In July, Prostatepedia is talking about advances in urology, radiation therapy, oncology and immunotherapy for prostate cancer.
Dr. Oliver Sartor, one of the leading researchers in advanced prostate cancer today, has the following to say about this month’s conversations.
Three of the biggest areas in prostate cancer right now are: 1) the use of the checkpoint inhibitor PD-1 to treat men with mismatch DNA repair defects, 2) the use of either PARP inhibitors or platinums to treat mismatch DNA repair defects, and 3) better imaging techniques.
Within the next year or two, we’ll be able to define a subset of patients who will benefit from the PD-1 inhibitors that Dr. Charles Drake discusses in his conversation on immunology. I anticipate that PD-1 inhibitors may be meaningful for around 10% of men.
The FDA recently approved Keytruda (pembrolizumab) for those with mismatch DNA repair mutations, which applies to a subset of prostate cancer patients. This story will be meaningful to watch as testing for these mutations becomes more prevalent.
As Dr. Daniel Petrylak alludes to, there are now a variety of rapidly moving clinical trials looking at the combination of three DNA repair defects—BRCA1, BRCA2, and ATM. Data to support the use of PARP inhibitors in men with this combination of repair defects is rapidly evolving. This practice remains unproven in prostate cancer, though, despite promising preliminary data published by Dr. Joaquin de Mateo in the New England Journal of Medicine in 2016. [See Prostatepedia June 2016 for a conversation with Dr. Mateo about his work.]
But I do want to make sure that Prostatepedia readers are aware that if you have metastatic prostate cancer and a DNA repair defect—like BRCA1, BRCA2, and ATM—there is some reasonable preliminary data to support using carboplatin. We have a manuscript at press right now that shows that if you have an inherited BRCA2 mutation, there is better activity if a carboplatin plus a taxane are administered as opposed to just giving you a taxane alone. Thus carboplatin appears to be an option for men with certain DNA repair alterations.
Advances in imaging are also discussed in several of the conversations that follow. PSMA imaging is moving quickly. Axumin (fluciclovine F18) is the new imaging technique on the block with FDA approval. I think that in using these newer imaging techniques we will be able to define oligometastatic disease groups more and more efficiently. The consequences will be less therapy that just sets patients up to fail and, hopefully, more therapy that, if targeted to those lesions, will have a meaningful effect.
Stay tuned: the prostate cancer field is evolving really fast right now. I believe some men with advanced disease will potentially have molecularly targeted therapies available to them within the next several years.