A Phase 3 Study of JNJ-78278343 and Docetaxel Versus Docetaxel in Patients With Metastatic Castration-Resistant Prostate Cancer

The primary objective is to evaluate whether the administration of pasritamig in combination with docetaxel prolongs radiographic progression-free survival compared to docetaxel monotherapy in patients with metastatic castration-resistant prostate cancer. This investigation assesses the clinical benefit of a T-cell-redirecting agent targeting human kallikrein 2.

This clinical trial involves 629 male participants diagnosed with metastatic castration-resistant prostate cancer. The study population consists of individuals within specific age ranges who have demonstrated progressive disease, defined by increasing prostate-specific antigen levels or the emergence of new lesions in the lymph nodes, bones, or viscera. Eligible participants must have progressed following treatment with at least one androgen receptor pathway inhibitor but have received no more than two different agents. Selection requires specific hematologic parameters, including minimum thresholds for hemoglobin, neutrophils, and platelets. The use of transfusion or growth factors within 14 days prior to randomization is prohibited.

This Phase 3, randomized, open-label study is designed to evaluate the efficacy of pasritamig (JNJ-78278343) in combination with docetaxel compared to docetaxel monotherapy for the treatment of metastatic castration-resistant prostate cancer. The primary objective is to determine if the combination therapy prolongs radiographic progression-free survival (rPFS), which is assessed via CT, MRI, or bone scan based on RECIST v1.1 and PCWG3 criteria. The research methodology involves a screening period to confirm eligibility based on prostate-specific antigen (PSA) levels, disease progression, prior androgen receptor signaling pathway inhibitor (ARPI) use, and specific laboratory thresholds for hemoglobin, neutrophils, and platelets. Following randomization, participants receive either the test combination or the comparator regimen. The study is estimated to occur between April 2026 and October 2030.

JNJ-78278343 is an experimental T-cell-redirecting agent administered as a solution for injection/infusion via intravenous use.

Docetaxel is administered as a solution for infusion through intravenous use.

Prednisone is used as a comparator and is administered in tablet form via the oral route.

The primary efficacy endpoint is radiographic progression-free survival (rPFS). This is defined as the interval from randomization to the first occurrence of radiographic disease progression, death from any cause, or both.

Radiographic progression is determined according to the PCWG3 and RECIST v1.1 criteria. Assessment is performed via CT, MRI, or bone scan and is evaluated by an independent central radiographic review (BICR).