Dose Escalation and Expansion Study of GSK3359609 in Participants With Selected Advanced Solid Tumors (INDUCE-1)

Inclusion Criteria

• Capable of giving signed, written informed consent.
• Male or female, age 18 to 93 years (at the time consent is obtained).
• Histological or cytological documentation of an invasive malignancy that was diagnosed as locally advanced/metastatic or relapsed/refractory and is of one of the following tumor types: bladder/urothelial cancer of the upper and lower urinary tract; cervical; colorectal (includes appendix); esophagus, squamous cell; head and neck carcinoma; melanoma; malignant pleural mesothelioma (MPM); non-small-cell lung cancer (NSCLC), prostate; Microsatellite Instability-High/deficient mismatch repair (MSI-H/dMMR) tumor (Part 1B and Part 2B) and Human Papilloma Virus (HPV)-positive or Epstein-Barr (EBV)-positive tumor (Part 1B and Part 2B).
• Disease that has progressed after standard therapy for the specific tumor type, or for which standard therapy has proven to be ineffective, intolerable, or is considered inappropriate, or if no further standard therapy exists; exceptions are in these tumor types in which pembrolizumab single agent may be a standard: NSCLC, head and neck squamous cell cancer (HNSCC), bladder/urothelial cancer, MSI-H/dMMR cancers and melanoma and cervical cancer. In Part 2B pembrolizumab combination expansion cohorts, prior treatment with anti-Programmed cell death protein 1(PD-1)/ Ligand-1 (L1) may not be required. 1) Participants must not have received more than 5 prior lines of therapy for advanced disease including both standards of care and investigational therapies. 2) Participants who received prior PD-1/L1 therapy must fulfill the following requirements (Part 1B [except PK/PD cohort]/ Part 2B):a) Have achieved a CR, PR or SD and subsequently had disease progression while still on PD-1/L1 therapy; b) Have received at least 2 doses of an approved PD-1/L1 inhibitor (by any regulatory authority), c) Have demonstrated disease progression as defined by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 within 18 weeks from the last dose of the PD-1/L1 inhibitor. The initial evidence of disease progression is to be confirmed by a second assessment no less than four weeks from the date of the first documented Progressive Disease (PD) (the confirmatory scan could be the Baseline eligibility scan for this study). 3) In Part 2A 5-fluorouracil (FU)/platinum combination with GSK3359609 and pembrolizumab cohort, participants must not have received prior systemic therapy administered in the recurrent or metastatic setting (with the exception of systemic therapy given as part of multimodal treatment for locally advanced disease).
• Archival tumor tissue obtained at any time from the initial diagnosis to study entry; a fresh tumor biopsy using a procedure that is safe for the participant on a lesion not previously irradiated unless lesion progressed will be required if archival tissue is unavailable.
• Agree to undergo a pre-treatment and on treatment biopsy and have disease amenable to biopsy required in pharmacokinetic (PK) / pharmacodynamics (PD), dose randomized HNSCC, Melanoma dose expansion and Biomarker cohorts..
• Measurable disease per RECIST version 1.1. Palpable lesions that are not measurable by radiographic or photographic evaluations may not be utilized as the only measurable lesion. Any measurable lesion biopsied at Screening cannot be followed as a target/index lesion unless agreed upon by GlaxoSmithKline (GSK).
• Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-1.
• Life expectancy of at least 12 weeks.
• Adequate organ function.
• QT interval corrected for heart rate according to Fridericia's formula (QTcF) <450 milliseconds (msec) or QTcF <480 msec for participants with bundle branch block.
• A female participant is eligible to participate if she is not pregnant (as confirmed by a negative serum beta-human chorionic gonadotrophin [beta-hCG] test in females of reproductive potential), and not lactating or reproductive potential agre