Top KOLs Discussing KEYNOTE-C93
KEYNOTE-C93 Key Slides & Visuals
ESMO 2026 slides
| Pembrolizumab | Carboplatin + paclitaxel | HR (95% CI); one-sided P | |
|---|---|---|---|
| Randomized, n | 149 | 150 | — |
| PFS events, n (%) | 69 (46.3) | 94 (62.7) | — |
| Median PFS, months (95% CI) | 38.2 (17.9–NR) | 8.4 (6.8–10.4) | 0.57 (0.42–0.79); P = 0.0002 |
| 24-month PFS rate | 55.4% | 31.0% | — |
| 36-month PFS rate | 52.8% | 30.0% | — |
| Patients at risk at 12 / 24 / 36 months | 93 / 75 / 36 | 53 / 40 / 14 | — |
| Pembrolizumab | Carboplatin + paclitaxel | |
|---|---|---|
| Measurable disease per BICR at baseline, n | 145 | 145 |
| Objective response rate, % (95% CI) | 64.1 (55.8–71.9) | 62.1 (53.6–70.0) |
| Complete / partial response | 33.8% / 30.3% | 26.2% / 35.9% |
| Disease control rate, % (95% CI) | 70.3 (62.2–77.6) | 69.0 (60.8–76.4) |
| Median duration of response (responders, 93 vs 90) | Not reached | 10.2 months |
| Response lasting 24 / 36 months or longer | 77.0% / 70.7% | 41.3% / 40.0% |
| Pembrolizumab | Carboplatin + paclitaxel | HR (95% CI); P | |
|---|---|---|---|
| Median OS, months (95% CI) | Not reached (NR–NR) | Not reached (38.9–NR) | 0.77 (0.52–1.15); p = 0.10 |
| 36-month OS rate (95% CI) | 70.7% (62.4–77.5) | 62.0% (53.1–69.8) | — |
| Status at this interim analysis | — | — | Prespecified significance criterion not met (The Lancet); follow-up ongoing |
KOL-Made Infographics
Summary graphic posted by a physician from the abstract before the presentation (not a conference slide). Values are as the author drew them. Click to enlarge.
@DrRishabhOncoChemotherapy-free, or chemotherapy plus immunotherapy?
Is chemotherapy alone the right comparator?
The abstract itself notes that the preferred first-line therapy for dMMR advanced or recurrent endometrial cancer is chemotherapy plus an immune checkpoint inhibitor, then maintenance immunotherapy. KEYNOTE-C93 compared pembrolizumab with chemotherapy alone, and The Lancet paper states that it “did not compare pembrolizumab monotherapy with the current standard of care (immunotherapy plus chemotherapy).” The discussant, Christian Marth, MD, put the question on screen, “Is chemo only an adequate control arm?”, next to DOMENICA (dostarlimab) and LEAP-001 (pembrolizumab plus lenvatinib), which also used carboplatin-paclitaxel as control. Physicians on X raised the same caveat: Ana Maderuelo, MD, wrote “not compared with chemo-IO,” and Amol Akhade, MD, asked whether to “Wait for IO plus Chemo vs IO alone trial ?”
LBA12 discussant slides (Christian Marth, ESMO 2026) · The Lancet, Oct 26, 2026Who progresses early on pembrolizumab alone?
The PFS curves crossed early: estimated PFS was 75% vs 76% at 6 months before separating to 67% vs 40% at 12 months (The Lancet). Marth’s slides placed the NRG-GY018 (pembrolizumab plus chemotherapy) and KEYNOTE-C93 PFS curves side by side as an illustration, with the label “Chemo plus pembro: +10 patients without progression at 24 months”; this is a cross-trial illustration, not a randomized comparison. His take-home messages: “IO plus chemo results in better oncological outcome than pembro alone but with the price of a higher toxicity,” and translational research should focus on identifying primary pembrolizumab-resistant endometrial cancer. He also stressed that dMMR endometrial cancer “is not a homogeneous group,” citing tumor mutational burden, immune clusters and Lynch vs methylation-driven dMMR.
