Do I need 6th Pluvicto infusion? PSA undetectable for 6 months.

[LongTimeRunning]

I've been on the PSMAddition trial having had 5 of 6th infusions. PSA undetectable (<0.02) since June (it was 0.31 in early May when accepted into trial with relatively low burden PSMA-avid lesions).

Aug 4 CT/bone scans showed significant reductions in size and activity of lesions (prior to 3rd treatment). Oct scans showed smaller amounts of reductions in size and activity, but now only low grade activity in one area and very low grade activity in another area (prior to 5th treatment). Pluvicto could very well have helped, though ADT surely is playing a major role. Once the study data results get published out we can get a better idea of the relative contributions.

Overall I've tolerated the treatments well and platelets, neutrophils and other blood counts that take a minor to modest hit do bounce back afterwards, though not to pre-treatment levels.

Coming up to the 6th and final treatment, one of the docs is concerned about my borderline neutrophil counts (1.5) measured 1 week before the infusion and thought I should wait until they bounce back up before further treatment. Given the low PSA, good bone response and uncertainty regarding the effectiveness of a 6th Pluvicto treatment at this time, is the extra exposure to toxicity of the 6th infusion worth the opportunity (or uncertainty), however slight, to clean up as many bad cells as possible?

[Hidden]

Ask the trial Drs, set you up with growth factor, or prophylactic antibiotics.

I for one would find a way to complete the treatment cycle.

[LongTimeRunning in reply to Hidden]

We did touch on use of drugs to support white cell growth if necessary, but focused more on the benefits of postponing the next treatment vs not postponing it.

[Tall_Allen]

There is more toxicity if you have a smaller tumor load. It can damage your kidneys. Discuss risk/benefit with the trial investigator.

[LongTimeRunning in reply to Tall_Allen]

Yeah, I did talk about this with the nuclear medicine doc, especially whether or not its worth it do even do the 6th. Not a lot of solid data showing benefit of 5 vs 6 treatments, more like what happens after 1-2 or doing them all. He wasn't too worried about some of the common toxicity as I haven't reported dry mouth or other treatment symptoms, liver numbers good, and my GFR for kidneys > 100, etc., but he was concerned about the effect of treatment on the neutrophils.

I appreciated that he was more concerned about me as a patient rather than a trial participant and he felt waiting a few weeks to see if my neutrophils will recover would be reasonable and then maybe do an 80% dose. Trial doc was supportive after discussing with him, though whether or not an 80% dose as part of the trial can be done is a different issue.

....I just got back my local lab bloodwork and see that my neutrophils trended down for the 3rd week in a row to 1.3 (under the cut off) so it seems like his concerns were justified.

[TWTJr]

I had 5 infusions with PSA after the fifth <0.1. Before the sixth, my renal function collapsed, bone marrow collapsed, and I needed several months of transfusions, and am now on permanent dialysis due to radiation induced renal injury. PSA remains <0.1 but need dialysis 3x/week.

I would NOT take a sixth dose due to increasing risk/reward, if I were you.

[LongTimeRunning in reply to TWTJr]

Thanks for relaying this info. Really sorry to hear that this happened to you, though.

As Tall Allen mentioned to, the risk vs reward is something to take serious. I'm of the same mind as Terminal to just to plow through all the treatments and hit it hard (who said you need testosterone to be aggressive!), but need to seriously weight the cumulative effect of radiation. In my case, for all I know, in the 2 months since my last scans, the mets may be almost completely resolved anyway.

One thing that favours not doing another dose, at least immediately, is what happened to the 2.1 cm met on my L2 vertebrae (in short, I think it was the ADT at work).

The L2 was the biggest met found on my first scans and was one of the factors getting me into the screening for the trial. However, when I got my PSMA-scan as part of trial screening it wasn't expressing any PSMA (other mets were) and after 2 LU77 doses it was nearly completely resolved (according to bone scan interpretation) or considered resolved (according to CT scan interpretation). It's possible the LU77 helped, but given no PSMA expression in this area, it might be reasonable to assume that it was the ADT that was doing its job.

[TWTJr in reply to LongTimeRunning]

Good luck; one thing I have learned in my 24 years of war against PCA is there is no one right way or wrong way. Often it depends on what is available when you need it. Additionally, I will add that stereotactic radiation can be quite useful for focal lesions.

