Phase 1 Study in Patients With Advanced Solid Malignancies to Evaluate the Safety of ATOR-1017

Major Inclusion Criteria: A patient is eligible to be included in the study if all the following criteria apply: * Has a diagnosis of advanced and/or refractory solid malignancy (histologically or cytologically documented) * Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Has a minimum of one measurable tumor lesion * Has acceptable hematologic and clinical chemistry laboratory values Major Exclusion Criteria: A patient is excluded if any of the following criteria apply: * Has not recovered from AEs to at least grade 1 by CTCAE version 5.0 due to prior anti-cancer medications * Has symptomatic, steroid-dependent or progressive brain metastasis/metastases * Has a history of another primary malignancy, except for: a) Malignancy treated with curative intent and with no known active disease within 2 years prior to first dose of ATOR-1017, b) Adequately treated non-invasive basal skin cancer or squamous cell skin carcinoma, c) Adequately treated uterine cervical cancer stage 1B or less * Has an autoimmune disorder requiring immune modulating treatment during the last 2 years * Receives treatment with systemic immunosuppressant medication (except for inhaled and low dose systemic corticosteroids, i.e. ≤10 mg prednisolone or equivalent per day) * Is a female patient who is pregnant or nursing