Two Experimental Prostate Cancer Treatments Discontinued: AZD9750 and AZD8359

Two experimental prostate cancer drug development programs have been discontinued, according to an October 30, 2026, pipeline update. The decision affects AZD9750, an androgen receptor (AR) degrader, and AZD8359, a STEAP2-targeted T-cell engager, both of which were undergoing early clinical investigation in metastatic prostate cancer.

AZD9750 was an oral AR degrader designed to eliminate the androgen receptor rather than simply block its signaling. Preclinical studies had demonstrated activity against mutated and amplified forms of AR associated with resistance to existing hormonal treatments. However, development was discontinued following an assessment of pharmacokinetic and pharmacodynamic data. The phase 1/2 ANDROMEDA trial (NCT07336446) had originally planned to enroll approximately 300 patients but stopped recruitment after enrolling only six. No detailed clinical efficacy results have been publicly reported.

AZD8359 used a different approach. This experimental T-cell engager targeted STEAP2, a protein expressed in prostate cancer, while preferentially recruiting CD8+ cytotoxic T cells. Preclinical experiments suggested that this design could preserve tumor-cell killing while reducing cytokine release compared with conventional T-cell engagers. The phase 1/2 CRIUS-1 trial (NCT07529717), which began in May 2026 and planned to enroll 42 patients, was affected by a strategic decision to discontinue the development program. No specific clinical safety or efficacy failure was publicly identified as the reason.

Importantly, discontinuation of a drug development program does not necessarily mean that its clinical trial has already been formally classified as terminated. At the time of this report, publicly available trial records still listed ANDROMEDA as active but not recruiting and CRIUS-1 as recruiting. Registry updates may follow the development decisions.

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