Extended Follow-up Outcomes of Australian Patients with Advanced Cutaneous Squamous Cell Carcinoma Treated with Cemiplimab on EMPOWER-CSCC-1
| Thursday, August 14, 2025 |
| 10:15 AM - 10:22 AM |
| Ballroom 2 and 3 |
Overview
Dr Catherine Bennett
Speaker
Dr Catherine Bennett
Medical Oncology Fellow
Peter MacCallum Cancer Centre
Extended Follow-up Outcomes of Australian Patients with Advanced Cutaneous Squamous Cell Carcinoma Treated with Cemiplimab on EMPOWER-CSCC-1
Abstract
BACKGROUND
Immune-checkpoint inhibitors have revolutionised the treatment of advanced cutaneous squamous cell carcinoma (CSCC). The phase II multi-national EMPOWER-CSCC-1 study demonstrated a significant overall response rate in patients with advanced CSCC treated with the programmed cell death-1 inhibitor cemiplimab. However, durability of these responses are not described beyond the published median follow-up of 42.5 months at the final analysis. We report long-term outcomes for Australian patients (n=54, 28% total cohort) from groups 1-3 of EMPOWER-CSCC-1 beyond trial follow-up.
METHODS
A retrospective multi-centre analysis was conducted at five Australian sites. Primary outcomes were duration of response (DoR), progression-free (PFS) and overall survival (OS) using Kaplan-Meier estimates with 95% confidence intervals. Outcomes for patients receiving cemiplimab re-treatment were evaluated for those who had disease progression after completing fixed duration treatment.
RESULTS
54 patients (91% male) were identified, median age 71 years, 70% had a head and neck primary, 85% had metastatic CSCC and 15% locally advanced CSCC. Median follow-up was 77 (IQR 72 – 86) months. Of 39 (72%) responders, 5-year DoR was 65% (95% CI: 47-78). Ten responders progressed after completing fixed duration cemiplimab therapy, 8 of these within 3 years of treatment initiation. The median PFS was 56.4 months (95% CI: 19.2 months – NR) and median OS not reached (95% CI: 52.8 months – NR), with 5-year PFS of 48% (95% CI: 34-61) and 5-year OS 60% (95% CI: 45-72). Four patients received a second course of cemiplimab for disease progression after initial response, with three of these patients remaining progression-free at data cut-off.
CONCLUSION
Long-term follow-up confirms durable responses to cemiplimab in patients with advanced CSCC treated on EMPOWER-CSCC-1, with the majority of progression occurring within the first 3 years of treatment initiation. Efficacy outcomes in Australian patients were numerically favourable in comparison to the overall study population.
Immune-checkpoint inhibitors have revolutionised the treatment of advanced cutaneous squamous cell carcinoma (CSCC). The phase II multi-national EMPOWER-CSCC-1 study demonstrated a significant overall response rate in patients with advanced CSCC treated with the programmed cell death-1 inhibitor cemiplimab. However, durability of these responses are not described beyond the published median follow-up of 42.5 months at the final analysis. We report long-term outcomes for Australian patients (n=54, 28% total cohort) from groups 1-3 of EMPOWER-CSCC-1 beyond trial follow-up.
METHODS
A retrospective multi-centre analysis was conducted at five Australian sites. Primary outcomes were duration of response (DoR), progression-free (PFS) and overall survival (OS) using Kaplan-Meier estimates with 95% confidence intervals. Outcomes for patients receiving cemiplimab re-treatment were evaluated for those who had disease progression after completing fixed duration treatment.
RESULTS
54 patients (91% male) were identified, median age 71 years, 70% had a head and neck primary, 85% had metastatic CSCC and 15% locally advanced CSCC. Median follow-up was 77 (IQR 72 – 86) months. Of 39 (72%) responders, 5-year DoR was 65% (95% CI: 47-78). Ten responders progressed after completing fixed duration cemiplimab therapy, 8 of these within 3 years of treatment initiation. The median PFS was 56.4 months (95% CI: 19.2 months – NR) and median OS not reached (95% CI: 52.8 months – NR), with 5-year PFS of 48% (95% CI: 34-61) and 5-year OS 60% (95% CI: 45-72). Four patients received a second course of cemiplimab for disease progression after initial response, with three of these patients remaining progression-free at data cut-off.
CONCLUSION
Long-term follow-up confirms durable responses to cemiplimab in patients with advanced CSCC treated on EMPOWER-CSCC-1, with the majority of progression occurring within the first 3 years of treatment initiation. Efficacy outcomes in Australian patients were numerically favourable in comparison to the overall study population.
Biography
Catherine is currently practising as a Medical Oncologist at Auckland City Hospital in New Zealand. She recently completed a fellowship at Peter MacCallum Cancer Centre in head and neck and skin cancer.
Session Chair
Tim Clay
St John Of God Subiaco Hospital
