Camrelizumab combined with cetuximab and chemotherapy in recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC): 1-year outcomes from the phase II trial.

Abstract

6030 Background: Pembrolizumab or cetuximab combined with platinum-based-chemo are standard first-line regimen for R/M HNSCC, but the efficacy is far from optimal. We conducted an open-label, single-arm, Simon' s two-stage, phase II study of camrelizumab (PD-1 monoclonal antibody) with cetuximab and cisplatin-based chemotherapy as first-line treatment in R/M HNSCC (NCT05673577). The outcomes from the 1 st stage showed promising efficacy. Methods: Eligible patients with R/M HNSCC not amenable to curative treatment were enrolled. Patients were treated with camrelizumab 200mg Q3W, cetuximab 400mg/m 2 loading dose followed by 250mg/m 2 weekly, cisplatin 75mg/m 2 Q3W, and nab-paclitaxel 125mg/m 2 on d1, d8 (21-day cycle), for up to 6 cycles. Maintenance therapy with camrelizumab 200mg Q2W, cetuximab 500mg/m 2 Q2W were given until intolerable toxicity or disease progression. Primary endpoint of this study is objective response rate (ORR). Secondary endpoints include progression-free survival (PFS), overall survival (OS), disease control rate (DCR), adverse events (AEs) (CTCAE v5.0) andmolecular biomarkers will be tested as exploratory endpoints. Results: Between April 2023 and September 2024, 41 patients were enrolled. The confirmed ORR per RECIST 1.1 was 90.0% (95% CI: 75.0-97.0), which met the prespecified criteria for the primary endpoint of ORR. The confirmed DCR was 100.0%. With the median follow-up duration of 14.5 months, the median PFS was 13.2 months (95% CI: 9.3-NR). The 1-year PFS rate was 54.6% (95% CI: 39.1-76.1). The median OS was not reached. The 1-year and 2-year OS rates were 88.4% (95% CI: 78.2-100.0) and 84.6% (95% CI: 72.8-98.3), respectively. The most common grade 3-4 AEs related to chemotherapy included neutropenia (16.7%), anemia (7.1%). Possible grade 3-4 targeted therapy-related AE was rash (7.1%). Additionally, 14.3% of the patients were administered anti-angiogenic medications to treat reactive cutaneous capillary endothelial proliferation mucositis that was specifically induced by camrelizumab. These AEs were manageable with dose modification. Conclusions: Camrelizumab combined with cetuximab and cisplatin-based chemotherapy showed encouraging efficacy and tolerability in the scenario of first-line R/M HNSCC. Further evaluation including a phase III study is warranted. Clinical trial information: NCT05673577 . Demographics and baseline characteristics. 　 　 N=41 (100%) Age Median (range) 59 (34-72) Sex-n (%) Male/Female 36/5 (87.8% vs. 12.2%) HNSCC Primary site of disease Larynx 15 (36.5%) Oral Cavity 14 (34.1%) Oropharynx 4 (9.8%) HPV-pos 1 (25.0% of Oropharynx) HPV-neg 2 (50.0% of Oropharynx) unclear 1 (25.0% of Oropharynx) Hypopharynx 4 (9.8%) Others 4 (9.8%) Distant metastasis-n (%) 19 (46.3%) ECOG Performance Status-1 vs. 2 (%) 39 vs. 2 (95.1% vs. 4.9%)