---
schema_version: "secwatch.filing_event.v1"
accession: "0001708599-25-000138"
form_type: "8-K"
ticker: "SER"
cik: "0001708599"
company_name: "Serina Therapeutics, Inc."
filed_at: "2025-12-10T23:59:59+00:00"
generated_at: "2026-05-16T13:39:04.683833+00:00"
event_type: "regulatory"
sentiment: "neutral"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Serina submits complete response to FDA clinical hold for SER-252 Parkinson's program

## Summary
- Complete response submitted Dec 9, 2025, addressing FDA's clinical hold on SER-252 related to trehalose excipient.
- Submission includes detailed data package on trehalose as subcutaneous excipient and revised protocol for SAD phase.
- FDA clinical hold does not involve apomorphine drug substance, mechanism of action, enFuse device, or 505(b)(2) pathway.
- Global site start-up continues; first-patient-in for Phase 1b registrational study targeted for Q1 2026, subject to hold resolution.
- Company acknowledges FDA's engagement and expects SAD phase initiation in Q1 2026 pending regulatory and ethics approvals.

## SEC filing metadata
- accession: 0001708599-25-000138
- form_type: 8-K
- ticker: SER
- cik: 0001708599
- company_name: Serina Therapeutics, Inc.
- filed_at: 2025-12-10T23:59:59+00:00
- event_type: regulatory
- sentiment: neutral
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1708599/000170859925000138/0001708599-25-000138-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1708599/000170859925000138/ser-20251210xserinatofdare.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001708599-25-000138
- JSON: https://secwatch.observer/filing/0001708599-25-000138.json
- Plain text: https://secwatch.observer/filing/0001708599-25-000138.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.