Epidermal Growth Factor Receptor Inhibitors
Epidermal growth factor receptor (EGFR) inhibitors are being considered as a potential therapy for Cushing’s disease. EGFR inhibitors work by blocking EGFRs from sending signals that would trigger tumor growth or production of proopiomelanocortin, the precursor to ACTH. In this way, it may lower ACTH production. EGFR inhibitors were studied in a small Phase 2 trial, but the results of that study are unknown.
Retinoic acid, a compound that results from the metabolism of vitamin A, is being investigated as a potential treatment for Cushing’s disease. Researchers think that retinoic acid plays a role in both lowering cortisol levels and potentially reducing the size of the tumor. So far, retinoic acid has only been tested in small proof-of-concept studies, and larger trials are needed.
Seliciclib (R-roscovitine or CYC202) is an investigational oral medicine being developed to treat Cushing’s disease, as well as several cancers, rheumatoid arthritis, and cystic fibrosis. Seliciclib is a cell cycle inhibitor aimed at targeting the tumor in the pituitary gland. The experimental therapy is being tested in Phase 2 trials.