bicalutamide no longer as effective?

[kreg001]

After more than two years of bicalutamide monotherapy and repeated PSA<0.1 I just received a 0.6. Before the bicalutamide my PSMA scan showed activity in only the seminal vesicle region. PSA was 2.5 at that time. Lupron had ceased being effective. Bicalutamide had a terrific response. I don’t think PSMA will be very reliable at a PSA of 0.6. I had the free Color DNA testing done and report states I have no genetic markers for PCa. I am a chemist. I guess my PCA had environmental origins.

Group mind: What next?

In the good news department I love my new knee.

[Tall_Allen]

Unfortunately, PCa eventually adapts to feed on bicalutamide. Sometimes, when it is withdrawn, PSA actually goes down. It's time for bigger guns.

[kreg001 in reply to Tall_Allen]

Thank you. Antagonist to agonist. Sneaky disease.

[Tall_Allen in reply to kreg001]

Bicalutamide isn't just an androgen antagonist, it's a very weak androgen antagonist. The cancer easily adapts to it.

[kreg001 in reply to Tall_Allen]

Thanks.

[Magnus1964]

Wait to see if you get more PSA rises. Then move on to zytiga.

[kreg001 in reply to Magnus1964]

Or firmagon?

[Justfor_]

For others reading this. My theory is that the Bicalutamide mechanism gets circumvented under excessive dosage. Minimum Effective Dose prolongs it's time to failure. Two years now, currently at 1/10 the standard dosage, PSA=0.016.Classic case of More is not better.

[kreg001 in reply to Justfor_]

My daily has been 10mg. Are you doing well on 2 mg daily?

[Justfor_ in reply to kreg001]

Well, it is 25mg/5days (equivalent to 5mg/day) and you can assess for yourself from here:

healthunlocked.com/prostate...

My main concern is NOT to drive into extinction the "friendly cells" (aka the hormone sensitive ones), hence, diving deep into undetectable PSA is to be avoided. Low Yes, undetectable No.

Also, this may be of interest to you:

healthunlocked.com/fight-pr...

Since you were too low (1/5 of standard dosage) why didn't you try to up it and see if PSA declines? My test would be ten days at standard dosage 50mg/day and PSA retest. If PSA doesn't drop to approx 50%, then you probably have failed this drug. Been there done that November last. Everything is documented in my first link.

[Positive22 in reply to Justfor_]

Intend to agree with your comments. My oncologist plan is to start out with min. doses and check every 3 months on effectiveness.

[Ian99]

I was on Bicalutamide for 7 years, less a 2 year vacation. Dosage was 150mg daily. Needed tamoxifen to counter SEs but it was tolerable. It did the job imo so I don’t question it now. Now on Zoladex since 2021.

[kreg001 in reply to Ian99]

Thank you.

[DennisDworak in reply to Ian99]

Some years ago I was also on bicalutamide mono therapy of 150 mg daily and it kept my PSA at 1 or less for 6 1/2 years. I was really glad to have those years. Only SE I had was I developed some amount of man boobs but they didn’t really bother me much. After that I went on Prednisone and Zytiga. Good Luck.

[Ian99 in reply to DennisDworak]

Interesting. Thanks for sharing. I am now on Zytiga and Prednisolone.. but also on Zoladex. Are you no longer taking an ADT ?

[Dynamo in reply to Ian99]

Hi Ian.. My Prednisone & Zytiga worked for about 2 years.. I have never been on any ADT as I was dead set against any of that stuff going in my body.. So I had an Orchiectomy in 2019 and don't regret it a bit.. But my PSA started going up on Zytiga so they gave me a PSMA scan and found just two spots on 2 pelvic lymph nodes.. So after a consult with a RO he said he could do SBRT.. So I had 5 sessions of SBRT this summer (easy peasy) and my PSA went down right away.. A month after it was done l was all the way down to 0.01 and it has stayed there now for 4 months so my MO & I are very happy with that... I am now in remission & hoping it stays that way.. BUT my MO insists that I stay on Prednisone & Zytiga maybe forever as I am tolerating it well..

And of course he won't let me get any testosterone replacement.. Damn.. But hey

I turned 80 now & feel pretty decent.. (some fatigue) I have battled this cancer since 1995 when I had my prostatectomy and am hoping I got a little break now.. I have gone thru 9 Docs in my 28 year history.. (they either retired or moved away and I had to fire one young incapable lady Onco..) But no Lupron in my body.. Sorry Good Luck..

[Ian99 in reply to Dynamo]

Well done. Good luck to you.

[MateoBeach]

Mechanism of bicalutamide failure is antagonist to agonist switching mutations. Poison becomes food for the AR. What to do now is stop the bical and recheck PSA in a few weeks. If it has gone down then that is what happened. Other ARSIs are much less susceptible to this form of failure, especially darolutamide.

[kreg001 in reply to MateoBeach]

Thank you.

[Positive22]

Just started on bicalutamide combined with Lupron Depot-6 month. My PSA is 1.5 trying to drive it lower but expect results will be short term . 1 tablet per day with no side-effects so far. Thankful.

[j-o-h-n]

My M.O. took me off Casodex and replaced it with Nubeqa.... (Still on Lupron) starting on March 3, 2023. PSA dropped from 1.26 to 0.80 as of November 8, 2023.

That is the lowest it has been since March 21, 2016 when it was 0.71. In the seven intervening years the highest my PSA was 8.33 on 12/05/2012.

So, as Paul Harvey would say "So that's the rest of the story".

Good Luck, Good Health and Good Humor.

j-o-h-n Sunday 12/03/2023 5:27 PM EST

[docbulldog in reply to j-o-h-n]

John, sure wish I was having your success with Nubeqa. PSA was 750 after 4 rounds of LU—177 , then dropped from program and went to a Docetaxel/carboplatin. But after four infusions, which are spread out over usually four weeks, my plateletcount was very low and so I had to drop that program , even though my PSA drop down to approximately 180.

I was able to start in Nubeqa three months ago but my most recent PSA count was at 224. So it appears to be a failure with that drug.

I see my oncologist tomorrow. Hopefully we have a another plan. I’m running out of options. I feel pretty good, don’t have pain, a little wobbly and weak for age 80 but have a good attitude.

I’ve been on Lupron and Xgeva since 2014. It seems like I had the best results with Xtandi 2019-2021 for about 2 1/2 years. Trying to convince my oncologist to go back and try Xtandi may be combined with a low-dose of Docetaxel.

???

[j-o-h-n in reply to docbulldog]

From the end of your post above:

I’ve been on Lupron and Xgeva since 2014. It seems like I had the best results with Xtandi 2019-2021 for about 2 1/2 years. Trying to convince my oncologist to go back and try Xtandi may be combined with a low-dose of Docetaxel.

Why not post your comment as a new POST to see what kind of feed back you'll get. Hopefully it's what you need, BEAT THE BASTARDS.

Good Luck, Good Health and Good Humor.

j-o-h-n Monday 12/04/2023 8:08 PM EST