First-in-Human Study to Evaluate AZD8359 STEAP2 TCE in Participants With Prostate Cancer

Inclusion Criteria: * Histologically confirmed diagnosis of adenocarcinoma of the prostate or neuroendocrine differentiated prostate cancer * Surgically or medically castrated with serum testosterone levels ≤ 50 ng/dL (≤ 1.75 nmol/L) * PSA value at screening should be ≥ 1ng/mL * Evidence of disease progression within 6 months prior to screening * Part A Participants should have received at least 2 prior approved systemic therapies for prostate cancer with at least one androgen receptor pathway inhibitor and at least one taxane regimen if amenable * Part B Participants should have received an androgen receptor pathway inhibitor for metastatic hormone sensitive prostate cancer or metastatic castration resistant prostate cancer (mCRPC). No prior taxane treatment for mCRPC is allowed for Module 1 and 2 Part B patients * Adequate organ function * Body weight ≥ 35 kg Exclusion Criteria: * Any clinically relevant cardiac abnormalities such as QT prolongation or uncontrolled cardiac arrythmias * All prior treatment-related adverse events must have resolved to Grade ≤ 2 * History of Grade ≥ 3 cytokine release syndrome or Grade ≥ 2 immune effector cell-associated neurotoxicity syndrome with prior therapy * Active or prior documented autoimmune or inflammatory disorders within the past 3 years * Prior exposure to any STEAP2 targeted agents or TCEs for prostate cancer