Clinical data | |
---|---|
Other names | ITI1549 |
Routes of administration | Unspecified [1] |
Drug class | Non-hallucinogenic serotonin 5-HT2A receptor agonist [2] [3] |
ITI-1549 is a putatively non-hallucinogenic serotonin 5-HT2A receptor agonist which is under development for the treatment of mood disorders and other psychiatric disorders. [1] [4] [5] [2] [3] In addition to acting at the serotonin 5-HT2A receptor, it is also an antagonist of the serotonin 5-HT2B receptor and an agonist of the serotonin 5-HT2C receptor. [3] [6] The drug's route of administration has not been specified. [1]
Serotonergic psychedelics like psilocybin and lysergic acid diethylamide (LSD) are agonists of the serotonin 5-HT2A receptor which activate both the β-arrestin and Gq signaling pathways. [3] In 2023, activation of the Gq pathway, but not the β-arrestin pathway, was linked with the production of hallucinogenic-like effects in animals. [3] [7] [8] [9] However, findings in this area are seemingly conflicting, with Gq-selective serotonin 5-HT2A receptor agonists also reported to be non-hallucinogenic. [10] Serotonin 5-HT2A receptor agonists are of interest for the potential treatment of psychiatric disorders like depression and anxiety, but the hallucinogenic effects of serotonergic psychedelics serve as a barrier and partial limiting factor in this regard. [11] [12]
ITI-1549 has high affinity for the serotonin 5-HT2A receptor (Ki = 10.2 nM) and acts as a partial agonist of the β-arrestin pathway with an intrinsic activity of 72% (relative to α-methylserotonin). [3] Conversely, unlike serotonergic psychedelics, ITI-1549 does not activate the Gq pathway. [3] Hence, it is a biased agonist of the serotonin 5-HT2A receptor. [3] In accordance with the preceding, ITI-1549 does not produce the head-twitch response (HTR), a behavioral proxy of psychedelic effects, in animals. [3] [13] [14] However, similarly to serotonergic psychedelics, ITI-1549 has been found to produce anxiolytic-like and prosocial effects in animals. [3] Antidepressant-like and psychoplastogenic effects of ITI-1549 in animals have yet to be assessed or reported. [3] In any case, various other non-hallucinogenic serotonin 5-HT2A receptor agonists selective for the β-arrestin pathway have been found to produce antidepressant-like effects in animals. [8] [11] [15]
In addition to the serotonin 5-HT2A receptor, ITI-1549 has high affinity for the serotonin 5-HT2B receptor (Ki = 4.8 nM). [3] However, it acts as an antagonist of this receptor rather than as an agonist (IC50 = 13.8 nM). [3] Based on these findings, continuous administration of ITI-1549 is not expected to pose a risk of cardiac valvulopathy. [3] This is in contrast to serotonergic psychedelics, which act as potent serotonin 5-HT2B receptor agonists. [16] [17] ITI-1549 is additionally a potent agonist of the serotonin 5-HT2C receptor (Ki = 21 nM; EC50 = 40 nM) as well. [6]
The drug is a small molecule, but its chemical structure does not yet seem to have been disclosed. [1] [4] It is said to be chemically unrelated to existing plant-derived and synthetic serotonergic psychedelics. [3] However, its structure was disclosed in a 2024 patent. [6]
As of February 2024, ITI-1549 is in the preclinical stage of development for psychiatric disorders. [1] [4] [2] A phase 1 clinical trial is being planned and is expected to commence in late 2024 or early 2025. [18] The drug is under development by Intra-Cellular Therapies. [1] [4] [2] ITI-1549 was first described in the scientific literature by 2023. [3]
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ITI-1500 Non-Hallucinogenic Psychedelic Program: In 2023, we introduced the ITI-1500 program. This program is focused on the development of novel non-hallucinogenic psychedelics for the treatment of mood, anxiety and other neuropsychiatric disorders without the liabilities of known psychedelics, including the hallucinogenic potential and risk for cardiac valvular pathologies. Our lead product candidate in this program, ITI-1549, is advancing through IND enabling studies and is expected to enter human testing in late 2024 or early 2025.
Pipeline: [...] ITI-1500 Series: ITI-1549 – Mood and Other Neuropsychiatric Disorders [...] ITI-1500 series is our portfolio of Non-Hallucinogenic Psychedelics. ITI-1549 is our lead product candidate in this program.
Although the specific signaling cascades mediating the HTR have not been conclusively identified, Gq and β-arrestin2 have been implicated. Recent studies with different existing and novel agents, including DOI, found that the HTR was correlated with Gq efficacy but not with β-arrestin2 recruitment.114