LBA12 discussant slides (Christian Marth, ESMO 2026)Who could choose a chemotherapy-free start?
Marth quoted the authors’ view on his take-home slide: KEYNOTE-C93 “suggest pembrolizumab monotherapy can be a clinically relevant, chemotherapy-free, first-line treatment option for patients with dMMR advanced or recurrent endometrial carcinoma who prioritize tolerability and quality of life.” Grade 3 or higher treatment-related adverse events were 18.1% vs 50.7%, and quality-of-life scores favored pembrolizumab at week 12. OS did not meet its significance criterion at this interim analysis, with most patients in the chemotherapy arm receiving immunotherapy after progression. In the Merck release, Slomovitz said the findings “could help provide an additional treatment option beyond carboplatin plus paclitaxel in combination with KEYTRUDA for these patients.”
LBA12 discussant slides (Christian Marth, ESMO 2026) · Merck release, Oct 26, 2026 · ESMO 2026 abstract LBA12 (program)Physician reactions to KEYNOTE-C93
🔬 Four important discussions from the final Presidential Sessions at #ESMO26! 💊 KEYNOTE-C93: Pembrolizumab monotherapy improved PFS in dMMR advanced or recurrent endometrial cancer, although the prespecified non-inferiority criterion was not met. An important step toward chemotherapy-free treatment. 🎯 Sacituzumab tirumotecan (sac-TMT): Impressive results in previously treated endometrial cancer, with improved PFS (7.2 vs 3.9 months) and OS (19.0 vs 12.1 months). ADCs are clearly changing the landscape! 🧬 MOIO trial: Can we safely extend immunotherapy intervals to every 3 months? The trial stopped early, leaving the question statistically unresolved and highlighting the challenges of treatment de-escalation. 📊 Non-inferiority: Who decides how much efficacy we can afford to lose? A great reminder that statistical margins must also reflect clinical judgment and patient preferences. Four discussions that could shape how we design trials and treat patients in the coming years. 💚 @osutcuoglu @uyargalip @kbaskurtt @tubaugurdr @drOrhunakdogan @myESMO #ESMO26 #ESMO2026 #Oncology #Immunotherapy #EndometrialCancer #ADC #ClinicalTrials
Context: The Lancet reports that overall survival, the trial's other primary endpoint, did not meet its prespecified statistical significance criterion at the interim analysis; the abstract, paper and Merck release do not describe a non-inferiority criterion.
KEYNOTE-C93/GOG-3064/ENGOT-en15: Phase 3, randomized, open-label study of first-line (1L) pembrolizumab (pembro) vs carboplatin (C) + paclitaxel (P) in mismatch repair-deficient (dMMR) advanced or recurrent endometrial carcinoma (a/rEC) Brian Slomovitz https://t.co/AN7PYhm53R
Pembrolizumab alone for dMMR advanced ca endometrial cancer ? Wait for IO plus Chemo vs IO alone trial ? Nice discussion by Dr Marth @OncoAlert @myESMO #esmo26 https://t.co/FLbfPIkv4K
🩷 #ESMO26 KEYNOTE-C93 (ph III): pembrolizumab alone vs carboplatin/paclitaxel in 1L dMMR endometrial cancer. PFS 38.2 vs 8.4 mo (HR 0.57) 3y PFS 52.8% vs 30.0% Chemo-free option? OS not significant; not compared with chemo-IO. #gynonc https://t.co/s16wMyLpyG
First-line pembrolizumab versus carboplatin plus paclitaxel in participants with mismatch repair-deficient advanced or recurrent endometrial cancer (KEYNOTE-C93/GOG-3064/ENGOT-en15): https://t.co/7WqLsdXkZb
Pembro superior to carbolatin paclitaxel in dMMR endometrial cancer !!! Wonderful data from KeynoteC93 in #ESMO2026
🚨 38.2 vs 8.4 MONTHS! Can we eliminate chemotherapy in first-line dMMR endometrial cancer? #ESMO26 LBA12 | KEYNOTE-C93 Pembrolizumab vs Carbo/Paclitaxel: 🔥 PFS: 38.2 vs 8.4 months (HR 0.57) 🔥 Grade ≥3 TRAEs: 18.1% vs 50.7% 🔥 Median response duration: NR vs 10.2 months A major step toward chemotherapy-free treatment! OS remains immature. @myesmo @ESMO_open @ASCO @oncoalert
Posted on October 26 before the presentation, from the abstract released that morning.
