SABCS 2020: What's Hot, Including a Major Chemotherapy Trial

Plus: 'Vogl, New York' Has New Role

Nick Mulcahy

December 04, 2020

The "hottest" presentation at the upcoming 2020 San Antonio Breast Cancer Symposium (SABCS) comes from RxPONDER (abstract GS3-00), a major randomized clinical trial assessing use of a recurrence score among women with lymph node-positive, early-stage breast cancer to determine who might safely forgo chemotherapy.

That's the word from Virginia Kaklamani, MD, from the University of Texas Health Sciences Center San Antonio. Kaklamani, a professor of medicine in the Division of Hematology/Oncology, is co-director of the meeting that runs online December 8-11.

If the new trial sounds familiar, that's because it's a lot like the TAILORx trial, the results of which were first presented in 2018 and have changed practice in women with early-stage disease and no lymph node involvement.

"This is the lymph-node positive TAILORx. It's extremely important," Kaklamani told Medscape Medical News, adding that both trials involved women with HR-positive, HER2-negative disease.

If the RxPONDER trial, she explained, shows similar outcomes between women randomized to adjuvant endocrine therapy alone vs endocrine therapy plus chemotherapy, then clinicians "can potentially avoid giving chemotherapy to a large number of women who are currently receiving it."

Because women with nodal involvement (one to three positive axillary nodes) are at a higher risk of recurrence, RxPONDER may provide needed insight on the management of these types of breast cancers, Kaklamani suggested.

Both trials have used the 21-tumor gene expression assay (Oncotype Dx) to determine recurrence-risk status.

Kaklamani also spotlighted the phase 3 CONTESSA trial (abstract GS4-01) in 600+ patients with locally advanced or metastatic breast cancer that is HR-positive and HER2-negative and has been previously treated with a taxane.

The trial features an experimental oral taxane, tesetaxel. The primary objective is to compare the efficacy of tesetaxel plus a reduced dose of capecitabine (Xeloda) vs the approved dose of capecitabine alone. Presented data will include progression-free survival (PFS) results, indicating about a 3-month PFS advantage with tesetaxel, which is taken once every 3 weeks.

"Oral drugs are convenient for patients and, despite limitations, they are, all in all, a revolution in cancer treatment," noted Kaklamani, adding that they beneficially eliminate the need for time-consuming infusions and related clinic visits as well as drug ports. 

It will be interesting to see what Steven Vogl, MD, a private practitioner in the Bronx, New York City, has to say about CONTESSA and the rest of the SABCS.

He is usually a commentator from the meeting floor, whose self-introduction, "Vogl, New York," is well-known to perennial meeting attendees, as reported in a Medscape Medical News profile piece some years ago.

This year the medical oncologist will also serve as the chair of the "View from the Trenches" session, which is devoted to summarizing the meeting's most important findings for everyday practitioners.

A number of years ago, Vogl proposed the idea of this where-the-rubber-meets-the-road session to SABCS meeting planners, which they then adopted. This year, Kaklamani invited Vogl to run the session and he accepted.

Vogl is a "really smart guy who is always right on" with his comments and questions, and he will be the first-ever independent, community-based oncologist to chair a meeting session, said Kaklamani.

Other Hot Topics

Another hot topic featured at the meeting will be the use of CDK4/6 inhibitors in the adjuvant treatment of HR-positive and HER2-negative disease that has a high-risk of recurrence, Kaklamani said. New data from two trials, monarchE and PENELOPE-B, will be presented.

First, there will be an update from the monarchE trial (abstract GS1-01). The first results from this trial were reported in September at the ESMO Virtual Congress 2020 and featured abemaciclib (Verzenio). The positive outcome represented the first treatment improvement in this high-risk setting in more than 20 years, according to experts.

A similar trial, PENELOPE-B (abstract GS1-02), looks at palbociclib (Ibrance) in a somewhat different population — those patients with high relapse risk after neoadjuvant chemotherapy. "These are even higher risk ER+ patients [than those in monarchE], which is why they received chemotherapy before surgery," commented Kaklamani.

In triple negative disease, there will be additional efficacy endpoint data from the phase 3 KEYNOTE-355 study (abstract GS3-01) of pembrolizumab (Keytruda) vs placebo (plus chemotherapy for all patients) as first-line therapy for locally recurrent inoperable or metastatic triple-negative breast cancer.

A meta-analysis (abstract GS4-08) of data on circulating tumor cells (CTCs), which are shed from the primary tumor into the bloodstream, may point to their value as a tool to determine whether or not a breast cancer treatment is effective. "CTCs allow you to assess how a treatment is doing before you do scans, which typically occur 3 months or so later," explained Kaklamani.

CTC results can be assessed in 3 to 4 weeks and allow clinicians to change treatments if CTC volume increases. However, a previous study of CTCs did not show a clinical benefit with the tool among patients treated mainly with chemotherapies. What's different about the new study, which is from an international group of investigators, is in the treatments patients with metastatic breast cancer received. "This study is from a different era — with targeted therapies," said Kaklamani.

In the new study, changes in CTC levels (with a reduction being a good result) between baseline (pretreatment) and follow-up were analyzed to determine whether they were associated with overall survival.

COVID Sessions

On the meeting's first day, SABCS will feature a special session on COVID-19 and breast cancer. The meeting organizers sought to separate the wheat from the chaff in this subject, as much has already been written, published, or presented.

"We received a lot of abstracts on COVID that were studies that were poorly done. We tried to tease through them and select the well-researched ones," acknowledged Kaklamani.

The organizers included two patient advocates who have had COVID-19, including during treatment for breast cancer, as participants in the meeting session. The session will also feature global perspectives, with presenters from Brazil, Italy, and the Netherlands. 

Plenary Lectures

The meeting's two plenary lectures will focus, respectively, on the increasingly used clinical approach of neoadjuvant therapy in breast cancer, and research in the time of a pandemic.

Elizabeth Mittendorf, MD, PhD, a surgical oncologist and director of the Breast lmmuno-Oncology program and co-director of the Breast Cancer Clinical Research Program at the Dana-Farber/Brigham and Women's Cancer Center, Boston, will present "Local Regional Management Following Neoadjuvant Therapy: Minding the Knowledge Gaps."

Ned Sharpless, MD, director of the National Cancer Institute (NCI), will present "Advancing Cancer Research During Challenging Times."

Editor's note: An earlier version of this story inaccurately said that overall survival data will be part of the KEYNOTE-355 presentation (abstract GS3-01).

Kaklamani has disclosed consulting fees with Amgen, Eisai, Puma, Celldex, AstraZeneca, and Athenex; fees for non-CME services received directly from commercial interest or their agents from Pfizer, Celgene, Genentech, Genomic Health, Puma, Eisai, and Novartis; and contracted research with Eisai.

Nick Mulcahy is an award-winning senior journalist for Medscape. He previously freelanced for HealthDay, MedPageToday and has had bylines on WashingtonPost.com, MSNBC, and Yahoo. Email: nmulcahy@medscape.net and on Twitter: @MulcahyNick

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