Would an intact PTEN but AKT1 mutation still suggest benefit with capivasertib?

Biologically plausible, yes, but not clinically established in prostate cancer. This is an important distinction.

Capivasertib inhibits AKT1/2/3, and activating AKT1 alterations can produce pathway dependence. Indeed, outside prostate cancer, capivasertib has demonstrated activity in tumors selected ...

I suspect this is true based on data largely from the breast cancer literature. Given that capivasertib is a pan-isoform AKT inhibitor, it is likely that clinical benefit will be observed in patients with AKT activating molecular alterations.

In the CAPItello-291 clinical trial (Turner et al., PMID 3...

AKT is downstream of PTEN. Capivasertib is a selective inhibitor of all three AKT isoforms (AKT1-3). It acts by binding to AKT and inhibiting the phosphorylation of downstream substrates.

Analysis of the NCI-MATCH precision medicine trial found that in patients harboring an AKT1 E17K mutation, capiva...