Epidermal Growth Factor Receptor Inhibitors in Advanced Cutaneous Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

Patients with advanced cutaneous squamous cell carcinoma (cSCC) who are not eligible for or who fail to respond to anti-PD1 immunotherapy have few treatment options. Epidermal growth factor receptor (EGFR) inhibitors have been investigated as a therapeutic option for advanced cSCC; however, data are limited to small single-arm trials or retrospective studies. A systematic review and meta-analysis was conducted to PRISMA guidelines (CRD42023394300). Studies reporting on outcomes of EGFR inhibition in advanced cSCC were identified. Objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and adverse event (AE) rate were pooled using a random effects model and the inverse variance method. Twelve studies (six prospective, six retrospective) were identified, representing 324 patients. Pooled ORR was 26% (95% confidence interval [CI] 18-36), median PFS was 4.8 months (95% CI 3.9-6.6) and median OS was 11.7 months (95% CI 9.2-14.1). Any grade AEs occurred in 93% of patients (95% CI 85-97) while grade 3 and higher AEs occurred in 30% (95% CI 14-54). These results were similar between anti-EGFR monoclonal antibodies (MAbs) and tyrosine kinase inhibitors (TKIs). EGFR inhibitors can be considered in patients with advanced cSCC who are contraindicated for or progress on first-line anti-PD1 immunotherapy. Future studies should evaluate their activity and safety following anti-PD1, identify predictive biomarkers for their efficacy and explore combination approaches.