In this podcast, experts Hope S. Rugo, MD, FASCO; Fabrice André, MD, PhD; Nadia Harbeck, MD; and Heather McArthur, MD, MPH; discuss updates from the SERENA-6, evERA, PREcoopERA, and TRAK-ER trials of oral selective estrogen receptor degraders (SERDS) in patients with hormone receptor–positive/HER2-negative (HR+/HER2–) early, advanced, and metastatic breast cancer (MBC). These results were presented at European Society for Molecular Oncology (ESMO) Breast 2026.

Oncology Town Hall: Updates From Berlin: Oral SERDs in HR+/HER2– Metastatic Breast Cancer — What the Latest Data Really Tell Us

OncLive® On Air

# Full Transcript

**Podcast:** OncLive® On Air

## Participants

- **Hope Rugo** (OncLive On Air)
- **Fabrice André** (OncLive On Air)
- **Nadia Harbeck** (OncLive On Air)
- **Hedda MacArthur** (OncLive On Air)

## Transcript

Hello and welcome to this podcast focusing on oral SERDs data for hormone receptor positive HER2 negative breast cancer. In this episode, which includes excerpts from a recent educational symposium, Drs. Hope Rugo, Fabrice André, Nadia Harbeck, and Hedda MacArthur will discuss key trial updates from ESMO breast 2026. This activity is provided by PER and support for the

recorded by an educational grant from Stemline Therapeutics Inc. In the first segment, Drs. André and MacArthur present data from the Serena 6 and Avera studies, followed by a panel discussion. Dr. André, In the next five minutes, I'm going to summarize this presentation from Dr. Bida from ESMO breast. And the idea was to look at the molecular epidemiology of the emergence of ESL1

Dr. Bida from ESL1 mutation. So this is an ancillary study from Serena 6 trial. And here I highlight two points. First is on the top. In Serena 6, remember that patient could enter at any point during the first line, aromatase inhibitor plus CDK4-6 treatment, as long as they had received at least six months of treatment.

Dr. So this is an inclusion criteria. And then the patient were tested for the emergence of ESL1 mutation. Dr. And 548 patients presented an ESR1 mutation, an emergence of mutation among the 3,256 patients tested.

Dr. Before we move forward, just remember the ESR1 mutation are mutations occurring on the gene that code for the estrogen receptor alpha. Dr. There are several few hotspot mutations. And when there is the mutation, then the receptor, estrogen receptor, becomes activated without the need for estrogen.

Dr. So it created an activation of the estrogen receptor. So in this study, they detected the emergence of this mutation that mediate resistance before the disease is progressing on imaging. Dr. What are the key data of this presentation?

Dr. The first one is on the top. Cumulative incidence of ESL1 mutation continued to rise steadily over the time on aromatized inhibitor plus CDK4-6. Dr. It means that during the trial, during the screening process, at every time there is emergence of ESL1 mutation.

Dr. The possible implication is that if we do a testing of ESL1 mutation on the plasma, CTDNA, we have to do it through the whole first-line therapy. Dr. The second set of data is about the distribution and allelic frequency.

Dr. Interestingly, 18% of the patient randomized had more than one distinct ESL1 mutation detected. And 94% of patients had at least one of the four most common mutations. They are described on the left. Overall, it's 538, 537, 380. Also, why I'm giving these details, because, nowadays, we do mutagen sequencing.

It's important to remember that most of the mutations are in this form. And maybe we can discuss if there are other mutati...

Oncology Town Hall: Updates From Berlin: Oral SERDs in HR+/HER2– Metastatic Breast Cancer — What the Latest Data Really Tell Us

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Oncology Town Hall: Updates From Berlin: Oral SERDs in HR+/HER2– Metastatic Breast Cancer — What the Latest Data Really Tell Us

Transcript

Built for investment professionals

Every day you wait, your competitors are findingedge in conversations you're not hearing.

Every day you wait, your competitors are finding
edge in conversations you're not hearing.