[PC-22]

Good day, I am also on the Addition trial. I have completed my 6th and final infusion mid August. So now I receive follow up scans on 12 week intervals. In fact I am scheduled for this Thursday so hoping for the best. I am glad that your trial doctor seems to be concerned about you as a patient and more than just a trial participant. I do not have that feeling about my doctor which concerns me.

Fortunately my blood counts have stayed within range the entire time, but going into the trial they all were on the high end or even slightly elevated. As of late September which was (week 6 of cycle 6) blood cells and platelets in range but most all of my white cell were toward the lower end of normal range.

You mentioned that you have had a reduction in size (And Activity). I don’t know how to read my scans but the notes I have received likewise indicates reduction in size of various lesions. If fact a few gone altogether I guess. But I don’t see anything that shows change in “Activity” for better or for worse. Please let know how I might find this information.

Anyway, it seems we are on a similar plane and thus I would like to follow you as I think you have greater understanding of CT and Bone scans than do I. I hope nothing but the best for you in your journey

[LongTimeRunning in reply to PC-22]

I hope your upcoming scans look good! Good luck!

I was told that I am "approved" for a 6th infusion if my white blood cells rebound, but I told them I will take this week off from blood draws, and see how I look next week and then the week after. Unless a really solid rebound I don't think I'll go in for the 6th.

There is some variation in how the scans are interpreted and written up. On request, the trial coordinator has been sending the me reports. Each time I get a CT scan, there is something new/incidental (non-cancerous) and sometimes differently worded that someone decides to include. Like mild calcification that finally led me to get on statins. They look at and compare the bone scan to the CT scan of the chest and the CT scan of the abdomen and pelvis for each date and over time. There are variations. Examples from my Oct scan:

CT abd/pelvis: "The faintly sclerotic lesion within the L2 vertebral body was stable."

CT of chest: "No evidence of thoracic metastasis." No mention of L2 on bone scan.

This is progress from the April scans: "A large sclerotic lesion was identified involving the L2 vertebral body" noted on both CT scans and bone scans.

I was sitting with the nuclear medicine doc and told him about a sclerotic lesion from 2019 seen on the CT scan that was mentioned on earlier 2023 CT scans that wasn't mentioned on the bone scan. He pulled up my bone scan and zoomed in out and around and said it was an non-cancerous "island" or something like that, of the type than anyone could have. This one wasn't mentioned on the Oct scans.

[PC-22 in reply to LongTimeRunning]

okay thank you for the details. I don’t know why but I don’t receive notifications or emails for this site any longer. I just decided to check. I really appreciate your information. Generally, when I get scans done, I get the reports the same day or perhaps the next. But this time I have not received clinical notes from any of them yet. I think the team was out on vacation this week or something. It’s not unusual for me to get a PA instead of my doctor, in fact I probably see the PA more than my MO. However, it’s always been the same PA. This week it was an entirely different PA. She is nice but since we did not have notes from my Bone or CT scans all we had available was labs. My Erythrocytes are a little low and my Lipase is a little high at 74 but other than that things appear okay so I guess I have to wait until next week to see if results from my scans are in the portal. It’s a bit of a shame though since I have to drive 500 miles to get to these appointments.

I really hope your blood counts start to get back in range. I’ve seen something about Nuelasta and a couple other drugs are supposed to help with that but I have no experience with these. I will continue to follow your progress as I wish nothing but the best for you.

[j-o-h-n]

Prostate cancer is so fucking complicated! Add 1 minus 2, Minus minus 1 and add 3. Oh to be a kid again and pitching for my baseball team....who knew?

Note: I wish to offer my apologies if I offended anyone regarding my so-called humor about "race" or "misogyny". To me, humor is boundless and since we entered this word crying, I thought it would be a good idea to exit laughing.

Good Luck, Good Health and Good Humor.

j-o-h-n Tuesday 12/19/2023 8:53 PM EST

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

The more humor the better...a crack or do about about doing math on lesions is needed every now and then....

[PC-22 in reply to j-o-h-n]

I too was a Pitcher in little league and in high school.

Hmmm🤔. Didn’t realize there was a potential connection between being a pitcher as a kid and advanced cancer as an adult. 😂🤣😎

[PC-22]

oops The last reply was intended to go to j-o-h-n.

[j-o-h-n in reply to PC-22]

Depends...... Southpaw?

Merry Right Handed Christmas.

Good Luck, Good Health and Good Humor.

j-o-h-n Sunday 12/24/2023 1:06 PM EST