A Phase 1 Trial of GEN1119 in Participants With Solid Tumors

The purpose of this trial is to learn about the safety and efficacy of GEN1119 when it is used for the treatment of participants with certain types of cancer. The trial has multiple parts. The first part of the trial will test different doses of GEN1119 to find out if it is safe and to determine what are the best doses to use. The second part will further refine this optimal dose. The third part continues to test the safety and how well GEN1119 works in additional participants with specific cancer types and at doses chosen based on the results of the first 2 parts of the trial. For each participant, the trial will last approximately 18 months but this may vary for each individual. This includes a Screening Period of up to 21 days before receiving trial treatment, an estimated 5 months of treatment (the duration of treatment may vary for each participant), and approximately 12.5 months of follow up after trial treatment ends (the duration of follow up may vary for each participant). Participation in the trial will require visits to the site, with more frequent visits during the first 6 weeks of treatment and then less frequent visits afterwards. At site visits, there will be various tests (such as blood draws) and procedures (such as recording of heart activity, computed tomography \[CT\] scans) to monitor whether the treatment is safe and effective. All participants will receive active drug; no one will be given placebo.