- Pembrolizumab, an inhibitor of programmed death ligand-1 (PD-L1), shows an overall objective response rate (ORR) of 9.1%, with manageable toxicity, in heavily pretreated advanced, metastatic esophageal cancer in a phase 2 trial.
- The ORR was higher in patients with advanced, metastatic esophageal squamous cell carcinoma (ESCC) than with advanced, metastatic adenocarcinoma of the esophagus and gastroesophageal junction.
Why this matters
- Treatment options are scant for advanced, metastatic ESCC and adenomas.
- A phase 3 trial of pembrolizumab is ongoing.
- Single-arm, multicenter, phase 2 KEYNOTE-180 trial in patients (n=121) with advanced, metastatic esophageal cancer that progressed after ≥2 lines of systemic therapy.
- ORR, the primary endpoint, was assessed by the Response Evaluation Criteria in Solid Tumors by central imaging review.
- Funding: MSD.
- Median duration of follow-up was 5.8 months.
- 47.9% of patients had PD-L1+ tumors.
- Among all patients, the ORR was 9.9% (95% CI, 5.2%-16.7%), with a median time to response of 4.1 months, but results varied by subgroups:
- ESCC patients: ORR, 14.3% (95% CI, 6.7%-25.4%);
- adenocarcinoma patients: ORR, 5.2% (95% CI, 1.1%-14.4%);
- PD-L1+ patients: ORR, 13.8% (95% CI, 6.1%-25.4%); and
- PD-L1− patients: ORR, 6.3% (95% CI, 1.8%-15.5%).
- 12.4% of patients had treatment-related grade 3-5 adverse events, with 1 death from pneumonitis.
- Single-arm, open-label design.