Past Its Peak: Freedom To Operate, Inc. Fails To Persuade PTAB To Institute Two Post-Grant Reviews For Patents Covering Psilocybin

Finnegan, Henderson, Farabow, Garrett & Dunner, LLP


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In Freedom to Operate, Inc. v. Compass Pathfinder Ltd.[1], the Patent Trial and Appeal Board ("the PTAB") denied the institution of post-grant review under 35 U.S.C. § 324 for U.S. Patent Nos. 10,954,259 ("the '259 patent") and 10,947,257 ("the '257 patent").
United States Intellectual Property
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In Freedom to Operate, Inc. v. Compass Pathfinder Ltd.1, the Patent Trial and Appeal Board ("the PTAB") denied the institution of post-grant review under 35 U.S.C. § 324 for U.S. Patent Nos. 10,954,259 ("the '259 patent") and 10,947,257 ("the '257 patent").


Freedom to Operate, Inc. filed two petitions requesting post-grant review of claims 1-23 of the '259 patent and claims 1-23 of the '257 patent. The '259 and '257 patents relate to the "large-scale production of psilocybin for use in medicine." PGR2022-00012 at 3, PGR2022-00018 at 3. Psilocybin is a plant-based psychedelic that is used with psychotherapy to treat conditions such as mood and alcoholic disorders. Id. These patents describe the development of a commercially scaled process for producing psilocybin. Id.

The '259 and '257 patents describe different psilocybin embodiments including Polymorph A, Polymorph A', Hydrate A, and Polymorph B. These have different X-Ray Powder Diffraction ("XRPD") patterns. Id. Psilocybin is a challenging active ingredient to formulate due its use in low dosages and poor flow characteristics, making it difficult to ensure content uniformity and tableting. Id. However, the inventors formulated psilocybin tablets using a non-standard filler, silicified microcrystalline cellulose, thus achieving a satisfactory product.

Claim Construction:

For the '259 patent, the Petition proposed construction of two claim terms:

"crystalline Polymorph A of psilocybin" and

"characterized by X-ray powder diffraction (XRPD) peaks at 11.5±0.1, 12.0±0.1, 14.5±0.1, 17.5±0.1, and 19.7±0.1 °2?."

PGR2022-00018 at 7.

For the '257 patent, the Petition proposed construction of two claim terms:

"crystalline psilocybin in the form Polymorph A" and

"characterized by peaks in an XRPD diffractogram at 11.5, 12.0, 14.5, 17.5, and 19.7°2? ± 0.1°2?."

PGR2022-00012 at 8.

  1. "crystalline Polymorph A of psilocybin" and "crystalline psilocybin in the form Polymorph A"

Petitioner argued that the above limitations should be construed as "a crystalline form of a single polymorphic phase of psilocybin defined by the patentee as Polymorph A." PGR2022-00012 at 8, PGR2022-00018 at 8. Petitioner argued the ordinary and customary definition of polymorph should apply and that was understood to be: "a solid crystalline phase of a given compound resulting from the possibility of at least two different arrangements of the molecules of that compound in the solid state." Id. Patent Owner opposed this construction, noting that "Polymorph A" has no plain and ordinary meaning in the art and must be construed in accordance with the patent claims, specification, and prosecution history which support Patent Owner's construction.

The PTAB agreed with Patent Owner. Even if there is a conventional definition of "polymorph," the inventors are "entitled to act as their own lexicographers to define 'Polymorph A' according to the recited peaks on the XRPD diffractogram." PGR2022-00012 at 9, PGR2022-00018 at 9-10. Furthermore, the prosecution histories of the patents are relevant to the construction of the claims. The examiner rejected original claims 1 in both applications as indefinite because they did not define "Polymorph A." Patent Owner amended the claims to define Polymorph A, adding the specific XRPD peaks recited in claim 1. Thus, the intrinsic evidence supported Patent Owner's proposed construction of the claims. PGR2022-00012 at 10, PGR2022-00018 at 10.

