Patent protection of psychedelic therapeutics: a page from the cannabis playbook?

As increasing numbers of U.S. states have legalized both medical and adult-use cannabis, another set of Schedule 1 controlled substances – psychedelics – has begun to emerge from the shadows. Psychedelics such as psilocybin, lysergic acid diethylamide (LSD), mescaline, and ayahuasca were designated along with cannabis as Schedule I controlled substances under the Controlled Substances Act of 1970. Recently, several U.S. cities, including Denver, Colorado and Oakland, California, have decriminalized possession of psilocybin-containing mushrooms and plants having psychedelic properties. In February 2020, the Washington D.C. Board of Elections voted to advance an initiative to decriminalize possession of plants and fungi containing psilocybin and other psychedelic agents. As was the case for cannabis, biomedical research into psychedelics ground nearly to a halt following the Schedule 1 designation. But, over the past 10 to 15 years, researchers at both universities and in the private sector have turned back to both cannabis and psychedelics as possible therapies for disorders that are intractable to standard pharmaceutical treatments. In 2019, FDA approved esketamine, a compound from a family of compounds known to have hallucinogenic effects, for treatment-resistant depression. As has been the case for cannabis, the renewed interest in psychedelics has brought with it an increase in patenting activity. Even though legalization of psychedelics has lagged behind that of cannabis, legal wrangling over patents covering psychedelics has not, as demonstrated by recent developments in the area of psilocybin-based therapeutics.

Psilocybin is a tryptamine alkaloid found in a number of fungal species, also known as “magic mushrooms.” The psychoactive and hallucinogenic properties of such fungi have been a part of traditional religious rituals of indigenous cultures in Central and South America for centuries. In the 1950s, scientists at Sandoz Ltd., isolated psilocybin from fungi. The first US patents covering psilocybin issued to Sandoz Ltd. in 1965: U.S. Patent No. 3,183,172, “Obtaining Psilocybin and Psilocin from Fungal Material” and U.S. Patent No. 3,192,111, “Method of Inducing Therapeutic Tranquilization with Psilocybin and Psilocin.”

More than 50 years later and long after the first Sandoz Ltd. patents had expired, U.S. Patent No. 10,519,175, “Preparations of Psylocybin, Different Polymorphic Forms, Intermediates, Formulations and Their Use” was issued to Compass Pathways, Ltd., on December 31, 2019. Compass Pathways describes themselves as a mental health care company with a focus on psilocybin therapy for treatment-resistant depression. Compass Pathways’ psilocybin therapy received Breakthrough Therapy designation from the FDA in 2018. Breakthrough Therapy designation provides expedited development and review of drug candidates.

The legal wrangling over U.S. Patent No. 10,519,175 (the ’175 patent) began shortly after issuance. Kohn &  Associates, PLLC filed a petition for Post Grant Review of the ’175 patent with the Patent Trial and Appeal Board (PTAB) at the United States Patent and Trademark Office (USPTO) on February 21, 2020 (Kohn &  Associates, PLLC v.  Compass Pathways Limited, Pet. for Post-Grant Review, PGR2020-00030, filed February 21, 2020). The petition identifies Kohn &  Associates, PLLC as the real party in interest. The petitioner asserted that the claims in the ’175 patent are invalid and should never have been granted because they are obvious in view of articles in scientific literature that published before the priority date of the patent. Claim 1 of the ’175 patent reads:

  1. A method of treating drug resistant depression comprising orally administering to a subject in need thereof a therapeutically effective amount of an oral dosage form, wherein, the oral dosage form comprises:

crystalline psilocybin in the form Polymorph A characterized by peaks in an XRPD diffractogram at 11.5, 12.0, 14.5, 17.5, and 19.7o2θ ± 0.1o2θ, wherein the crystalline psilocybin has a chemical purity of greater than 97% by HPLC, and no single impurity of greater than 1%; and

silicified microcrystalline cellulose.

The PTAB has set a deadline of May 26, 2020 for the Patent Owner to file a preliminary response to the petition, but noted that the Patent Owner may elect to waive the preliminary response in order to expedite the proceedings. Under the USPTO rules, we can expect a decision by the PTAB to either institute the review process or reject the petition within six months. We know from the cannabis industry that the PTAB treats disputes relating to claims covering cannabis no differently than claims to any other technology. (Insys Development Company, Inc. v. GW Pharma Limited and Otsuka Pharmaceutical Co., (IPR 2017-00503)). ( So, we can expect that whatever the PTAB decides, the Schedule I status of psilocybin is unlikely to factor into that decision.