Daniel George, MD, Duke University School of Medicine, Duke Cancer Institute, Durham, NC, discusses real-world utilization of advanced therapies for patients with metastatic castrate-sensitive prostate cancer (CSPC) over time by metastatic site and age.

This study was presented at the virtual ESMO Congress 2021.

Transcript

I'm Dr Dan George. I'm a medical oncologist and Professor of Medicine and Surgery in the Divisions of Medical Oncology and Urology at Duke University Medical Center.

It is my pleasure to review for you our recently presented poster at ESMO 2021 entitled "Real-World Utilization of Advanced Therapies by Metastatic Site and Age Among Patients with Metastatic Castration-Sensitive Prostate Cancer (mCSPC): A Medicare Database Analysis." On behalf of my coauthors and our sponsor, Pfizer-Astellas, I'm happy to present this work.

We've recognized that the field of metastatic castrate-sensitive prostate cancer has significantly changed in the last 5 years, with the data demonstrating level-one evidence for improved survival, with the concomitant use of androgen deprivation therapy and docetaxel, as well as novel hormonal therapies.

We wanted to look through a large Medicare database population at the utilization of these therapies now, before, and after those approvals. We're able to look from a wide timeframe, from 2010 all the way to 2018, with some clinical follow-up on these patients regarding these approaches.

What we're able to recognize is through, again, large numbers of patients, that the majority of patients are being treated, still today, with androgen deprivation therapy alone. The androgen deprivation therapy alone, or with concomitant non-steroidal anti-androgens, or first-generation anti-androgens, has been a standard, and really was the uniform standard of care for management of these patients up through 2013.

Then beginning in 2014, with the press releases and data from the CHAARTED study demonstrating a clinical benefit of docetaxel, we begin to see the use of docetaxel chemotherapy occurring, and we saw that somewhere around 7%-8% of patients.

Then we saw actually a little bit of a dropoff of docetaxel from 2017 and 2018, when the next-generation hormonal therapies, such as abiraterone, demonstrated a clinical benefit and overall survival benefit in the same patient population.

In this analysis, we looked at two subgroups. We looked at the subgroup of patients with visceral bone or node-only metastasis, and then we looked at the subgroups by age, patients less than 75 and patients older than 75.

What we found was that, in patients with visceral disease or bone disease, they were more likely to have treatment intensification. Still, the majority of patients, even in 2017 and 2018, were being treated with androgen deprivation therapy alone, what by most guidelines we'd consider to be a suboptimal therapy.

There may be multiple reasons for that, and we don't have enough granularity in the Medicare database to necessarily say why. Some of these reasons, we speculate, might have to do with dissemination and education of this level-one evidence with cost and coverage in some of these settings, and patients' out-of-pocket costs, and then patient preferences as well.

I think it represents an opportunity to inform standard of care practice better across our Medicare population. Likewise, we saw, when we looked at age for patients under 75 vs patients over 75, there was greater treatment intensification, either docetaxel or novel hormonal agent, addition to androgen deprivation therapy for those patients under age 75.

We still see in this population, again, the majority of patients receiving androgen deprivation therapy alone, or with historical nonsteroidal anti-androgens, but not the novel hormonal therapies or docetaxel that our data would support.

We do see these trends improving slightly over the course of the treatment periods from 2014 to 2016 and 2017 and 2018, but we're still dealing with probably two-thirds of the patients receiving standard ADT alone who are under 75.

When we look at the population over 75, we see a much less use of treatment intensification, very little docetaxel use in that population, and there may be an age bias towards that. As well, there's less use of novel hormonal agents, although that's picked up by the 2017-2018 period.

I think going forward it'll be important for us to follow these trends further, to understand if there's a plateauing effect, or if there's delayed adoption of these pathways and guidelines into practice, or if there are other factors that are really interfering with the greater adoption of this treatment modalities into this first-line setting. With that, thank you for your attention.