IV Sting: This phase I trial is trying to determine the recommended dose of a new intravenous therapy (GSK3745417), when given alone or in combination with a type of immunotherapy, in patients with solid cancer typesA Phase I First Time in Human Open Label Study of GSK3745417 Administered With and Without Anticancer Agents in Participants With Advanced Solid Tumors

Exclusion

• Active autoimmune disease that has required systemic disease modifying or immunosuppressive treatment within the last 2 years.
• Concurrent medical condition requiring the use of systemic immunosuppressive treatment within 28 days before the first dose of study treatment.
• Current unstable liver or biliary disease.
• History of vasculitis at any time prior to study treatment.
• Evidence or history of significant active bleeding or coagulation disorder.
• Active infection requiring systemic treatment, known human immunodeficiency virus infection, or positive test for hepatitis B surface antigen or hepatitis C.
• QT duration corrected for heart rate by Fridericia's formula (QTcF) more than (>)450 milliseconds (msec) or QTcF >480 msec for participants with bundle branch block.
• Recent history (within the past 6 months) of acute diverticulitis, inflammatory bowel disease, intra-abdominal abscess, or gastrointestinal obstruction.
• Recent history of allergen desensitization therapy within 4 weeks of starting study treatment.
• History or evidence of cardiovascular (CV) risk
• Recent (within the past 6 months) history of symptomatic pericarditis.
• History of idiopathic pulmonary fibrosis, interstitial lung disease, or organizing pneumonia, or evidence of active, non-infectious pneumonitis.
• History of (non-infectious) pneumonitis that required steroids or current pneumonitis.
• Recent history (within 6 months) of uncontrolled symptomatic ascites or pleural effusions.

• Prior treatment with the following agents:

  1. Stimulator of Interferon Genes (STING) agonist at any time.
  2. Anticancer therapy or investigational therapy or used an investigational device within 28 days or 5 half-lives of the drug, whichever is shorter.
  3. Checkpoint inhibitors, including Programmed death receptor-1 (PD-1), Programmed death Ligand-1 (PD-L1), PD-L2 and Cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitors within 28 days.
  4. Prior radiation therapy: permissible if at least 1 non-irradiated measurable lesion is available for assessment according to RECIST version 1.1 or if a solitary measurable lesion was irradiated, objective progression is documented.
• Pregnant and/or breast feeding participants or those who plan to become pregnant and/or breastfeed.
• Receipt of any live vaccine within 30 days of the start of study treatment.
• Prior allogeneic or autologous bone marrow transplantation or other solid organ transplantation.
• Major surgery less than or equal to (<=)28 days before the first dose of study treatment. Participants must have also fully recovered from any surgery (major or minor) and/or its complications before initiating study treatment.
• Participants with signs/symptoms suggestive of Coronavirus Disease-2019 (COVID-19) within 14 days of study entry, or with known exposure to COVID-19 within 14 days prior to study entry.
• Participants are excluded from Part 2A of the study if they have known hypersensitivity to dostarlimab or associated excipients.