Corcept Therapeutics, Inc. (CORT) - Overview of the Outstanding Legal Catalysts Impacting Corcept's Korlym (Mifepristone) Drug.

September 11, 2020

On September 2, 2020, the Hearing in Teva’s “Post Grant Review” challenging Corcept’s U.S. Patent Number 10,195,214 (which covers Corcept’s Korlym product) was held before the United States Patent & Trademark Office’s (“USPTO”) Patent Trial & Appeal Board (“PTAB”).  This was in PGR2019-00048, and we now expect the PTAB to issue its Final Written Decision in this PGR on or before November 20, 2020.  This email provides a detailed overview of the outstanding Cases involving Corcept's Korlym® (Mifepristone) drug that may be impacted by this upcoming Final Written Decision and additionally provides information regarding the Patents covering Korlym®.  Please note that shares of Corcept Therapeutics, Inc. (CORT) traded up more than 60% intraday on September 2, 2020 (the date of the Hearing); so the share price of Corcept should be clearly sensitive to further upcoming legal developments. 

The following three legal disputes involving Korlym are currently outstanding, which we believe may be significantly impactful for the share-price of Corcept Therapeutics, Inc. (CORT):

  1. “Corcept Therapeutics, Inc. v. Teva Pharmaceuticals USA, Inc.” (Case #18-03632 in the District of New Jersey);
  2. “Corcept Therapeutics, Inc. v. SUN Pharma Global FZE et al” (Case #19-15678 in the District of New Jersey); and
  3. Teva Pharmaceuticals USA, Inc. v. Corcept Therapeutics, Inc.” (PGR2019-00048 at the Patent Trial and Appeal Board).

Please note that detailed information on each of the above Cases is presented at the end of this email; however, what follows is a general overview of Corcept, its Patents, and a timeline of events that may be significantly impactful to the share-price of Corcept Therapeutics, Inc. (CORT).

According to Corcept’s website at Korlym.com, Korlym® is “a cortisol receptor blocker indicated to control hyperglycemia secondary to hypercortisolism in adult patients with endogenous Cushing’s syndrome who have type 2 diabetes mellitus or glucose intolerance and have failed surgery or are not candidates for surgery.”  Put simply, Korlym® is indicated for the treatment of high blood sugar in patients with type 2 diabetes and Cushing’s Syndrome.  The label indicates a starting dose of 300 mg once daily (with a maximum of 1200 mg a day), and concomitantly administering with a strong CYP3A inhibitor “only when necessary” (a maximum of 900 mg a day when administered concomitantly).  Please note that Korlym has been available since 2012, and it appears that substantially ALL of Corcept’s revenue is derived from sales of Korlym®.

Below is a timeline laying out key events in the three Cases involving Korlym.  Please note that additional details regarding these events are provided at the end of this email.

Corcept currently has 13 Patents listed in the FDA’s Orange Book that cover Korlym.  These Patents along with relevant information (including who the Patent is asserted against and Expiration Dates of the Patents) can be found in the Chart below.  Please note that the Patent at issue in Teva’s pending Post-Grant Review (“PGR”) is highlighted in Blue, and the Patent that was previously challenged in an IPR by Neptune Generics (and found Valid) is highlighted in green:

Patent NumberExpiration DateDefendant
8,921,34808/27/2028Teva, Sun
9,829,49508/15/2036Teva, Sun
9,943,52604/20/2036Voluntarily Dismissed against Teva (Jan 2020)
10,006,92408/12/2036 
10,151,76301/18/2037 
10,166,24204/20/2036Voluntarily Dismissed against Teva (Jan 2020)
10,166,24304/20/2036Voluntarily Dismissed against Teva (Jan 2020)
10,195,21406/19/2037Teva, Sun
10,231,98308/22/2038 
10,314,85008/22/2038 
10,495,65008/12/2036 
10,500,21603/05/2033Teva, Sun
10,660,90404/20/2036 

