An expert panel moderated by Sara Nunnery, MD, of Tennessee Oncology, convened to discuss the evolving endocrine treatment landscape for ESR1-mutated ER+/HER2-negative metastatic breast cancer. Dr. Nunnery was joined by Nan Chen, MD, of the University of Chicago; Irene Kang, MD, of the City of Hope; Pooja Advani, MBBS, MD, of the Mayo Clinic; and Fengting Yan, MD, PhD, of the Fred Hutchinson Cancer Center.
In the first segment of this roundtable series, the panel discusses the current treatment landscape, how it has evolved with new approvals and data, ongoing trials, and what might be on the horizon for patients with ESR1-mutated disease in the post-CDK4/6 inhibitor setting.
This transcript has been edited for clarity.
Dr. Nunnery: Hi, I’m Sarah Nunnery. I’m a breast medical oncologist at Tennessee Oncology in Nashville, Tennessee. I am with an incredible group of colleagues and breast oncologists here virtually today to talk about the current treatment landscape for metastatic hormone receptor-positive breast cancer, an area that is rapidly evolving every month. There are so many new options right now, and I’m really excited to chat with them and hear their perspectives. I would love to just start with introductions. And I’ll kick it over to Nan, if you want to introduce yourself first.
Dr. Chen: Hi. My name is Nan Chen. I’m a breast medical oncologist at the University of Chicago. I’m so happy to be here and really looking forward to the conversation.
Dr. Nunnery: Irene?
Dr. Kang: Hi, everyone. I’m Irene Kang. I’m at City of Hope in Orange County, Southern California. I’m also really looking forward to [discussing] such a timely topic.
Dr. Nunnery: And Pooja?
Dr. Advani: Hi, everyone. I’m a breast medical oncologist in Mayo Clinic in Florida and also serve as the director of a multidisciplinary practice here. I’m really excited to be in the midst of my colleagues and hear and learn from them.
Dr. Yan: My name is Fengting. I’m a breast oncologist at Fred Hutch. It’s very nice meeting everyone.
Dr. Nunnery: Great. Thank you so much for being here. I’m going to kick us off with just an open general question that I want to pose to each of you, and maybe we’ll just go around one at a time. I would love to hear–of all of the new data that we have seen come out in the last couple of years for metastatic hormone receptor-positive disease–is there a trial or data that you’re most excited about or that you have found has most impacted your clinical practice recently? I’ll start with Nan, I’ll kick it over to you first.
Dr. Chen: Yes, as you said, there’s really been so many changes in the last couple of years. If anything, the post-CDK4/6 world has gotten more complicated. The first one that comes to mind, and is probably just recency bias, but obviously gedatolisib very recently got approved in the PIK3CA wild-type population, both with fulvestrant with or without palbociclib. I think this is a really interesting drug because while it is a pan-pathway inhibitor, it does have activity in wild-type patients. Then secondly, of course, it’s with IV. I think it’s really interesting how this drug will be utilized, and I’m personally looking forward to finding the right patient population that this might be helpful for.
Dr. Nunnery: Absolutely. To have an option for patients who don’t have a PIK3CA mutation in that space is really exciting. What about Irene? Thoughts from you?
Dr. Kang: Yes. Just to pivot from Nan’s direction, I’m also just really excited about all the oral SERD combination data we have now: imlunestrant, abemaciclib, we have some elacestrant phase 2 data with various combinations, and then giredestrant with everolimus. We’re seeing really nice efficacy here in the progression-free survival world, upwards of nine months. Oral combinations, generally quite well tolerated, and really nice efficacy.
Dr. Nunnery: Absolutely. What about Pooja?
Dr. Advani: Yes, I think I agree with Irene. I’m excited that we have a menu of options for the post-CDK4/6 inhibitor, ESR1-mutated patient population. Then, more importantly, oral SERDs can be a really good backbone for other combinatorial agents, as Irene mentioned. We’ve already seen some of that data mature, particularly with NCCN [National Comprehensive Cancer Network] endorsement of the combination of imlunestrant and abemaciclib. I’ve personally used it in my clinical practice. I’m curious if others have used combination therapies. Although they’re not FDA approved, I do think that in the future we’ll probably be using certain monotherapy less and less and probably doing more of the combinations. I’m really excited about that.
Dr. Nunnery: Absolutely. And Fengting, what about you?
Dr. Yan: Of course, we participated with the gedatolisib [study], and I have been recommending it to a lot of my patients recently. It’s quite interesting how pan inhibitors behave differently from just the M2 and PIK3CA inhibitor. We are super excited. The only caveat would be hopefully we can have injections rather than infusions. Of course, weekly infusions, three weeks on, one week off can be still challenging for some patients. But overall, we have been super excited about it. We are running VIKTORIA-2 right now, so hopefully it can become one of the first-line options.
Dr. Nunnery: Amazing. And I couldn’t agree more.