Long-term results from the ATTRACTION-3 trial show nivolumab improves survival over chemotherapy for patients with advanced esophageal squamous cell carcinoma, according to data presented at the virtual ASCO GI Cancers Symposium (J Clin Oncol 39, 2021 (suppl 3; abstr 204).

“Previous results from the ATTRACTION-3 phase 3 trial demonstrated a significant improvement in overall survival and a favorable safety profile compared with taxane chemotherapy (CT) in previously-treated ESCC patients,” explained Keisho Chin, Cancer Institute Hospital, Tokyo, Japan, and colleagues, noting in the poster presentation that metastatic esophageal cancer has a poor prognosis and survival rate. Researchers reported three-year survival data from ATTRACTION-3, the first long-term efficacy and safety data of nivolumab in esophageal squamous cell carcinoma.

A total of 419 patients with unresectable advanced or recurrent ESCC refractory to 1 prior platinum-based CT were randomized to receive nivolumab(n=210) or chemotherapy(paclitaxel or docetaxel)(n=209).

The primary endpoint was overall survival. The median OS at the 3-year data cutoff in May 2020 was 10.91 months in the nivolumab arm versus 8.51 months in the chemotherapy arm. The OS rates at 24 months were 20.2% in the nivolumab arm versus 13.5% in the chemotherapy arm. At 36 months, the OS rates in the nivolumab and chemotherapy arms were 15.3% and 8.7%, respectively.

When looking at the subgroup analysis of overall survival by best overall response, median OS was 19.91 months in patients who experienced a complete response and 15.41 months in patients who experienced a partial response. Researchers also found OS was better in the nivolumab arm over chemotherapy arm when looking at patients with stable disease or progressive disease.

During the three-year follow-up period, no new safety signals were reported.

Dr Chin concluded that “nivolumab continued to show improved overall survival over chemotherapy in pretreated patients with advanced ESCC patients. Nivolumab showed a longer mOS than chemotherapy regardless of best overall response.”

Further monitoring of potential late-onset adverse events is continuing.—Kaitlyn Manasterski