22 min read
The ESMO 2026 Debates from the KOL Social Media Threads
Brian Shields
:
Oct 24, 2026, 12:19:39 PM
The ESMO 2026 Debates
Through day 2 of ESMO 2026, the most active physician threads on X were arguments, not applause: whether INTerpath-001 (RFS HR 0.58) beats what neoadjuvant immunotherapy already does, whether NATALEE's 6-year OS (HR 0.809, nominal one-sided P=0.019) counts as a survival win, whether three HER2 TOP1 ADCs are me-too drugs, and why higher pCR in two bladder trials did not move EFS. Every post below is verbatim and linked.
Before Madrid: who gets the standing ovation?
On October 19 an oncologist asked which ESMO 2026 trial would get a standing ovation. The replies ranged from comparator and endpoint questions to skepticism about standing ovations themselves.
On October 24 STAT reporter Adam Feuerstein, in the room for the INTerpath-001 presentation, posted: “Limited standing O, extended applause.” (journalist, context)
INTerpath-001: the vaccine vs. moving pembrolizumab before surgery
INTerpath-001 is the phase 3 trial of adjuvant intismeran autogene (V940/mRNA-4157, Moderna and Merck) plus pembrolizumab vs placebo plus pembrolizumab in resected stage IIB–IV melanoma. RFS HR 0.58 (95% CI 0.45–0.75); 24-month RFS 82.2% vs 70.0%. DMFS HR 0.62 (95% CI 0.45–0.85). OS was immature: HR 0.77 (95% CI 0.45–1.31), two-sided P=0.33. (ESMO 2026 LBA1, Georgina V. Long; data cutoff Jun 30, 2026) Intismeran is investigational. The argument started when the abstract posted on October 22: SWOG S1801, which moved pembrolizumab before surgery and compared it with adjuvant pembrolizumab, also reported an EFS HR of 0.58. (KOL Pulse INTerpath-001 page)

Context: NADINA tested neoadjuvant ipilimumab + nivolumab and SWOG S1801 tested neoadjuvant pembrolizumab. NADINA’s EFS hazard ratio was 0.32 (99.9% CI 0.15–0.66) at the primary analysis (Blank et al, NEJM 2024; the figure on the discussant’s slide) and 0.40 (95% CI 0.28–0.57) at the 2-year update (ESMO 2025, LBA57).
The discussant, Inge Marie Svane of the University of Copenhagen, raised the same questions on stage (slide above). Feuerstein described her tone as “measured.” (journalist, context)
Unresolved: No trial has compared intismeran with neoadjuvant immunotherapy. INTerpath-009 (NSCLC) tests the vaccine after neoadjuvant treatment. OS is immature.
Track oncology’s top KOLs in your specialty
Create a free account, pick the tumor types you cover, and go beyond the tweet — the intelligence pharma teams use to map influence and prepare for engagement:
- ✓Enhanced KOL profiles
- ✓Pharma influence & potential advisory-board patterns
- ✓2025 Open Payments financial analysis
- ✓Social-media sentiment & trend signals
NATALEE: is a nominal p-value an OS win?
NATALEE tested 3 years of ribociclib plus a nonsteroidal aromatase inhibitor vs NSAI alone in stage II–III HR+/HER2− early breast cancer (n=5,101). 6-year OS 91.9% vs 89.7% (difference 2.1%); 178 vs 205 deaths; HR 0.809 (95% CI 0.661–0.989); nominal one-sided P=0.019. The slide footnote calls the P value descriptive. Median follow-up 66.5 months. (ESMO 2026 LBA25, Dennis Slamon; data cutoff May 15, 2026) 6-year iDFS HR 0.741 (95% CI 0.646–0.849). (LBA25 abstract) Adjuvant ribociclib has been FDA approved since September 17, 2024; this readout does not change that.


Unresolved: NATALEE OS was not part of a multiplicity-controlled testing strategy. Whether a 2.1-point 6-year OS difference justifies 3 years of therapy, especially in N0 disease and outside the US, is open.
Breast cancer ADCs: crowded targets, one payload class
Three TOP1-payload ADC trials were presented in the same October 23 breast session, two of them HER2-directed in HER2-low disease. HORIZON-Breast06 (trastuzumab rezetecan, Jiangsu HengRui): chemo-naive PFS 16.6 vs 6.8 months, HR 0.25 (95% CI 0.19–0.33). (LBA13; data cutoff Mar 20, 2026) APEX-Breast01 (TQB2102, a biparatopic HER2 ADC): HR+/HER2-low PFS 16.4 vs 5.5 months, HR 0.29 (95% CI 0.22–0.39). (presented slide, Shusen Wang) PANKU-Breast01 (iza-bren, an EGFR×HER3 bispecific TOP1 ADC) in pretreated HR+/HER2− disease: PFS 8.18 vs 4.01 months, HR 0.41 (95% CI 0.33–0.53); grade ≥3 TRAEs 85.3% vs 65.8%; grade ≥3 neutropenia 53.7%, anemia 49.5%, thrombocytopenia 46.3%; ILD 1.1%, all grade 1–2. (LBA50, Bo Lan; KOL Pulse PANKU-Breast01 page) All three are investigational in these settings.


