As part of the European Society for Medical Oncology (ESMO) Congress 2025, CancerNetwork® spoke with a variety of experts about key takeaways from different late-breaking abstracts, oral presentations, and other sessions focused on potential advancements across cancer care. Presenting investigators highlighted updated results from clinical trials evaluating novel therapeutic strategies across different cancer populations, including breast cancer and lung cancer. 

Sara A. Hurvitz, MD, FACP, the Smith Family Endowed Chair in Women’s Health and senior vice president and director of the Clinical Research Division at the Fred Hutch Cancer Center, and tumor chair in breast oncology for the ONCOLOGY® editorial advisory board, first discussed findings from the phase 3 VIKTORIA-1 trial (NCT05501886). Her presentation highlighted how VIKTORIA-1 was “the first study to demonstrate a statistically significant and clinically meaningful improvement in progression-free survival [PFS] with PAM inhibition” for patients with PIK3CA wild-type advanced breast cancer.

Data from the trial showed that gedatolisib plus fulvestrant (Faslodex) and palbociclib (Ibrance) produced a median PFS of 9.3 months (95% CI, 7.2-16.6) vs 2.0 months (95% CI, 1.8-2.3) with fulvestrant alone (HR, 0.24; 95% CI, 0.17-0.35; P <.0001). Additionally, gedatolisib plus fulvestrant yielded a median PFS of 7.4 months (95% CI, 5.5-9.9), reducing the risk of progression or death by 67% vs fulvestrant monotherapy (HR, 0.33; 95% CI, 0.24-0.48; P <.0001).

Next, Xiuning Le, MD, PhD, spoke about her presentation on data from the phase 1/2 SOHO-01 trial (NCT05099172). In her presentation, Le, an associate professor in the Department of Thoracic/Head and Neck Medical Oncology of the Division of Internal Medicine at the University of Texas MD Anderson Cancer Center, described sevabertinib as a “potential new targeted therapy for patients with HER2-mutant non–small cell lung cancer [NSCLC].”

Among 81 patients with previously treated HER2-mutated advanced NSCLC who received sevabertinib in cohort D, the study treatment produced an overall response rate (ORR) of 64% (95% CI, 53%-75%) and a median duration of response (DOR) of 9.2 months (95% CI, 6.3-13.5). Among 55 patients who received prior HER2 antibody drug conjugates (ADCs) in cohort E, the ORR was 38% (95% CI, 25%-52%), and the median DOR was 8.5 months (95% CI, 5.6-16.4). Moreover, regarding 73 patients with treatment-naive disease in cohort F, these respective values were 71% (95% CI, 59%-81%) and 11.0 months (95% CI, 8.1-not evaluable).

Finally, Erica Mayer, MD, MPH, director of breast cancer research at Dana-Farber Cancer Institute and associate professor of Medicine at Harvard Medical School, detailed results from the phase 3 evERA trial (NCT05306340). In her presentation, Mayer stated that giredestrant plus everolimus (Afinitor) may “represent a new, effective, all-oral treatment option in the post-CDK 4/6 inhibitor setting” for those with estrogen receptor (ER)–positive, HER2-negative advanced breast cancer.

Across the intent-to-treat population, data revealed a median PFS of 8.77 months (95% CI, 6.60-9.59) with giredestrant plus everolimus vs 5.49 months (95% CI, 4.01-5.59) with standard endocrine therapy plus everolimus (HR, 0.56; 95% CI, 0.44-0.71; P <.0001). Among patients with ESR1-mutated disease, the median PFS was 9.99 months (95% CI, 8.08-12.94) vs 5.45 months (95% CI, 3.75-5.62) in each respective arm (HR, 0.38; 95% CI, 0.27-0.54; P <.0001).