Association Between Platinum-Free Interval and Subsequent Treatment for Patients With Recurrent Endometrial Cancer
In this video, Paulina Haight, MD, talks about her team's study where they sought to determine the association between platinum-free interval and the response to subsequent treatment for patients with recurrent endometrial cancer. Dr Haight discusses the four big conclusions that could be drawn from the study, including the patient response rates to repeat platinum vs lenvatinib/pembrolizumab, what is next for research on this topic, and what other physicians can take away from this study.
Additional Resource:
Haight PJ. Platinum-free interval and response to platinum retreatment or lenvatinib/pembrolizumab in patients with recurrent endometrial cancer. Poster presented at: The Society of Gynecologic Oncology (SGO) 2023 Annual Meeting on Women’s Cancer; March 16-18, 2024; San Diego, CA. Accessed March 7, 2024. www.sgo.org/events/annual-meeting/
For more SGO 2024 coverage, visit the Newsroom.
TRANSCRIPTION:
Paulina J. Haight, MD: I'm Polly Haight. I'm one of the gynecologic oncology fellows at The Ohio State University. And today I'm going to be talking about platinum-free interval and response to platinum retreatment versus lenvatinib/pembrolizumab in patients with recurrent endometrial cancer.
Consultant360: Please provide some background and an overview of your poster discussion at the SGO 2024 meeting titled, “Platinum-free interval and response to platinum retreatment or lenvatinib/pembrolizumab in patients with recurrent endometrial cancer.”
Dr Haight: So, platinum-free interval is defined as the time from the last platinum-based treatment until disease progression. And this is something that's really utilized for a lot of our patients with recurrent ovarian cancer because there have been a lot of studies that show that patients with a longer platinum-free interval will benefit the most from a platinum re-challenge. The significance of a platinum-free interval though, in endometrial cancer, is really unknown. So, we decided to determine the association between platinum-free interval and the response to subsequent treatment for patients with recurrent endometrial cancer.
And to do this, we used a large multi-institutional database that's called the Endometrial Cancer Molecularly Targeted Therapy Consortium that was initially started out of Duke under Dr Secord. And from that database, this was a retrospective subproject, so we included all patients with persistent or recurrent endometrial cancer who had received first line treatment with platinum-based chemotherapy. And then second-line treatment with a repeat platinum-based regimen versus lenvatinib/pembrolizumab. And we looked at the overall response rate to that second line of treatment and stratified by the platinum-free interval.
C360: How do the results of this study impact clinical practice?
Dr Haight: I think that you can really draw about four big conclusions from our study, and I think that the first thing is that those patients who had a longer platinum-free interval were more likely to be retreated with platinum. So, here we're really looking at sort of physician choice in terms of whether or not they decide to treat a patient with repeat platinum versus an alternative regimen. Patients that had a shorter platinum-free interval were just as likely to be retreated with a platinum versus lenvatinib/pembrolizumab. I think that the second conclusion you can draw from the study is that response rates to the second-line treatment were really similar regardless of the regimen that was chosen.
So, patients who received repeat platinum and patients who received lenvatinib/pembrolizumab had very similar response rates. It was 58% for platinum and 49% for lenvatinib/pembrolizumab. And I think really interestingly this was true despite the fact that the patients that were in the group that received lenvatinib/pembrolizumab had a significantly shorter platinum-free interval. It was 4.6 months versus almost 13 months for those patients that received repeat platinum. I think the third thing to draw from the study is that a longer platinum-free interval was associated with improved response to second line treatment. So, essentially that that longer platinum-free interval was prognostic. So patients who had a platinum-free interval that was more than 12 months had a response rate to second line treatment that was 68% versus 47% for those patients that had a platinum-free interval that was less than 12 months. And then I think most importantly, when we looked at any given platinum-free interval, the response rate did not differ between patients who received repeat platinum versus lenvatinib/pembrolizumab.
Dr Haight: So with inpatients with a short platinum-free interval or 12 months or less, response rates did not differ —they were 47 and 44 percent. When platinum-free interval was more than 12 months, again, response rates did not differ between repeat platinum and lenvatinib/pembrolizumab, it was 67 and 75 percent. So I think it's really interesting in light of recent advances in endometrial cancer that have ultimately impacted the treatment paradigms that includes results of some of our more recent clinical trials like RUBY and GY018. And we have a lot of decisions to make when we have a patient who comes to us with recurrent endometrial cancer in terms of deciding what that second treatment line should be.
And I think that results of the study really tell us that maybe it's not so much the decision that we make in terms of second-line treatment regimen for these patients, it might just be more of the fact that their platinum-free interval is going to be just generally prognostic for them. And so I think making sure that we treat patients on a case-by-case basis and considering toxicity profile and context of the individual is going be really important.
C360: What's next for research on this topic?
Dr Haight: In terms of what's next, we have a manuscript that's forthcoming. We're planning to expand our analysis a little bit instead of just looking at patients who got repeat platinum or patients who got lenvatinib/pembrolizumab as that second line treatment, we're going to expand to other second-line treatment regimens as well, so things like hormonal treatment or immunotherapy alone or other cytotoxic chemotherapies and see whether or not that plays a role in terms of response rates.
C360: What are the overall take-home messages from this study and then from our conversation today?
Dr Haight: I think the biggest take-home point is that a platinum-free interval and endometrial cancer seems to be prognostic, but maybe not necessarily predictive of response to a specific therapeutic regimen. And so I think treatment decisions shouldn't necessarily be driven by a platinum-free interval alone for our patients with recurrent endometrial cancer.
Thank you so much for listening and make sure to take a look at the rest of our content at SGO this weekend.