The primary purpose of this study is to assess the safety, tolerability, and pharmacokinetics, and to identify the optimal dose of ADRX-0706 in patients with select advanced solid tumors.

This is a 2 part study. The Phase 1a will consist of a dose escalation of ADRX-0706 to evaluate initial safety and tolerability in patients with select advanced solid tumors, and to identify the recommended dose to be used in the Phase 1b. The Phase 1b will further evaluate the safety and tolerability, as well as preliminary efficacy, and identify the optimal dose of ADRX-0706 in patients with urothelial cancer, triple negative breast cancer, and cervical cancer.

Inclusion Criteria:

• Phase 1a Dose Escalation: Subjects with histologically confirmed select advanced solid tumors, including urothelial carcinoma (UC), head and neck squamous cell carcinoma (HNSCC), breast cancer, cervical cancer, ovarian cancer, non-small cell lung cancer (NSCLC), and pancreatic cancer. Subjects must have received at least one prior systemic regimen and have no other therapy available known to provide meaningful clinical benefit in the opinion of the investigator.
• Phase 1b Dose Expansion: Subjects with urothelial cancer, triple negative breast cancer or cervical cancer with disease progression after at least one prior systemic regimen and no standard treatment options available and considered appropriate in the opinion of the investigator, unless subject refuses standard therapy.
• Measurable disease according to RECIST version 1.1
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
• Adequate hematologic, liver, and renal function

Exclusion Criteria:

• Active and uncontrolled central nervous system metastases
• Significant cardiovascular disease
• History of another malignancy other than the one for which the subject is being treated on this study within 3 years
• Receipt of any anticancer or investigational therapy within 5 elimination half-lives or 14 days (whichever is less)
• Any P-gp inducers/inhibitors or strong CYP3A inhibitors received within 14 days prior to the first dose of study drug
• Receiving systemic antimicrobial treatment for active infection; routine antimicrobial prophylaxis is permitted