Nimotuzumab combined with chemotherapy plus immunotherapy as first-line treatment for advanced esophageal squamous cell carcinoma.

344 Background: Esophageal squamous cell carcinoma (ESCC) is the primary type of esophageal cancer with poor prognosis in China. Chemotherapy plus immunotherapy as first-line standard treatment has limited benefit in advanced ESCC patients. Nimotuzumab, a humanized anti-EGFR antibody, exhibited favorable efficacy in advanced ESCC with good safety profile. We explored the efficacy and safety of nimotuzumab as first-line therapy for patients with advanced ESCC. Methods: In this retrospective study, patients were aged ≥ 18 years with histologically diagnosed advanced ESCC, ECOG of 0-3, given nimotuzumab (400 mg, Q3W) combined with chemotherapy (paclitaxel: 300-400mg and platinum: 400-500mg or tegafur: 60mg/bid, Q3W) plus immunotherapy (PD-(L)1: 200-240 mg, Q3W). They assigned into two groups: metastasis group and locally advanced group. The primary endpoint was overall survival (OS). Secondary endpoints were progression-free survival (PFS), objective response rate (ORR) and safety. Results: As of July 2024, 58 patients were enrolled (metastasis group: n=20, locally advanced group: n=38). The median age was 59.5 years (range: 44-80). The median follow-up was 32.59 months (95% CI: 23.0, 36.7). The ORR was 74.1% (95% CI: 0.6, 0.8). Survival analysis showed that the 1-year OS was 79.16% (95% CI: 64.5, 88.3) and 2-year OS was 57.38% (95% CI: 41.3, 70.5), 1-year PFS and 2-year PFS was 64.41% (95% CI: 49.4, 76.0) and 32.80% (95% CI: 19.7, 46.5), respectively. The median OS (mOS) was 31.01months, the median PFS (mPFS) was 17.84 months. Nimotuzumab plus chemotherapy and immunotherapy displayed a favorable survival outcomes both in metastasis group and locally advanced group with OS (1-year OS: 77.76% and 80.37%; 2-year OS: 62.21% and 55.91%) and PFS (1-year PFS: 53.46% and 69.99%; 2-year PFS: 25.06% and 36.66%), the mOS was not reached and 31.01 months, mPFS was 18.27 months and 16.69 months, respectively. There were 74.1% patients occurred grade 1-2 adverse events (AEs), and 13.8% occurred grade 3-5 AEs. The most common AEs included nausea (60.3%), myelosuppression (51.7%), leukopenia (41.4%), thrombocytopenia (29.3%), and neutropenia (24.1%). No serious treatment-related AEs or death recorded. Conclusions: This study demonstrated a favorable survival profile and acceptable toxicity in first-line treatment of advanced ESCC patients with nimotuzumab regimen. Further prospective study needed to certify in order to benefit more patients.