ESMO 2026 | KEYNOTE-C93 (LBA12): Can we omit chemotherapy in 1L dMMR advanced/recurrent endometrial cancer? Pembrolizumab monotherapy vs Carboplatin–Paclitaxel (n=299) 📊 Key results: • Median PFS: 38.2 vs 8.4 months (HR 0.57; p=0.0002) ✅ • 3-year PFS: 52.8% vs 30.0% • 3-year OS: 70.7% vs 62.0% (HR 0.77; not statistically significant) • ORR: 64.1% vs 62.1% • Grade ≥3 treatment-related AEs: 18.1% vs 50.7% • Better quality of life with pembrolizumab. Important caveat: Comparator was chemotherapy alone, NOT the current chemo-immunotherapy standard. #ESMO26 #EndometrialCancer #KEYNOTEC93 @OncoAlert @myESMO
Posted on October 26 before the presentation, from the abstract released that morning.
Can dMMR Endometrial Cancer Go Chemo-Free in the First Line? Can dMMR endometrial cancer go chemo-free in 1L? KEYNOTE-C93: pembrolizumab monotherapy improved PFS vs carboplatin–paclitaxel; OS is still immature. Magnitude of benefit & toxicity await LBA12. @GynCancerMD @myESMO @GOG #ESMO26 #GynOnc
Posted on October 21, before the abstract was released.
KEYNOTE-C93 Trial Design
KEYNOTE-C93 asked whether pembrolizumab alone, without chemotherapy, can be a first-line option for patients with mismatch repair-deficient advanced or recurrent endometrial cancer. It is sponsored by Merck (MSD outside the US and Canada) with the GOG Foundation and ENGOT as collaborators. Interim results were presented by Brian M. Slomovitz, MD, at ESMO 2026 (LBA12, Presidential Symposium III, October 26, 2026), with Christian Marth, MD, as discussant, and published the same day in The Lancet.
Study Design
Randomized 1:1, open-label, active-comparator controlled phase 3 (NCT05173987; GOG-3064; ENGOT-en15) at 122 centers in 24 countries. 299 randomized between February 22, 2022, and December 12, 2023. Stratified by disease status, histology and prior (neo)adjuvant chemotherapy.
Population
Adults with inoperable stage III or IV, persistent, advanced or recurrent endometrial cancer with centrally confirmed dMMR; no prior systemic therapy, except (neo)adjuvant therapy with recurrence at least 6 months after the last dose.
Interventions
Pembrolizumab 400 mg IV every 6 weeks for up to 18 cycles vs carboplatin (AUC 5 or 6) plus paclitaxel 175 mg/m² every 3 weeks for 6 cycles.
Endpoints
Dual primary: PFS by BICR (RECIST v1.1) and OS. Secondary: ORR (key secondary, per Merck), disease control, duration of response, investigator-assessed PFS, PFS2, safety and quality of life (EORTC QLQ-C30).
Interim Analysis
Prespecified interim analysis: PFS crossed its one-sided 0.025 boundary (P = 0.0002); OS did not meet its significance criterion (p = 0.10). The trial continues, with OS follow-up ongoing.
