Targeted Radionuclide Therapy?

[cfrees1]

I was diagnosed with ATM genetic defect, which is another DNA repair mutation much like BRCA-1/2 but up until now one that didn't respond to the treatments that have been effective with breast cancer patients (ie. parp inhibitors). This article is referring to targeted radionuclid therapy.

My question for you smart men out there, what do you know about this therapy. Should I be excited based on what this article suggests as a new therapy for my DNA repair defect? It certainly seems so, but I am not familar with this therapy at all, the side effects, the overall survival benefit etc. So if any of you can provide some more information, I would greatly appreciate it.

[GP24]

If you have a PSMA PET/CT done, you will see if you should try a Lu177 PSMA therapy. As the article says the gene test may just predict if a PSMA PET/CT will work.

[cfrees1 in reply to GP24]

As of now, the volume of cancer is too small to find with imaging, so I'm castrate resistant with no evidence of mets. But I do have small, but present PSA. So my interest in a treatment like this would be in lieu of full scale chemo in the future. If targeted radio therapy shows promise for people with DNA repair defects, perhaps that offers an alternative treatment path? That is my hope anyway.

[GP24 in reply to cfrees1]

The article does not mention a new therapy. If the test is positive it makes sense to have a PSMA PET/CT and maybe a PSMA therapy following that. Please read it again.

Today, more than half of the CRPC patients without mets on CT/bone scan will show mets on a PSMA PET/CT. So if you want to see where the mets are, which harbor the resistant cells, have a PSMA PET/CT.

[GP24 in reply to GP24]

I now learned that 98% of the nmCRPC patents show lesions on a PSMA PET/CT:

auajournals.org/doi/abs/10....

pbs.twimg.com/media/EDI78Cu...

[tango65 in reply to cfrees1]

Ga 68 PSMA PET/CT can detect metastases with very low PSA.

jnm.snmjournals.org/content...

(See figure 2, PSA and detection rate).

This is a list of clinical trials for Ga 68 PSMA PET/CT:

clinicaltrials.gov/ct2/resu...

If there were metastases treatment with Lu 177 PSMA or Ac 225 PSMA could be effective in your situation and control the cancer for a while. Based in the article, it is possible that you cancer expresses more PSMA because of the genetic defect and it could be more susceptible to the Lu 177 PSMA therapy.

This a list of Lu 177 PSMA clinical trials in the USA:

clinicaltrials.gov/ct2/resu...

[Tall_Allen]

If you put Lu 177 or Ac 225 in the search bar, you will find reports from several men who have had it.

[vandy69]

With an ATM defect you should be eligible for the PARP inhibitor, Lynparza. Dr. Charles “Snuffy” Myers prescribed it for me with that same genetic defect and it worked for about 9 months.

Best Wishes. Never Give In.

Mark, Atlanta

[cfrees1 in reply to vandy69]

Thanks, yes, Parp works great for BRCA 1/2 but not so great for ATM. That's why I was pleased to see that this discussion was just DNA Repair problems in general. Hopefully it is something that will work well. At the present time, apalutamide is working great so I'm not actively considering an alternative, but this looks like it might be a good match for me.