• Patient must be 18 years of age or over, at the time of signing the informed consent.

• Have a diagnosis of locally advanced, unresectable, refractory and/or metastatic solid tumors

• Have a tumor that is accessible and is willing to consent to tumor biopsies during the study.

• Have at least one measurable site of disease according to RECIST 1.1 criteria; The lesions should be either previously non irradiated or progressive lesions after irradiation, that can be accurately measured at baseline (for measurable lesions) with computed tomography (CT) or magnetic resonance imaging (MRI).

• Part A, B and C: Have at least one intratumorally injectable lesion (measurable and/or non-measurable based on RECIST 1.1), that can be accurately measured at baseline (for measurable lesions) with computed tomography (CT) or magnetic resonance imaging (MRI) or positron emission tomography-computed tomography (PET-CT); or clinical examination and which is suitable for repeated measurement.

• Part B and C (only for dose expansion cohort): Have paired pre- and on treatment tumor biopsies for patients with metastases that are safely accessible as determined by the investigator.

• Patients with brain metastasis must have stable disease and must be neurologically asymptomatic and not requiring corticosteroid treatment.

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

• Have a predicted life expectancy of 12 weeks or more.

⁃ Able to comply with study procedures in the Investigator's opinion.

⁃ Adequate organ function determined within 4 weeks prior to screening

⁃ Patient is male or female.

⁃ Contraceptive use by women must be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.

⁃ Patient is capable of giving signed informed consent.