Data Cut
Data cutoff April 24, 2026; median follow-up 36.5 months (abstract) or 36.7 months, range 28.4–50.0 (Merck). Safety population 149 vs 144.
KEYNOTE-C93 in the News
KEYNOTE-C93 Questions
What is the KEYNOTE-C93 trial?
KEYNOTE-C93 (GOG-3064/ENGOT-en15; NCT05173987) is a Merck-sponsored, open-label, randomized phase 3 trial run with the GOG Foundation and ENGOT at 122 centers in 24 countries. Adults with inoperable stage III or IV, persistent, advanced or recurrent endometrial cancer with centrally confirmed mismatch repair deficiency (dMMR) and no prior systemic therapy (prior (neo)adjuvant therapy allowed if recurrence came at least 6 months after the last dose) were randomized 1:1 to pembrolizumab 400 mg every 6 weeks for up to 18 cycles or carboplatin plus paclitaxel every 3 weeks for 6 cycles. Between February 2022 and December 2023, 299 patients were randomized (149 vs 150).
What did KEYNOTE-C93 show at ESMO 2026?
At the prespecified interim analysis (data cutoff April 24, 2026; median follow-up 36.5 months in the abstract), median PFS by blinded independent central review was 38.2 months with pembrolizumab vs 8.4 months with carboplatin plus paclitaxel, HR 0.57 (95% CI 0.42–0.79), one-sided P = 0.0002, crossing the prespecified boundary. The 36-month PFS rate was 52.8% vs 30.0%. Results were presented by Brian M. Slomovitz, MD (LBA12, Presidential Symposium III, October 26, 2026) and published in The Lancet.
Did pembrolizumab improve overall survival?
Not at this analysis. OS is the trial’s other primary endpoint. Medians were not reached in either arm, the HR was 0.77 (95% CI 0.52–1.15), p = 0.10, and The Lancet reports that the prespecified significance criterion for OS was not met at the interim analysis. The 36-month OS rate was 70.7% vs 62.0% (descriptive). In the chemotherapy arm, 85.2% of patients with progression by central review received crossover pembrolizumab or another PD-1/PD-L1 inhibitor off study. Merck reports that the trial is continuing and OS follow-up is ongoing.
Was pembrolizumab alone better tolerated than chemotherapy?
Grade 3 or higher treatment-related adverse events occurred in 18.1% (27 of 149) with pembrolizumab vs 50.7% (73 of 144) with carboplatin plus paclitaxel; the most common was anemia (2.0% vs 18.1%). Treatment-related adverse events led to discontinuation in 9% vs 15%, and two vs one treatment-related deaths occurred. Global health status/quality of life improved more with pembrolizumab from baseline to week 12 (between-group difference 7.02 points, 95% CI 2.54–11.50).
Did KEYNOTE-C93 compare pembrolizumab with chemotherapy plus immunotherapy?
No. The comparator was carboplatin plus paclitaxel alone. The abstract notes that the preferred first-line therapy for dMMR advanced or recurrent endometrial cancer is chemotherapy plus an immune checkpoint inhibitor followed by maintenance, and The Lancet paper states that the study did not compare pembrolizumab monotherapy with that standard of care. The discussant, Christian Marth, MD, asked whether chemotherapy alone is an adequate control arm.
Is first-line pembrolizumab monotherapy approved for dMMR endometrial cancer?
No. In the US, KEYTRUDA (pembrolizumab, Merck) is approved in endometrial cancer in combination with carboplatin and paclitaxel followed by KEYTRUDA alone for primary advanced or recurrent disease; as a single agent for MSI-H or dMMR advanced disease that has progressed after prior systemic therapy; and with lenvatinib for pMMR or non-MSI-H disease after prior systemic therapy. In the EU, the monotherapy indication requires progression on or after platinum-containing therapy. First-line pembrolizumab monotherapy is investigational; Merck says the results will be shared with regulatory authorities worldwide.