Primary cemiplimab treatment for orbital squamous cell carcinoma is effective and may alleviate the need for orbital exenteration

Abstract

Purpose: To evaluate the effectiveness of cemiplimab, a Programmed-cell-death-1(PD-1) protein inhibitor, for the treatment of cutaneous periocular-locally-advanced squamous-cell-carcinoma (POLA-SCC) with orbital-invasion.

Methods: Multicentre real-world retrospective study. Demographic and clinical data were collected and analysed for patients with biopsy-proven POLA-SCC(AJCC-T4) with orbital-invasion who were treated with cemiplimab at one of four tertiary medical centres in 2019-2022.

Results: The cohort included 13 patients, 8 males and 5 females, of median age 76 years (IQR65-86). The median duration of treatment was 5.0months (IQR3.5-10.5) and the median follow-up time, 15.0 months (IQR10.5-30). The overall response rate was 69.2%. Complete response was documented in seven patients (53.8%), partial response in two (15.4%), stable disease in one (7.7%), and progressive disease in two (15.4%); in one patient (7.7%), response was not evaluable. Six complete responders (46.1% of the cohort) received no further treatment and did not have a recurrence during an average follow-up of 6.14 (±6.9) months from treatment cessation. None of the patients underwent orbital-exenteration. The majority of adverse events were mild (grade-1), except for a moderate increase in creatinine level (grade-2), severe bullous dermatitis (grade-3), and myocarditis (grade-5) in one patient each. Four patients (30.7%) died during the follow-up period, all of whom had an Eastern-Cooperative-Oncology-Group score of 4 at presentation.

Conclusions: To our knowledge, this is the largest study to date on cemiplimab therapy for cutaneous POLA-SCC with orbital-invasion. Treatment was shown to be effective, with an overall response rate of 69.2%. Cemiplimab holds promise for the treatment of patients with tumours invading the orbit as it may alleviate the need for orbital exenteration.

Fig. 1. Treatment timeline and follow-up of each of the 13 patients with locally advanced squamous cell carcinoma treated with cemiplimab.

Patient’s response to treatment is stated on the right (CR complete response, PR partial response, SD stable disease, PD progressive disease, NE not evaluable). ◇ represents cemiplimab treatments given during follow-up.

Fig. 2. MRI scans of an 82-year-old man with squamous cell carcinoma with orbital involvement.

A Before treatment; post-contrast coronal T1 fat-saturated image showing an ill-defined low enhancing mass penetrating the right orbit with globe compression. B Before treatment; post-contrast axial T1 fat-saturated image showing an ill-defined low enhancing mass penetrating the right orbit. C Before treatment; post-contrast sagittal T1 fat-saturated image showing an ill-defined low enhancing mass extending from the right forehead to the left orbit, advancing along the orbital and penetrating the right orbit. D After treatment; post-contrast coronal T1 image showing a complete response. E After treatment; post-contrast axial T1 image showing a complete response. F After treatment; post-contrast sagittal T1 image, showing a complete response. *indicates the tumor before treatment.