Corcept Therapeutics Announces Promising Results of Human Microdosing Study of Selective GR-II Antagonist

MENLO PARK, CA--(Marketwire - May 1, 2008) - Corcept Therapeutics Incorporated (NASDAQ: CORT) announced today that its lead selective GR-II antagonist, CORT 108297, produced promising results in a human microdosing study. "The compound was extremely well absorbed, demonstrated good bioavailability and had a half-life that appears compatible with once-a-day oral dosing in this 'first-in-man' study," said Robert Roe, M.D., President of Corcept Therapeutics. Corcept had previously announced its discovery of three series of structurally different compounds that are potent blockers of the cortisol receptor but do not block the progesterone or any of the other steroid receptors in in vitro assays. "These microdosing results increase our confidence that we will be able to develop cortisol antagonists that are not abortifacients," continued Dr. Roe.

"There is increasing evidence that excess cortisol may play a role in the pathogenesis of several important metabolic diseases including diabetes, obesity and hypertension, in addition to Cushing's Syndrome and psychiatric illnesses. A selective cortisol antagonist will have clear advantages should it be demonstrated that cortisol receptor blockade has clinical utility. Separating antagonist activity at the cortisol receptor from the progesterone receptor is a significant achievement in medicinal chemistry; this effort was led by Robin Clark, PhD, our Director of Medical Chemistry, working with his associates at Argenta Discovery," said Joseph Belanoff, M.D., Corcept's Chief Executive Officer.

Corcept is studying disease states associated with excess production of cortisol, the "stress" hormone. Corcept is currently running Phase 3 clinical trials using CORLUX®, a cortisol and progesterone receptor antagonist, for the treatment of the psychotic features of psychotic depression, a severe psychiatric illness, and Cushing's Syndrome, a life-threatening illness stemming from tumors that produce cortisol or its precursor. In 2007, Corcept also released results of a pilot study indicating that CORLUX successfully mitigated the weight gain and metabolic disturbances associated with use of Zyprexa, a leading antipsychotic medication marketed by Eli Lilly and Company.

The microdosing study was conducted at Pharmaceutical Profiles Ltd. (Nottingham, UK) under MHRA regulatory authorization and was coordinated by Xceleron Ltd. (York, UK), an exploratory clinical development specialist and leader in the field of human microdosing.

About CORT 108297

CORT 108297 is a non-steroidal, potent, competitive antagonist at the GR-II (cortisol) receptor. In in vitro binding affinity and functional assays it does not have affinity for the PR (progesterone), ER (estrogen), AR (androgen) or GR-I (mineralocorticoid) receptors.

About Human Microdosing

Human microdosing involves the administration of sub-pharmacological doses of candidate drugs to human subjects without extensive animal testing. It is now accepted as a valuable tool in drug screening. Use of human microdosing allows companies to gain key information 12-18 months faster than using the conventional drug development paradigm.

About Corcept Therapeutics Incorporated

Corcept Therapeutics Incorporated is a pharmaceutical company engaged in the development of GR-II antagonist drugs for the treatment of severe psychiatric and metabolic diseases. Corcept's lead product, CORLUX, is currently in Phase 3 clinical trials for the treatment of the psychotic features of psychotic depression and Cushing's Syndrome. The Company is also engaged in preparation for clinical trials to evaluate CORLUX for the mitigation of weight gain induced by antipsychotic medications and continued development work on its proprietary, selective GR-II antagonists. For additional information about the company, please visit www.corcept.com.

Statements made in this news release, other than statements of historical fact, are forward-looking statements, including, for example, statements relating to Corcept's clinical development programs, the role of cortisol in the pathogenesis of metabolic diseases, and the potential for CORT 108297 to selectivity bind only to the cortisol receptor in human studies. Forward-looking statements are subject to a number of known and unknown risks and uncertainties that might cause actual results to differ materially from those expressed or implied by such statements. For example, there can be no assurances that Corcept will pursue further activities with respect to the clinical development of CORLUX, CORT 108297, or any of its other proprietary, selective GR-II antagonist candidates. These and other risk factors are set forth in the Company's SEC filings, all of which are available from our website (www.corcept.com) or from the SEC's website (www.sec.gov). We disclaim any intention or duty to update any forward-looking statement made in this news release.