Mifepristone II: the “wonder years”…

Posted on Sunday 16 January 2011

In December, the Phase 3 results for Corlux for the treatment of Cushing’s Syndrome are due out and investors have been showing an appetite for the stock as of late. This was evidenced by the unusual volume on Friday, which was a half-day for the equity markets. “Approximately 710,100 shares changed hands, a 970.6 percent increase over its 65-day average volume.”

Comment: I think the potential market for Corlux lies mainly in the treatment of psychotic depression. The latter has a 0.4% incidence in the general population vs. 2% for major depressive disorder. Psychotic depression is much more common in hospitalized psychiatric patients. It has classically been treated with ECT which is falling by the wayside as reimbursement has dramatically dropped. The alternative drug treatments are not as effective. The potential market is therefore many multiples of the Cushing’s market. These are expensive patients to treat by conventional means. I expect it will also have an off-label use in treatment-resistant depression.

from Seeking Alpha  Nov 29, 2010 [stock market news & financial analysis]

In the last post [Mifepristone I: the outer layer…], I looked at the only two published scientific articles for Mifepristone in Psychotic Depression before 2006. This is how Dr. Charles Nemeroff described those studies in a 2002 review article [New directions in the development of antidepressants: the interface of neurobiology and psychiatry. Human Psychopharmacology 2002; 17 Suppl 1: S13-16].
    … Bellanof and colleagues conducted a double-blind, placebo-controlled, crossover study to assess the effects of mifepristone in psychotic depression. The patients received a 600 mg dose of mifepristone followed by 4 days of placebo and then another 600 mg dose of mifepristone, with no washout period. The original pilot study enrolled five patients (3 male, 2 female). The Hamilton Depression Rating Scale (HAMD) total score fell significantly (31%) during mifepristone treatment compared with only a very small decline (7%) with placebo. The results were particularly striking in terms of the consistency and rapidity of the response. Similar results were obtained using the Brief Psychiatric Rating Scale (BPRS), with scores falling by 32.5% with mifepristone and only 0.5% with placebo, thus highlighting the efficacy of mifepristone on psychotic symptoms. A second study has now been conducted to assess different doses of mifepristone (50, 600 and 1200 mg). Changes in the BPRS score showed evidence of a dose-response with regard to reduction in psychosis, with a 32%, 40% and 52% reduction in the score with doses of 50, 600 and 1200 mg, respectively. Similarly, of eight patients enrolled in each group, there were only two responders (defined as a 50% decline in symptom severity) in the 50 mg group compared with seven in the 600 mg group and six in the 1200 mg group. A large-scale, placebo-controlled, double-blind trial is currently underway.
Besides the mistakes in protocol and the part about "dose-response" [maybe he had an earlier version of the articles], it’s the music that stands out – "results were particularly striking in terms of the consistency and rapidity of the response."
    In the next five years we can expect to have available within our pharmacological armamentarium both aCRF1 receptor antagonist for the treatment of depression and anxiety and a GC receptor antagonist for the rapid reversal of psychotic major depression. These are just two of the many examples of how further advances in neurobiology impact upon psychiatry. Indeed, it seems remarkable that the tricyclic antidepressants were developed only 40–50 years ago and there is now a wide array of drugs with different mechanisms of action available for the treatment of depression. In the future, it is certain that there will be a further increase in the number of antidepressants available to treat this devastating disorder.
Here’s Dr. Alan Schatzberg‘s version [New approaches to managing psychotic depression. Journal of Clinical Psychiatry 2003,64 Suppl 1:19-23].
    Mifepristerone is a potential GR antagonist that has shown potential for rapidly reversing psychotic symptoms in delusional depression. Belanoff et al conducted a small, double-blind, placebo-controlled, crossover study of 5 patients with psychotic major depression… All patients showed substantial improvements in their HAM-D scores while receiving mifepristerone, and 4 of the 5 patients showed substantial improvement in their BPRS scores. In a more recent study, Belanoff et al conducted an open-label trial of mifesterone in 30 in-patients with psychotic major depression… More than 40% of patients taking the 2 higher doses had a greater than 50%reduction in their HAM-D scores and more than 60% demonstrated at least a 30% reduction in BPRS scores. This strategy may open up some alternative methods for treating delusional depression that are more acceptable than ECT.
These are just a couple of many excited references to these studies at medical meetings or in review articles [usually in Supplements]. In those "Wonder Years" at the dawn of our new century, the fact that Dr. Nemeroff was on Corcept‘s Scientific Advisory Board, or that Dr. Belanoff was the CEO of Corcept, or that Dr. Schatzberg was the founder and a Board member of Corcept were unmentioned in these reviews. And the studies made it into some other literature as well [Securities and Exchange Commission: Form 8-K, May 26, 2004].

