3 Key Takeaways
Plain English Summary- 01Core Finding
Between March 19, 2024, and August 1, 2025 (final follow-up, October 17, 2025), a total of 704 patients were screened, and 497 were enrolled and randomized.
- 02Study Evidence
Tested in a randomized controlled trial (704 patients) at the Phase III stage.
- 03Practical Meaning
Large Phase III clinical evidence — long-term durability and rare subgroup effects remain under study.
What This Means for You
Izalontamab brengitecan significantly improved PFS and OS vs chemotherapy in patients with recurrent or metastatic ESCC whose disease had progressed after first-line treatment. These findings support izalontamab brengitecan as a new second-line treatment for this population in China.
The Discovery
To evaluate the efficacy (real-world effectiveness in the trial) and safety of izalontamab brengitecan compared with chemotherapy in patients with advanced ESCC who progressed after first-line programmed cell death 1 protein (PD-1)/programmed cell death 1 ligand 1 (PD-L1) inhibitor plus platinum-containing chemotherapy. This Phase 3, open-label, randomized clinical trial was conducted across 80 hospitals in China. Patients with recurrent or metastatic ESCC that had progressed with first-line PD-1/PD-L1 inhibitor plus platinum-containing chemotherapy were enrolled. Between March 19, 2024, and August 1, 2025 (final follow-up, October 17, 2025), a total of 704 patients were screened, and 497 were enrolled and randomized. The dual primary end points were progression-free survival (PFS) assessed by blinded independent central review according to Response Evaluation Criteria in Solid Tumors version 1.1 and overall survival (OS). Of 497 patients who underwent randomization (median age, 61.0 years [range, 34-76]; 448 male patients [90.1%]), 493 received study treatment. At this interim analysis, izalontamab brengitecan demonstrated statistically significant improvement in both PFS and OS. Median PFS by blinded independent central review was 4.17 months (95% CI, 3.61-4.53 months) with izalontamab brengitecan vs 1.97 months (95% CI, 1.61-2.73 months) with chemotherapy (hazard ratio, 0.50; 95% CI, 0.40-0.63; log-rank P <.001). Median OS was 9.79 months (95% CI, 7.89-11.01 months) with izalontamab brengitecan vs 7.20 months (95% CI, 6.18-7.82 months) with chemotherapy (hazard ratio, 0.63; 95% CI, 0.48-0.82; log-rank P <.001). Grade 3 or higher treatment-related adverse events occurred in 212 of 249 patients with izalontamab brengitecan and 147 of 248 patients (59.3%) with chemotherapy and were predominantly hematologic.
How It Works, Simply
This gastroenterology research focuses on mucosal barrier & gut microbiome modulation. Researchers evaluated it using a randomized controlled trial (704 patients) at the Phase III stage of medical research.
3 Key Takeaways
Clinical Takeaways- 01Core Finding
Between March 19, 2024, and August 1, 2025 (final follow-up, October 17, 2025), a total of 704 patients were screened, and 497 were enrolled and randomized.
- 02Study Evidence
Tested in a randomized controlled trial (704 patients) at the Phase III stage.
- 03Practical Meaning
Large Phase III clinical evidence — long-term durability and rare subgroup effects remain under study.
Key Numbers
Biological Mechanism & Study Design
Study Design & Cohort
Randomized controlled trial
Randomized controlled trial (704 patients) · Phase III
Biological Pathway & Modality
Mucosal barrier & gut microbiome modulation
Intervention: Izalontamab Brengitecan in Recurrent or Metastatic Esophageal Squamous Cell
Experimental Findings & Endpoints
To evaluate the efficacy and safety of izalontamab brengitecan compared with chemotherapy in patients with advanced ESCC who progressed after first-line programmed cell death 1 protein (PD-1)/programmed cell death 1 ligand 1 (PD-L1) inhibitor plus platinum-containing chemotherapy.
This Phase 3, open-label, randomized clinical trial was conducted across 80 hospitals in China. Patients with recurrent or metastatic ESCC that had progressed with first-line PD-1/PD-L1 inhibitor plus platinum-containing chemotherapy were enrolled.
Between March 19, 2024, and August 1, 2025 (final follow-up, October 17, 2025), a total of 704 patients were screened, and 497 were enrolled and randomized. The dual primary end points were progression-free survival (PFS) assessed by blinded independent central review according to Response Evaluation Criteria in Solid Tumors version 1.1 and overall survival (OS).
Of 497 patients who underwent randomization (median age, 61.0 years [range, 34-76]; 448 male patients [90.1%]), 493 received study treatment. At this interim analysis, izalontamab brengitecan demonstrated statistically significant improvement in both PFS and OS.
Median PFS by blinded independent central review was 4.17 months (95% CI, 3.61-4.53 months) with izalontamab brengitecan vs 1.97 months (95% CI, 1.61-2.73 months) with chemotherapy (hazard ratio, 0.50; 95% CI, 0.40-0.63; log-rank P <.001). Median OS was 9.79 months (95% CI, 7.89-11.01 months) with izalontamab brengitecan vs 7.20 months (95% CI, 6.18-7.82 months) with chemotherapy (hazard ratio, 0.63; 95% CI, 0.48-0.82; log-rank P <.001).
Grade 3 or higher treatment-related adverse events occurred in 212 of 249 patients with izalontamab brengitecan and 147 of 248 patients (59.3%) with chemotherapy and were predominantly hematologic.
Clinical Translation & Practice Context
Izalontamab brengitecan significantly improved PFS and OS vs chemotherapy in patients with recurrent or metastatic ESCC whose disease had progressed after first-line treatment.
These findings support izalontamab brengitecan as a new second-line treatment for this population in China.
The Bottom Line · Clinical Pearl
“Izalontamab brengitecan significantly improved PFS and OS vs chemotherapy in patients with recurrent or metastatic ESCC whose disease had progressed after first-line treatment.”
Published in JAMA · Current Stage: Phase III