Unresolved: No trial has shown a HER2 TOP1 ADC improves outcomes after another TOP1 ADC. OS is immature in all three HER2-low/HR+ readouts.
Bladder cancer: higher pCR, no EFS benefit
Two phase 3 trials added a PD-1 inhibitor to neoadjuvant gemcitabine/cisplatin and continued it after cystectomy in cisplatin-eligible MIBC. KEYNOTE-866 (pembrolizumab): EFS HR 0.88 (95% CI 0.71–1.10), OS HR 1.00 (95% CI 0.79–1.27), pCR 44.4% vs 35.8%. (ESMO 2026 4735O; data cutoff Jan 26, 2026) ENERGIZE (nivolumab): EFS HR 0.94 (95% CI 0.72–1.24), pCR 39.1% vs 29.6%. (ESMO 2026 4736O) NIAGARA (durvalumab) met EFS (HR 0.68) and OS (HR 0.75) with pCR 37.3% vs 27.5% and is FDA approved. (KOL Pulse NIAGARA page) On October 24, VOLGA (cisplatin-ineligible or refusing): durvalumab + 3 cycles of neoadjuvant enfortumab vedotin vs control (a third arm added tremelimumab), EFS HR 0.51 (95% CI 0.38–0.67), 24-month EFS 64% vs 45%; OS HR 0.58 (95% CI 0.40–0.83), 24-month OS 78% vs 69%; pCR 45% vs 10%. (ESMO 2026 LBA2, Tom Powles; data cutoff Mar 2, 2026) Durvalumab + EV is investigational in MIBC and under FDA Priority Review. (KOL Pulse VOLGA page)


Context: per the presented design slides, ENERGIZE required GFR ≥50 mL/min and KEYNOTE-866 GFR ≥60 mL/min. The discussant's slide listed 24-month control-arm EFS of 70.0% (KEYNOTE-866), 71.6% (CA017-078) and 59.8% (NIAGARA).
Unresolved: Why NIAGARA was positive and KEYNOTE-866 and ENERGIZE were not. Whether adjuvant EV adds benefit after neoadjuvant EV.
KEYNOTE-B49: a 0.7-month PFS gain, no OS gain
KEYNOTE-B49 (Merck, LBA51) added pembrolizumab to chemotherapy in PD-L1 CPS ≥1 HR+/HER2− metastatic breast cancer after endocrine therapy. PFS 6.7 vs 6.0 months, HR 0.74 (95% CI 0.58–0.95), P=0.0089, meeting the primary endpoint at the interim analysis. (presented slide; IA data cutoff Sep 22, 2025) OS at the final analysis: 21.0 vs 22.2 months, HR 1.04 (95% CI 0.81–1.33), P=0.6185, not significant. Grade ≥3 treatment-related AEs 37.6% vs 32.7%. (presented slides; FA data cutoff Mar 16, 2026)
Unresolved: Whether any HR+ subgroup (ER-low, higher PD-L1) benefits enough to use pembrolizumab with chemotherapy.
ECLYPse: don't drop the EC
ECLYPse is a single-arm phase 2 trial (n=25) in BRAF V600E metastatic colorectal cancer progressing on encorafenib + cetuximab (EC). Patients continued EC with FOLFIRI. It met its primary endpoint: 6-month PFS rate 66.7% (12 of 18 evaluable). Median PFS 7.1 months; ORR 15.0%; disease control 80%; median OS not reached. (presented slides, Maria Alessandra Calegari; data cutoff May 8, 2026) No randomized comparison.

Unresolved: Single-arm, 25 patients. A randomized trial would be needed to make EC beyond progression a standard.
More from ESMO 2026
- ESMO 2026 conference page: themes, top physician voices and trial buzz by tumor type
- ESMO 2026 trials: every trial with physician posts
- ESMO 2026 slide library: presented slides by tumor and trial
FAQ
What was the main debate about INTerpath-001 at ESMO 2026?
INTerpath-001 added the individualized mRNA vaccine intismeran to adjuvant pembrolizumab in resected stage IIB-IV melanoma (RFS HR 0.58, 95% CI 0.45-0.75; OS immature, HR 0.77). Oncologists debated whether the comparator was right, because SWOG S1801 also reported an EFS HR of 0.58 by moving pembrolizumab before surgery, and NADINA showed benefit with neoadjuvant ipilimumab + nivolumab. Others noted INTerpath-001 enrolled node-negative and micrometastatic patients who are not neoadjuvant candidates. Intismeran is investigational.
Did NATALEE show an overall survival benefit?
At the 6-year analysis, OS was 91.9% vs 89.7% (HR 0.809, 95% CI 0.661-0.989) with a nominal one-sided P=0.019. The presented slide labels the P value descriptive; OS was not tested within a multiplicity-controlled strategy. Physicians disagreed on whether to call it an OS benefit. Adjuvant ribociclib has been FDA approved since September 17, 2024.
Why did KEYNOTE-866 and ENERGIZE miss while NIAGARA was positive?
No one has a confirmed answer. KEYNOTE-866 (EFS HR 0.88) and ENERGIZE (EFS HR 0.94) had numerically higher pCR but did not improve EFS; NIAGARA met EFS (HR 0.68) and OS (HR 0.75). Physicians on X pointed to differences in eligibility, control-arm outcomes and event definitions. These are cross-trial comparisons, not head-to-head results.
What did oncologists say about new HER2 ADCs in breast cancer?
HORIZON-Breast06 (trastuzumab rezetecan) and APEX-Breast01 (TQB2102) both beat chemotherapy on PFS in HER2-low disease, and PANKU-Breast01 (iza-bren) beat chemotherapy in pretreated HR+/HER2- disease. Oncologists called the HER2 TOP1 ADC space crowded, questioned whether the new agents add anything over trastuzumab deruxtecan, debated whether the hematologic toxicity of iza-bren (an EGFRxHER3 ADC) is manageable, and asked for non-TOP1 payloads.
KOL Pulse tracks what oncologists and hematologists are discussing on X. Every post quoted here is full, verbatim and links to its source. Posts from journalists and investors are labeled as context. Michiel Strijbos is co-founder and CMO of AitriumOS (per his X profile). Eric D. Whitman states in his post that he participated in INTerpath-001.