Planned FDA Investigational New Drug Application: SPC-15 for the Treatment of PTSD

Silo Pharma today announced that it has chosen to partner with Allucent, a global full-service clinical research organization, to support their planned submission of an investigational new drug (IND) application to the US Food and Drug Administration (FDA) for a phase 1 clinical trial of SPC-15 for the treatment of posttraumatic stress disorder (PTSD).¹

SPC-15 is a its intranasal prophylactic and novel serotonin 4 (5-HT4) receptor agonist that utilizes biomarkers for the treatment of PTSD, anxiety, and other stress-induced affective disorders. Early data on SPC-15 indicate that its optimized patient safety profile and therapeutic delivery may provide additive benefits for combating stress-induced pathophysiology at both behavioral and neural levels.²

Allucent is a global provider of comprehensive drug development solutions, and helps to bring new therapies forward by solving the distinct challenges faced in the biopharma space.

“We believe that a partnership with Allucent is a significant move forward in bringing our novel PTSD therapeutic to the clinic,” said Eric Weisblum, the CEO of Silo. “With Allucent’s expertise, we believe our IND will provide a sound rationale for clinical development, beginning with protocols for dose-ranging studies to assess the pharmacokinetics and safety profile for SPC-15. We expect to receive positive preclinical results in these categories which should meet the FDA’s clinical trial standards.”

Silo Pharma conducted preclinical studies of SPC-15 in collaboration with Columbia University under a sponsored research agreement and option. Data from an IND-enabling GLP-compliant toxicology and toxicokinetic study, as well as findings from a drug-device study of the formulation-specific intranasal spray system used for SPC-15 drug delivery, are expected in early 2026. With this data, Silo Pharma intends to pursue the FDA’s 505(b)(2) accelerated regulatory pathway for clinical development of SPC-15.

“Moving forward, we intend to seek the FDA’s 505(b)(2) regulatory pathway for approval of SPC-15, a drug development route that can significantly shorten clinical timelines for FDA approval and reduce drug development costs,” Weisblum added.²

Silo Pharma currently expects to submit the IND in 2026 and initiate its first in-human SPC-15 trial following the FDA’s approval.

With no new PTSD drug approvals in the US in nearly 25 years, SPC-15 could help meet the vast need in the PTSD space. The only 2 PTSD treatments currently approved by the FDA target the depressive symptoms, whereas SPC-15 is designed to increase stress resilience in high-risk populations, representing a new approach to treatment.

With now 2 recent major failures to broach the PTSD treatment space, MDMA-assisted therapy and brexpiprazole plus sertraline,^3,4 SPC-15 may have a difficult road ahead.

References

1. Silo Pharma partners with Allucent to support planned FDA Investigational New Drug application for SPC-15 as a therapeutic for PTSD. News release. November 17, 2025. Accessed November 17, 2025. https://www.globenewswire.com/news-release/2025/11/17/3189119/0/en/silo-pharma-partners-with-allucent-to-support-planned-fda-investigational-new-drug-application-for-spc-15-as-a-therapeutic-for-ptsd.html

2. Silo Pharma advances PTSD Drug SPC-15 toward planned 2025 IND submission with pre-clinical study data expected in Q3 2025. News release. July 8, 2025. Accessed November 17, 2025. https://www.biospace.com/press-releases/silo-pharma-advances-ptsd-drug-spc-15-toward-planned-2025-ind-submission-with-pre-clinical-study-data-expected-in-q3-2025

3. Duerr HA. FDA issues CRL to Lykos for MDMA-assisted therapy. Psychiatric Times. August 10, 2024. https://www.psychiatrictimes.com/view/fda-issues-crl-to-lykos-for-mdma-assisted-therapy

4. Kuntz L. FDA Advisory Committee votes against recommending brexpiprazole plus sertraline for PTSD. Psychiatric Times. July 18, 2025. https://www.psychiatrictimes.com/view/fda-advisory-committee-votes-against-recommending-brexpiprazole-plus-sertraline-for-ptsd