Immune Checkpoint Inhibitors in Nuclear Protein in Testis Carcinoma Treatment: Evidence of Limited Clinical Benefits from a Case Series.

Nuclear protein in testis (NUT) carcinoma is an extremely rare and aggressive malignancy characterized by NUTM1 gene rearrangement. It frequently develops in the lungs or the head and neck region as a poorly differentiated squamous cell carcinoma. The prognosis is generally poor and particularly dismal in cases with a pulmonary origin. Given the lack of an established standard treatment and the rapid disease progression, recently, immune checkpoint inhibitors (ICIs) have attracted attention, particularly in combination with platinum-based chemotherapy. We report a case series of four patients with pulmonary NUT carcinoma who received ICI-containing regimens as first-line therapy. Three patients received ICIs in combination with platinum-based chemotherapy and showed transient tumor shrinkage, although all ultimately experienced disease progression and died. One patient received ICI monotherapy owing to poor performance status and showed no clinical response. The median progression-free and overall survival were 53 and 108 days, respectively. Given the limited treatment options for NUT carcinoma, a combination of ICIs with platinum-based chemotherapy may represent a potential first-line treatment option. However, their efficacy remains limited.