Corcept Therapeutics has received notice that it will be issued a new patent in the U.S. covering the use of Korlym (mifepristone), in combination with strong CYP3A inhibitors, to treat patients with Cushing’s syndrome.
Upon issuance from the U.S. Patent and Trademark Office, the company plans to add the new patent (PCT/US2018/020336) to the U.S. Food and Drug Administration’s Approved Drug Products with Therapeutic Equivalence Evaluations publication, otherwise known as the Orange Book. Korlym is currently covered by five patents in this book.
The Orange Book compiles data, including their patent and exclusivity information, on therapeutic products approved by the FDA on the basis of their safety and effectiveness.
Titled, “Concomitant Administration of Glucocorticoid Receptor Modulators and CYP3A Inhibitors,” the patent will protect the concomitant use of Korlym and strong CYP3A inhibitors until 2037.
“This patent covers an important finding of our research — that with proper dose modulation, Korlym can safely be administered in combination with medications that are strong CYP3A inhibitors,” Joseph K. Belanoff, MD, CEO of Corcept, said in a press release.
“Strong CYP3A inhibitors include antiviral, antibiotic, antifungal, and antidepressant medications from which many patients taking Korlym could benefit,” he added. “Korlym’s label instructs doctors how to do this safely.”
Results from a previous study revealed that treatment with the antifungal medicine, ketoconazole (sold under the brand name Nizoral), can change the way the body distributes and absorbs Korlym.
Ketoconazole has the potential to inhibit steroid hormone production, and is sometimes used off-label to treat Cushing’s. However, it can strongly inhibit the CYP3A enzyme, which is critical for the normal deconstruction of Korlym into three active compounds.
Researchers found that concomitant treatment with ketoconazole led to increased blood levels of some Korlym metabolites. Still, it did not change the medicine’s therapeutic effect, as cortisol and ACTH (adrenocorticotropic hormone) blood levels were reduced in Cushing’s patients.
While the two therapeutic agents can be safely combined, Korlym might need dose adjustments when used in combination with ketoconazole. The new patent provides information on safe ways to do so.