Triple combination treatment with anti-EGFR monoclonal antibody, low-dose chemotherapy, and anti-PD1 immune check-point inhibitors for recurrent and/or metastatic head and neck squamous cell carcinoma: A single institute experience.

Abstract

e17514 Background: The 1st line treatment of recurrent and/or metastatic head and neck squamous cell carcinoma (R/M SCCHN) was EXTREME regimen established by Vermorken at al since 2008. Recently in ESMO 2018, Keynote-048 presented frontline pembrolizumab monotherapy or combined chemotherapy had a better overall survival than EXTREME regimen, though with poor PFS (3.2m-3.4m) and response rate (19-23%). But chemotherapy plus pembrolizumab showed a shorter duration of response than the pembrolizumab alone. Therefore, role of chemotherapy as a partner of IO is debated. We presented a retrospective report of triple combination treatment of cetuximab, low-dose chemotherapy and anti-PD1 check-point inhibitor for R/M SCCHN patients as a e-publication in ASCO 2018. This is a update report. Methods: We retrospectively reviewed charts of R/M SCCHN patients who started triple combination of cetuximab, low-dose chemotherapy and anti-PD1 therapy during the period of Feb. 2017 till Jan.31 2018. The contents of combinations, previous treatments, duration of combination treatments, best response, and adverse effects were recorded. Data cutoff is Jan.15 2019. Results: Total 15 patients reviewed. The mean age was 55.4 years (age range 32 – 71 years). Previous treatments included chemotherapy (80%), anti-EGFR (33.3%), anti-PD1 check-point inhibitor (53.3%). The median duration of follow up was 434 days (range 187–707 days). Complete response was observed in 3 patients (20%), partial response in 7 patients (46.7%), stable disease in 4 patients (26.6%) and disease progression in 1 (6.6%). Objective response rate(CR+PR) observed was 66.7%. Clinical benefit rate(CR+PR+SD) observed was 93.3% . Dose of Cetuximab was 250-500mg/m2 every 2-3 weeks. Combination of chemotherapy included PF, TP, or docetaxel monotherapy. Doses were Cisplatin 30-50mg/m2, 5-FU 600-1000mg/m2, or docetaxel 20-30mg/m2; all in every 2-3 weeks. Anti-PD1 immune check-point inhibitors included Nivolumab 1-3mg/kg or Pembrolizumab 1-2mg/kg, every 2-3 weeks. Six patients (40%) died: 2 due to progression of disease, 1 due to tumour bleeding, 2 due to pneumonia, and 1 due to fungemia. Conclusions: Our real-world report might suggest a possible role of ADCC effect of cetuximab and less-toxic chemotherapy as a partner of IO. Further prospective study of triple combination therapy with biomarker evaluation is recommended.