While national phase entries for Compass’s WO2023114097 PCT are not due until June 2024 (30 months from the priority date), all claims relating to co-use of psilocybin and an antidepressant were canceled in the company’s US entry for its earlier WO2020212952 PCT.

Nevertheless, many of Compass’s provisional applications, filed as early as April 17, 2019, make explicit reference to the administration of psilocybin “in combination with one or more treatments”, including “anti-depressant or anti-anxiety drugs, such as SSRIs, tricyclic antidepressants (TCAs), monoamine oxidase inhibitors (MAOIs), or serotonin norepinephrine reuptake inhibitors (SNRIs).”

Compass’s provisional applications are evidently not the only prior art potentially relevant to UHB’s claims. In March 2023, Porta Sophia filed a third-party submission with the USPTO in response to UHB’s application. Porta Sophia’s submission included a collection of prior art documents the organization described as “material to the patentability of all 20” of UHB’s originally-filed claims.

As noted above, UHB elected to prosecute claims directed specifically to the use of escitalopram and psilocybin. However, even with this restricted claim set, Porta Sophia’s submission points to the existence of a body of prior art that brings into question the novelty and non-obviousness of UHB’s now-patented methods. In spite of the submission, none of UHB’s claims were disallowed; nor, in fact, did UHB even receive a single prior art rejection.

In their evaluation of UHB’s application, the assigned examiner cited a 2022 publication from Becker, et al. as the ‘closest art’. The publication, which was (perhaps not so coincidentally) the culmination of a UHB, Matthias Liechti-led, trial investigating how antidepressants interact with psilocybin, described how escitalopram pretreatment “reduced bad drug effects” of psilocybin.

Interestingly, however, the publication also described how pretreatment “had no relevant effect on positive mood effects of psilocybin”. Such a finding would appear to contradict one goal of UHB’s claimed method, wherein the combined use of psilocybin and an antidepressant induces “a more positive psychological state in the individual … compared with the psychedelic alone.” (Perhaps, had they needed to overcome it as prior art, they could have even asserted that it ‘taught away’?)

Despite some of the similarities between the effects described in the publication and the claims in the patent, in the Notice of Allowance, the examiner explained that the limitations included in the company’s amended independent claim were not taught by Becker, et al. (2022). These limitations include specific psilocybin and escitalopram dose ranges and pretreatment time periods.

As a result, the claims were allowed and UHB was granted its patent. However, it is unclear if or how MindMed, as a beneficiary of the issuance, intends to leverage this newly granted patent, considering the company’s drug development pipeline does not include psilocybin. Further, it is also unclear how the administration of psilocybin to patients on escitalopram could constitute infringement of this patented method, and if so, whether MindMed intends to enforce its claims.

For parties interested in employing the drug combination in clinical trials, patent infringement may not be a concern (at least, not right away). As Graham Pechenik explained in an earlier thread, 35 U.S.C. § 271(e)(1), also known as the Hatch-Waxman “Safe Harbor”, makes an exception for otherwise-infringing acts when they are “solely for uses reasonably related to the development & submission of information” for FDA approval.

It is in medical practice, when psilocybin and escitalopram are both administered to a patient, where infringement could arguably be a greater risk (although clinicians themselves are rarely targets, and are shielded from some forms of infringement liability). And even where a single entity is not responsible for administering (or inducing the administration of) both the psilocybin and the escitalopram, the doctrine of divided patent infringement may apply in instances “where more than one party may have participated in a patent’s claimed steps.” (In the case of MindMed’s patent, for instance, there could be liability for divided infringement, if one party is  “directing or controlling” the actions of the other, or together acting as a “joint enterprise”.)

In addition to eliciting concerns of infringement for anyone not participating in a clinical trial for FDA approval, the granting of UHB’s patent raises another question: did the patent examiner deviate from standard lines of reasoning in their reliance on “unmet medical need” as a partial rationale for its issuance? To date, our team has been unable to identify instances where equivalent lines of reasoning have been offered by a patent examiner in support of the issuance of other patents. (And are unaware of any legal relevance for such a rationale, outside of a special program like the COVID-19 “Patents for Humanity”.)