ASCO GU 2025: continuous ADT performs (slightly) better than intermittent ADT

[Maxone73]

But, who am I to say if a 15% difference is small or not?

A phase 3 analysis from the S9346 trial confirms that continuous ADT (CAD) is superior to intermittent ADT (IAD) in metastatic hormone-sensitive prostate cancer (mHSPC), even for patients with strong PSA responses.

Among 1,523 patients, those who achieved a complete PSA response (≤0.2 ng/mL) had a 43% lower risk of death compared to partial responders.

However, IAD was consistently linked to worse survival, with a 15% higher risk of death than CAD, regardless of PSA response or disease extent. These findings highlight that CAD remains the optimal treatment strategy, and IAD should not be considered a safe alternative for mHSPC.

prostatewarriors.com/2025/0...

[KocoPr]

Without reading the study i am betting there are way to many variables like cancer stage, mutations, timing of starting and stopping IADT in relation to PSA levels.

[GreenStreet]

Need to look into this more but not encouraging

[32Percenter]

Again and again they beat to death a 13 year-old study with a clear design flaw. In SWOG-9346 the iADT arm didn't end their vacation until PSA reached 10 or 20, "at the physician's discretion". A PSA of 10 or 20 is a LOT of cancer in most patients, and if you're waiting until a lot of cancer's present to restart ADT it's already gained a strong foothold, and has likely undergone unfavorable mutations. In short, the deck was stacked against the iADT group in SWOG-9346 thanks to the study's design. If you point this out in the other forum though, the resident expert will just shrug and tell you "It's the best info we have" rather than acknowledge this is a problem, and then tell you iADT is inferior.

Fortunately, the A-DREAM study and the EORTC 22389 "De-Escalate" trial are both underway with RESPONSIBLE parameters, and the prostate cancer world will soon be able to move on from the awful SWOG-9346 study.

[Maxone73 in reply to 32Percenter]

Fair point!