** Shares of drugmaker Corcept Therapeutics CORT.O fall 16.5% to $37.25 premarket

** Last year, the U.S. FDA declined to approve Corcept's drug application for relacorilant to treat hypertension in Cushing's syndrome patients

** FDA had warned Corcept "on several occasions" about concerns with the clinical program and to "expect significant review issues" if they submitted, the regulator's letter dated January 28 showed

** UBS analyst Ashwani Verma said the letter was made public on the FDA's website on Thursday around 4 pm E.T.

** Corcept has one year to conduct new clinical trials or the application may be withdrawn, the letter stated

** The original CRL was dated December 30, 2025, and this January 28 version is a corrected version issued in response to communications from Corcept, the letter showed

** The company did not immediately respond to Reuters request for comment

** CORT fell 30.9% in 2025

(Reporting by Kamal Choudhury in Bengaluru)

((Kamal.Choudhury@thomsonreuters.com;))