A Study to Assess Adverse Events, Change in Disease Activity and How Intravenous ABBV-253 Moves Through the Body in Adult Participants With Advanced Solid Tumors

Cancer is a condition where cells in a specific part of body grow and reproduce uncontrollably. The purpose of this study is to assess adverse events, change in disease activity and pharmacokinetics of ABBV-253. ABBV-253 is an investigational drug being developed for the treatment of advanced solid tumors. This open-label study consists of two parts. In Part 1 (ABBV-253 dose escalation), participants with any of the eligible cancer types will receive 1 of 4 (or more) doses of ABBV-253. Each cohort receives a higher dose, lower dose, or the same dose of ABBV-253 than the previous group. In Part 2 (ABBV-253 dose optimization), a new group of participants with NSCLC will be randomly put into pre-determined dose groups to receive 1 of 3 doses of ABBV-253. Approximately 130 participants will be enrolled in the study at approximately 11 sites worldwide. Participants will receive intravenous (IV) infusion of ABBV-253, as part of the 4 year study. There may be higher treatment burden for participants in this trial compared to their standard of care due to study procedures. Participants will attend regular visits during the study at a hospital or clinic. The effects of the treatment will be checked by medical assessments, blood tests, checking for side effects and completing questionnaires.