Terran’s Fast Filing on 4-OH-DiPT Prodrug
On Thursday July 13, 2023, a patent application titled Salts and Solid Forms of 4-Hydroxy-N,N-Diisopropyltryptamine Hemi-Glutarate and Hemi-Succinate was published. The PCT, filed by Terran Biosciences, includes claims to solid forms of 4-OH-DiPT hemiglutarate, the very same compound Reunion and Mindset have been competing over.
The PCT claims the benefit of six provisional applications. Surprisingly, Terran’s first four provisional applications were filed on January 6, 2022, just one week after the broad nature of RE104 was uncovered for the first time following the publication of the company’s patent application on December 30, 2021. That’s an impressive turnaround, especially over the holiday season.
As Graham Pechenik noted in his December 30, 2021 twitter thread—the day Reuion’s patent application published—there was some uncertainty regarding which precise prodrug RE104 referred to, as the company’s published application included both “4-hemiglutarate & 4-hemisuccinate of 4-HO-DiPT”.
Accordingly, Terran’s first four provisionals included prophetic examples describing how to perform a salt and polymorph screen of the two 4-HO-DiPT prodrugs 4-hemiglutarate and 4-hemisuccinate that Pechenik had referenced in his Twitter thread. Solid forms of the prodrugs “having at least one improved property compared to previously known sold forms” were claimed (such properties still to be determined, given no screen had yet been done).
The company’s initial four prophetic provisionals, which were filed presumably in order to secure the earliest priority date possible, were followed by two further provisionals. This time the company included data that it had generated in advance of the June 30, 2022 filing date (having now done the salt and polymorph screen).
Based on the scope of Terran’s later provisionals, at this point the company refined its focus to cover only solid forms of 4-OH-DiPT hemiglutarate hydrochloride (HCl). This narrowed focus suggests that between filing its first and follow-on provisionals, Terran had determined the prodrug that was of particular interest to Field Trip/Reunion. Indeed, in a January 2022 press release, Field Trip disclosed: “The preferred prodrug, FT-104, comprises the endogenous, natural compound glutaric acid as a hemi-ester. As such, FT-104 has been given a common name, Isoprocin Glutarate, for simplicity.”
Indeed, despite claiming priority back to all six provisionals, Terran’s ultimate PCT only included claims covering 4-OH-DiPT hemiglutarate HCl.
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The PCT includes a broad generic claim to “a solid form of 4-OH-DiPT hemi-glutarate hydrochloride”, a generic claim to the solid form “wherein the solid form is crystalline”, and several specific claims to the crystalline polymorph (as well as a pharmaceutical composition claim, and a number of method of use claims).
Terran’s generic “solid form” claim was found to lack novelty, in view of the disclosure in Field Trip’s patent application of a solid “white ‘cake.’” Terran’s generic “crystalline” form claim was found novel, but to lack an inventive step, since even though Field Trip’s solid white “cake” was an amorphous form (and not crystalline), “it would have been obvious to one of skill in the art to crystallize the solid product.”
However, in the written opinion, Terran’s specific claim to its defined crystalline polymorph was found to satisfy the requirements for novelty, inventive step, and industrial applicability. This specific polymorph claim can now be pursued under the Patent Prosecution Highway (PPH), which typically leads to swift allowance in most countries (in the U.S., often in as little as six months).
If granted, Terran’s newly-published patent application would add a wrinkle of complexity to an already complicated intellectual property contest.