Complete response of a large basosquamous carcinoma following treatment with cemiplimab and vismodegib.

The anti-PD-1 antibody cemiplimab has demonstrated effectiveness in the setting of locally advanced basal cell carcinoma (BCC) and squamous cell carcinoma. We describe a case of a large, locally invasive basosquamous carcinoma, an aggressive type of BCC, invading the left sternocleidomastoid muscle with near compression of the left internal jugular vein producing a severe anaemia secondary to ulceration and chronic blood loss. The patient was initially started on vismodegib monotherapy but failed to respond. He was then started on cemiplimab in addition to vismodegib. Improvement was noted after one cycle. After 21 cycles of cemiplimab, the left shoulder ulcerated lesion was completely re-epithelialised. He remains in complete remission after 31 cycles of cemiplimab in addition to vismodegib.