ASP1002 is a bispecific antibody designed to target advanced or metastatic cancers, including advanced prostate cancer. Bispecific antibodies are innovative therapeutic agents that can simultaneously bind to two different molecular targets, enhancing their potential efficacy in treating complex diseases such as cancer.

ASP1002 specifically targets:

1. Claudin 4 (CLDN4): A tight-junction protein that is frequently overexpressed in various cancers, including advanced prostate cancer.
2. CD137 (4-1BB): A co-stimulatory molecule that activates T cells, amplifying their response against tumor cells.

By engaging both CLDN4 on cancer cells and CD137 on T cells, ASP1002 is designed to stimulate a robust antitumor immune response. This dual-targeting mechanism aims to enhance the body’s ability to combat tumors that express CLDN4, such as those found in advanced prostate cancer.

Preclinical studies have demonstrated that ASP1002 activates T cells in the presence of CLDN4-expressing cancer cells, suggesting significant antitumor activity.

ASP1002 is currently being evaluated in a Phase 1 clinical trial. This study is an open-label, multicenter trial aimed at determining the safety, tolerability, and optimal dosing of ASP1002 in adult patients with locally advanced or metastatic solid tumors, including prostate cancer, expressing CLDN4.

CLDN4 is frequently overexpressed in prostate cancer cells compared to normal prostate cells. Studies have shown that metastatic prostate cancer cell lines, such as PC3, LNCaP, and DU145, exhibit higher levels of CLDN4 than benign prostate cells.

Additionally, immunohistochemistry analyses have confirmed increased CLDN4 expression in high-grade prostate cancer specimens compared to benign prostatic hyperplasia tissues.

Clinical trial.