Cetuximab for Immunotherapy-Refractory/Ineligible Cutaneous Squamous Cell Carcinoma

Area of Science:

• Oncology
• Dermatology
• Immunotherapy

Background:

• Advanced cutaneous squamous cell carcinoma (CSCC) has limited treatment options after immune checkpoint inhibitor (ICI) failure.
• The efficacy of cetuximab in ICI-refractory or ineligible CSCC patients requires further investigation.

Purpose of the Study:

• To evaluate the effectiveness of cetuximab in patients with locally-advanced or metastatic CSCC.
• To compare outcomes based on the timing of cetuximab administration relative to prior ICI therapy.

Main Methods:

• Retrospective analysis of 23 patients with advanced CSCC across three cohorts: immediate ICI failure, non-immediate ICI failure, and no prior ICI.
• Primary endpoint: overall response rate (ORR). Secondary endpoints: disease-control rate (DCR), progression-free survival (PFS), overall survival (OS), time-to-response (TTR), and toxicity.

Main Results:

• Cetuximab demonstrated high ORR (64% in immediate ICI failure cohort, 80% in no prior ICI cohort) and DCR (91% and 80%, respectively).
• Patients receiving cetuximab immediately after ICI failure experienced rapid (TTR 2.0 months) and durable responses, with a median PFS of 17.3 months.
• Cetuximab was well-tolerated across all treatment groups.

Conclusions:

• Cetuximab is an effective treatment option for advanced CSCC patients with ICI failure or contraindications.
• Administering cetuximab immediately following ICI failure may offer particularly fast and durable responses, potentially establishing it as a preferred subsequent therapy.