Trial to Evaluate the Safety and Preliminary Efficacy of GEN1079 in Participants With Advanced Solid Tumors

Key Inclusion Criteria:

All Parts:

* Must have histologically confirmed selected solid cancers.
* Have measurable disease according to Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. The measurable lesion(s) must be outside the field of prior radiation therapy unless there is documented progression in the lesion(s).
* Must provide formalin-fixed paraffin-embedded tumor tissue (aspirates and bone specimens are not acceptable), archival or fresh, collected after discontinuation of their most recent anticancer treatment and prior to the first administration of GEN1079. If an archival specimen is unavailable, a procedure for obtaining a fresh tumor biopsy must be performed, provided it is performed according to standard of care and is deemed safe by the investigator.
* Has acceptable laboratory test results prior to trial treatment administration, including platelet count \>150×10\^9/litre (L).

Parts 1 and 2:

* Have histologically confirmed selected solid cancers that are metastatic or unresectable.
* Prior protocol defined therapy is permitted, with no restrictions on the number of prior lines of therapy received or the time since the most recent therapy.

Part 3:

* Have histologically confirmed selected solid cancer that is metastatic or unresectable.
* Must have received a defined number of prior lines of a protocol defined regimen.

Key Exclusion Criteria:

* Has intercurrent illness or known history of any of the following that could affect compliance with the protocol or interpretation of the results, including but not limited to:

  * Autoimmune diseases, eg, systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), neuromyelitis optica (NMO), myasthenia gravis (MG), cold agglutinin disease (CAD), atypical hemolytic uremic syndrome (aHUS), immunoglobulin A (IgA) nephropathy, inflammatory bowel disease (IBD; Crohn's and ulcerative colitis).
  * Grade ≥3 allergic reactions to prior monoclonal antibody therapy.
  * Known history of interstitial lung disease (ILD) Grade ≥3 or prior or ongoing noninfectious pneumonitis with evidence of progressive fibrotic changes on baseline imaging, unless clinically and radiologically stable for ≥6 months with preserved pulmonary function (eg, diffusing capacity of the lungs for carbon monoxide \[DLCO\] ≥ 50% predicted).
  * Disorders associated with platelet function defects, decreased number of platelets (eg, splenomegaly, chronic liver disease or bleeding disorders such as hemophilia or Von Willebrand disease), or a known history or high risk of bleeding events requiring transfusions or hospitalizations.
* Treatment with any plasma-based therapy within 7 days prior to Cycle 1 Day 1.
* Any history of intracerebral arteriovenous malformation (shunts), cerebral aneurysm, spinal cord compression (from disease), carcinomatous meningitis, or stroke. Note: Transient ischemic attack \>1 month prior to screening is allowed.
* Participants who, in the event of a medical complication during the trial treatment period, would be unable to temporarily discontinue and restart anticoagulant/antiplatelet therapy using appropriate bridging strategies (eg, low molecular weight heparin) in alignment with local standard of care.

Note: Other protocol-defined Inclusion and Exclusion criteria may apply.