Tonymax reports on the PLATO Clinical Trial (Enzalutamide/Xtandi))

[tonymax]

PLATO is a 2 stage Clinical Trial with 500 patients (80% in Australia, rest in Finland, UK and USA).

 

On Stage1 everyone gets Enzalutamide (no placebo).  [Xtandi is the brand name for Enzalutamide]

 

Those continuing in Stage 2 are randomised: 50% of patients to Abiraterone plus placebo and 50% of patients to Abiraterone plus Enzalutamide.  Both arms in Stage 2 also get Prednisone to go with the Abiraterone.

 

Stage 2 is double blind so neither doctor or patient know which arm you are in.

 

Also in Stage 2 they do not do PSA tests but track the tumour with scans. That sounds a little scary! If I get twitchy, I may have to cheat – or just turn off the brain, lie back and think of England.

 

To qualify for Stage 2 you need to continue to meet the original general requirements for the trial.

 

The original changeover point from Stage 1 to Stage 2 was defined as a 25% increase in PSA over a 1 or 2 month period following the nadir (lowest point).

 

This has now been relaxed by adding a second additional requirement – growth in tumours or metastases as shown by CT or bone scan.

 

All men on the trial  had to have CT or bone scan visible tumours or metastases at the start of Stage 1.

 

My tumour was only discovered at PSA 70 just before start of Stage 1.  Given they now know where it is, they may be able to track its growth at lower PSA’s but the effect of adding this second requirement would likely give me more time on Stage 1 than originally which should be a positive – my tumour is probably currently invisible at PSA 13.

 

I have a Clinical Trial consultation every 4 weeks and, of course, I chat with the other guys in the waiting room – and they with me.

 

I started the trial in June 2014 – most guys started between Jan 2014 and June 2014.  Their PSA’s at start of the trial vary a lot – 30 to 500 on the guys I have talked to.

All seem to be getting a reasonable response but the details vary a lot – how fast it drops, how low it goes, how long it stays there etc etc.

 

I have not spoken to anyone yet who is on stage 2.

 

With the trial we are doing two sequences of PSA tests to monitor results:

 

1.Local pathology lab (Douglass)

Results 65 (June 14), 38, 25, 15, 20 (end Nov) and 13 (23 Dec)

 

2.Official trial pathology lab in Singapore

Singapore result end Nov was 14.

 

It looks like my PSA results are bottoming out in the 10-15 range and the local end Nov result is incorrect.

 

What side effects have I had from my treatment so far on the trial?  My main side effect from Lucrin over the last 11-12 years has been fatigue – in my case always there but manageable.

The only side effect I get from Enzalutamide is substantially increased fatigue – to the point of needing a doze most afternoons.

 

Talking to doctors and patients, substantially increased fatigue is the main Enzalutamide side effect for most men.

 

 

[alanbarlee]

Thanks Tony - great rundown.

 

It seems a little strange that the offending lymph node was only visible to CT scan when the PSA got up to 70.

 

My experience with lymph nodes was:

Post-RP (with PSA still 4.3), no enlarged nodes were visible via CT. 18 months later, at PSA 9.8, two enlarged (16 & 19 mm) nodes were visible. 18 months further on, the PET/CT identified 6 active nodes up to 22 mm, at PSA 24.8.

 

ADT was started 4 months later at PSA 33 (a bit high in retrospect). CT scanning 9 months later showed little change in size, but PSA had dropped to 3.2, indicating that metabolic activity had greatly reduced within a still enlarged group of nodes. 

 

9 months after that, PSA had dropped to 0.3, and the CT scan showed only one somewhat enlarged node (13 mm). 

 

A year later, little had changed - PSA 0.3 and node size 11 mm. 

 

4 years on, after a variety of medications including Zytiga, PET/CT was showing only one moderately active node, only slightly enlarged at 8 mm, with PSA at 2.1. Currently PSA is 0.5, possibly plateauing.

 

 

I present this history to give you a feel for PSA vs CT node size (at least in my experience).  Under treatment, there is also a clear delay between metastatic decline and node shrinkage while PSA is declining (although your’s has been dropping from a higher level and (perhaps as a consequence) at a slower rate than in my case.  I would expect the morphology of your PCa-affected nodes to appear relatively unchanged for a little while yet.  It’s good to know that you’ve got another possible option within the trial - and you still have yet another shot in the locker - that of stereotactic radiation to hit any problem nodes.

 

Best of luck with all this

[tonymax]

Yes Alan I agree about how long it took them to see my right pelvic lymph node tumour with the CT scan.

I suspect they were not looking hard enough which is rather irritating.

 

Getting on to the trial at PSA 30 instead of PSA 70 would have been nice.

 

However it was also complicated by the 8 week shutdown on recruitment here in Australia during Mar/Apr (because we were recruiting faster than the overseas sites) and the small drop in my PSA during May (against a general background of fast increase).

 

So I am generally reconciled that we may have done as well as possible – no way of knowing now anyway.