  1. "characterized by X-ray powder diffraction (XRPD) peaks at 11.5±0.1, 12.0±0.1, 14.5±0.1, 17.5±0.1, and 19.7±0.1 °2?" and "characterized by peaks in an XRPD diffractogram at 11.5, 12.0, 14.5, 17.5, and 19.7°2?±0.1°2?"

Petitioner argued that the above limitations should be construed as "[i]dentifiable by reference to an X-ray diffractogram that discloses within normal experimental error peaks at 11.5, 12.0, 14.5, 17.5 and 19.7±0.1°2?." PGR2022-00012 at 11, PGR2022-00018 at 11. Petitioner asserted these limitations are not defined in the specification, and the specification does not explain the basis for the claimed range of the peak locations ("±0.1°2?"). Furthermore, the Petitioner argued its proposed construction "allows for experimental error and variation that would be expected by a person of ordinary skill, [and] is the one that fits best with the specification and the way a person of ordinary skill would read an XRPD diffractogram." Id.

Patent Owner contended these limitations should have their plain and ordinary meaning as the XRPD peaks are "expressly recited with a standard precision accepted within the art of '±0.1°2?' and do not require further construction." PGR2022-00012 at 12, PGR2022-00018 at 12. If Patent Owner wanted a broader range, it argued, it would have used the term "about" to modify the XRPD peak values in its claims. Id.

The PTAB agreed with Patent Owner's position since the claim language already factors in some degree of experimental error with the variance of "±0.1°2?." To support their constructions, both parties cited to USP Chapter <941> on XRPD from years 2000 and 2012. Patent Owner cited USP 24, which states "2? values 'should typically be reproducible to ± 0.10' or a total variance of 0.20 degrees." PGR2022-00012 at 14, PGR2022-00018 at 14, Petitioner's expert, Dr. Lidin, cited the USP 35 from 2012, contending that "USP 35 <941> accepts a tolerance of ±0.20°2? in XRPD data generated using modern techniques and instrumentation." Id. Contrary to Dr. Lidin's testimony, USP does not state it accepts a tolerance of "±0.20°2?." USP 35 states that "[t]he agreement in the 2?-diffraction angles between specimen and reference is within 0.2° for the same crystal form." Id. By stating it is "within 0.2" degrees, USP is consistent USP 24 cited by Patent Owner. Thus, the intrinsic and extrinsic evidence support construing the variance "±0.1°2?" according to its plain and ordinary meaning without additional experimental error.

Inoperative Invention:

Petitioner asserts that claims 1-23 of the '259 and '257 patents are unpatentable under 25 U.S.C. §§ 101 and 112 for claiming an inoperative invention. However, Petitioner's arguments hinged on its incorrect construction of "Polymorph A" which the PTAB rejected, as discussed above. PGR2022-00012 at 15-16, PGR2022-00018 at 16. Thus, the PTAB was not persuaded that Petitioner's proposed construction should be applied to render the claims unpatentable.


Petitioner asserted claims 1-12, 15, and 16-23 of the '259 patent, and claims 1-9, 15, 16, and 21 of the '257 patent are unpatentable as obvious. While Petitioner relied on numerous different prior art references for its obviousness challenges, the PTAB only addressed the disclosure of Folen for its Institution Decisions.

Folen is an article entitled, "X-Ray Powder Diffraction Data for Some Drugs, Excipients, and Adulterants in Illicit Samples," published in the Journal of Forensic Science. PGR2022-00012 at 17, PGR2022-00018 at 17. Folen discusses that "[t]he development of new compounds with the potential for drug abuse necessitates a continuous accumulation of analytical data in the forensic laboratory." Id. Thus, Folen presents "X-ray powder diffraction data not available in the literature." Id. Table 2 of Folen provides X-ray diffraction data and relative intensities of peaks for different compounds including psilocybin. Folen provides "d-spacing values for psilocybin, which can be converted to °2? (as recited by the '257 patent claims) using Bragg's Equation." PGR2022-00012 at 17-18, PGR2022-00018 at 18.

