Durable and Dramatic Response to Checkpoint Inhibition Combined with
IDO1 Inhibitor Celecoxib in a Patient with p16+ Metastatic Sinonasal
Background: Sinonasal undifferentiated carcinoma (SNUC) is an
exceedingly rare head and neck malignancy. No consensus exists on
treatment for metastatic disease. Case: A 56-year-old female was
diagnosed with SNUC after endorsing sinus congestion, diplopia, and
right orbital pain. Initially treated with surgery and radiation, she
later developed significant metastatic disease. She demonstrated
progression of her hepatic metastases under pembrolizumab therapy.
However, the addition of ipilimumab and an IDO1 inhibitor resulted in
significant improvement in her lesions as well as an ongoing durable
response. Her regimen was complicated by immune-related adverse events
successfully treated with steroids. Conclusion: Dual checkpoint
inhibition deserves consideration when treating metastatic SNUC,
especially after single agent therapy has failed. The positive effect of
this treatment may be augmented by IDO1 inhibition.