A Phase I Study of [225Ac]-AZD2284 in Patients With Metastatic Castration-Resistant Prostate Cancer

Main Inclusion Criteria:

• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.

• Histologically confirmed diagnosis of adenocarcinoma of the prostate orneuroendocrine differentiated prostate cancer.

• Must have had prior bilateral orchiectomy and/or ongoing androgen-deprivationtherapy and a castrate level of serum/plasma testosterone (< 50 ng/dL or < 1.7nmol/L).

• At least one metastatic lesion present on baseline Computed Tomography (CT),Magnetic Resonance Imaging (MRI), or bone scan obtained ≤ 28 days prior to the firstdose of Investigational Medicinal Product (IMP). Participants may havenon-measurable lesions including bone only metastases.

• Adequate organ function

Main Exclusion Criteria:

• Treatment with any radiopharmaceutical within 6 weeks of the first dose ofInvestigational Medicinal Product (IMP).

• Radiation therapy (RT) within 28 days prior to the first dose and all RT-relatedevents have not recovered to Grade ≤ 1.

• Administration of any systemic cytotoxic or investigational therapy ≤ 28 days of thefirst dose of IMP or 5 half-lives, whichever is shorter.

• All prior treatment-related adverse events must have resolved to Grade ≤ 1.

• Concurrent severe and/or uncontrolled illness not related to cancer and/or socialsituation that would limit compliance with study requirements.

• Known or suspected allergies or contraindications to any of the investigationaldrugs or any component of the investigational drug formulation.

• Clinically relevant proteinuria