Teva filed its “Post Grant Review” challenging Corcept’s U.S. Patent Number 10,195,214 on May 7, 2019.  Please note that we currently believe that Teva’s strategic choice to only file a challenge on the ‘214 Patent may be a good indication that Teva believes that this is Corcept’s most-important Patent.  It is also worth noting that the ‘214 Patent is the longest expiring Patent that is asserted against both Teva and Sun.  Also, note that at the time of Teva’s Petition, Neptune Generics had already filed an Inter Partes Review challenging U.S. Patent Number 8,921,348 (this Petition was instituted on February 15, 2019).  A Final Written Decision upholding the validity of the challenged Patent was issued on February 10, 2020.  Neptune subsequently elected not to Appeal this Decision.

In order to better understand the Patents at issue in these Cases and their relative importance, we studied the Patents’ abstracts and how they may relate to the core aspects of Korlym® (as indicated by the Korlym label).  Below are links to the asserted Patents and a copy of their abstracts:

  • 8,921,348“The present invention provides a method for optimizing levels of mifepristone in a patient suffering from a mental disorder amenable to treatment by mifepristone. The method comprises the steps of treating the patient with seven or more daily doses of mifepristone over a period of seven or more days; testing the serum levels of the patient to determine whether the blood levels of mifepristone are greater than 1300 ng/mL; and adjusting the daily dose of the patient to achieve mifepristone blood levels greater than 1300 ng/mL.”
  • 9,829,495: “This invention provides for an improved method for differentially diagnosing ACTH-dependent Cushing's syndrome. Current practice for differentially diagnosing ectopic ACTH syndrome and Cushing's Disease measures relative ACTH concentrations from the inferior petrosal venous sinus compared to fluid obtained from a periphery venous sample. This is performed before and after administration of exogenous corticotropin releasing factor, or after administration of metyrapone. This invention uses glucocorticoid receptor antagonists to induce release of endogenous CRH which stimulates ACTH to increase in patients with ectopic ACTH syndrome but not in those with Cushing's Disease.”
  • 10,195,214“Applicant provides methods of treating diseases including Cushing's syndrome and hormone-sensitive cancers by concomitant administration of a glucocorticoid receptor antagonist (GRA) and steroidogenesis inhibitors, and by concomitant administration of a GRA and CYP3A inhibitors. Applicant provides methods of treating diseases including Cushing's syndrome and hormone-sensitive cancers by concomitant administration of mifepristone and ketoconazole. Subjects treated with CYP3A inhibitors or steroidogenesis inhibitors may suffer from toxicity or other serious adverse reactions; concomitant administration of other drugs would be expected to increase the risk of such toxicity and adverse reactions. Applicant has surprisingly found that GRAs may be administered to subjects receiving CYP3A inhibitors or steroidogenesis inhibitors such as ketoconazole without increasing risk adverse reactions; for example, Applicant has found that mifepristone may be concomitantly administered with ketoconazole (a CYP3A inhibitor and a steroidogenesis inhibitor), providing safe concomitant administration of the GRA and ketoconazole. In embodiments, the GRA dose may be reduced.”
  • 10,500,216“The present invention provides a method for altering the pharmacokinetics of mifepristone upon oral administration. Mifepristone absorption into the blood is increased upon administration with meals. The method of the invention can benefit patients suffering from conditions including psychiatric illnesses and hormonal disorders.”

Please note that although we believe that to a certain extent all the Patents above seem to generally relate to the administration and optimization of dosage of Korlym to Patients, it currently appears to us that the ‘214 Patent reads directly on the Label for Korlym.  That is, the ‘214 Patent specifically states that mifepristone can be concomitantly administered with ketoconazole (a CYP3A inhibitor).  Similarly, the Korlym label reads: “Korlym should be used with extreme caution in patients taking ketoconazole … The benefit of concomitant use of these agents should be carefully weighed against the potential risks. Mifepristone should be used in combination with strong CYP3A inhibitors only when necessary, and in such cases the dose should be limited to 300 mg per day.”


