ESMO 2025 : A brief overview

ESMO 2025 Oncology Updates: Practice-Changing Clinical Trials and Treatment Guidelines

Author: DP’s Oncology Notes
Category: Congress Highlights | ESMO 2025
Published: December 28, 2025
Reading Time: 12 minutes

🎯 Executive Summary

The European Society for Medical Oncology (ESMO) Congress 2025, held in Berlin from October 17–21, concluded with record-breaking attendance of 37,000 participants and unprecedented momentum in cancer therapeutics. Through ongoing coverage via the ESMO Daily Reporter into December 2025, multiple pivotal trials have emerged that promise to reshape clinical practice across nearly every major cancer type.

This comprehensive update synthesizes the most significant findings in genitourinary, upper gastrointestinal, hepatobiliary, head and neck, and non-melanoma skin cancers, alongside transformative advances in immunotherapy resistance and patient outcomes.

💊 Genitourinary Cancers: A New Era of Perioperative Immunotherapy

The genitourinary oncology landscape has undergone seismic shifts at ESMO 2025, with groundbreaking trials establishing immunotherapy as the standard-of-care backbone across disease stages.

🔬 Muscle-Invasive Bladder Cancer: The KEYNOTE-905/EV-303 Breakthrough

Perhaps no trial has generated more anticipation than KEYNOTE-905/EV-303, which delivered a “dramatic and major clinical benefit” for patients with muscle-invasive bladder cancer (MIBC) who are ineligible for or have declined cisplatin-based chemotherapy—a historically underserved population.

The perioperative combination of enfortumab vedotin (Padcev), a nectin-4-targeted antibody-drug conjugate (ADC), with pembrolizumab (Keytruda), a PD-1 checkpoint inhibitor, when given before and after radical cystectomy, demonstrated:

• ✅ 60% reduction in event-free survival (EFS) events (HR 0.40; 95% CI 0.28–0.57; P<0.0001)

• ✅ 50% reduction in risk of death

• ✅ 57.1% pathologic complete response (pCR) versus 8.6% with surgery alone

• ✅ Manageable safety profile without increased surgical mortality

Clinical Impact: This represents the first and only systemic regimen to demonstrate a durable overall survival benefit exclusively in cisplatin-ineligible MIBC. The median EFS was not reached in the enfortumab vedotin arm versus 15.7 months in the control arm, fundamentally changing how oncologists approach this previously treatment-limited population.

📖 Read More:

• Merck Press Release

• OncoDaily KEYNOTE-905 Analysis

🧬 Non-Muscle-Invasive Bladder Cancer: The POTOMAC Trial

Demonstrating that immunotherapy benefits extend earlier in disease progression, the phase III POTOMAC trial enrolled 1,018 BCG-naive, high-risk non-muscle-invasive bladder cancer (NMIBC) patients from more than 120 sites across 12 countries.

The addition of durvalumab (Imfinzi), a PD-L1 checkpoint inhibitor, to bacillus Calmette-Guérin (BCG) induction and maintenance therapy achieved:

• ✅ 32% reduction in disease-free survival (DFS) event risk (HR 0.68; P=0.0154)

• ✅ Statistically significant and clinically relevant enhancement compared to BCG alone

• ✅ Manageable safety profile consistent with individual agent profiles

Clinical Pearl: This trial establishes durvalumab plus BCG as a potential new standard of care for BCG-naive, high-risk NMIBC patients, expanding the immunotherapy footprint to non-metastatic disease. The benefit was sustained throughout the follow-up period, with secondary analyses confirming that BCG maintenance (not induction alone) was critical to achieving the improvement.

📖 Read More: POTOMAC Trial Summary

🎯 Prostate Cancer: Precision in Progression

EMBARK Trial: ADT + Enzalutamide in Biochemical Recurrence

The EMBARK trial, an 11-year global study, confirmed that ADT plus enzalutamide (Xtandi) in men with biochemical recurrence and negative conventional imaging achieved a 41% reduction in the hazard of death with an absolute 9% overall survival improvement at eight years.

