Study of JANX014 in Subjects With Metastatic Castration-Resistant Prostate Cancer

• JANX014 (Biological): JANX014 will be administered via IV dosing

Primary outcomes

• Incidence of Dose Limiting Toxicities (DLTs) [2 years]
• Incidence of adverse events (AE) and Serious Adverse Events (SAE) [2 years]

Secondary outcomes

• Area under the curve from time 0 to t of JANX014 (AUC0-t) [up to 2 years]
• Maximum observed concentration of JANX014 (Cmax) [up to 2 years]
• Number of participants who develop anti-drug antibodies against JANX014 [up to 2 years]
• Prostate Specific Antigen (PSA) response [up to 2 years]
• Overall Response Rate [up to 2 years]
• Duration of Response [up to 2 years]
• Radiographic Progression Free Survival (rPFS) [up to 2 years]

Sex: Male, ages: 18 Years to any

Inclusion Criteria:

* Male ≥18 years of age at the time of signing informed consent
* Histologically or cytologically confirmed adenocarcinoma of the prostate
* For Dose Escalation: Having mCRPC that progressed after at least one novel anti-androgen therapy and at least one taxane containing regimen. Participants who have actively refused a taxane containing regimen or are medically unsuitable to receive taxane are eligible.
* Adequate organ function
* For Dose Expansion Part: Have received ≤ 2 anti-androgen therapies in either the HSPC or CRPC setting and no more than 1 prior taxane regimen in the HSPC setting. Participants who have actively refused a taxane regimen or are medically unsuitable to receive taxane are eligible.

Exclusion Criteria:

* Prior solid organ transplant
* Prior treatment with any CAR-T cell therapy, approved or investigational T-cell engager therapy, and prior receipt of radioligand therapy
* Clinically significant cardiovascular disease