• Adenocarcinoma of the prostate without small cell features
• Metastatic disease documented by positive bone scan (for bone disease) or metastatic lesions on CT or MRI (for soft tissue/visceral disease)
• Resolution of acute effects of any prior therapy
• ECOG PS 0-1
• No known or suspected CNS disease
• Must be treatment naive at the mCSPC stage
  • However, treatment with a first-generation antiandrogen is allowed
• No investigational products within 30 days
• Adequate organ function

• Have histologically or cytologically confirmed adenocarcinoma of the prostate without small cell histology
• Has current evidence of metastatic disease documented by either bone lesions on bone scan and/or soft tissue disease shown by computed tomography scan (CT)/magnetic resonance imaging (MRI)
• Has prostate cancer progression while receiving androgen deprivation therapy (ADT) (or post bilateral orchiectomy) within 6 months before Screening
• Has disease that progressed during or after treatment with one next-generation hormonal agent (NHA) for hormone sensitive prostate cancer (HSPC) metastatic hormone sensitive prostate cancer (mHSPC) or non metastatic hormone sensitive prostate cancer (nmHSPC), for at least 8 weeks (at least 14 weeks for participants with bone progression) Note: Participants may have received abiraterone acetate and docetaxel or darolutamide and docetaxel for HSPC. However, participants must have received no more than six cycles of docetaxel and had no radiographic disease progression while receiving docetaxel
• ECOG PS 0-1
• Has ongoing androgen deprivation with serum testosterone <50 ng/dL (<1.7 nM)
• Has had prior treatment with Poly polymerase inhibitors (PARPi) or were deemed ineligible to receive treatment by the investigator or have refused PARPi treatment
• Has adequate organ function
• Has provided tumor tissue from a fresh core or excisional biopsy from soft tissue not previously irradiated. Samples from tumors progressing at a prior site of radiation are allowed
• Participants who have adverse event (AEs) due to previous anticancer therapies must have recovered to ≤Grade 1 or baseline. Participants with endocrine-related AEs who are adequately treated with hormone replacement therapy (HRT) or participants who have ≤Grade 2 neuropathy are eligible
• Human immunodeficiency virus (HIV)-infected participants must have well controlled HIV on antiretroviral therapy (ART)
• No presence of gastrointestinal condition
• No history of pituitary dysfunction
• No poorly controlled diabetes mellitus
• No active or unstable cardio/cerebro-vascular disease, including thromboembolic events
• Has not received a taxane-based chemotherapy and or NHA for metastatic castration-resistant prostate cancer (mCRPC)
• Has not received prior treatment with radium for prostate cancer
• Does not have a "superscan" bone scan defined as an intense symmetric activity in the bones and diminished renal parenchymal activity on baseline bone scan such that the presence of additional metastases in the future could not be evaluated
• Has known additional malignancy that is progressing or has required active treatment within the past 3 years
• No known active central nervous system (CNS) metastases

• Has histologically- or cytologically-confirmed adenocarcinoma of the prostate without small cell histology
• Must provide a core or excisional biopsy from soft tissue or bone biopsy within 1 year of screening and after developing mCRPC. Participants with bone metastasis only must provide an archival tumor tissue specimen.
• Has prostate cancer progression within 6 months prior to screening, as determined by the investigator, by means of one of the following: PSA progression as defined by a minimum of 2 rising PSA levels with an interval of ≥1 week between each assessment where the PSA value at screening should be ≥2 ng/mL; radiographic disease progression in soft tissue based on RECIST criteria with or without PSA progression; radiographic disease progression in bone defined as the appearance of 2 or more new bone lesions on bone scan with or without PSA progression. 
• Has ongoing androgen deprivation with serum testosterone <50 ng/dL (<2.0 nM)
• Patients receiving bone resorptive therapy must be on stable doses
• ECOG PS 0-1
• Has received docetaxel for mCRPC. Prior treatment with 1 other chemotherapy for mCRPC is allowed. Up to 2 second-generation hormonal manipulations (eg, abiraterone acetate, enzalutamide, apalutamide, darolutamide or other next-generation hormonal agents [NHA]) are allowed. Participants who received prior ketoconazole for metastatic disease may be enrolled. If docetaxel chemotherapy is used more than once (eg, once for metastatic hormone-sensitive and once for mCRPC), it will be considered as 1 therapy. Prior docetaxel for metastatic hormone-sensitive prostate cancer (mHSPC) is allowed if ≥4 weeks have elapsed from the last dose of docetaxel prior to Day 1 of Cycle 1
• No immunodeficiency or systemic steroid use
• No active autoimmune disease within 2 years
• No known HIV/HBV/HCV
• No known CNS mets
• No superscan bone scan
• No symptomatic ascites or pleural effusion

