Pembrolizumab, PD-1 Blocking Immune Checkpoint Inhibitor, for the Management of Periocular Sebaceous Carcinoma

PURPOSE: To evaluate the efficacy of pembrolizumab, a programmed death-protein 1 (PD-1) immune checkpoint inhibitor, in the management of advanced ocular sebaceous carcinoma with pagetoid conjunctival spread, as well as in recalcitrant, recurrent, and metastatic disease. METHODS: Five patients with ocular sebaceous carcinoma were included in the study. Three patients had advanced disease with diffuse eyelid involvement and pagetoid conjunctival spread, 1 had recalcitrant recurrent eyelid disease, and 1 had orbital recurrence with regional lymph node metastasis. All patients were treated with pembrolizumab (200 mg intravenous every 3 weeks). RESULTS: Three cases with diffuse upper eyelid involvement and pagetoid spread on the bulbar conjunctiva showed no response after receiving an average of 7 cycles of pembrolizumab therapy, and they underwent surgical excision. One case, who presented with orbital recurrence and lymph node metastasis after the excision of the right upper eyelid involvement with pagetoid spread, underwent surgical excision of the orbital mass with positive margins and neck lymph node dissection. After 8 cycles of pembrolizumab therapy, there was no recurrence or new metastatic lesion at 60 months of follow-up. Another case with diffuse left upper eyelid involvement, who had been treated with multiple surgeries and external beam radiotherapy, developed recurrent sebaceous carcinoma and received 9 cycles of pembrolizumab therapy. At 48 months of follow-up, there was no recurrence or new metastasis. Tumor mutation burden was ≤7.6 Mut/Mb in all 5 patients. CONCLUSION: Pembrolizumab, a PD-1 immune checkpoint inhibitor, does not appear to be effective as a first-line treatment for advanced sebaceous carcinoma with pagetoid spread. However, there might be a place for pembrolizumab in the treatment of recurrent and metastatic cases.