Recently, Compass Pathways issued a press release stating “that it has been granted US Patent No 10,519,175 (“the ‘175 patent”), relating to methods of treating drug-resistant depression with a psilocybin formulation, by the US Patent and Trademark Office.” According to COMPASS, “the patent covers the use of COMPASS’s synthesized investigational psilocybin formulation, COMP360, in a psilocybin therapy protocol for patients with treatment-resistant depression.”
Given that psilocybin is an old drug, how did COMPASS get a patent covering its psilocybin product?
Answer: By recognizing that COMP360 is a novel crystalline form, COMPASS’s IP team at Cooley LLP was able to craft a patent strategy leading to the issuance of the ‘175 patent despite 60 years of prior art related to the compound psilocybin.
Below we discuss the scope of COMPASS’s ‘175 patent and the clever IP strategy that led to the company’s success in acquiring that patent.
Claims of COMPASS’s US Patent No. 10,519,175
The ‘175 patent issued from COMPASS Pathways’s U.S. Patent Application No. 16/155,386 (“the ‘386 application”), which we discussed in a previous article. During the prosecution of the ‘386 application, COMPASS amended the claims into the version which ultimately issued into the ‘175 patent. The issued claims include a single independent claim (claim 1) and twenty dependent claims. Claim 1 defines the the following subject matter:
“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 19.7°2θ±0.1°2θ, 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.”
Dependent claims 2 – 21 all require the elements recited in claim 1 in addition to the further limitations specified by each dependent claim. Accordingly, all of the claims in the ‘175 patent require specific crystalline form attributes. In other words, all of the claims in COMPASS’s patent issued on account of incorporating the crystalline form data into the claims.
Patent Examiner’s Reason for Granting COMPASS’s Patent
The patent examiner at the USPTO explained the importance of its crystalline form data. The examiner’s reason for allowing Compass’s claims was the difference between (A) the characteristics of the crystalline form of psilocybin recited in Compass’s claims and (B) the characteristics of the crystalline form of psilocybin recited in “the closest prior art of record, Folen.” See Folen, V. A., X-ray powder diffraction data for some drugs, excipients, and adulterants in illicit samples. Journal of Forensic Science 1975, 20, 348-372.
The Genius of COMPASS Pathways’s Patent Strategy – Claiming Crystalline Forms
Psilocybin is an old compound. Psilocybin has been known since at least 1958, when Hofmann isolated it from so-called “magic mushrooms.” Given that patents are only granted on “new” and “non-obvious” subject matter, acquiring a patent for COMPASS’s product, COMP360 was not an easy ask. Nevertheless, COMPASS’s lawyers (Sandhya Deo of Cooley LLP) were able to pull a rabbit out of a hat in getting an allowance for U.S. Patent No. 10,519,175.
Recognizing that psilocybin was a known compound, the IP team focused on the novel features of COMPASS’s product, COMP360. That product apparently has new, non-obvious crystallographic features, which can be included in the definition of COMPASS’s invention, adding novelty despite all of the prior art related to psilocybin.
Crystalline form patents often provide pharmaceutical companies with opportunities for acquiring patent exclusivity on drugs that have already existed in the prior art, such as psilocybin in the case of COMPASS’s product, COMP360. According to Barash Law,
“A solid-form patent strategy is even more important in drug repurposing where older chemical entities which either never made it to market or which were used in a different indication are being re-tasked. While new method of treatment patents may be available in such circumstances, more valuable composition of matter/drug substance patents should be considered when scientifically reasonable. Such strategies may involve creating new polymorphs, crystalline or amorphous salts or cocrystals to create a new composition of matter estate and Orange Book listing protections.”
In drafting the claims to crystalline form inventions, the applicant often relies on analytical data collected from x-ray diffraction experiments. “Because it can be difficult to characterize crystalline forms using organic chemistry nomenclature, one often relies on solid-state analytical data as a surrogate to define the metes and bounds of such claims.” Such is the case with COMPASS’s claim strategy in US Patent No 10,519,175. Although the claims are method claims (not composition of matter claims), COMPASS relied on solid-state analytical data to define the metes and bounds of those method claims: “…crystalline psilocybin in the form Polymorph A characterized by peaks in an XRPD diffractogram at 11.5, 12.0, 14.5, 17.5, and 19.7°2θ±0.1°2θ.”
Crystalline Form Patents for Psychedelics
COMPASS’s remarkable achievement in acquiring US Patent No 10,519,175 raises questions about other crystalline form patents. Prior to COMPASS’s patent grant, many in the art considered “old” psychedelic compounds unpatentable by virtue of their being part of the public domain. However, COMPASS’s success with psilocybin crystalline form patents suggests that other “old” compounds could be packaged into new, patentable inventions by leveraging opportunities created by x-ray crystallography. Will crystalline form patents be the next gold rush for companies pursuing IP on previously known compounds?