OncLive Polls Highlight Top Votes on Anticipated Breast Cancer Abstracts at ESMO 2025

With the 2025 ESMO Congress kicking off on October 17, buzz around potentially practice-changing and practice-informing abstracts, late-breaking abstracts, and sessions is generating excitement among breast oncologists across social media platforms.

Ahead of the highly anticipated congress, OncLive® launched 2 informal polls on X and LinkedIn to identify the most exciting breast cancer–related abstracts.

What Were the X and LinkedIn Poll Results of the Top Breast Cancer Abstracts and Topics?

The first poll initiated on X and LinkedIn highlighted 4 breast cancer abstracts, including 291O: DESTINY-Breast11, LBA20: ASCENT-03, LBA13: monarchE, and LBA17: VIKTORIA-1, which garnered a total of 23 votes on X and 49 votes on LinkedIn. Of note, the most anticipated abstract of the 4 trials is the phase 3 DESTINY-Breast11 trial (NCT05113251), accumulating votes from 65.2% of respondents on X and 61% on LinkedIn. Of note, the trial evaluates the efficacy and safety of neoadjuvant fam-trastuzumab deruxtecan-nxki (Enhertu; T-DXd) for the treatment of patients with high-risk, HER2-positive early nonmetastatic breast cancer.1 Furthermore, the phase 3 monarchE trial (NCT03155997) landed second place in the X poll, receiving votes from 21.7% of respondents. The study is investigating the efficacy and safety of abemaciclib (Verzenio) for the treatment of patients with high-risk, node-positive, early-stage, hormone receptor (HR)–positive, HER2-negative breast cancer.2

On LinkedIn, however, the phase 3 ASCENT-03 trial (NCT05382299) earned second place (24%) in the poll. The study is assessing sacituzumab govitecan-hziy (Trodelvy) for the treatment of patients with previously untreated, locally advanced, inoperable or metastatic triple-negative breast cancer (TNBC).3 The remaining votes went to ASCENT-03 on X (8.7%), monarchE on LinkedIn (6%), and the phase 3 VIKTORIA-1 trial (NCT05501886; X, 4.3%; LinkedIn, 8%).

In a second poll, we asked breast cancer experts which topics they’re most excited to learn more about at the congress. Topics included antibody-drug conjugates (ADCs), CDK4/6 inhibitor approaches, targeted therapy, and early-stage management. With a slight variation of trends on X and LinkedIn, the topic that is generating the most buzz on both platforms is ADCs (X, 69.2%; LinkedIn, 72%). For X, this was followed by targeted therapy (15.4%), CDK4/6 inhibitors (7.7%), and early-stage management (7.7%). For LinkedIn, this was followed by CDK4/6 inhibitors (12%), targeted therapy (9%), and early-stage management (7%).

Read on for more information about the 4 highly anticipated trials presented at the 2025 ESMO Congress, along with session dates and times.

291O: DESTINY-Breast11: Neoadjuvant trastuzumab deruxtecan alone (T-DXd) or followed by paclitaxel + trastuzumab + pertuzumab (T-DXd-THP) vs SOC for high-risk HER2+ early breast cancer (eBC)

Session time: Saturday, October 18, 16:30-16:42

The DESTINY-Breast11 trial evaluated neoadjuvant trastuzumab deruxtecan followed by the combination of paclitaxel, trastuzumab (Herceptin), and pertuzumab (Perjeta; THP) for the treatment of patients with high-risk, locally advanced HER2-positive early-stage breast cancer. Patients were randomly assigned to receive either trastuzumab deruxtecan alone, trastuzumab deruxtecan followed by THP, or doxorubicin and cyclophosphamide followed by THP.1

High-level results from the study, published in May, revealed that neoadjuvant trastuzumab deruxtecan plus THP demonstrated a statistically significant and clinically meaningful improvement in the primary end point of pathologic complete response rate compared with standard of care (SOC), which consisted of dose-dense doxorubicin and cyclophosphamide followed by THP. The secondary end point of event-free survival was not mature at the time of the analysis, although an early positive trend favored trastuzumab deruxtecan plus THP vs SOC.4

LBA20: ASCENT-03: A randomized phase 3 study of sacituzumab govitecan (SG) vs chemotherapy (chemo) in patients (pts) with previously untreated advanced triple-negative breast cancer (TNBC) who are unable to receive PD-(L)1 inhibitors (PD-[L]1i)

Session time: Sunday, October 19, 9:15-9:25

The open-label ASCENT-03 trial investigates and compares the progression-free survival (PFS) between sacituzumab govitecan compared with physician’s choice of treatment in previously untreated patients with locally advanced, inoperable or metastatic TNBC.3 Notably, patients on the study are randomly assigned to receive either sacituzumab govitecan alone at 10 mg/kg on days 1 and 8 of a 21-day cycle, or physician’s choice of treatment, which consists of either paclitaxel at 90 mg/m2 on days 1, 8, and 15 of a 28-day cycle; nab-paclitaxel (Abraxane) at 100 mg/m2 on days 1, 8, and 15 of a 28-day cycle; or gemcitabine at 1000 mg/m2 plus carboplatin at area under the curve 2 on days 1 and 8 of a 21-day cycle. An update in May from Gilead, the developer of sacituzumab govitecan, demonstrated that the study met its primary end point of PFS.5

LBA13: monarchE: primary overall survival (OS) results of adjuvant abemaciclib + endocrine therapy (ET) for HR+, HER2-, high-risk early breast cancer (EBC).

