECIST) version 1.1

• Life expectancy of at least (≥)12 weeks

• Availability of formaldehyde-fixed paraffin-embedded (FFPE) archival tumor tissuefor submission to Sponsor/central laboratory for retrospective central testing; forparticipants without archival tissue, a biopsy from either primary or metastatictumor lesion, deemed medically feasible, must be taken

• Adequate hematologic, end-organ, and cardiovascular function, as defined in theprotocol

Exclusion Criteria:

• Inability or unwillingness to swallow pills

• Malabsorption syndrome or other condition that would interfere with enteralabsorption

• Known hypersensitivity or intolerance to ingredients from the study drug formulationincluding patients with rare genetic disorders such as galactosaemia,glucose-galactose intolerance or congenital lactase deficiency

• Known uncontrolled central nervous system (CNS) metastases (progressing or requiringanticonvulsants or corticosteroids for symptomatic control) and/or carcinomatousmeningitis

• Known active or uncontrolled bacterial, viral, fungal, mycobacterial (including butnot limited to tuberculosis and atypical mycobacterial disease), parasitic, or otherinfection (excluding fungal infections of nail beds), or any major episode ofinfection requiring treatment with intravenous antibiotics or hospitalization within 2 weeks prior to the start of drug administration (related to the completion of thecourse of antibiotics, except if for tumor fever) or 6 months for any intracranialabscess

• Has a positive test at screening for hepatitis B virus, hepatitis C virus, or forhuman immodeficiency virus (HIV), per local diagnostic standard and in accordancewith local laws and regulations

• Uncontrolled diabetes or symptomatic hyperglycemia (i.e., well controlled defined asa screening hemoglobin A1c <8% and no urinary ketoacidosis)

• Significant cardiovascular/cerebrovascular disease within 6 months prior to Day 1 ofstudy drug administration

• Alcohol or drug dependence or abuse

• Patients with known Werner (WRN) syndrome

• Prior treatment with any WRN helicase inhibitor

• Treatment with moderate or strong CYP3A4 inducers within 14 days prior to initiationof study treatment

• Treatment with moderate or strong CYP3A4 or P-glycoprotein inhibitors within 14 daysprior to initiation of study treatment

• Pregnancy, breastfeeding, or intention of becoming pregnant during the study

Additional Exclusion Criteria for the Combination with Pembrolizumab Only:

• Active or history of autoimmune disease or immune deficiency with some exceptions

• History of interstitial lung disease or pneumonitis

• Treatment with systemic immunosuppressive medication (such as corticosteroids)within 2 weeks prior to initiation of study treatment with some exceptions

• Treatment with organ transplant/graft tissue