The goal of this study is to start treatment with the NOTCH1 inhibitor brontictuzumab in an attempt to control tumors and prolong survival. The therapy involves participant being given the drug brontictuzumab to treat adenoid cystic carcinoma (ACC) with NOTCH 1 mutations. This is considered an investigational treatment.

Treatment:

Participant will receive brontictuzumab by vein over 30 minutes one time every 3 weeks.

Clinic Visits:

On Day 1 of Cycle 1 and then every 3 weeks from then on:

• Participant will have a physical exam
• Blood (about 3 teaspoons) will be drawn for routine tests.

Every 6 weeks, participant will have an MRI and CT scan to check the status of the disease.

Length of Treatment:

Participant may continue taking brontictuzumab for as long as the doctor thinks it is in their best interest. Participant will no longer be able to take the drug if the disease gets worse, they develop another illness that prevents receiving more treatment, or if intolerable side effects occur.

Brontictuzumab is not FDA approved or commercially available. It is currently being used for research purposes only.

Inclusion Criteria:

1. Eastern Cooperative Oncology Group (ECOG) performance status 0 to 1
2. Organ and marrow function as follows: absolute neutrophil count (ANC) ≥1000/mm3, platelets ≥50,000/dL, hemoglobin ≥8 g/dL, bilirubin ≤ 1.5 times the upper limit of normal, serum creatinine ≤1.5 mg/dL or creatinine clearance ≥50 mL/min, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 3 times the upper limit of normal.
3. Central Nervous System (CNS) metastases allowed if subject does not require steroids, brain metastases are clinically stable without symptomatic progression
4. Capability to understand and comply with the protocol and signed informed consent document.

Exclusion Criteria:

1. Major medical conditions that might affect study participation (e.g. uncontrolled pulmonary, renal, or hepatic dysfunction, uncontrolled infection, cardiac disease)
2. Inability or unwillingness to abide by the study protocol or cooperate fully with the investigator.

Adverse event collection with three week treatment cycle.