TAK‑653 (Osavampator)
Selective AMPA-receptor positive allosteric modulator (ampakine). Takeda-developed antidepressant candidate that met its Phase 2 primary endpoint in depression.
WHAT IS TAK-653 (OSAVAMPATOR)?
Detailed overview
TAK-653 (osavampator, development code NBI-1065845) is a selective AMPA-receptor positive allosteric modulator (PAM) developed by Takeda. Unlike classic ampakines, it has virtually no intrinsic agonist activity: it amplifies signaling only when neurons are already releasing glutamate, by slowing the desensitization and internalization of the AMPA receptor. This strictly glutamate-dependent action underlies its favorable safety profile: in rats it shows roughly a 419-fold safety margin to the convulsant dose, versus the narrow window of older ampakines. Downstream it strengthens BDNF-mTOR signaling and long-term potentiation (LTP), producing a ketamine-like antidepressant effect but without the dissociation associated with ketamine. In healthy volunteers it was well tolerated up to single doses of 18 mg and repeated doses up to 9 mg/day, with no serious adverse events, seizures or convulsions. In the Phase 2 SAVITRI trial it met its primary endpoint in major depressive disorder (as adjunctive treatment); development continues in Phase 3. It is not approved anywhere.
Mechanism
AMPA-PAM (glutamate-dependent)
Half-life
33-48 hours
Onset
Hours (acute cortical), weeks (antidepressant)
Legal status
Investigational, Phase 3, not approved anywhere
Safety
Side effects, stop signs, contraindications
Side effects · 6
- Overstimulation, agitation from amplified glutamatergic (AMPA) signaling
- Headache (the most commonly reported unpleasant effect)
- Sleep disturbance, heightened alertness if dosed late in the day
- Theoretical seizure/convulsion risk in those predisposed to epilepsy (though the preclinical safety margin is wide and no convulsions occurred in human studies)
- Limited human safety data: investigational, unapproved compound, full side-effect spectrum still unknown
- Long half-life (33-48 h) gives a cumulative effect, steady state over several days
Contraindications · 4
- Personal or family history of epilepsy/seizures (theoretical risk from glutamatergic potentiation)
- Avoid combining with other strong glutamatergic or stimulant compounds (overstimulation risk)
- Pregnancy and breastfeeding: no clinical safety data, avoid
- Not an approved drug, investigational; not recommended for self-treatment of major depression without clinical supervision
Related Nootropics
Same therapeutic category
Studies
Related research and clinical findings
TAK-653, an AMPA receptor potentiator with minimal agonistic activity, produces an antidepressant-like effect with a favorable safety profile in rats
Hara H, Suzuki A, Kunugi A, et al.
Central nervous system effects of TAK-653, an investigational alpha-amino-3-hydroxy-5-methyl-4-isoxazole receptor (AMPAR) positive allosteric modulator in healthy volunteers
Dijkstra F, et al.
Strictly regulated agonist-dependent activation of AMPA-R is the key characteristic of TAK-653 for robust synaptic responses and cognitive improvement
Suzuki A, et al.
TAK-653 Reverses Core Depressive Symptoms in Chronic Stress-Induced Monkey Model
Li L, et al.
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