spec sheet6 rows
Apimostinel (NRX-1074) is the understudy in the rapastinel story: developed by the same company, Naurex, using the same core idea of gently boosting NMDA receptor signaling at the glycine co-agonist site rather than blocking the channel like ketamine does. Naurex called this class of drugs Stinels, framing them as neuroplastogens meant to trigger rapid synaptic strengthening and antidepressant effects without dissociation. Allergan acquired Naurex in 2015 largely to get the entire Stinel franchise, including apimostinel as a potentially more potent follow-on to rapastinel, and moved it into Phase I/II testing. But when rapastinel, the lead compound and more advanced sibling, failed its own Phase III depression trials, Allergan shut down the whole glycine-site NMDA program in 2019, and apimostinel never got the chance to run its own late-stage trial.
- designed to avoid ketamine-style dissociation
- positive allosteric mechanism distinct from channel-blocking NMDA drugs
- supported preclinical evidence for rapid synaptic plasticity effects
- Naurex nicknamed this whole drug class Stinels, and a 2025 mechanistic paper still uses that name to describe how they work as NMDA receptor positive allosteric modulators.
- Apimostinel never got a dedicated Phase III trial of its own; it was discontinued on the strength of its sibling compound's failure, not its own late-stage results.
Mechanism
Glycine-site partial / positive modulator at the , the same Stinel mechanism as rapastinel; intended to fine-tune rather than block signaling, promoting plasticity without channel blockade.
Safetyrisks and cautions, not medical advice
Dissociation is the effect this class was built to avoid, and across roughly 270 people dosed in Phase 1 and a 151-patient single-infusion Phase II in depression, the stinels have held to that better than ketamine does. What none of those studies produced is a public safety readout; the trials finished and the findings stayed in house. The compound is also not finished. A fresh Phase 1 ran to completion in 2023 under a new sponsor and an academic Phase II is enrolling now, so treat the tolerability picture as early rather than settled, with no repeat-dose or long-term human data at all.
History
Developed by Naurex as a follow-on to rapastinel; acquired by Allergan in 2015 along with the rest of the glycine-site NMDA franchise; reached Phase I/II testing before Allergan discontinued the entire program in 2019 following rapastinel's Phase III failure.
Subjective profileweighing the evidence above
A compound that never got to fail on its own terms; it was shelved by association when its more advanced sibling drug went down first.
Resources
This entry is here for reference.
Research
1 listed here; entry last updated July 2026
Reviews
My notesprivate to this device
FAQ
Is apimostinel related to rapastinel?
Yes, both came from Naurex's glycine-site NMDA Stinel program and share the same core mechanism; apimostinel was developed as a potentially more potent follow-on.
Why was development stopped?
Allergan discontinued the entire Stinel program in 2019 after rapastinel, the lead and more advanced compound, failed its Phase III depression trials, taking apimostinel down with it before it reached its own late-stage testing.
Limitations of the evidence
- limited human efficacy data (program ended before late-stage trials)
Notes and cautions
- IV-only dosing in early studies