Session time: Friday, October 17, 14:50-15:00

The phase 3 global monarchE trial is assessing adjuvant abemaciclib plus endocrine therapy for HR-positive, HER2-negative, high-risk early breast cancer. Patients on the trial (n = 5637) were randomly assigned to receive either abemaciclib at 150 mg plus endocrine therapy or endocrine therapy alone.2,6

Of note, data from a preplanned interim analysis of overall survival (OS) revealed that approximately 80% of patients who were followed for at least 4 years showed a benefit with adjuvant abemaciclib in terms of reducing the risk of developing invasive disease-free survival events (HR, 0.680; 95% CI, 0.599-0.772; nominal P < .001). Of note, the OS data in the intention-to-treat population were immature.

LBA17: Gedatolisib (geda) + fulvestrant ± palbociclib (palbo) vs fulvestrant in patients (pts) with HR+/HER2-/PIK3CA wild-type (WT) advanced breast cancer (ABC): first results from VIKTORIA-1

The phase 3, open-label, global, VIKTORIA-1 study evaluated gedatolisib plus fulvestrant (Faslodex) with or without palbociclib (Ibrance) for the treatment of patients with HR-positive/HER2-negative advanced breast cancer with PIK3CA wild-type. Patients on the study were randomly assigned 1:1:1 to 3 treatment arms.7 In arm A, patients received gedatolisib at 180 mg once weekly on days 1, 8, and 15 for 3-weeks-on/1-week-off, plus palbociclib at 125 mg daily for 21-days-on/7-days-off, with fulvestrant at 500 mg on days 1 and 15 of cycle 1 and then every 4 weeks. In arm B, patients were treated with gedatolisib at 180 mg once weekly on days 1, 8, and 15 for 3-weeks-on/1-week-off, plus fulvestrant at 500 mg on days 1 and 15 of cycle 1, then every 4 weeks. Patients in arm C received fulvestrant at 500 mg on days 1 and 15 of cycle 1, then every 4 weeks. Of note, the median PFS in arm A was 9.3 months (95% CI, 7.2-16.6) vs 2.0 months (95% CI, 1.8-2.3) in arm C (HR, 0.24; 95% CI, 0.17-0.35; P < .0001), and the median PFS in arm B was 7.4 months (95% CI, 5.5-9.9) vs 2.0 months in arm C (HR, 0.33; 95% CI, 0.24-0.48; P < .0001).

Want to learn more about why these abstracts are generating buzz? Check out this preview article featuring exclusive expert insights and visit our conference coverage page for real-time updates on these presentations and more throughout the meeting.

References

1. Trastuzumab deruxtecan (T-DXd) alone or in sequence with THP, versus standard treatment (ddAC-THP), in HER2-positive early breast cancer. ClinicalTrials.gov. Updated August 3, 2025. Accessed October 2, 2025. https://clinicaltrials.gov/study/NCT05113251
2. Endocrine therapy with or without abemaciclib (LY2835219) following surgery in participants with breast cancer (monarchE). ClinicalTrials.gov. Updated April 20, 2025. Accessed October 2, 2025. https://clinicaltrials.gov/study/NCT03155997
3. Study of sacituzumab govitecan-hziy versus treatment of physician’s choice in patients with previously untreated locally advanced inoperable or metastatic triple-negative breast cancer (ASCENT-03). ClinicalTrials.gov. Updated September 5, 2025. Accessed October 2, 2025. https://clinicaltrials.gov/study/NCT05382299
4. Enhertu followed by THP before surgery showed statistically significant and clinically meaningful improvement in pathologic complete response in patients with high-risk HER2-positive early-stage breast cancer in DESTINY-Breast11 phase III trial. News release. AstraZeneca. May 7, 2025. Accessed October 2, 2025. https://www.astrazeneca.com/media-centre/press-releases/2025/enhertu-improved-pcr-in-early-stage-breast-cancer.html
5. ASCENT-03: Trodelvy demonstrates highly statistically significant & clinically meaningful improvement in progression free survival in patients with first-line metastatic triple-negative breast cancer who are not candidates for checkpoint inhibitors. News release. Gilead. May 23, 2025. Accessed October 2, 2025. https://www.gilead.com/news/news-details/2025/ascent-03-trodelvy-demonstrates-highly-statistically-significant--clinically-meaningful-improvement-in-progression-free-survival-in-patients-with-first-line-metastatic-triple-negative-breast
6. Adjuvant abemaciclib plus endocrine therapy for hormone receptor–positive, human epidermal growth factor receptor–negative, high-risk early breast cancer: results from a preplanned monarchE overall survival interim analysis, including 5-year efficacy outcomes. J Clin Oncol. 2024;42(9):987-993. doi:10.1200/JCO.23.01994
7. Sullivan B, Gorbatchevsky I, Layman R, Mayer E. VIKTORIA-1 pivotal phase 3 topline results from PIK3CA wild-type cohort. Celcuity. July 28, 2025. Accessed October 2, 2025. https://ir.celcuity.com/wp-content/uploads/2025/07/Celcuity-Phase-3-VIKTORIA-1-Topline-Results.pdf