Practice-Changing: This represents the most apparent survival benefit in localized and biochemically recurrent prostate cancer management, establishing ADT plus enzalutamide as the preferred approach for this setting.

PSMAddition Trial: Lutetium-177-PSMA-617

In the metastatic arena, the PSMAddition trial demonstrated that adding lutetium-177-labeled PSMA-617 (vipivotide tetraxetan), a targeted radionuclide therapy, to standard androgen-deprivation therapy and an androgen receptor pathway inhibitor (ARPI) achieved:

• ✅ 28% reduction in progression risk for radiographic progression-free survival

• ✅ Median rPFS extending from 7.4 months to 17.6 months

• ✅ 63% reduction in risk of cancer returning, need for hormone therapy, or death

📖 Read More: Post-ESMO GU Highlights

📊 Key Trials Summary Table

Cancer Type	Trial	Intervention	Key Result	HR/Benefit
Bladder (MIBC)	KEYNOTE-905	EV + Pembrolizumab perioperative	57.1% pCR vs 8.6%	HR 0.40 (EFS)
Bladder (NMIBC)	POTOMAC	Durvalumab + BCG	DFS benefit	HR 0.68
Prostate (BCR)	EMBARK	ADT + Enzalutamide	9% OS gain at 8 years	HR 0.59
Prostate (mHSPC)	PSMAddition	Lu-PSMA-617 + ADT/ARPI	Median rPFS 17.6 vs 7.4 mo	28% risk reduction
Gastric/GEJ	FORTITUDE-101	Bemarituzumab + mFOLFOX6	OS improvement (FGFR2b+)	Biomarker-driven
Gastric/GEJ	EDGE-Gastric	Domvanalimab + Zimberelimab + FOLFOX	Median OS 26.7 mo	62-69% ORR
HCC	ABC-HCC	Atezo + Bev vs TACE	mTTFS 14.6 vs 9.5 mo	HR 0.55
iCCA	LBA11	Toripalimab + Lenvatinib + GEMOX	mEFS 18.0 vs 8.7 mo	HR 0.59
HNSCC	EV-202	EV + Pembrolizumab	39% ORR, 9.8% CR	Rapid response
CSCC	C-POST	Adjuvant Cemiplimab	68% recurrence reduction	HR 0.32

🍽️ Upper Gastrointestinal Cancers: Integration of Targeted and Immunotherapy Strategies

🎯 Gastric and Gastroesophageal Junction Cancer

FORTITUDE-101: FGFR2b-Targeted Precision Medicine

The FORTITUDE-101 trial demonstrated that the first-in-class anti-FGFR2b antibody bemarituzumab, when added to mFOLFOX6 chemotherapy, significantly improved overall survival in patients with FGFR2b-overexpressing (≥10% tumor cell staining) unresectable, locally advanced, or metastatic gastric or gastroesophageal junction (GEJ) cancer.

Key Takeaway: This result validates the biomarker-driven precision medicine approach, wherein molecular profiling directs targeted therapies to patient populations most likely to benefit.

EDGE-Gastric: Dual PD-1/TIGIT Blockade

The EDGE-Gastric trial (Arm A1) presented a 26-month update with first overall survival results from the dual PD-1/TIGIT blockade strategy. Domvanalimab (anti-TIGIT) plus zimberelimab (anti-PD-1) combined with FOLFOX achieved:

• ✅ Median overall survival of 26.7 months and median PFS of 12.9 months

• ✅ 62% ORR in PD-L1-positive patients (TAP ≥1%)

• ✅ 69% ORR in PD-L1-high patients (TAP ≥5%)

Clinical Significance: These findings underscore dual immune checkpoint blockade as a promising next-generation immunotherapy strategy with durable, sustained responses extending well beyond two years in advanced gastric, GEJ, and esophageal adenocarcinoma.