Petitioner relies solely on Folen and its expert's testimony regarding Folen to support its claim that Folen suggests the recited XRPD peaks of Polymorph A. Petitioner asserts "[t]he first three of these peaks [i.e., 11.4, 12.0, and 14.4] are directly within the claimed range of ± 0.1°2?. The second two peaks [i.e., 17.7 and 19.5] are within ± 0.2°2?." PGR2022-00012 at 18, PGR2022-00018 at 19. Petitioner asserts a person of ordinary skill would recognize that Folen uses older equipment and manual methods of assigning d-values which could create variability when measuring exact peak locations. Furthermore, Petitioners expert Dr. Kaduk's analysis of Folen "demonstrates that these three predominant crystalline forms of psilocybin existed as early as 1975, and that variable amounts of these three phases could be expected in historical samples of psilocybin made and used in clinical trials before 2017." PGR2022-00012 at 19, PGR2022-00018 at 19.

The PTAB was not persuaded by Petitioner's argument. Petitioner admitted that Folen taught peaks at 17.7 and 19.5°2?, and those peaks are not within ±0.1°2? of 17.5 and 19.7°2?. PGR2022-00012 at 20, PGR2022-00018 at 20. Petitioner also failed to cite support for its proposition that older equipment might create some variability in measuring exact peak locations. Id. Petitioner's expert also cited no objective evidence to support his assertions. As the PTAB gives "little to no weight to such unsupported expert testimony," the PTAB did not find those arguments persuasive. Id.


Petitioner asserted that claims 1-7, 21, and 22 of the '259 patent, and claims 1-13 of the '257 patent failed to meet the enablement requirement. Specifically, Petitioner asserted that in the '259 patent, the specification "does not teach how to analyze the claimed pharmaceutical composition to determine whether the claimed characteristics of Polymorph A or its purity limitations are present." PGR2022-00018 at 22. Regarding the '257 patent, Petitioner asserted that the specification does not "does not teach how to analyze the claimed oral dosage form to determine whether the claimed characteristics of Polymorph A or its purity limitations are present . . . or to determine whether silicified microcrystalline cellulose ("SMCC") is present in the claimed particle size ranges." PGR2022-00012 at 22.

Patent Owner contended that Petitioner's argument was premised on an incorrect interpretation of the law of enablement because whether a claim is enabled "has nothing to do with whether a particular claim element may be 'analyzed' or have its presence 'determined' as Petitioner alleges." PGR2022-00012 at 23, PGR2022-00018 at 23.

The PTAB agreed with the Patent Owner that Petitioner did not show that the claims were not enabled.

Thus, the Petitioner failed to show it was more likely than not that any of the challenged claims of the '259 and '257 patents were unpatentable. That finding led to denial of each of the PGRs.


These denials of institution shed light on the importance of claim construction for the institution for post-grant reviews. The Petitioner was unable to persuade the PTAB to adopt its proposed claim constructions, the PTAB did not agree with Petitioner's unpatentability arguments. A solidly supported claim construction can go a long way in supporting unpatentability arguments. Furthermore, even if there is an accepted plain and ordinary meaning of a term, the inventors are free to define a term differently from this plain and ordinary meaning.

This decision also reaffirms the importance of backing up all arguments with supporting evidence. Here, the PTAB found some of Petitioner's testimony unsupported, and the PTAB ultimately concluded that the evidence in the record supported Patent Owner's argument.

As a final note, it will be interesting to watch the rise of patents granted in relation to Schedule I substances under the Controlled Substances Act in the United States. While these substances may not be manufactured, distributed, or possessed in the United States2, the USPTO has granted patents for Schedule I substances, including these psilocybin patents. As independent states legalize specific Schedule I substances, the number of patents for Schedule I patents could very well continue to increase in the coming years-and is an industry to watch.


1 PGR2022-00018, Paper 16 (P.T.A.B. June 22, 2022), PGR2022-00012, Paper 18 (June 22, 2022).

2 21 U.S.C.A. § 841 (West 2018).

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