Unlike bladder cancer, prostate cancer has highly effective androgen-pathway inhibitors (ARPIs) that extend survival. This success has pushed chemotherapy and, by extension, ADC development to later treatment lines as clinicians prioritize other novel mechanisms of action first.

The EMBARK trial showed that enzalutamide monotherapy was superior to standard ADT monotherapy for metastasis-free survival. This suggests potent AR antagonism may be a more effective strategy than simply depleting the testosterone ligand, challenging the long-held dogma of ADT being the fundamental building block for systemic prostate cancer therapy.

Beyond efficacy, new therapies like bispecifics require significant institutional support. Clinicians need training for unfamiliar side effects like CRS, and facilities need resources like observation units and admission protocols, creating a steep implementation curve for clinical practice.

After years of successfully intensifying hormonal therapy, the focus in prostate cancer is shifting toward de-intensification. Researchers are exploring intermittent therapy for top responders and developing non-hormonal approaches like radioligands to spare patients the chronic, life-altering side effects of permanent castration.

For antibody-drug conjugates (ADCs) to make a meaningful impact in prostate cancer, the clinical development bar is exceptionally high. Merely showing activity in late-line settings is insufficient; the true measure of success is demonstrating superiority over the established chemotherapy standard, docetaxel.

Despite the presence of PIK3CA mutations in some triple-negative breast cancer (TNBC) tumors, Phase III trials with AKT inhibitors have been negative. Currently, there is insufficient evidence to support using PI3K/AKT pathway inhibitors for TNBC in clinical practice.

Clinical trials combining potent ARPIs like abiraterone and enzalutamide have consistently failed. Once the androgen receptor pathway is maximally suppressed by one agent, adding another with a similar mechanism provides no further clinical advantage, much like hammering a nail that is already flush with the wood.

The panel suggests AKT inhibitor trials in prostate cancer have been disappointing due to suboptimal biomarker selection (e.g., PTEN IHC). A similar drug in breast cancer showed significant survival benefit when using a more precise NGS-based strategy, indicating a potential path forward if the right patient population is identified genetically.

Three 2025 trials (AMPLITUDE, PSMA-addition, CAPItello) introduced personalized therapy for metastatic hormone-sensitive prostate cancer. However, significant benefits were confined to narrow subgroups, like BRCA-mutated patients. This suggests future success depends on even more stringent patient selection, not broader application of targeted agents.