• Two poster presentations will feature novel findings of preclinical metaplasticity research and updated data from the recent apimostinel Phase 1 qEEG biomarker study
• Company will host its 3^rd annual R&D Day with investigators and key opinion leaders to share new insights ahead of an upcoming Phase 2 MDD study with zelquistinel

Gate Neurosciences, a clinical-stage biotechnology company using precision medicine to develop next-generation neuroscience therapies, today announced upcoming activities at the 2024 annual meeting of the American Society of Clinical Psychopharmacology (ASCP), being held in Miami Beach, FL, from May 28-31, 2024.

The company will present new preclinical and clinical data supporting its NMDAR PAM portfolio and will share novel insights from internal research on the biological mechanisms of neuroplasticity and synaptic function.

Specifically, Gate Neurosciences will highlight its cutting-edge research on how a single dose of neuroplasticity-enhancing drugs can trigger both rapid-onset (i.e. hours) and long-lasting therapeutic effects (i.e. weeks), a phenomenon termed ‘event-driven pharmacology’. Gate’s new preclinical and clinical insights have yielded critical findings on CNS-specific ‘event-driven pharmacology’ and the importance of dosing intervals to optimize plasticity treatments.

The company plans to share these new insights at its 3^rd annual R&D Day at the conference with leading members of the scientific community in attendance. The session will also include updates on an upcoming Phase 2 study with a once-weekly oral program, zelquistinel (GATE-251), for Major Depressive Disorder.

Gate Neurosciences 3^rd Annual R&D Day at ASCP 2024:

Location: Loews Hotel Miami Beach, Florida

Date: Tuesday, May 28, 2024

Time: 12:15 p.m. to 1:45 p.m.

“Over the past few years, the Gate team has made considerable progress in understanding mechanisms that rapidly and durably enhance synaptic function for treating CNS diseases. Dosing these compounds the right way is critical to success,” stated Mike McCully, CEO of Gate Neurosciences. “We look forward to sharing our new data and insights with the psychiatry community at the ASCP conference and discussing updated plans for our Phase 2 study of once-weekly oral zelquistinel in depression.”

Poster Presentation Details:

Poster #T14 Title: Apimostinel, a Novel NMDAR Modulator with Rapid-Acting, Sustained Effects and Favorable Drug-Like properties: Preclinical Studies

Abstract Number: T14

Presentation Session: Poster Session II, Salon 4

Presentation Date and Time: 12:30pm – 2:25pm, Thursday May 30^th 2024

Lead Author: Jeffrey Burgdorf, PhD

Poster #T14 details new preclinical data supporting apimostinel as an acute psychiatry drug candidate with lasting metaplasticity effects. Key takeaways include:

• Single dose of apimostinel acutely enhanced LTP with metaplasticity lasting 7 days, and produced robust antidepressant-like effects without ketamine-like side effects
• Apimostinel dose-dependently enhanced qEEG alpha in correlation with CSF exposure, as a biomarker of NMDA receptor target activation
• Repeat doses of apimostinel led to larger and longer-lasting metaplastic effects

At the Society of Biological Psychiatry (SOBP) Annual Meeting earlier this month, Gate presented additional data on the specific NMDAR PAM mechanism of action of apimostinel.

Poster #T21 Title: A Phase 1 Safety, Pharmacokinetics (PK) and Quantitative Electroencephalography (qEEG) Pharmacodynamics Study of Single and Multiple Ascending Doses of Intravenous Apimostinel Compared with Placebo in Healthy Volunteers

Abstract Number: T21

Presentation Session: Poster Session II, Salon 4

Presentation Date and Time: 12:30pm – 2:25pm, Thursday May 30^th 2024

Lead Author: Ronald M. Burch, MD PhD

Poster #T21 is the first scientific presentation of findings from the apimostinel Phase 1 clinical trial assessing safety and qEEG biomarkers. Key takeaways include:

• Apimostinel was generally safe and well-tolerated following multiple doses from 1-25mg
• Apimostinel dose-dependently stimulated qEEG alpha power
• qEEG alpha power stimulation with apimostinel was consistent with CSF Cmax drug concentrations that maximally stimulate NMDA receptors in vitro
• qEEG alpha power stimulation with apimostinel was consistent with efficacious doses in a previous Phase 2a clinical MDD study

Full abstracts will be published by ASCP following the conclusion of the 2024 Annual Meeting.

About Gate Neurosciences

Gate Neurosciences, headquartered in Indianapolis, is a precision medicine biotechnology company focused on advancing next-generation central nervous system (CNS) treatments that address the growing needs in mental health. The company is developing a portfolio of novel mechanisms of action that enhance synaptic function to address neuropsychiatric and neurocognitive diseases, including major depressive disorder. Using learnings from extensive clinical, preclinical and translational data, along with a better understanding of CNS development challenges, the company is advancing its clinical pipeline using evidence-driven, precision psychiatry approaches.

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