Early Insights from ASCO 2025: Press Briefing Highlights with Clinical Impact

ASCO Press Briefing Recap

A press briefing held on May 21, 2025, spotlighted pivotal findings across breast cancer, diagnostics, and metabolic therapy in a preview of the data set to shape discussions at the 2025 ASCO Annual Meeting.

From the first overall survival (OS) benefit with a PI3K inhibitor in hormone receptor–positive/HER2-negative disease to the promise of artificial intelligence–assisted HER2 scoring and emerging real-world evidence linking GLP-1 agonists to reduced cancer risk, these early disclosures point to meaningful shifts in oncology practice.

Here’s a quick recap of the top takeaways to come out of the first press briefing of the meeting:

IMforte Trial: Lurbinectedin Plus Atezolizumab Improves Survival in ES-SCLC

Results from the phase 3 IMforte trial (NCT05091567) showed that maintenance treatment with lurbinectedin (Zepzelca) and atezolizumab (Tecentriq) significantly improved both progression-free survival (PFS) and overall survival (OS) compared with atezolizumab alone in extensive-stage small cell lung cancer (ES-SCLC).1 Median PFS more than doubled (5.4 vs 2.1 months), and OS increased to 13.2 months vs 10.6 months with monotherapy. Although adverse effects were more frequent with the combination, they were manageable, with low rates of treatment discontinuation. This marks the first phase 3 study to demonstrate both PFS and OS benefits for first-line maintenance in ES-SCLC, suggesting potential for a new standard of care. However, experts stressed that outcomes remain modest overall, underscoring the ongoing need for improved therapies in this aggressive disease.

INAVO120 Trial: Inavolisib Triplet Extends OS in PIK3CA-Mutant, HR+ Breast Cancer

Final OS results from the phase 3 INAVO120 trial (NCT04191499) showed that adding inavolisib (Itovebi) to palbociclib (Ibrance) and fulvestrant (Faslodex) significantly extended OS in patients with PIK3CA-mutant, hormone receptor–positive, HER2-negative, endocrine-resistant advanced breast cancer.2 Median OS was 34.0 months with inavolisib vs 27.0 months with placebo (HR, 0.67; P = .0190), marking the first time a PI3K pathway–targeted agent has demonstrated a survival benefit. The triplet also maintained its strong PFS benefit (17.2 months vs 7.3 months) and significantly delayed time to first chemotherapy (35.6 vs 12.6 months). Safety was manageable, with slightly higher rates of grade 3/4 adverse effects and low treatment-related discontinuation. These results support the FDA-approved use of inavolisib as a meaningful advance for this difficult-to-treat breast cancer subtype.

AI-Enhanced Training Boosts HER2 Scoring Accuracy Across Pathologists

Artificial intelligence (AI)–assisted training using the ComPath Academy platform significantly improved pathologists’ accuracy in HER2 immunohistochemistry (IHC) scoring, particularly for HER2-low and HER2-ultralow breast cancers.3 Among 1940 readings across 105 global pathologists, AI support raised overall scoring accuracy from 89.1% to 96.1% and increased concordance from 0.506 to 0.798. Sensitivity in identifying low-expression categories improved dramatically, reducing HER2-null misclassification by 2.24%—a meaningful shift that could expand patient access to HER2-targeted antibody-drug conjugates. ASCO President Robin Zon, MD, FASCO, FACP, emphasized the clinical impact of more accurate HER2 categorization, highlighting the potential for improved treatment access. Plans are underway to expand AI training globally and assess real-world clinical effects via a multicenter implementation study.

GLP-1 Agonists Linked to Modest Reduction in Obesity-Related Cancer Risk

GLP-1 receptor agonists were associated with a modest 7% reduction in obesity-related cancer incidence compared with DPP-4 inhibitors in patients with type 2 diabetes.4 The study, which analyzed over 170,000 patients, showed no increased cancer risk with GLP-1 agonists and identified reductions in colon and rectal cancer specifically. All-cause mortality was also slightly lower in the GLP-1 group, particularly among women. While the effect size was small and follow-up was short, researchers noted the findings expand the potential value of GLP-1–directed therapies beyond metabolic benefits. Further long-term research is needed to confirm durability and safety.

References

1. Paz-Ares L, Borghaei H, Liu SV, et al. Lurbinectedin (lurbi) + atezolizumab (atezo) as first-line (1L) maintenance treatment (tx) in patients (pts) with extensive-stage small cell lung cancer (ES-SCLC): primary results of the phase 3 IMforte trial. Presented at: 2025 ASCO Annual Meeting Pre-Briefing on Regular Abstracts. May 21, 2025. Abstract 8006.
2. Turner N, Im SA, Saura C, et al. INAVO120 phase III trial final overall survival (OS) analysis of first-line inavolisib (INAVO)/placebo (PBO) + palbociclib (PALBO) + fulvestrant (FULV) in patients (pts) with PIK3CA-mutated, hormone receptor-positive (HR+), HER2-negative (HER2–), endocrine-resistant advanced breast cancer (aBC). Presented at: 2025 ASCO Annual Meeting Pre-Briefing on Regular Abstracts. May 21, 2025. Abstract 1003.
3. De Brot, M, Mulder D, Shaaban A, et al. Use of artificial intelligence assistance software for HER2-low and HER2-ultralow IHC interpretation training to improve diagnostic accuracy of pathologists and expand patients’ eligibility for HER2-targeted treatment. Presented at: 2025 ASCO Annual Meeting Pre-Briefing on Regular Abstracts. May 21, 2025. Abstract 1014.
4. Mavromatis LA, Surapaneni A, Mehta S, et al. Glucagon-like peptide-1 receptor agonists and incidence of obesity-related cancer in adults with diabetes: a target-trial emulation study. Presented at: 2025 ASCO Annual Meeting Pre-Briefing on Regular Abstracts. May 21, 2025. Abstract 10507.