An Open-label, Dose Escalation Study to Investigate the Safety, Pharmacokinetics, Pharmacodynamics and Clinical Activity of GSK3326595 in Participants With Solid Tumors and Non-Hodgkin's Lymphoma

Inclusion criteria: * Males and females greater than or equal to (\>=)18 years of age (at the time consent is obtained) * Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1 or 2 * Diagnosis of non-resectable or metastatic solid malignancy (as defined in the protocol) or NHL * Presence of evaluable disease * Adequate organ function (as defined in the protocol) * Reproductive criteria (as defined in the protocol). Exclusion Criteria: * Malignancy attributed to prior solid organ transplant * Leptomeningeal disease, spinal cord compression, or brain metastases that require immediate central nervous system (CNS)-specific treatment in the opinion of the Investigator (for example \[e.g.\], for symptomatic disease) * History of a second malignancy, excluding non-melanoma skin cell cancer within the last three years * Evidence of severe or uncontrolled systemic diseases, or serious and/or pre-existing medical or other condition that could interfere with participant's safety, obtaining informed consent or compliance to the study procedures, in the opinion of the Investigator * Any clinically significant gastrointestinal (GI) abnormalities that may alter absorption such as malabsorption syndrome or major resection of the stomach and/or bowels. * Select cardiac abnormalities (as defined in the protocol) * History of sensitivity to any of the study medications, or components thereof or a history of drug or other allergy that, in the opinion of the investigator or Medical Monitor, contraindicates their participation. * History of optic nerve neuropathy or neuritis.