📖 Read More:

• EDGE-Gastric Study Details

• ESMO Daily Reporter: Upper GI Cancer Updates

🔄 Perioperative D-FLOT: New FDA-Approved Standard

Perioperative FLOT chemotherapy (fluorouracil, leucovorin, oxaliplatin, docetaxel) remains the cornerstone for locally advanced, resectable gastric and GEJ cancers. However, the addition of durvalumab (Imfinzi) to this regimen, establishing D-FLOT as a new therapeutic standard, has achieved recent FDA approval with significantly improved survival and pathological response rates.

🏥 Hepatobiliary Cancers: Expanding Systemic Options Across the Disease Continuum

🔬 Hepatocellular Carcinoma: Challenging the Locoregional Paradigm

ABC-HCC Trial: Atezolizumab + Bevacizumab vs TACE

The landmark ABC-HCC phase IIIb trial compared atezolizumab plus bevacizumab (immunotherapy-based systemic therapy) with transarterial chemoembolization (TACE), the traditional standard of care, in patients with intermediate-stage HCC not amenable to curative surgery or ablation.

First interim analysis (168 patients):

• ✅ Median time to failure of treatment strategy: 14.6 months with atezo + bev versus 9.5 months with TACE (HR 0.55; 95% CI 0.36–0.83; P=0.0043)

• ✅ No toxicity-associated treatment discontinuations (8% vs 0% with TACE)

Practice-Changing Impact: This “potentially practice-changing” finding offers a systemic immunotherapy alternative for patients with TACE-related contraindications—including extensive bilobar tumor load, decompensated liver disease, and severe comorbidities—who would otherwise have severely limited options.

CARES-009: Perioperative IO Strategy

Parallel perioperative data from the CARES-009 trial (China-specific population with 80% hepatitis B virus prevalence) showed that camrelizumab (anti-PD-1) plus rivoceranib (selective VEGFR2 inhibitor) achieved:

• ✅ 42.1-month median event-free survival versus 19.4 months with surgery alone (HR 0.59; P=0.004)

• ✅ 35.1% major pathological response rate versus 7.5% with surgery

📖 Read More: ESMO Daily: Liver Cancer Immunotherapy

🧪 Intrahepatic Cholangiocarcinoma: The Neoadjuvant Window

Encouraging neoadjuvant data emerged for resectable, high-risk intrahepatic cholangiocarcinoma (iCCA) using the “GOLP” regimen (gemcitabine, oxaliplatin, lenvatinib, and anti-PD-1 toripalimab):

• ✅ 18.0-month median event-free survival versus 8.7 months with surgery alone

• ✅ Manageable toxicity (26% grade ≥3)

Emerging Strategy: While this patient population remains predominantly Asian, the data validate systemic neoadjuvant chemotherapy plus immunotherapy strategies in resectable iCCA—an area of significant unmet need awaiting confirmation in Western cohorts.

📖 Read More: Progress in Liver and Bile Duct Cancer

🗣️ Head and Neck Squamous Cell Carcinoma: The Bispecific Antibody Revolution

🔬 Rybrevant (Afamitresgene Derufeucan): Phase Ib/II Success

Johnson & Johnson’s bispecific antibody Rybrevant (afamitresgene derufeucan), targeting both EGFR and MET, demonstrated promising Phase Ib/II efficacy in HPV-negative head and neck squamous cell carcinoma (HNSCC):

• ✅ Progression-free survival and overall response rates higher than drugs currently available

• ✅ Superior duration of response

• ✅ Progressing to phase III (OrigAMI-5) with pembrolizumab + platinum chemotherapy

💉 Enfortumab Vedotin Plus Pembrolizumab: ADC + ICI Combination

The EV-202 trial cohort focusing on recurrent or metastatic HNSCC with PD-L1 combined positive score (CPS) ≥1 achieved:

• ✅ 39% overall response rate (95% CI 24.2%–55.5%)

• ✅ 9.8% complete response rate and 29.3% partial response rate

• ✅ Rapid responses (median 6.4 weeks to first response)

• ✅ Durable benefit with manageable toxicity

Clinical Impact: This regimen offers a meaningful option for the previously treatment-limited population of recurrent or metastatic HNSCC patients, an area of significant unmet clinical need.

