A Phase 1 Study of ATV-1601 in Patients With Advanced Cancer That Have AKT1 E17K Mutations

Inclusion Criteria:

1. Histologically or cytologically confirmed metastatic or advanced-stage solidmalignant tumor or HR+/HER2- breast cancer.

2. Have progressed on, were intolerant to, or experienced disease recurrence afterstandard therapy and have no available effective or tolerable treatment options toderive clinically meaningful benefit.

3. Tumor must have documented specific mutation profile as outlined below based onlocal laboratory testing.

4. Participants with solid tumors or HR+/HER2- breast cancer with AKT1 E17K mutations.

5. Measurable disease according to RECIST v1.1 criteria.

6. Formalin-fixed paraffin-embedded tumor specimen available for submission.

7. Eastern Cooperative Oncology Group performance status of 0 or 1.

Exclusion Criteria:

1. Previously documented activating mutations in KRAS, NRAS, HRAS, or BRAF.

2. Inadequate bone marrow reserve or organ function.

3. Clinically significant abnormalities of glucose metabolism.

4. Participants who are symptomatic or have uncontrolled brain metastases.

5. Requires treatment with certain medications.

Participants must meet other inclusion/exclusion criteria.