Inclusion Criteria:
- Histologically or cytologically confirmed diagnosis of an advanced, unresectable and/or metastatic or relapsed/refractory solid tumour. Patient must have at least one measurable lesion (according to Response Criteria in Solid Tumours (RECIST 1.1)).
- Patient must have exhausted or refused established treatment options for the malignant disease, or is not eligible for established treatment options.
- Has a lesion amenable to pre-treatment and on-treatment biopsy and patient consents to both biopsies.
- Medically fit and willing to undergo all mandatory trial procedures.
- Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1.
- Adequate organ function or bone marrow reserve as demonstrated at screening by the following laboratory values:
- Absolute neutrophil count ≥ 1.5x10\^9/L (≥ 1.5x10\^3/μL, ≥ 1500/mm3); platelet count ≥ 100x10\^9/L (≥ 100x10\^3/μL, ≥ 100x10\^3/mm3), without the use of hematopoietic growth factors within 4 weeks of start of trial medication
- Haemoglobin ≥ 90 g/L (≥ 9.0 g/dL, ≥ 5.6 mmol/L)
- Estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73m\^2 (as determined by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula)
- Aspartate transaminase (AST) and alanine transaminase (ALT) ≤ 3 x ULN if no demonstrable liver metastases, or otherwise ≤ 5 x ULN if transaminase elevation is attributable to liver metastases.
- Total bilirubin ≤ 1.5 x ULN, except for patients with Gilbert's syndrome: total bilirubin ≤ 3.0 x ULN or direct bilirubin ≤ 1.5 x ULN
- partial thromboplastin time (PTT) / activated partial thromboplastin time (aPTT) <1.5 x ULN
- Patients ≥18 years of age or over the legal age of consent in countries where that is greater than 18 years at the time of signature of the informed consent form (ICF).
- Signed and dated written ICF in accordance with International Council for Harmonisation- Good Clinical Practice (ICH-GCP) and local legislation, obtained before performing any protocol related procedures that are not part of normal standard of practice care. Note: If a patient declines to participate in the voluntary biobanking component of the trial, he/she will not be excluded from other aspects of the trial.
Further inclusion criteria apply
Exclusion Criteria:
- Any investigational or antitumour treatment within 4 weeks or 5 half-life periods prior to the first treatment whichever is shorter.
- Prior STING agonist therapy.
- Prior intolerability of a anti-programmed cell death protein 1 (PD-1) or anti-programmed cell death ligand 1 (PD-L1) therapy.
- History of allergy or hypersensitivity to study agent components.
- Immunosuppressive therapies including, but not limited to, systemic corticosteroids at doses exceeding >10 mg/day of prednisone or equivalent, and tumour necrosis factor-alpha blockers.
- Persistent toxicity from previous treatments (including immune related Adverse Events (irAEs)) that has not resolved to Grade ≤1, except for alopecia, xerostomia, and immunotherapy related endocrinopathies.
- Evidence of active, non-treatment related autoimmune disease, except for endocrinopathies.
- History or complication of pneumonitis or interstitial lung disease within the last 12 months, or any prior pneumonitis related to immunotherapy.
Further exclusion criteria apply