Who should read this?
1. Importance of early tumor testing (somatic)
2. People with newly diagnosed metastatic hormone-sensitive prostate cancer whose tumour shows PTEN loss, and anyone being offered capivasertib as part of their treatment.
Which cancer is this about?
This study focused on metastatic hormone-sensitive prostate cancer (mHSPC) in people whose cancer has a molecular change called PTEN loss or deficiency.
Why this matters
PTEN is a gene that normally helps control cell growth. When PTEN is lost, cancer cells can activate another growth pathway (the PI3K/AKT pathway), allowing the cancer to keep growing even when testosterone signalling is blocked.
The aim of this approach is to block two pathways at the same time:
• androgen signalling (with hormone therapy and abiraterone), and
• the AKT pathway (with capivasertib).
Treatment studied
The trial compared:
• Capivasertib + abiraterone + prednisone/prednisolone + ADT
versus
• Placebo + abiraterone + prednisone/prednisolone + ADT
Results
Time to cancer progression on scans (radiographic progression-free survival):
Median 33.2 months with the capivasertib combination
vs 25.7 months with standard treatment alone
Hazard ratio 0.81 (95% CI 0.66–0.98)
This means the risk of cancer progression on scans was reduced by about 19% over time with the addition of capivasertib.
Overall survival
At the time of reporting, overall survival data were still immature:
Hazard ratio 0.90 (95% CI 0.71–1.15)
(approximately 26% of the planned survival data available; not statistically significant at that stage)
Side effects (what to expect)
People receiving capivasertib had higher rates of:
• diarrhoea
• skin rash
• higher blood sugar levels
These side effects were generally manageable but require regular monitoring.
Key takeaway
Test early for PTEN loss. Early tumour (somatic) testing at diagnosis can identify people who may benefit from treatment escalation.
For those with PTEN-deficient disease, adding capivasertib can extend cancer control on scans, but this needs to be balanced against higher rates of side effects and closer follow-up.