    CORCEPT THERAPEUTICS ANNOUNCES FIRST QUARTER 2004 RESULTS: Corcept Therapeutics Incorporated (NASDAQ: CORT) today reported financial results for the first quarter ended March 31, 2004. Total operating expenses were $2.6 million for the first quarter of 2004 compared to total operating expenses of $2.9 million in the first quarter of 2003. In the first quarter of 2004, research and development expenses decreased to $1.6 million from $3.2 million in the first quarter of 2003. This decrease was primarily due to decreases in clinical trial expenses because of the completion of two double-blind trials for the treatment of psychotic major depression [PMD] in 2003… As of March 31, 2004, Corcept had cash, cash equivalents and marketable securities of $9.0 million… Subsequent to the end of the first quarter, Corcept completed its initial public offering, in which the company sold 4,500,000 shares of common stock at $12 per share. The net proceeds of this offering were $49.0 million.

    “During the first quarter, we made significant progress toward our goal of providing a much needed treatment for patients affected by psychotic major depression, or PMD” said Dr. Joseph Belanoff, Corcept’s chief executive officer. “We believe that the funds raised in our initial public offering combined with the cash already on hand will enable us to complete the clinical development of CORLUX™ for the treatment of PMD. We plan to commence pivotal Phase III trials designed to replicate the statistically significant results of the double-blind clinical study we completed last December. Because of the serious nature of PMD and the lack of approved drugs for the disorder, the FDA has granted a Fast Track designation for CORLUX™ for the treatment of the psychotic features of PMD.”

    PMD is a serious psychiatric disorder that affects approximately three million people annually in the United States. It is more prevalent than either schizophrenia or manic depressive illness. The disorder is characterized by severe depression accompanied by delusions, hallucinations or both. People with PMD are approximately 70 times more likely to commit suicide than the general population and often require lengthy and expensive hospital stays. There is no FDA-approved treatment for PMD. Corcept Therapeutics Incorporated is a pharmaceutical company engaged in the development of drugs for the treatment of severe psychiatric and neurological diseases. Corcept’s lead product, CORLUX™, is currently in Phase III clinical trials for the treatment of the psychotic features of psychotic major depression. The drug is administered orally to PMD patients once per day for seven days. CORLUX™, a potent GR-II antagonist, appears to mitigate the effects of the elevated and abnormal release patterns of cortisol…

It’s not immediately apparent what "This decrease was primarily due to decreases in clinical trial expenses because of the completion of two double-blind trials for the treatment of psychotic major depression [PMD] in 2003" or "We plan to commence pivotal Phase III trials designed to replicate the statistically significant results of the double-blind clinical study we completed last December" are referring to. The next study published came out in 2005-2006 and it was from Stanford. The next actual  Corcept study wasn’t published until the end of 2006. But in early 2004, Corcept Stock joined those two Mifepristone articles in the land of the promising, emerging, new directions, exciting things that were in our virtual future – mentioned periodically in both the Psychiatric  Supplements and the Investment Blogs in glowing terms [Alan Greenspan’s term, Irrational Exuberance, comes to mind].

What they were waiting for during the "wonder years" were the Phase III Clinical Trials that would determine the fate of Corcept‘s plan to submit Corlux™ to the FDA. But, as we will see, not everyone agreed that this Emperor was fully clothed.
  1.  
    Ivan the Terrible
    January 18, 2011 | 6:38 PM
     

    Hmmm… what’s this about no FDA-approved treatments for psychotic depression? Schatzberg should know better than to put out a marketing trope like that.

    Fact is, there are several well accepted treatments for psychotic depression – some antidepressant drugs alone; combinations of antidepressant and antipsychotic drugs; and ECT. All of them work a hell of a lot better than mifepristone. What’s more, the FDA doesn’t control the practice of medicine – we physicians do. People shouldn’t be fooled by Schatzberg’s smoke and mirrors factory over at Corcept Therapeutics, Inc.

Sorry, the comment form is closed at this time.