Induction chemotherapy plus camrelizumab followed by concurrent chemoradiotherapy for unresectable locally advanced esophageal squamous cell carcinoma (ImpactCRT): Long-term outcomes of a single-arm phase II trial.

Abstract

4059 Background: Concurrent chemoradiotherapy (CCRT) is the standard treatment for unresectable locally advanced esophageal squamous cell carcinoma (ESCC), with 3-year overall survival (OS) approximately 30%. Induction chemoimmunotherapy followed by CCRT appears promising, but long-term efficacy remains unclear. In the ImpactCRT study, induction chemotherapy plus camrelizumab followed by CCRT has shown promising efficacy in patients with unresectable locally advanced ESCC. Here, we reports long-term outcomes with ≥3-year follow-up. Methods: ImpactCRT was a prospective, single-arm, phase II study at the First Affiliated Hospital of Sun Yat-sen University. Eligible patients were aged 18–75 years with untreated, unresectable locally advanced ESCC (cT1–4bN0–3M0 or M1 limited to supraclavicular nodes). Patients received two 21-day cycles of induction therapy with albumin-bound paclitaxel (260 mg/m²), carboplatin (AUC 5), and camrelizumab (200 mg) on day 1, followed by two 28-day cycles of fluorouracil (750 mg/m² per 24 h for 5 days) and cisplatin (75 mg/m² on day 1) administered concurrently with radiotherapy (50–63 Gy in 25–28 fractions). The primary endpoint was the 1-year OS rate in the per-protocol set (PPS). The trial was registered with ChiCTR (ChiCTR2000034304). Results: Between July 12, 2020, and October 14, 2022, 49 patients were enrolled; all completed induction chemoimmunotherapy, and 46 received CCRT and comprised the PPS. As of January 1, 2026, median follow-up among surviving patients was 53.7 months (range 41.1–65.5). In the PPS, the 1-, 2-, 3-, and 4-year OS rates were 87.0% (95% CI 77.7–97.3), 73.9% (95% CI 62.3–87.8), 65.2% (95% CI 52.8–80.5), and 60.9% (95% CI 48.3–76.7), respectively. Corresponding PFS rates were 71.7% (95% CI 59.8–86.0), 63.0% (95% CI 50.5–78.7), 56.5% (95% CI 43.9–72.8), and 50.0% (95% CI 37.5–66.8). Median OS was not reached (95% CI 40.7 months–not reached), and median PFS was 45.5 months (95% CI 26.7–not reached). Disease progression occurred in 17 patients (37.0%), all within 3 years after treatment (median 6.1 months; range 2.9–35.2): locoregional failure in 7 (15.2%), distant metastasis in 5 (10.9%), and simultaneous locoregional and distant failure in 5 (10.9%). During follow-up, 20 patients (43.5%) died, including 12 (26.1%) due to disease progression. Grade 3 late toxicities occurred in three patients, all esophageal strictures; no grade ≥3 late toxicities were observed in the lung, heart, or other organs. Conclusions: Induction chemotherapy plus camrelizumab followed by CCRT showed improved long-term survival and acceptable late toxicity in unresectable locally advanced ESCC. Median PFS exceeded three years and appeared superior to previous reports. This regimen warrants further evaluation in randomized controlled trials. Clinical trial information: ChiCTR2000034304.