For high-risk, PTEN-deficient metastatic prostate cancer, a proposed strategy to maximize benefit while minimizing toxicity is sequential intensification. Clinicians can administer a triplet of ADT, an ARPI, and docetaxel first, and only after the chemotherapy course is complete, add the AKT inhibitor capivasertib to avoid severe, overlapping toxicities.

The CAPITELLO-281 trial showed the AKT inhibitor capivasertib delayed disease progression in PTEN-deficient prostate cancer. However, without a demonstrated overall survival benefit yet, its path to becoming a new standard of care is uncertain. This highlights the growing debate over whether delaying progression is a sufficient endpoint to justify added toxicities when survival isn't improved.

Because PTEN loss is an early, truncal mutation in prostate cancer, clinicians should perform NGS testing on the first day a patient is seen. This proactive approach ensures that crucial biomarker information is not lost and is available to guide future treatment decisions, such as the use of an AKT inhibitor, should the disease progress.

In the CAPITELLO-281 trial, PTEN-deficient patients receiving standard-of-care abiraterone had a median time to progression of about two years. This is shorter than expected for the general population, prospectively validating PTEN deficiency as a biomarker for a more aggressive disease phenotype with poor outcomes.

The AKT pathway, activated by PTEN loss, drives cancer growth independently of the androgen receptor, which controls PSA production. This discordance means clinicians cannot rely on PSA alone and must use systematic imaging to detect progression in this specific patient subgroup.

Using capivasertib in the hormone-sensitive setting is preferred because the cancer is more likely dependent on the AKT pathway for growth. In later, castration-resistant stages, additional genetic alterations can emerge, creating redundant growth signals and potentially diminishing the inhibitor's efficacy.

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.

Exploratory analysis shows that while patients with 100% PTEN loss have a much worse natural history than those with 90% loss, the therapeutic effect of capivasertib is stable across this spectrum. The drug effectively targets the pathway regardless of the magnitude of loss, making it a robust option for this entire subgroup.

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.