🎯 Amivantamab: Overcoming Checkpoint Inhibitor Resistance

In patients with HPV-unrelated recurrent or metastatic HNSCC who had progressed on prior checkpoint inhibitor and platinum-based chemotherapy, subcutaneous amivantamab (EGFR/MET bispecific antibody) monotherapy every 3 weeks demonstrated:

• ✅ 45% overall response rate

• ✅ Rapid responses (6.4 weeks median to first response)

• ✅ Durable responses (7.2-month median duration)

• ✅ 6.8-month median progression-free survival

• ✅ Median overall survival not reached

📖 Read More: Amivantamab HNSCC Data

🌟 Non-Melanoma Skin Cancers: The Adjuvant Immunotherapy Paradigm

🏆 Cutaneous Squamous Cell Carcinoma: C-POST Trial and FDA Approval

The phase III C-POST trial represents a watershed moment in non-melanoma skin cancer therapy. In 415 high-risk cutaneous squamous cell carcinoma (CSCC) patients, adjuvant cemiplimab (Libtayo), a PD-1 inhibitor, following surgery and radiotherapy achieved:

• ✅ 68% reduction in recurrence or death risk (HR 0.32; 95% CI 0.20–0.51; P<0.001)

• ✅ 24-month disease-free survival: 87.1% with cemiplimab versus 64.1% with placebo

• ✅ Median DFS not reached in the cemiplimab arm (49.4 months in placebo)

• ✅ Benefit consistent across biomarker subgroups (PD-L1 TPS ≥1% and <1%)

• ✅ Preserved quality of life (EORTC QLQ-C30)

FDA Approval: This dramatic 69% risk reduction resulted in FDA approval on October 8, 2025, establishing cemiplimab as the first and only immunotherapy approved in the adjuvant setting for CSCC.

High-risk disease criteria:

• Extracapsular extension with lymph node involvement (≥20 mm)

• Perineural invasion of named nerves

• In-transit metastases

• T4 primary tumors with bone invasion

• Local recurrence with additional adverse features

📖 Read More: FDA Approval Details

🧬 Immunotherapy Breakthroughs: Overcoming Checkpoint Inhibitor Resistance

The field of acquired ICI resistance has become a major research focus, with several novel strategies emerging that show remarkable clinical benefit in heavily pre-treated populations.

🔬 GDF-15 Blockade: Overcoming Acquired Resistance

The GDFATHER-01 trial, a first-in-human Phase I/IIa study, investigated visugromab, a neutralizing anti-GDF-15 antibody, combined with nivolumab in patients with advanced cancers refractory to prior anti-PD-(L)1 therapy.

Long-term follow-up (77 heavily pre-treated patients with NSCLC, UC, HCC):

• ✅ 61.5% complete responses or complete metabolic responses

• ✅ Median duration of response: 32.2 months (NSCLC), 28.8 months (UC), 19.4 months (HCC)

• ✅ Response levels deeper than initial approved ICI treatment regimens

• ✅ 61.5% of responses still ongoing, indicating sustained durability

Breakthrough Finding: These results, published in Nature, represent a conceptual breakthrough in resensitizing tumors to immune attack through blockade of GDF-15, a critical resistance factor in acquired checkpoint inhibitor refractoriness.

🧪 mRNA Immunotherapy: PD-L1 and IDO1 Dual Targeting

mRNA-4359, an mRNA-based therapy encoding PD-L1 and IDO1 antigens to elicit T-cell responses against tumor and immunosuppressive cells, combined with pembrolizumab, demonstrated encouraging results in checkpoint inhibitor-resistant/refractory melanoma.

