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Updated: Jan 3, 2026

Testing Cancer Immunotherapeutics in a Humanized Mouse Model Bearing Human Tumors
Published on: December 16, 2022
Targeting PD-L1 Initiates Effective Antitumor Immunity in a Murine Model of Cushing Disease
Hanna R Kemeny1,2, Aladine A Elsamadicy1,2, S Harrison Farber1,2
1Duke Brain Tumor Immunotherapy Program, Department of Neurosurgery, Duke University Medical Center, Durham, North Carolina.
Purpose:
Although pituitary adenoma is classified as benign, Cushing disease is associated with significant morbidity due to the numerous sequelae of elevated cortisol levels. Successful therapy for Cushing disease remains elusive due to high rates of treatment-refractory recurrence. The frequent emergence of lymphocytic hypophysitis following checkpoint blockade for other cancers, as well as the expression of PD-L1 on pituitary adenomas, suggest a role for immunotherapy.
Experimental Design:
This study confirms PD-L1 expression on functioning pituitary adenomas and is the first to evaluate the efficacy of checkpoint blockade (anti-PD-L1) therapy in a preclinical model of Cushing disease.
Results:
Herein, treatment with anti-PD-L1 was successful in reducing adrenocorticotropic hormone plasma levels, decreasing tumor growth, and increasing survival in our model. Furthermore, tumor-infiltrating T cells demonstrated a pattern of checkpoint expression similar to other checkpoint blockade-susceptible tumors.
Conclusions:
This suggests that immunotherapy, particularly blockade of the PD1/PD-L1 axis, may be a novel therapeutic option for refractory Cushing disease. Clinical investigation is encouraged.

