An Open-label, Multicenter, Phase 1/2a Study to Investigate the Safety, Tolerability, Pharmacokinetics, and Antitumour Activity of WEF-001 in Participants With Advanced KRAS- Mutant Solid Tumours.

Inclusion Criteria: * Advanced KRAS-mutant solid tumor: pancreatic ductal adenocarcinoma, colorectal cancer, non small cell lung cancer, platinum-resistant serous ovarian cancer, cholangiocarcinoma or urothelial bladder cancer * Progressive disease following at least one line of standard of care therapy * Measurable disease as defined by RECIST v1.1 * ECOG ≤ 1 Exclusion Criteria: * Active systemic infection requiring anti-infective therapy within 28 days prior to first dose of IMP * Active cardiovascular disease * Having a second active primary malignancy, requiring systemic administration of any cancer-related therapy * Liver dysfunction * Untreated brain metastasis and/or unstable neurological dysfunction * Inflammatory bowel disease * Active and untreated hyperthyroidism * Lupus erythematosus within past 5 years