Orally Bioavailable Androgen Receptor Degrader, Potential Next-Generation Therapeutic for Enzalutamide-Resistant...

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Current androgen receptor (AR)-targeting drugs for prostate cancer are often inactivated by resistance mechanisms.
• There is a critical need for novel drugs with distinct mechanisms to treat castration-resistant and drug-resistant prostate cancers.

Purpose of the Study:

• To evaluate UT-34, a second-generation AR pan antagonist, as a potential next-generation prostate cancer therapeutic.
• To investigate the mechanism of action and efficacy of UT-34 in preclinical models of prostate cancer.

Main Methods:

• UT-34 was tested in AR binding and transactivation assays, and biophysical methods were used to study its binding to the AR AF-1 domain.
• In vitro and in vivo studies included Western blot, gene expression, proliferation assays, pharmacokinetic analysis, and xenograft studies in prostate cancer cell lines and animal models.
• The mechanism of AR degradation and potential off-target effects were assessed.

Main Results:

• UT-34 effectively inhibited wild-type and mutant ARs, and suppressed proliferation and growth in both enzalutamide-sensitive and -resistant prostate cancer models.
• UT-34 induced tumor regression in enzalutamide-resistant models, suggesting AR degradation is crucial for this effect.
• Mechanistically, UT-34 promotes a distinct AR conformation, leading to AR degradation via the ubiquitin proteasome pathway, with a good safety profile.

Conclusions:

• UT-34 demonstrates potent anti-cancer activity and a favorable safety profile in preclinical studies.
• UT-34 possesses the essential characteristics of a next-generation therapeutic agent for advanced prostate cancer.