The Palliative Benefits of Lutetium-177-PSMA

This interview is part three of a roundtable led by Dr. Daniel George, Professor of Medicine, and Surgery in the Duke Cancer Institute, featuring Dr. Oliver Sartor, Medical Director of the Tulane Cancer Center; Dr. Preston C. Sprenkle, urologic surgeon and a urologic oncologist at Yale University; and Dr. Rana McKay, GU medical oncologist at the University of California-San Diego.

In this segment, Dr. George asked Dr. McKay to discuss the palliative benefits of Lutetium-177 PSMA. Dr. McKay explained that, with respect to quality of life in end stage castration-resistant prostate cancer, patients receiving Lutetium have reduced symptom burden compared to those receiving only standard of care.

Dr. Daniel George:

Rana, I want to turn to you now on this, the second abstract, that really was looking at the use of these, these bone pain surveys and pain surveys in general to really assess the response of pain to Lutetium-177 PSMA from the VISION Study. And there was a nice abstract on that. Do you want to give us your takeaways in terms of its palliative benefits as well?

Dr. Rana R. McKay:

Yeah, absolutely. So I think, thinking about where these patients were along their disease course, these are pretty refractory patients. As we already heard, with regards to the eligibility criteria, they received prior taxanes, they’ve received AR inhibition. They were randomized to Lutetium with standard of care versus just a standard of care alone. And that standard of care really varied from the majority of patients were getting next generation AR targeted therapy, but also steroids or SBRT metastasis directed therapy, other palliative things that we may utilize in end stage CRPC.

I think quality of life assessments can sometimes be, not to say difficult, but there’s an art to it. And how you roll the quality of life surveys, which surveys you choose to do, the time points that you complete the surveys, who’s actually completing the surveys.

The particular endpoint that was looked at here was time to deterioration of symptoms, which was prolonged in patients receiving Lutetium compared to just the standard of care arm. And you would kind of hypothesize that, that is what you would see, because this is an effective life prolonging therapy and patients stayed on therapy longer and you would kind of hypothesize that yes, we would delay the time to deterioration of symptoms.

I think more data is needed regarding looking at are we actually making patients feel better and how dramatically are we doing that? And the other thing about quality of life is while things can be statistically significant, I think we need to understand, well is that clinically meaningful? What does it mean to have X grade change on a certain scale? How does that translate into what a patient may feel?

And then again, who’s completing these surveys? If there’s dropout towards the tail end of people being on therapy, then you’re not capturing that data. And generally it’s the people that are not feeling well that are not completing the survey.

I think we have to interpret these kinds of things with caution, but I think as we move the field forward, I think actually coming up with consensus guidelines around how to implement quality of life measures in the context of phase 3 trials and developing that in a very systematic manner, would probably be ideal, I think for the field as a whole.

Watch part four of the roundtable segment to hear Dr. Sartor’s honest take on Lutetium-177 PSMA as a treatment.

In additional segments, the panel discusses an overview of lutetium-177-PSMA and the VISION study, PSMA PET scans, the limitations and advantages of lutetium-177-PSMA, and additional PSMA therapies being studied.