Symptoms Related to Bone Metastasis in Men Receiving Lutetium-177 PSMA-617 for Prostate Cancer - Brian Gonzalez

March 29, 2022

Alicia Morgans is joined by Brian Gonzalez to discuss work he presented at GU ASCO 2022 on patient-reported quality of life metrics among men receiving prostate-specific membrane antigen (PSMA) radioligand therapy (RLT) for the treatment of metastatic castration-resistant prostate cancer (mCRPC). This study being discussed treated 50 patients, between 2015 to 2017,  with up to 4 cycles of 177Lu-PSMA-617 every 6 weeks. Patients completed a validated assessment of bone metastasis-related pain prior to each cycle and 6 or 12 weeks after the last cycle.  Dr. Gonzalez concluded that PSMA-RLT with 177Lu-PSMA resulted in improvements in bone metastasis-related symptoms. At follow-up, 38-42% of patients completing PRO assessment reported clinically meaningful improvements in bone metastasis-related pain, a significant contributor to quality of life.


Brian D. Gonzalez, Ph.D., Associate Member, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL

Alicia Morgans, MD, MPH, Genitourinary Medical Oncologist, Medical Director of Survivorship Program at Dana-Farber Cancer Institute, Boston, Massachusetts

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Alicia Morgans: Hi, my name is Alicia Morgans and I'm a GU Medical Oncologist at Dana-Farber Cancer Institute. I'm so excited to have here with me today, Dr. Brian Gonzalez, who's an associate member at Moffitt Cancer Center in Florida. Thank you so much for being here with me today.

Brian Gonzalez: Happy to do it.

Alicia Morgans: Wonderful. I wanted to talk with you a little bit about a presentation you gave at GU ASCO 2022, all back in person, really excited to be there with you and to see your poster on patients who had received lutetium PSMA treatment and report on the quality of life that those patients experienced during their treatment.

Brian Gonzalez: Yeah.

Alicia Morgans: Can you tell us a little bit about the project?

Brian Gonzalez: Certainly, yeah. It's part of a larger project looking at what are the impacts on patient reported outcomes and quality of life among patients receiving radionuclide therapy for prostate cancer. There are a lot of outcomes that these trials are asking these patients to assess, and the broader project is focused on, are we asking the right questions? Are there specific questions we might be targeting to patients receiving radionuclide therapy? And so as part of that Department of Defense-funded project, we're looking to develop a new measure for patients receiving radionuclide therapy.

But this project specifically was looking at a previous trial looking at patients receiving lutetium PSMA, a study led by Michael Hofman at Peter MacCallum Cancer Center in Australia. And in that study, patients reported on bone metastasis-related outcomes. We were fortunate to find that patients, on average, reported improved outcomes in bone metastasis pain and functional ability, despite the pain that they might be experiencing. And so we were excited to see that patients, on average, were reporting improvement in those outcomes.

And then we also looked at whether patients were reporting clinically significant improvement. So not just statistically significant improvement. And there we looked at, in this trial that patients reported on these outcomes every 4 weeks, but then again once after their fourth injection, we found that, on average, patients were reporting clinically significant improvement in over a third of patients were in this trial. And so we were excited to see that these drugs are having this kind of improvement in bone metastasis-related outcomes.

Alicia Morgans: That's so important, especially for patients with advanced disease as bone pain is probably one of the most feared complications that patients can experience from their cancer. When you say clinically significant, not just statistically significant, what do you mean, and how does that actually apply to patient care?

Brian Gonzalez: Sure. In patient reported outcome surveys, we'll ask patients to complete the survey and we'll score their responses and we'll come up with a score on a range of, let's say, 0 to 100. And whether a patient scored a 60 one day and a 59 the other day, that might be an improvement, but it's not really an impactful improvement in terms of their quality of life. They're not significantly better after that small improvement.

So what will happen is, researchers will look into what level of improvement, how big of a change on that survey do we need to see before you start to feel it as a patient? And so that's what we focused on. So that's been published in previous research on what level of improvement we need to see before it's clinically significantly impactful, noticeable by the patient. "I feel better than I did before. Maybe not great, but better than before." And so that's what we focused on, is that range of improvement. And over a third for the three outcomes that we focused on reported clinically significant improvement.

Alicia Morgans: As I said, I do think that's really, really important, particularly in this population. Were there other outcomes that you assessed that may or may not have been affected during treatment?

Brian Gonzalez: Sure. There were other outcomes that were assessed as part of that trial. They've been published before, so we were focusing us on, and we're the first to report on, bone metastasis-related outcomes in that project.

Alicia Morgans: Wonderful. So if you had to give a message to the research community, the clinical community, patients on where we need to go from here and how you think this information can really be integrated into clinical practice, what would that message be?

Brian Gonzalez: It would be that, although there were a significant drop off in the number of patients who were able to stay on trial for this project, those who were able to remain on this protocol did report significant improvement in bone metastasis-related outcomes. That's an important piece of information for patients to know as they're deciding whether to join trials or when these drugs become available as part of standard of care, whether that's worthwhile to them. And so it's important information for that shared decision making that should occur.

Alicia Morgans: Absolutely. And then the final piece I'd love to hear is just on the project that you are working on with your team, the Department of Defense-supported work, where you're trying to help us as clinicians understand which domains are actually the most important for patients who are receiving radioligand therapy so we can prospectively integrate those into our trials and as patients. Which domains are you thinking about?

Brian Gonzalez: Well, there are lots of domains. Many of them might be covered by existing measures, but some of them may not by traditional measures that are commonly used in prostate cancer literature. One of those includes dry mouth. That's commonly reported as a symptom in patients in these trials. There are others, too, that might be kind of surprising.

So in interviews with patients, as part of this project, we're learning that there are surprising issues that we hadn't thought of as perhaps inhibiting their quality of life. One of them is social functioning. So we find that patients are basically radioactive after these injections for a few days, and they're supposed to receive several of them. And so that impacts their ability to interact in the social environment with their spouses in their homes, and so there may be surprising outcomes that we should focus on as part of this measure.

Alicia Morgans: That's really interesting and I do have patients who have mentioned things like that. And certainly, these are things that if we put the proper supports in place, then we might improve patient's social functioning.

Brian Gonzalez: Certainly.

Alicia Morgans: But, really, if we don't measure it, we don't even know that it's an issue. So I commend you in the team and love the qualitative background work that you're doing to really ensure that you know how to best support these patients. So thank you so much for your time and your expertise. Thank you for reporting. Again, the first information we have on pain improvement, 30%. Really a big deal for these patients who are receiving this lutetium PSMA novel treatment. Thank you.

Brian Gonzalez: Indeed. Thank you.