A Study to Assess the Safety, Tolerability, Pharmacokinetic, Pharmacodynamic, Immunogenicity and Antitumour Activity of IPN60300 in Adults With Locally Advanced or Metastatic Solid Tumours

This study aims to find the right dosage and evaluate the safety and effectiveness of the drug IPN60300 in adults with advanced solid tumours, which are cancers that have spread to other parts of the body from their original location. All participants will receive the drug by injection. Study Phases: * Phase Ia: Participants with certain types of tumours will be treated in cohorts of increasingly higher doses of the drug to determine the safe and effective dose range (a high and a low dose). * Phase Ib: Participants with a specific tumour type will receive one of the two doses identified in phase Ia. The dose level will be assigned randomly (by chance). Study Periods: Screening: Up to 28 days before first IPN60300 injection to determine eligibility. Treatment: Starts with the first dose of IPN60300 and continues until it needs to be stopped due to harmful effects, the disease getting worse, or if the participant decides to stop taking part in the study, the investigator's decision to stop treatment, death or the study is terminated early by the sponsor. Participants will undergo blood tests, urine collections, physical examinations, and clinical evaluations.