A trial to learn how safe AZD9750 is and how well it works in people with metastatic prostate cancer when given with or without other anticancer drugs

Prior treatment

• Participants with other cardiovascular diseases as defined by any of the following: (a) Symptomatic heart failure (as defined by New York Heart Association class ≥ 2) or recent hospitalisation for heart failure (< 6 months). (b) Uncontrolled hypertension > 160/90 mmHg. (c) Acute coronary syndrome /acute myocardial infarction, unstable angina pectoris, coronary intervention procedure with percutaneous coronary intervention, or coronary artery bypass grafting within 6 months, symptomatic angina pectoris. (d) Cardiomyopathy of any aetiology. (e) Presence of clinically significant valvular heart disease. (f) History of atrial or ventricular arrhythmia requiring treatment; subjects with atrial fibrillation and optimally controlled ventricular rate (mean HR < 90 bpm over 24 hours or mean HR < 90 bpm on resting ECG) are permitted. (g) Transient ischaemic attack, or stroke within 6 months prior to screening. (h) Participants with symptomatic hypotension at screening.
• Unresolved treatment-related toxicities from previous anticancer therapy of CTCAE Grade ≥ 2 (with exception of vitiligo, alopecia).
• Prior treatment with an AR-PROTAC.

Lab values

• Participants with any of the following cardiac criteria: (a) Mean resting QTcF > 450 milliseconds obtained from triplicate ECGs and averaged, recorded within 5 minutes. (b) Any factors that increase the risk of QTc prolongation such as the congenital long QTc syndrome or family history of long QTc syndrome, or unexplained sudden death under 40 years of age in first-degree relatives, or any concomitant medication known to prolong the QTc interval within 5 half-lives of the first dose of study intervention (see Appendix H 1), as well as factors that increase the risk of arrhythmic events such as uncorrected abnormalities in serum electrolytes (ie, sodium, potassium, calcium, magnesium). (c) Resting heart rate > 90 bpm or < 45 bpm. (d) Any clinically important abnormalities in rhythm, conduction or morphology of resting ECG (eg, complete left bundle branch block, or QRS duration > 120 ms, PR interval > 220 ms, second- or third-degree atrioventricular block), and clinically significant sinus node dysfunction not treated with pacemaker. (e) Baseline LVEF < 50%, or clinically significant diastolic dysfunction/LVEDP increase/pulmonary hypertension.

Other

• Participants with pathological finding consistent with any presence of small cell carcinoma, predominant neuroendocrine carcinoma, or any predominant histology other than prostate adenocarcinoma.
• Brain metastases, or spinal cord compression.

• Participant must be ≥ 18 years at the time of signing the informed consent form.
• Life expectancy of ≥ 12 weeks.
• Histologically or cytologically confirmed diagnosis of adenocarcinoma of the prostate.
• Documented metastatic disease by conventional imaging by clear evidence of at least one bone lesion and/or at least one soft tissue lesion.
• Surgically or medically castrated, with serum testosterone levels ≤ 50 ng/dL (≤ 1.75 nmol/L) within (≤) 28 days before first dose of study intervention.
• Participants who have had disease progression while undergoing continuous ADT following standard treatment of metastatic prostate cancer, per PCWG3 guidance. (a) PSA progression defined by a minimum of 3 rising PSA levels with an interval of ≥ 1 week between each determination. (b) Radiographic progression of soft tissue disease by RECIST v1.1 (Eisenhauer et al 2009) with or without PSA progression. (c) Radiographic progression of bone metastasis with 2 or more documented new bone lesions on a bone scan with or without PSA progression.
• ECOG performance status score of 0 or 1.
• Adequate bone marrow and organ function as defined by the protocol.
• Participant must be male (as assigned at birth), inclusive of all gender identities.
• Contraceptive use by men or women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.