Heavily pre-treated cohort (median 3 prior ICI lines, up to 8 lines):

• ✅ 24% overall response rate

• ✅ 60% disease control rate

• ✅ All responders had pre-treatment PD-L1 tumor proportion score ≥1%

• ✅ Remarkably good safety profile: mostly grade 1–2 adverse events

• ✅ Median duration of response not yet reached (median follow-up 19.9 weeks)

🎯 VISTA Blockade: Emerging Data

Solnerstotug, a selective anti-VISTA antibody, combined with cemiplimab in patients with advanced solid tumors resistant to prior PD-(L)1 therapy, showed:

• ✅ 14% overall response rate (5 of 35 patients)

• ✅ Responses across multiple tumor types: Merkel cell carcinoma, MSI-high colorectal cancer, head and neck cancer, and esophageal cancer

• ✅ Rare, low-grade cytokine release syndrome: safe profile

📖 Read More: ESMO Daily: Novel ICI Resistance Strategies

📋 Emerging Treatment Algorithm Shifts and Clinical Practice Implications

🔄 Perioperative Immunotherapy Expansion

Historically, immunotherapy was reserved for advanced, metastatic disease. ESMO 2025 has definitively demonstrated that perioperative (neoadjuvant and adjuvant) immunotherapy benefits extend to:

• Muscle-invasive bladder cancer

• Gastric and esophageal cancers

• Hepatocellular carcinoma

• Cutaneous squamous cell carcinoma

Action Item: Oncologists must now routinely evaluate patients for perioperative immunotherapy eligibility and timing.

🧬 Biomarker-Driven Precision Oncology

FORTITUDE-101 (FGFR2b in gastric cancer) and emerging DKK1 biomarker strategies underscore that:

• Single-agent development has largely plateaued

• Future approvals will increasingly depend on companion diagnostic validation

• Molecular profiling is becoming a standard-of-care prerequisite for treatment planning

🎯 Dual Checkpoint and Beyond

EDGE-Gastric’s durability with dual PD-1/TIGIT blockade and emerging VISTA and GDF-15 data suggest the field is moving toward:

• Rationally designed, mechanistically complementary combinations

• Rather than empirical multi-drug regimens

💊 ADC Evolution and Non-Cross-Resistant Payloads

While topoisomerase I inhibitor-based ADCs continue to deliver, novel eribulin-based ADCs like SMP-656 are emerging with non-cross-resistant mechanisms, providing options for ADC-exposed populations.

📖 Read More: Novel ADCs from Asia

🎓 Conclusion: Key Clinical Takeaways for 2026

ESMO 2025 has solidified immunotherapy’s role across the cancer continuum—from non-metastatic to advanced disease—while simultaneously opening new windows for overcoming ICI resistance through GDF-15 blockade, mRNA-based strategies, and VISTA inhibition.

✅ Immediate Practice Implications:

1. Integrate perioperative immunotherapy into curative-intent pathways where appropriate

2. Prioritize molecular profiling to inform targeted therapy selection

3. Leverage dual checkpoint blockade in chemotherapy-containing regimens for advanced disease

4. Remain alert to emerging strategies for ICI-resistant patients

The Bottom Line: The therapeutic armamentarium has expanded substantially, and personalized, multimodal approaches increasingly define modern cancer care. As the field advances toward 2026, these ESMO 2025 datasets will catalyze protocol amendments, guideline updates, and regulatory submissions that reshape standard-of-care algorithms across multiple malignancies.

📚 Key References and Source Links

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Blog: DPS Oncology Notes
Tags: #ESMO2025 #Oncology #ClinicalTrials #Immunotherapy #PrecisionMedicine #BladderCancer #ProstateCancer #GastricCancer #HeadAndNeckCancer #SkinCancer

Disclaimer: This blog post summarizes publicly available data from ESMO Congress 2025 and related sources for educational purposes. Treatment decisions should be made in consultation with qualified healthcare professionals based on individual patient circumstances.

ESMO 2025 : A brief overview

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