A Study of Two Dose Levels of Vobramitamab Duocarmazine in Participants with Metastatic Castration-resistant Prostate Cancer (TAMARACK)

Prior treatment

• Received > 3 total prior therapies for mCRPC.
• Received >1 prior taxane-containing regimen for prostate cancer. A second taxane regimen of < 60 days used as bridging for lutetium-177 is permitted.
• Prior treatment with any B7-H3 targeted agent for cancer
• Contraindications to the use of corticosteroid treatment
• Prior stem cell, tissue, or solid organ transplant
• Participants with a known history of BRCA mutation (germline or somatic) are not eligible unless they received prior treatment with a PARP inhibitor where available, indicated and tolerated.

Other illness

• Any underlying medical or psychiatric condition impairing participant's ability to receive, tolerate, or comply with the planned treatment or study procedures
• Use of products that have published anti-prostate cancer activity or are known to decrease PSA.

Age

• Another hematologic or solid tumor ≥ stage 1 malignancy that completed surgery, last dose of radiotherapy, or last dose of systemic anti-cancer therapy ≤ 2 years from first dose of study treatment. Participants who had curative therapy for localized malignancy are eligible

Other

• Untreated, symptomatic central nervous system (CNS) metastasis

• Histologically confirmed adenocarcinoma of the prostate without evidence of neuroendocrine differentiation, signet cell, or small cell features
• Participants must have ≥ 1 metastatic lesion that is present on magnetic resonance imaging (MRI), computed tomography (CT), or bone scan obtained ≤ 28 days prior to initiation of study treatment
• Tumor progression at study entry documented by PSA or imaging per PCWG3 criteria
• Received 1 prior ARAT for metastatic or non-metastatic, castrationsensitive or castration-resistant prostate cancer. A second ARAT regimen of < 60 days used as bridging to lutetium-177 is permitted.
• Availability of archival or formalin-fixed paraffin-embedded (FFPE) tumor tissue sample for participants with metastasis to internal organs
• Acceptable physical condition and laboratory value