ATTRACTION-3: Nivolumab significantly improves OS in advanced ESCC

Treatment with nivolumab led to significantly improved overall survival (OS) in patients with advanced oesophageal squamous cell carcinoma (ESCC), according to updated results of the ATTRACTION-3* study presented at ASCO GI 2021.

This open-label, phase III trial involved 419 patients, of whom 96 percent were Asians, with advanced ESCC who were intolerant to a prior fluoropyrimidine/platinum-based chemotherapy. Participants were randomized to receive either intravenous nivolumab 3 mg/kg every 2 weeks (n=210, median age 64 years) or physician’s choice of chemotherapy** (n=209, median age 67 years). Patients continued treatment until disease progression, unacceptable toxicity, or consent of study withdrawal. [ASCO GI 2021, abstract 204]

At 3-year follow-up, patients who received nivolumab had a significantly longer OS (median 10.9 vs 8.5 months; hazard ratio [HR], 0.79; p=0.0264) than those who received chemotherapy.

The estimated 3-year OS rate was also higher in the nivolumab group than the chemotherapy group at 24 months (20.2 percent vs 13.5 percent) and 36 months (15.3 percent vs 8.7 percent).

The significant OS benefit with nivolumab vs chemotherapy was also evident regardless of best overall response (BOR), including stable disease (median 17.4 vs 9.4 months; HR, 0.45; p=0.0041) and progressive disease (median 10.9 vs 6.2 months; HR, 0.56; p=0.0292).

Although not significant, a longer median OS was also observed in patients with complete and partial responses in the nivolumab arm vs the chemotherapy arm (median 19.9 percent vs 15.4 percent; HR, 0.84; p=0.5701).

However, there was no significant difference in progression-free survival rate at 3 years between the nivolumab and the chemotherapy arms (4.3 percent vs 1.6 percent).

“[With regard to safety, even though] most patients experienced the first select treatment-related adverse event (TRAE) within 3 months of starting nivolumab, … no new safety concerns were reported during [this] 3-year follow-up [period],” said study author Dr Keisho Chin from the Department of Gastroenterology at the Cancer Institute Hospital of Japanese Foundation for Cancer Research in Tokyo, Japan.

“[In this updated analysis,] nivolumab demonstrated a clinically meaningful improvement in long-term OS in comparison with chemotherapy in patients with advanced ESCC,” said Chin.

“Nivolumab [treatment also demonstrated] a longer median OS than chemotherapy regardless of BOR, … and no major late-onset select TRAEs were observed; however, it is [still] necessary to continue monitoring AEs,” he added.

*ATTRACTION-3: Study of nivolumab in unresectable advanced or recurrent esophageal cancer

**Chemotherapy: Docetaxel 75 mg/m² every 3 weeks or paclitaxel 100 mg mg/m² daily for 6 weeks and then a week off