Pluvicto treatment failing??

[docbulldog]

I am 3 weeks away from my 3rd LU-177 treatment and am a bit concerned. My PSA when starting Pluvicto was 308 8/30/22 and climbed to 413 before a slight drop to 368 on 9/19/22(approx 4 weeks after 1st injection.

Today I received my lab results from 10/21/22 and PSA was at a shocking 545.

Is Pluvicto not working? What will be next?

I feel my PSA got way out of hand during 10 chemo treatments of Docetaxel which I started on 7/16/21 with PSA at 20.13 and completed 02/17/22 with PSA at 13.33. I then started Cabazitaxel 5/19/22 with PSA at 63. since then it climbed steadily..6/8..92...7/5..141..8/17..211..9/14..413 on up to current 10/21...545

I feel I will be dropped from Pluvicto treatment today during my tele-conference with the U of Washington and will be left hanging..

Any good suggestions?

[Tall_Allen]

Are you a candidate for Xofigo?

[docbulldog in reply to Tall_Allen]

I am scheduled for scans next week which will have a lot to do with determining if I continue with Pluvicto. I will meet with my local Onc after. I will bring up Xofigo. Thank you!

[RyderLake1]

Hello,

I read somewhere that for 20% of men who take the PSMA PET scan it shows no PSMA avidity. If that is the case, then they have one of the nastier forms of PCa (neuroendocrine or small cell) and Pluvicto (lutetium) is not going to work. I am surprised that wasn't picked up by your PET scan. You might want to ask that question. I agree with Tall Allen, time to try something else.

[docbulldog in reply to RyderLake1]

Thank you, my CT and bone scan next Monday should tell the story. Yes my local oncologist needs to get aggressive and find something new if I need to jump into that.

[RJ-MN]

My experience with Lu177 so far has been 3 dosings. When I started on June 22 my PSA was 148. #1 caused it to fall to 110. During #2's 6 weeks PSA rose to 128, and during #3's 6 weeks it has risen to 152. (Thus, -38, +18, +24.) Still, soft tissue mets have disappeared on scans and metastatic pain has ceased. Followup SPECT scans show a marked reduction in most index lesions' SUVs while other mets appear to grow. It's a mixed bag but seems to me worth continuing at this stage. However, I do not know if I will receive #4 tomorrow. So much depends upon the perspective/mood of the provider.

[Jasdog in reply to RJ-MN]

I think your results with Lu177 is what is expected from that treatment...disease regression. I can't recall seeing anything on it lowering the PSA number but I could be wrong!

[noahware in reply to RJ-MN]

We have to remember that all stage 4 treatments are essentially palliative, not curative. So if you had pain and the treatment is reducing pain, I would say that treatment is "working" almost by definition.

I never had any pain, but I was seeing similar results on scans as you: some old mets clearing, but brand new mets also appearing (now in the skull). The official word is my disease is "essentially stable" but numbers getting worse with every session except my first (just had my fifth).

Good luck to us!

[docbulldog]

Thank you, your reply’s are encouraging. I’m looking forward to upcoming scans and moving on to #3.

[lokibear0803]

My knee jerk is to consider having discordant disease, i.e. more FDG+ than desirable for PSMA-based therapy to work well. Regardless, if you wish to continue with RLT-based targeted therapy:

1– Sometimes patients change up to Ac-225 after Lu-177 fails to work; but this may have the same problem.

2– There is also Th-227, which if I understand correctly also uses PSMA affinity; regardless, as per TA, it decays into Ra-223 so serves that secondary benefit for bones. Again, this has the PSMA avidity question for you.

3– Also I know about copper-based diagnostic + therapy using Cu-64 + Cu-67 isotopes. Importantly, this does not depend on PSMA; it targets the gastrin-releasing peptide receptor (GRPr). I believe the imaging agent is referred to as Bombesin. So for disease that is not PSMA-avid, one can consider GRPr-avidity…I hope, anyway. This is one of my fallback cards to play:

urologytimes.com/view/fda-a...

Here is an interview with Oliver Sartor wrt targeting both PSMA-avid and GRPr-avid with Lu-177 (if I’m reading correctly):

urotoday.com/video-lectures...