Below is a summary of the three specific legal disputes regarding Korlym:

Corcept Therapeutics, Inc. v. SUN Pharma Global FZE et al” (Case #19-15678 in the District of New Jersey)

Corcept filed this Case against SUN Pharma in the District of New Jersey on July 22, 2019.  In its original Complaint, Corcept alleged that Sun’s Abbreviated New Drug Application (“ANDA”) No. 213387 is Infringing Corcept’s 8,921,348; 10,195,214; and 9,829,495 Patents.  Corcept then filed an Amended Complaint on January 23, 2020 adding U.S. Patent Number 10,500,216 to its allegations.  Sun filed its Answer and Counterclaims on January 31, 2020.  Please note that in its Counterclaims, Sun writes that its “… proposed products in Abbreviated New Drug Application (“ANDA”) No. 213387 do not and will not infringe any valid and enforceable claim of U.S. Patent Nos. 8,921,348 (“the ʼ348 Patent”) and 9,829,495 (“the ʼ495 Patent”), and that each and every claim of the ʼ348, ʼ495, 10,195,214 (“the ʼ214 Patent”) and 10,500,216 (“the ‘216 Patent”) patents (together, “the patents-in-suit”) are invalid for failure to satisfy one or more provisions of Title 35 of the United States Code, including but not limited to, 35 U.S.C. §§ 102, 103 and/or 112, and/or based on other judicially created bases for invalidation.” (Emphasis added)  Given the above, it currently appears that Sun Pharma may not be challenging its Infringement of the ‘214 or ‘216 Patents.  The Markman Hearing in this Case is currently scheduled to be held in February 2021, and the Trial has not yet been scheduled.

“Corcept Therapeutics, Inc. v. Teva Pharmaceuticals USA, Inc.” (Case #18-03632 in the District of New Jersey)

Corcept filed this Case against Teva in the District of New Jersey on March 15, 2018.  In its Original Complaint, Corcept alleged Infringement of only U.S. Patent Numbers: 8,921,348; and 9,829,495.  At the time of Teva’s Paragraph IV Notice Letter to Corcept, it appears that Corcept was in the process of obtaining additional Patents to cover Korlym.  Corcept then filed an Amended Complaint on July 6, 2018 adding U.S. Patent Number 9,943,526 to its allegations.  On October 12, 2018, Teva received Tentative Approval of its ANDA from the FDA.  Please note that in its Approval letter, the FDA writes that final approval cannot be Granted until “the date the court decides that the '348 and '495 patents are invalid or not infringed” among other conditions.  The FDA also wrote the following in a footnote near the end of its Tentative Approval letter: “The Agency notes that the '924 and '526 patents were submitted to the Agency after submission of your ANDA. Litigation, if any, with respect to these patents would not create a statutory stay of approval.”  Corcept then filed two additional Cases against Teva, which added U.S. Patent Numbers: 10,166,242; 10,166,243; 10,195,214; and 10,500,216.  These three Cases were consolidated with Case #18-03632 being designated as the Lead Case.  Corcept then subsequently Voluntarily Dismissed the ‘526, ‘242, and ‘243 Patents from this Case, leaving the 4 asserted Patents as indicated in the chart above.  In its Answer, Teva asserted that each Patent is Invalid and Not Infringed.  The 7-day Trial in this Case is currently scheduled to commence on February 2, 2021.

Teva Pharmaceuticals USA, Inc. v. Corcept Therapeutics, Inc.” (PGR2019-00048 at the Patent Trial and Appeal Board)

The United States Patent & Trademark Office’s (“USPTO”) Patent Trial & Appeal Board (“PTAB”) Granted Institution of this Proceeding on November 20, 2019.  The Hearing in Teva’s “Post Grant Review” challenging Corcept’s U.S. Patent Number 10,195,214 was held on September 2, 2020.  We previously provided extensive information regarding this proceeding in our emails covering the Hearing on September 2, 2020.  (Please review those emails for more in depth information.)  We believe that the USPTO’s Final Written Decision deadline is generally one year from the date that the PGR was instituted; so a Final Written Decision is expected by November 20, 2020.

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