Dr. Allison Zibelli and Dr. Megan Kruse highlight the PALMIRA and LEONARDA-1 trials, a new standard of care in the treatment of hand-foot syndrome for patients receiving capecitabine, and other key breast cancer studies that will be featured at the 2023 ASCO Annual Meeting. TRANSCRIPT Dr. Allison Zibelli: Hello. I'm Dr. Allison Zibelli, your host for the ASCO Daily News Podcast. I'm an assistant professor of medicine and a breast medical oncologist at the Sidney Kimmel Cancer Center at Jefferson Health. My guest today is Dr. Megan Kruse, a breast medical oncologist at the Cleveland Clinic Taussig Cancer Institute. We'll be discussing key abstracts in breast cancer that will be featured at the 2023 ASCO Annual Meeting.   Our full disclosures are available in the show notes and disclosures of all guests on the podcast can be found on our transcript at asco.org/DNpod.   Megan, it's great to speak with you today.   Dr. Megan Kruse: Thank you for having me.  Dr. Allison Zibelli: Let's begin with Abstract 1001. This is the PALMIRA trial, a study of second-line endocrine therapy plus palbociclib in HER2-negative ER-positive patients. We all have patients who have progressed on a CDK4/6 inhibitor, and this trial investigated a possible treatment approach for these patients. What are your thoughts?  Dr. Megan Kruse: I think this is a really tough space to know what to do, so I'm glad that we're getting more data to help inform our treatment decisions here. And I think it's also really tough for patients to wrap their heads around letting a CDK4/6 inhibitor go when many of them have done so well with it in the first-line treatment setting. So, in this study, patients were randomized to either continue on with their CDK4/6 inhibitor in the second line, the palbociclib specifically, along with a different endocrine therapy versus just switching to a different endocrine therapy alone. And what I thought was interesting was that the progression-free survival for both arms of the study were actually pretty similar. But that if you look at six-month progression-free survival as a particular endpoint, there were more encouraging results in the patients that continued on with the maintenance palbociclib along with the alternate endocrine therapy compared to what they received in the first line. So, I think this leaves the door open for certain patients to maintain ongoing benefit from their first-line CDK4/6 inhibitor with a switch in the endocrine therapy in the second line.    The challenging thing is it's hard to know who these patients are. I didn't see anything yet in the abstract that would suggest a differential population where this approach would be more successful. But the authors do note that there are some additional biomarker analyses that are pending. So, I hope that we see some data there when the full abstract is presented to get a sense of who might be a good candidate for this approach within the hormone receptor-positive HER2-negative metastatic breast cancer population.  Dr. Allison Zibelli: Thank you for that, Megan. I am not alone in finding these patients very hard to treat once they progress on a CDK4/6 inhibitor because there really is no standard of care in this space. So, I'm hoping this will provide some additional guidance for this patient population.  Dr. Megan Kruse: Yeah, I agree. Absolutely. I think the patients in the second line are now very different biologically after they've received CDK4/6 inhibitor. So, knowing what to do in this space really challenges our historical standards of care and I think it's a big gap in knowledge.   Dr. Allison Zibelli: Next, let's talk about Abstract 1007. This was a study about fixed-dose capecitabine and metastatic breast cancer. We all know that the package insert dose for capecitabine is probably too high, and a lot of us have been tinkering with the dose and scheduling in the absence of good evidence for that approach. This study looked at the efficacy