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.

Inclusion criteria:

• Participant must be ≥18 years of age, at the time of signing the informed consent.
• Participants with histologically or cytologically documented, locally advanced, or metastatic solid tumors, that relapsed or were refractory after being previously treated with standard of care therapy; or for which there is no available established therapy; or standard therapy is contraindicated or not deemed appropriate by the treating investigator.
• Participants must have measurable disease per Response Evaluation Criteria in Solid Tumours (RECIST) version 1.1.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1.
• Male and female participants Contraceptive use by men or women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
• Adequate bone marrow function within 7 days before first dose of study intervention,
• Adequate renal function within 7 days before first dose of study intervention,
• Adequate hepatic function or laboratory abnormalities indicating hepatic injury within 7 days before first dose of study intervention,
• Prothrombin time or international normalised ratio (INR) ≤1.5 × ULN.
• At the time of screening, a tumour tissue specimen is required for enrolment into the dose escalation and dose optimisation portions of the study for retrospective central laboratory determination.
• Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF).
• Have a life expectancy of more than 3 months for disease-related mortality, as evaluated by the investigator.

Exclusion Criteria:

• Known second malignancy either progressing or requiring active treatment within the last 2 years prior to first dose of study intervention.
• Residual toxicity from prior anticancer therapy that are NCI CTCAE version 5.0 Grade 2 or higher. Stable chronic Grade 2 toxicities from previous treatments may be eligible per the judgement of investigator.
• History of major surgery within 4 weeks prior to the first dose of study intervention.
• Previous solid organ transplantation.
• Pre-existing, acute or chronic severe corneal disorders, sequelae from severe corneal disorders, or a history of corneal transplantation.
• Active brain metastases or leptomeningeal metastases with exception to asymptomatic and treated brain metastases (i.e. no neurological symptoms, no requirements for corticosteroids and lesions <1.5 cm), which are stable and not expected to become symptomatic in the next 3 months in the opinion of the investigator.
• History of stroke or significant cerebrovascular disease (ie, transient ischemic attack) within 6 months prior to initiation of study intervention.
• History of clinically significant cardiac disease within 6 months prior to the initiation of study intervention, including but not limited to unstable angina, acute myocardial infarction, endoscopic or open-heart cardiac surgery, or heart failure classified as New York Heart Association Grade 2 or higher.
• History of clinically significant respiratory disease within 6 months prior to the initiation of study intervention, including severe chronic obstructive pulmonary disease or asthma.
• History of noninfectious interstitial lung disease (ILD)/pneumonitis/radiation pneumonitis that required steroids or has current ILD/pneumonitis.
• Clinically significant gastrointestinal disorder including bleeding, occlusion, diarrhoea >Grade 1, malabsorption syndrome, ulcerative colitis, inflammatory bowel disease or partial bowel obstruction.
• Any evidence of severe active infection or inflammatory condition.
• Significant concurrent, uncontrolled medical condition that would put participants at unacceptable risk from study participation or preclude them from complying with study procedures as per investigator assessment, including, but not limited to renal, hepatic, haematological, gastrointestinal, endocrine, pulmonary, neurological, cerebral, or psychiatric disease.
• Participants with uncontrolled human immunodeficiency virus (HIV). HIV infected participants are eligible if they meet criteria described in the protocol.
• Known active infection with hepatitis B virus (HBV) OR hepatitis C virus (HCV). Participants are eligible if they meet criteria described in the protocol.
• Ongoing immunosuppressive therapy, including systemic corticosteroids. NOTE: Physiologic replacement or use of topical or inhaled corticosteroids are allowed.
• Concurrent participation in another therapeutic treatment trial, previous participation should respect the minimum of 5 half-lives or 4 weeks before the study intervention initiation (whichever is shorter).
• Participants accommodated in an institution because of regulatory or legal order; prisoners or participants who are legally institutionalised.
• For French participants only: participants are under court protection, not affiliated to a social security system or protected adults.

Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, annotated case report form, statistical analysis plan, and dataset specifications.

Patient level data will be anonymized and study documents will be redacted to protect the privacy of study participants.

Where applicable, data from eligible studies are available 6 months after the studied medicine and indication have been approved in the US and/or EU.

Further details on Ipsen's sharing criteria and process for sharing are available here (https://www.ipsen.com/science/clinical-trials/clinical-data-transparency/).