875P - A phase II clinical trial of camrelizumab combined with cetuximab and chemotherapy in recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC)

Background

The efficacy of current first-line rigmens for R/M HNSCC is far from ideal, with ORR less than 50%. 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).

Methods

Eligible patients with R/M HNSCC not amenable to curative treatment were enrolled. Patients were treated with camrelizumab 200mg Q3W, cetuximab 400mg/m² loading dose followed by 250mg/m² weekly, cisplatin 75mg/m² Q3W, and nab-paclitaxel 125mg/m² on d1, d8 (21-day cycle), for up to 6 cycles. Maintenance therapy with camrelizumab 200mg Q2W, cetuximab 500mg/m² Q2W were given until intolerable toxicity or disease progression. Simon's minimax design was applied, if 9 of the 21 patients achieve PR or CR in the first stage, another 19 patients will be included. The endpoints include ORR, PFS, OS, safety, etc, and molecular biomarkers will be tested as exploratory endpoints.

Results

By the data cutoff date of May 1st, 2024, 21 patients were enrolled in the stage 1, with the median follow-up duration of 9.2 months. The confirmed ORR was 90.5% (19/21; CR, n=1; PR, n =18), meeting pre-planned criteria for trial continuation. The 6-month PFS and OS rate were both 90.2%. The estimated 1-year PFS and OS rate were 70.3% and 82.7%, respectively. Grade 3 or above treatment-related adverse events were observed in 47.6% patients. One patient discontinued camrelizumab due to pneumonia, and two patients discontinued cetuximab due to acneiform rash. Three patients reported fatal AEs, which were caused by tumor hemorrhage in the re-irradiated site, severe infectious pneumonia and choking due to swallowing, respectively. In stage 2, 18 patients were enrolled so far. Preliminary analysis was conducted on patients available for ORR analysis (stage 1 and 2, n=32), showing that the confirmed plus unconfirmed ORR reached 93.8% (30/32).

Conclusions

Camrelizumab combined with cetuximab and cisplatin-based chemotherapy were well tolerated and showed promising clinical efficacy in the scenario of first-line R/M HNSCC.

Clinical trial identification

NCT05673577.

Editorial acknowledgement

Funding

Clinical Research Project of Shanghai municipal Health Commission in Health Industry, 202340122 (2023-2026).

Disclosure

All authors have declared no conflicts of interest.