The goal of this trial is to learn about the antibody acasunlimab (an antibody also known as GEN1046) when it is used alone and when it is used together with standard of care treatment (docetaxel) or another antibody cancer drug, pembrolizumab (with or without chemotherapy), for treatment of patients with certain types of cancer. All subjects will receive active drug; no one will receive placebo.

This trial has 2 parts. The purpose of the first part is to find out if acasunlimab at various doses is safe and to find out the best doses of acasunlimab to use. The purpose of the second part is to give acasunlimab to more subjects to see how well the doses of acasunlimab selected in the first part work against cancer when given alone and how well they work when given with pembrolizumab with or without chemotherapy.

Trial details include:

• The average trial duration for an individual subject will be about 74 weeks.
• The average treatment duration for an individual subject will be about 21 weeks.
• The visit frequency will be weekly at first and lessening over time until visits are only once every 3 weeks.

The trial is an open-label, multi-center safety trial of acasunlimab (GEN1046). The trial consists of 2 consecutive parts: a first-in-human (FIH) dose escalation (phase 1) and an expansion (phase 2a). The expansion part of the trial will be initiated once the Recommended Phase 2 Dose (RP2D) has been determined.

Key Inclusion Criteria:

For Dose Escalation:

• Have a histologically or cytologically confirmed non-CNS solid tumor that is metastatic or unresectable and for whom there is no available standard therapy

For Expansion:

• Have histologically or cytological confirmed diagnosis of relapsed or refractory, advanced and/or metastatic NSCLC, EC, UC, TNBC, SCCHN, or cervical cancer who are not anymore candidates for standard therapy For separate expansion cohorts: metastatic NSCLC without prior systemic treatment regimens for metastatic disease.

For Both Dose Escalation and Expansion

• Have measurable disease according to RECIST 1.1
• Have Eastern Cooperative Oncology Group (ECOG) 0-1
• Have an acceptable hematological status
• Have acceptable liver function
• Have an acceptable coagulation status
• Have acceptable renal function

Key Exclusion Criteria:

• Have uncontrolled intercurrent illness, including but not limited to:

  • Ongoing or active infection requiring intravenous treatment with anti-infective therapy, or any ongoing systemic inflammatory condition requiring further diagnostic work-up or management during screening.
  • Symptomatic congestive heart failure (Grade III or IV as classified by the New York Heart Association), unstable angina pectoris or cardiac arrhythmia
  • Uncontrolled hypertension defined as systolic blood pressure ≥ 160 mmHg and/or diastolic blood pressure ≥ 100 mmHg, despite optimal medical management
  • Ongoing or recent evidence of autoimmune disease
  • History of irAEs that led to prior checkpoint treatment discontinuation
  • Prior history of myositis, Guillain-Barré syndrome, or myasthenia gravis of any grade
  • History of chronic liver disease or evidence of hepatic cirrhosis
  • History of non-infectious pneumonitis that has required steroids or currently has pneumonitis
  • History of organ allograft (except for corneal transplant) or autologous or allogeneic bone marrow transplant, or stem cell rescue within 3 months prior to the first dose of acasunlimab
  • Serious, non-healing wound, skin ulcer (of any grade), or bone fracture

• Any history of intracerebral arteriovenous malformation, cerebral aneurysm, new (younger than 6 months) or progressive brain metastases or stroke

• Prior therapy:

  • Radiotherapy within 14 days prior to first dose of acasunlimab. Note: palliative radiotherapy will be allowed.
  • Treatment with an anti-cancer agent (within 28 days or after at least 5 half-lives of the drug, whichever is shorter), prior to acasunlimab administration. Accepted exceptions are bisphosphonates (e.g., pamidronate, zoledronic acid, etc.) and denosumab

• Toxicities from previous anti-cancer therapies that have not adequately resolved

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.