• ECOG PS 0-1
• Subjects who relapsed, progressed, or were intolerant to standard therapy, have a disease for which no therapy with a known overall survival benefit exists or are not a candidate for these therapies, and have one of the following cancers:

i. Histologically confirmed locally advanced/metastatic HER2-negative breast cancer, with deleterious or suspected deleterious BRCA1/2 mutation, that progressed on, was intolerant to, was refused, or ineligible for (PARPi).

ii. Histologically confirmed locally advanced/metastatic HGSOC (high-grade serous ovarian cancer), including primary peritoneal cancer (PPC) and fallopian tube cancer (FTC), that progressed on, was intolerant to, refused, or ineligible to maintenance treatment with a PARPi.

iii. Histologically confirmed locally advanced/metastatic CRPC, with deleterious or suspected deleterious BRCA1/2 mutation, that progressed on, was intolerant to, refused, or ineligible for PARPi.

iv. Histologically confirmed locally advanced/metastatic pancreatic cancer with deleterious or suspected deleterious BRCA1/2 mutation that progressed on, was intolerant to, refused, or ineligible for maintenance treatment with a PARPi.

v. Locally advanced/metastatic tumors with deleterious or suspected deleterious germline or somatic HRR mutation or HRD phenotype.

Cohort-Expansion Stage Single Agent and Combination:

b) HER2-negative BRCAm Breast cancer cohort: i. Histologically confirmed locally advanced/metastatic HER2-negative Breast cancer with deleterious or suspected deleterious BRCA1/2 mutation have documented radiographic disease progression during or following their last systemic anticancer therapy and that progressed on, was intolerant to, refused, or ineligible for treatment with a PARPi.

c) Platinum-resistant HGSOC cohort: i. Histologically confirmed locally advanced/metastatic HGSOC, including primary peritoneal cancer (PPC) and fallopian tube cancer (FTC), that progressed on, was intolerant to, refused, or ineligible to maintenance treatment with a PARPi and who have platinum-resistant disease, defined by platinum free interval of less than 6 months ii. Platinum-refractory disease (progression on first-line treatment or within 4 weeks of completion) are excluded.

d) Platinum-sensitive HGSOC cohort - expansion combination only: i. Histologically confirmed locally advanced/metastatic HGSOC, including PPC and FTC, that progressed on, refused, or ineligible to maintenance treatment with a PARPi, and who have platinum-sensitive disease, defined by platinum free interval of more than 6 months e) mCRPC cohort: i. Subjects with metastatic, castration-resistant adenocarcinoma of the prostate with deleterious or suspected deleterious BRCA1/2 mutation, that progressed on, or was intolerant, refused, or ineligible to PARPi.

f) HRRm advanced solid tumors cohort: i. Locally advanced/metastatic tumors with deleterious or suspected deleterious germline or somatic HRR mutation or HRD phenotype.

• No known symtomatic brain mets

Inclusion Criteria:

• Participants with histologically/cytologically confirmed advanced recurrent or metastatic solid tumor malignancy
• Part 1 (dose escalation): Participants must have had disease progression on or following all available standard of care (SOC) therapies known to confer clinical benefit.
• Part 2 (dose expansion): Participants may be enrolled following disease progression that has progressed after at least 1 available standard therapy; or for whom standard therapy has proven to be ineffective or intolerable or is considered inappropriate; or for whom a clinical trial of an investigational agent is a recognized SOC.
• Measurable Disease

Exclusion Criteria:

• History of another malignancy within 2 years prior to the first trial intervention administration (unless the malignancy was treated with curative intent with low risk of recurrence [e.g., nonmelanoma skin cancer, histologically confirmed complete excision of carcinoma in situ, or similar] which are allowed to enroll).
• Therapy with Immunosuppressive doses of systemic medications, such as steroids (doses >10 mg/day prednisone or equivalent daily) within 2 weeks before trial intervention administration
• Have known active central nervous system (CNS) metastases and/or leptomeningeal disease (LMD).
• Active and clinically relevant bacterial, fungal, or viral infection that is not controlled or requires systemic antibiotics, antifungals, or antivirals, respectively.
• Ascites or pleural effusion that is symptomatic and/or requiring drainage within 2 weeks prior to the first trial intervention administration.
• Have active hepatitis B virus (HBV) or hepatitis C virus (HCV), or participants with human immunodeficiency virus (HIV).
• Any medical condition that, in the investigator's or sponsor's opinion, poses an undue risk to the participant's participation in the trial.

• Histologically confirmed locally advanced, recurrent, or metastatic incurable solid tumors
• Must have tumor specimen available
• Measurable disease
• ECOG PS 0-1
• Life expectancy at least 12 weeks
• Phase 1a- must have exhausted all standard therapies for their disease
• Phase 1b- must have disease that has progressed after at least one available standard therapy
• Some cohorts are tumor-type specific- please contact study team to see if tumor type is eligible at any time during the study
• No active HBV/HCV or chronic or acute EBV
• No history of autoimmune disease
• No symptomatic or actively progressing CNS mets