Overview

The purpose of this study is to see how safe and effective ABBV-CLS-579 is when used alone or in combination with programmed cell death protein-1 (PD-1) inhibitors in treating solid cancers.

ABBV-CLS-579 is an investigational drug being developed for the treatment of solid tumors. The study has two arms - Monotherapy and Combination Therapy. In the monotherapy arm, participants will receive ABBV-CLS-579 alone, in increasing doses. In the combination therapy arm, escalating doses of ABBV-CLS-579 will be given in combination with a PD-1 inhibitor. Adult participants with a diagnosis of some solid tumors for which no effective standard therapy exists, or has failed will be enrolled.

Participants will receive oral ABBV-CLS-579 capsule alone or in combination with intravenous (IV) PD-1 inhibitor. Participants will receive study drug treatment until disease progresses or discontinued.

There may be a higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the course of the study at a hospital or clinic. The effect of the treatment will be checked by medical assessments, blood tests, checking for side effects, and completing questionnaires.

Eligibility

Inclusion Criteria:

• Must weigh at least 35 kilograms (kg).
• Histologically or cytologically proven metastatic or locally advanced tumors (with measurable disease defined by Response Evaluation Criteria In Solid Tumors [RECIST] v1.1), for which no effective standard therapy exists, or where standard therapy has failed. Participants must have received at least 1 prior anticancer therapy for the indication being considered.
• An Eastern Cooperative Oncology Group (ECOG) performance status 2.
• Life expectancy of 12 weeks.
• Laboratory values meeting protocol criteria.
• QT interval corrected for heart rate < 450 msec (using Fridericia's correction), and no clinically significant electrocardiographic findings.

Exclusion Criteria:

• Untreated brain or meningeal metastases (participants with history of metastases are eligible provided they do not require ongoing steroid treatment and have shown clinical and radiographic stability for at least 28 days after definitive therapy).
• Unresolved Grade 2 or higher toxicities related to previous anticancer therapy except alopecia.
• History of hepatitis B, hepatitis C, or human immunodeficiency virus (HIV) infection.
• Recent history (within 6 months) of congestive heart failure (defined as New York Heart Association, Class 2 or higher), ischemic cardiovascular event, pericardial effusion, pericarditis or clinically significant arrythmia.
• Recent history (within 6 months) of Childs-Pugh B or C classification of liver disease.
• History of clinically significant medical and/or psychiatric conditions or any other reason that, in the opinion of the investigator, would interfere with participation in this study or would make the participant an unsuitable candidate to receive study drug.
• Known gastrointestinal disorders making absorption of oral medications problematic. Inability to swallow capsules.
• If treated with anti-programmed cell death protein-1 (aPD-1)/antiprogrammed cell death protein-ligand 1(aPD-L1) targeting or other immunostimulatory agents in the past: excluded if had prior pneumonitis, prior Grade 3 or higher immune mediated toxicity, hypersensitivity to administered drug or drug related toxicity requiring discontinuation.
• Active autoimmune disease requiring systemic treatment in past 2-years (exceptions for endocrinopathies, vitiligo or atopic conditions)
• History of solid organ transplant or allogeneic stem cell transplant.
• History of interstitial lung disease or pneumonitis.
• Major surgery 28 days prior to first dose of study drug.